Ferro-Cement for Canadian

Fishing Vessels

Compiled and Edited by W.G. Scott, C. Eng., P. Eng.

for

Industrial Development Branch, Fi sheries Service,

Department of the Environment

Ottawa

August 1971

This Report includes work contracted by

the Industrial Development Branch of the

Fisheries Service,

Department of the Environment,

and other related information

the originators of which have

kindly allowed us to reproduce.

Industrial Development Branch, Fisheries Servic~, Department of the Environment, Ottawa, Canada

I N D E X

SECTION A - Foreword by W.G. Scott

SECTION B - Reports of the Work Undertaken by the British Columbia Research Council:

Part I - Project 1968-69

Part II - Project 1969-70

Part III - Technical Supplement

SECTION C - Illustrations of Reinforcing Materials Studied

SECTION D - Regulatory Aspects of Ferro-Cement Vessel Construction:

Part I - W.E. Bonn, Ministry of Transport, Ottawa.

Part II - Lloyds Register of Shipping

SECTION E - Papemand Discussions on Ferro-Cement from the Conference on Fishing Vessel Construction Materials, Montreal, 1968.

SECTION F - Special Bibliographies:

Part I - Bigg, Delaney, Wood.

Part II - British Columbia Research Council

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FOREWORD

Early in 1966 the rapid upsurge of interest in ferro-cement

for fishing vessel construction prompted the Industrial Development

Branch of the then Department of Fisheries of Canada to begin examination

of this newer medium in some depth.

Our basic objectives were to produce quantitative data on the

physical and mechanical characteristics of ferro-cement which could lead

to the boats of that material being certified by the Board of Steamship

Inspection of Canada's Ministry of Transport.

important for vessels exceeding 15 gross tons.

This was especially

The other significant objective was ~o provide usable and

practical information on acceptable construction techniques. Many

fish boat owners provide their own labour in constructing vessels to

defray actual construction cost in dollar ter~s to them and many

smaller boatyards require guidance on acceptable engineering and

production steps.

Ferro-cement was considered as an excellent contender in the

smaller boat construction field which usually does not have the

engineering and production support inherent in larger vessel building

concerns. It uses a construction technique which can be carried out with

little training; it is economic in material costs, in the sense that there

is little or no scrap; it has important possibilities for these areas

where good boat ·-building woods (until now the traditional material for

hulls) are hard to come by; and above all vessels, once designed, can

be quickly constructed thus allowing them and their owners to pursue their

intended purpose - fishing.

This particular project was conducted in a way typical of our

usual method of working, whereby we contacted a group who were interested

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in initiating our studies. In this instance, the British Columbia

Research Council was chosen, and a program, as outlined in this

publication, was commenced.

Throughout the project we invited and obtained, very close

co-operation from the Headquarters and Regional staffs of the Marine

Regulations Branch of the Ministry of Transport.

As the project progressed, close attention was paid to any

published material on ferro-cement and a detailed bibliography has

been developed.

There were also many national and international authorities,

who provided useful comment to assist us, and to them we extend our

thanks.

Mention should also be made of the many provincial authorities

who helped us in this activity, in particular the Federal Provincial

Atlantic Fisheries Committee which sponsored the "Conference on Fishing

Vessel Construction Materials" in Montreal in October, 1968. All of

the pertinent papers (or comments) on ferro-cement from that conference

have been included in this report.

In Canada, interest and know~how in ferro-cement exists in

greater strength in British Columbia than elsewhere. Various companies

(and individuals) are engaged in ferro-cement construction not only for

high displacement-length vessels such as fishing vessels, but for other

marine uses.

These groups, being commercial enterprises, have every right

to safeguard their construction processes as they have borne development

costs ..

Our initial aim was to find out what this new medium offered

in strength values, and how it could be economically worked to reproduce

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lab test figures consistently, by people working by themselves, remote

from engineering consultation.

The construction style itself is appealing, certainly in so

far as support equipment is concerned. Much of the equipment is only

used for a short period; rental can well overcome the cash outlays and

problems of ownership. John Samson's and Geoff Wellens', "How to build

a Ferro-Cement Boat" is one piece of literature which lists everything

in detail required to construct a boat of ferro-cement.

To the best of the writer's knowledge, scantling lists "per se"

have not yet been developed for the various hull parts of a ferro-cement

boat. Lloyd's Register of Shipping, appearing in print as the most

frequently mentioned authority, does not have rules such as are published

for steel, glass or wooden vessels. We understand, however, that Lloyd's

is prepared to assess plans of proposed vesseLs and outline corrections

and alternatives.

Lloyd's has a set of tentative requirements which recommend

on the type of facility required; what steps must be taken during

construction; what basics it believes advisable in quality control of

materials and techniques. Of most importance in the Lloyd's measures

is the listing of various tests required and how these should be done.

The Canadian Ministry of Transport have adopted a considerate

position which is well explained in the paper read by Mr. W.E. Bonn at

the "Conference on Fishing Vessel Construction Materials" held in Montreal

in 1968. Basically, Canadian Steamship Inspection will certify on an

"experimental hull" basis, any unit exceeding 15 gross tons. The procedure

from design through delivery to the owner is similar to Lloyd's, however,

once a vessel enters service the surveys are more frequent than occur with

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other materials.

It should be emphasized that anyone contemplating a

construction in ferro-cement, if it is of a tonnage certifiable under

the Canada Shipping Act or if it is ·intended that it be built to a class

survey, should contact the respective authorities before any commitments

are made. In essence, don't ask for approval after it's done, find out

about it before you start. All Regulations change, often in a direction

which is less onerous and therefore cheaper.

In ferro-cement, there are several claims to "magic potions"

which enhance the material's possibilities and there are alternative

construction styles offered, each one claiming a particular advantage.

However, ferro-cement is a matter of developing a structural material

by human efforts, i.e. it has to be made as you go, comprising of mortar

and reinforcement to produce (if properly mixed and cured) a medium the

characteristics of which under test show tendencies approaching a

homogeneous material such as steel or aluminum.

It should not be confused or equated to reinforced concrete,

as many people would think, since it is not oriented the same way and

is therefore dissimilar.

We have to recognize that some reinforced concrete technology

is applicable to ferro-cement and with general construction forming a

field for continuing progress in our society, on should look forward to

gleaning new technical information from that environment.

The actual theories are more akin to thin shells of reinforced

concrete and not to the massive structures we see as pillars, girders,

floors', etc., in buildings.

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The writer's first experience in the material was when he

was privileged to see a variety of marine craft constructed of

ferro-cement during a visit to Vancouver. During that trip the

writer met numerous people from the ' local ferro-cement industry,

and was given a three day "immersion" course in ferro-cement boat

construction.

This visit really initiated the project report which

follows and which we believe has established factual information

and performance data on ferro-cement. The project is continuing

and additional reports will become available as progress is made

In our approach we purposely insisted that the methods

and materials should represent the style one could obtain from a

limited facility, low quality control operation using commercially

available, cheap and common material.

We did not look for excellent lab results with which

to "boost" the medium, and which could never be produced in reality

without considerable plant, specialist labour and other cost

escalators. Our view was to quantify the expected standards which

a modest production venture could achieve.

A number of people have helped put this publication together;

Professor G. Bigg of Carleton University, Ottawa, together with some of

his students prepared the bibliography; the mesh photographs are

by H. Schade of the Department's photographic unit; Lloyd's Register

of Shipping, Montreal, has kindly allowed us to incorporate its list of

tentative requirements.

Last, but not least we gratefully acknowledge the effort,

interest and enthusiasm of the British Columbia Research Council.

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In the beginning Art Kelly and Tom Mouat and more recently Bill English

and A.W. Greenius, put a lot of effort into this project and it is hoped that

the pages which follow will be helpful to readers.

W.G. Scott

30/4/71

Reports of the Work

Undertaken by the British Columbia

Research Council

Part I - Project 1968-1969

Part II - Project 1969-1970

Part III - Technical Supplement

I N D E X

CONTENTS OF THIS REPORT:

The present report consists of the following parts:

Part 1. A summary of the information derived from the literature survey and from the limited testing program, and its significance to fishin~ vessel construction.

Part 3. Recommendations for action to ensure orderly progress in the utilization of ferro-cement in fishing vessel construction.

Appendix 1. The scope of the project initiated in March, 1968, of which this report constitutes the Final Report.

Appendix 2. The paper "Ferro-cement as a Fishing Vessel Construction Material" by A.M. Kelly and T.W. Mouat, which contains most of the results of this project.

Appendix 3. Results of the freeze-thaw tests, carried out under Bub-contract at the University of Alberta and a discussion of the effect of 1/4" reinforcing rods and of 1114 gauge 1" square mesh hardware cloth. '

Appendix 4. Bibliography.

I

FERRO-CEMENT AS A FISHING VESSEL CONSTRUCTION MATERIAL

INTRODUCTION:

4

REPORT - PART I

To

Industrial Development Service Department of Fisheries of Canada

In March, 1968, the British Columbia Research Council contracted with the Department of Fisheries of Canada, Industrial Development Service, to carry out a study of ferro-cement as a fishing vessel construction material. The scope of the study is indicated in Appendix 1. Its objectives were:

1. To collect and collate as much as possible of currently available information on the properties of ferro-cement and on its use as a boat-building material.

2. To carry out a limited program of testing to determine the physical and mechanical properties of ferro-cement, as fabricated by conventional techniques.

The main results of the study were presented to the Conference on Fishing Vessel Construction Materials held in Montreal October 1 - 3, 1968, in the paper "Ferro-cement as a Fishing Vessel Construction Material" by A.M. Kelly and T. W. Mouat (Appendix 2). The freeze-thaw • tests, which were sub-contracted to the University of Alberta, were not completed in time for the above paper, and are now included as Appendix 3, along with a short discussion of the effect of reinforcing rods or heavy mesh.

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PART 1. SUMMARY OF INFORMATION DERIVED FROM LITERATURE SURVEY AND LIMITED TEST PROGRAM AND ITS SIGNIFICANCE TO FISHING VESSEL CONSTRUCTION.

Ferro-cement is an old boat-building material - its history goes back a hundred years. Its modern impetus started with Professor P.L. Nervi during World War II, with the encouragement of the Italian Navy. Construction of four vessels of 150 tons and over was started but not completed. After the war, Professor Nervi built a l65-ton motor sailer, and a 38-foot ketch, which appear to have been very successful.

In the 1960's ferro-cement construction of motorboats and yachts was taken up in England and New Zealand, and since then the popularity of ferro-cement has been growing at an ever increasing rate. The main centers of commercial activity at the present time are England, New Zealand, Florida, California and British Columbia. There is also evidence of substantial activity in the Communist world.

A striking feature of the present ferro-cement boat-building industry is its emphasis on "trade secrets". There is very little published information on the relationship bet,-1een the final properties of the ferro-cement and such factors as cement mix, type and disposition of reinforcing, and lay-up and curing procedures. There has been a brisk trade in licenses involving the transt'er of "secrets", in which Sea crete Ltd., Norfolk, U.K., and Ferro-Cement Ltd., Auckland, New Zealand, have been particularly active. There is very meagre information on quality control, the effect of stress concentrations, vibration and fatigue, or on the effect of adverse environmental conditions. This lack of reliable information poses a serious obstacle to the rational application of ferro-cement construction to vessels over 15 tons.

It was the lack of basic information on ferro-cement which led to the modest series of tests which have been done by the B.C. Research Council in parallel with the literature survey. It is significant that, despite their limited scope, they are already being quoted by boat­builders - mainly in the sense that the builders' (secret) method gives a better result - but factual data in support of such statements is virtually non-existent.

It should be made clear samples made and tested under the the best that could be produced. standard of "amateur" production, Marine Design Enterprises Limited with this in mind. There were no vision of panel fabrication. The made are described in Appendix 2.

at this point that the ferro-cement BCRC program were never intended to be Rather they were to represent a minimum and the contractor who made them, of Vancouver, was chosen and instructed engineering controls or on-site super­different types of samples which were

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The test program on the samples comprised tension, compression and shear (sample size 1 3/4" x 12") transverse'bending (5 3/4" x 12") membrane tests, both compressive and impact (12" x 12") and freeze-thaw cycling (4" x 16"). All samples were 3/4" thick. Mesh content was 1 to 12 layers of 1/2" hexagonal galvanized aviary wire and some samples contained 1/4" mild steel reinforcing bars on 2" centers, or one layer of 1114 gauge 1" square mesh hardware cloth.

Detailed results of the tests are given in Appendix 2 and Appendix 3. Briefly, they are as follows:

Tension:

Tensile strength increased almost linearly with the number of meshes. There was no evidence of levelling off, so presumably an even higher ratio of steel to cement would have been advantageous. There was little difference between panel directions. The maximum tensile strength (12 mesh layers) was 950 p.s.i., which is about twice the value for unreinforced concrete but below the values quoted by others for ferro-cement. Some commercial producers -e.g. Seacrete Ltd. - quote "ultimate tensile strength" in the{ 5000 p.s.i. range. This is believed to be derived tensile strength, from bending measurements, but no firm information is available.

Compression:

Compressive strength varied from 5000 to 9500 p.s.i. with little dependence on number of meshes. The value for unreinforced concrete is about 7000 p.s.i. The type of failure observed (splitting between meshes) indicates that cross-bonding of meshes is desirable, and good penetration is essential. Seacrete Ltd. quotes values from 7200 to 12,200 p.s.i., depending on time since fabrication.

Shear (across panel):

Shear strength varied roughly linearly with number of meshes from a mean of 50 p.s.i. to a mean of 100 p.s.i.

Transverse Bending:

Tests were in accordance with ASTM Designations A438-62 and C293-64, with allowances for sample thickness (3/4" instead of the 3" - 5" in the ASlM Specification). The modulus of rupture derived from these tests varied nearly linearly with number of mesh layers from a reean of 700 p.s.i. to a mean of 2500 p.s.i. In one panel, trowelled from both sides and not vibrated, the deleterious eff~ct of incomplete penetration was illustrated by shearing along the middle, neutral, axis.

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Membrane Test (compressive):

In this test a 12" x 12" panel was loaded cyclically by a 1" diameter piston, until failure occurred. The maximwn load borne varied from about 500 lbs (1 mesh layer) to as much as 2000 lbs (10 or 12 mesh layers). The panels were consistently more resistant to loads applied to the front, trowelled face.

Membrane Test (impact):

This was similar to the compressive test, with a falling weight substituted for the piston. The results of this test are more qualitative than quantitative, since the point of "failure" is difficult to define. Impact resistance was less than expected. Failure for panels with 2 - 4 layers of mesh was typically by cracking at from 27 to 200 inch-lbs. Failure for panels with six layers or more was typically by punching shear at from 36 to 300 inch-lbs. The high values of resistance were nearly all for impact on the front, trowelled face.

Freeze-tha'-T :

Eight samples from each of three panels containing one, six and twelve layers of mesh respectively.,,,ere cycled as far as possible in accordance with ASTM C 291-67. Electronic vibration equipment could not be used to determine mechanical condition because the thickness of the samples (3/4") was below the range of the equipment (3" - 5"). Instead, weight loss was determined 12 times for each sample during the passage from 0 to 309 freeze­thaw cycles. Weight loss in this kind of cycling is known to be correlated to resistance to natural weathering under freeze-thaw conditions. Loss of weight varied linearly with the number of cycles. The six-layer and twelve-layer samples proved satisfactorily resistant, with average weight losses after 309 cycles of 20% and 4% respectively. The only one-layer sample which survived to 309 cycles without disintegrating had lost 44% of its weight.

Although these tests must be considered preliminalY, it looks as if the resistance of good ferro-cement to natural freeze-thaw cycling should be very high.

Reinforcing Bars and Heavy Mesh:

The effect of 1/4" mild steel reinforcing bars on 2" centers at the median plane was explored in three panels, and the effect of a median layer of #14 gauge square mesh hardware cloth in one panel. With 1/4" rods t,,,o panels were made in the horizontal position, one trowelled on both sides, the other plywood-backed and trowelled on the top face, and one panel was made in the

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vertical position, trowelled on both sides. The panel with hardware cloth was made horizontally on a plywood backing, and trowelled on the top face. The last three panels were roughly twice as strong as a horizontally made. plywood-backed panel containing the same number of fine mesh layers, but no heavy reinforcing. It would be wrong, in our opinion, to attribute this increase in strength directly to the heavy reinforcing. Rather, we believe it is due to a better distribution of the fine mesh, which is held away from the median plane by the rods or heavy mesh, and is thus more effective. These test panels, and also the previous ones without heavy reinforcing~ show the importance and the difficulty of ensuring that the fine mesh aviary wire reinforcing is in the right place in the panel to do its job.

General Comments on Tests:

The variability of the test results, and the low strength values from some samples - samples from flat panels which might be thought easier to make well than a boat hull - illustrate a vital point with ferro-cement.

It has been widely stated that ferro-cement lends itself to non-professional construction, and that relatively unskilled labour can be employed. This is essentially true, but nevertheless some phases of the operation - for example the securing of ·the mesh, the cement mix, and the plastering - are very critical, and adequate craftsmanship is vital to success. As hull sizes increase, good quality control, with sound design and good construction techniques, will become more and more important.

Ferro-cement for Fishing Vessels:

The praises of ferro-cement have been sung so widely in recent months that we will limit ourselves here to a brief recapitulation.

1. The raw materials are widely available and cheaper than other boat-building materials. (A ferro-cement hull is estimated to cost in the order of 15% to 30% less than one in steel or

·wood, depending on size and construction method.) Of course, the hull is only part (on the average, about 60%) of the cost of the vessel.

2. Very little highly skilled labour is involved - although as noted earlier there are some critical steps that require care and experience.

3. Ferro-cement is well suited to "one-off" construction, since no expensive building, fixtures, or tools are required. The total capital investment can be very low.

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4. Ferro-cement should require very little maintenance. It is immune to rot and marine-borer attack. It becooles stronger with age, and shmvs no evidence of corrosion in sea water. As stated elsewhere it appears, from the limited data avail­able, to be very resistant to freeze-thaw cycling. It is resistant to abrasion.

5. The material is fire-proof, and is substantially more resistant to heat from a fire on board than fibreglass or aluminum or, under some conditions, even steel.

6. Ferro-cement boats are claimed to give some 10% more useful inside space (due to the absence of frames) than a wooden hull of the same overall dimensions. In some small vessel designs of about 40' overall length this is doubtless true. It is also claimed that condensation does not occur with ferro-cement. This is definitely not true under all typical conditions, and the lining necessary to prevent it will then encroach on the 10% extra space.

7. The acoustic properties of a ferro-cement hull, because of extra mass and panel stiffness, should be superior to other materials. tVhile this aspect has not been documented, it could lead to improved fish location and perhaps to more effective catching.

Some "question marks" in ferro-cement vessel construction are the following:

1. It is claimed that ferro-cement suffers less damage in a severe impact than wood or fibreglass, and that repair of the damage is quicker and cheaper. No quantitative data is available on the strength of such a repair, or on the long­term integrity of the bond between the patch and the undamaged ferro-cement. A similar situation occurs when the plastering of a hull, normally done in one continuous operation, is unavoidably interrupted. There are "recipes" for assuring a good bond of th"e new cement to the old, but no published measurements on the short- or long-term characteristics of the joint.

2. How strong is ferro-cement? One finds phrases in the liter­ature such as "innnensely strong", "comparable to wood", "as strong as steel". Comparison with other materials is difficult and misleading, because "strength" in the ship­building sense is a combination of a number of physical properties such as resistance to tension, shear and bending, ability to distribute localized stresses without failing,

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resistance to vibration and fatigue, etc. The strength required is also a function of the design, and the optimum design for ferro-cement is certainly different from that for wood or steel, and in fact has probably not yet been evolved.

An important factor in the subjective estimation of the strength of ferro-cement stems from the fact that the material cannot be produced much thinner than 3/4". For vessels up to about 40' long this gives a very strong, rather heavy hull, and because of the shell strength a minimum of internal support is required. The vast majority of the ferro-cement vessels built so far have been far under the 100' size for which longitudinal bending moments start to become appreciable. For this class of vessel ferro-cement is certainly adequately "strong". The real question is what happens in vessels large enough so that racking and bending moments are significant. Here the properties of the material will have -a major influence on the design of the vessel - and it is just these properties which at present are mysterious and ill-defined.

3. Quantitative information is needed on the effect of stress concentrations in ferro-cement, and the best method of distri­buting stress by additional stiffening, which usually would also be of ferro-cement.

4. There is no published data on the resistance of ferro-cement to vibration and fatigue. While it is not suggested that ferro-cement is deficient in this respect, the necessary data for design purposes must be available if over- and under-design of engine and machinery supports are to be avoided. With the continually increasing horsepower of main engines, and the increasing use of auxiliary pm.,er machinery, this factor will grow in importance as time goes on.

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PART l.. ACTION NEEDED.

To ensure orderly progress in the utilization of ferro-cement in fishing vessel construction, research is needed to establish the properties available in the material, and how to get and to use these properties to best advantage. This vital information must be made available to commercial shipbuilders and to individual fisherman­builders in a form which will meet their needs and will encourage sound economical construction.

Research on Ferro-cement:

The aspects of ferro-cement on which present information is inadequate and on which we believe research is needed are summarized below. Each item must be approached in two ways -one for the "shipyard", where a fair amount of soph~stication and specialization may pay dividends; the other for the "back-yard", i. e. the individual fisherman-builder who wants to use common materials and straightforward techniques.

1. Material:

2. Design:

3. Construction:

4. Operation:

To minimize cost for a specified strength Cement additives or substitutes Better sand sizing and control of mix Improved reinforcing, amount, type, treatment

(galvanized or ~ot?) Placing of reinforcing, cross tying Material specification

Most economical design for necessary strength Scantling tables and other design information Stiffening of edges and openings Engine and machinery bearers Installation of tanks in ferro-cement

Control of cost and quality Lay-up methods, curing Obtaining and testing of material samples Effect of joints and interrupted plastering Check points during construction Inspection and non-destructive testing of

critical elements of hull, e.g. keel, engine bearers, deck fittings (some development or adaptation of existing non-destructive testing methods will be required)

Efficiency and economy Noise, vibration, condensation, water-tightness Low maintenance construction and finish

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5. Studies on stress concentration J vibration and fatigue effects and other accelerated environmental testing, e.g. freeze-thaw, concentrated brine

6. Laboratory testing of hull sections and components

7. Strain-gauging of new or existing hulls

It is clear that a very worthwhile research program, extending over several years, could be set up to provide the basic information on the properties and use of ferro-cement which is now lacking. We are convinced that such a program would make a major contribution to the effective and safe utilization of ferro-cement in fishing vessel con­struction.

Certification of Ferro-cement Vessels:

For the would-be builder of a vessel over 15 tons, the burning question is how to obtain certification by the Canadian Department of Transport, without excessive expenditure or risk. In a paper, "Regulatory Aspects of Traditional and New Construction Materials", given at the Montreal Conference on Fishing Vessel Construction Materials, . October 1968, W.E. Bonn, Superintendent, Hulls and Equipment Division, Marine Regulations Branch, outlined the requirements which would lead to provis;i.onal certification for Home Trade "class III (not more than 20 miles offshore and not more than 100 miles from a port of refuge).

In addition to the economic penalty imposed by this limitation on operations, there are other serious problems which arise from lack of knowledge of the capabilities of the material, and from lack of experience in quality control. Appropriate scantling tables, such as are available for wood, steel, aluminum and fibreglass, do not exist. Suitable testing and inspection procedures have still to be evolved, and better guidelines for design and construction are urgently needed, especially by the individual fisherman-builder.

Until these needs are met, and full certification can be reasonably assured before construction is undertaken, ferro-cement will suffer a major disadvantage in relation to established materi.als. Many builders feel this is unfair, because of the extensive experience with ferro-cement going back to World \-Jar II. But in view of the lack of quantitative data and documentation on this experience, it is hard to see how the Department of Transport, in discharging its responsibilities to ensure safety at sea, could proceed otherwise at the present time.

The problem of certification must be resolved as quickly as possible, and this can only be done through the cooperation of all concerned. The leadership and initiative of the Department of Fisheries

- ,,-Industrial Development Service is playing, and will play, a . vital role in providing the mechanism for this cooperation. We feel that the time is ripe for a significant joint effort by the commercial ferro-cement shipbuilders towards the optimizat~on of design, construction and quality control in ferro-cement. Needless to say a corresponding effort by the public agencies is also required, and this must safeguard the interests of the fisherman-builder, whose means and needs are different, though not always radically different, from those of the commercial builder.

WNE/cz

. .~

ff/~~~ W.N. English, Head Division of Applied Physics

APPENDI.X 1.

BRITISH COLUMnl/.\ l1ESf:ARCH COUNCIL UNIVERSITY OF BRITISH COLUMBIA VANCOUVER 8, B. C.

J<'ebru.wy 9, ] 968

PROJEC'l' PHOPOSAL

To: Industrial DL!velopment Branch Dep3rtment of Fisheries Sir Charles TUPPC:l' Building River-siue Drive Ottawa, Ontario

Subject: FERRO-CEM;i:NT BOATS

A. OBJECT

1. To collect and collate as much as possihle of currently available infornntion on t11'2 properl;ies of "ferro-cement" and its usc RS a bontbuilding material.

2. '1'0 carry out a limHcd pro~rmn of testing to det.ermine the physical and mcchatdCRl properties of ferro-cement, as fabricated by conventional techniqUt~s.

B. BACKGROUND

Tmrards the close of Horld Hur II, Dr. Pier Luigi Nervi, of the Italian firm of Nervi and Bartoli, Engineers, developed a technique for fabricatin,:; bO,ltS from a cheap, strons, durable, lieht,,,eieht form of reinforc'=d concreee. Bauic8.lly, Nervi's method consisted of er,~cting a steel wire mesh in the desir2d form and impree;nating it ,,,ith a mortar made of Portland ceme nt Hnd fine sand. Pipe fram:=s and r(~inforcinr:; bars ~vcre used to nnintCl in ttw shape! before plast.Jring and to provide lonsitudlnal stiffeninG of the finlshed hull. The r,::;sultinS rratcri8.l, in Nervi's words, "d5.d not behave like reGular concrete, but presented all th,:! mechanical characteristics of a new material". He named this rrateriRI "Ferro­Cemento" j it is usually referred to in _e;nc;lish as "Ferl'o-Cem::mt".

Since that timc=., th,"!re ha<J been some developm:~nt VTork carried out; by ;)nu taur borttb1lildcrs, but very 1 i ttl(~ or[!;aniz(;d reSearch appenr.:; to 113ve been done. Y-=t, the pot~ntial of th'= TTlL'ltcrial ne ,211S good, especially in comp~tition with steel. Th2 IT'3.terbl is [;8ic1 to exceed \food in its str,C!r..~t[l- and stiffnesf3-to-\.re ir:b i; r<J.~ioG, yet b.:; cheapt~r thc:w \lood or steel by up to 60;G. It is v:i.rttully fre~ of rot, corrosion ;)nd electrolysis and appears quite durubl·:. (Indc.::d .. it is said to 2:1'0\1 st.rOD[.;er ,'lith age and

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Department of 1o'18heries February 9, 1968

water immersion.) The skills required to build.boats from this material are rather less than required when using more conventional materials, so savings in labour costs should also be attainable.

At a recent meeting in Ottawa bet"Teen Messrs. L. S. Bradbury, J. Frechet and VT. ~. Scott of the Department of Fisheries and A. M. · Kelly of the Council, the Department expressed interest in the subject. Suboequently, Messrs. Frechet and Scott" during a visit to Vancouver, inspected tim ferro-cement boats, one completed, one incomplete. They also met with Mr. John Samson, of Marine· Design Enterprises, who was instrumental in introducing the material to Canada. This proposal is a result of these meetings.

C. PROCEDURE

The project will be carried out in two phases: data collection and testing.

Phase I

A literature search will be conducted, covering the period 194tl- to the present, to determine what has been publlshed in the professional journals relating to ferro-cement. Particular attention will be paid to the Marine and Civil Engineering journals.

Concurrently, ive will enter into correspondence "dth all known Naval Architects, Marine EngIneers and professional builders who are engaged in the desie;n and/or constructlon of ferro-cement boats and other structures and as 11'any an19.teur builders as pOGsible within time and bu.dgetary constraints. It is hoped·that a good deal of useful information can be obtained economically in this rna,nner. In addition, those designers and builders "Tho are in or reasonably near the Vancouver area (including those in the North-ilestern U.S.A.) will be visited and interviewed at length.

The inforJ~~tion gathered in this phase will be collated and written up as a "state-of-the-art" revie",.

Phase II

A scheclule of tests, ou.tlined in the follmring sections, will be carried out. The test schedule should be consldered to be flexible and subject to modificat.ion as test results are accumulated. The procedures are based on assumed charact~ristics and practical strength valu::!s that have been estimated from verbal reports of actual service pcrfOrJi}':lOc8 of the materj.al. The proposed tests are intended to produce prt~liminary data as a basis for the desic;n of useful structures and of more sophisticated tests. In ~cncral,

-3-

Dep3rtment of Fisheries February 9, 1968

tests 1, 2, 3 and !j. are intended to roake dlrect compo.risons betvTeen ferro-cement and steel in such a 'my that formulas appl:i.cable to steel constructi.on can be acl:::\pted for use ld.th ferro-cement through substHution of appropriate factors. 'l'csts 5 and 6 are desie;ned to produce us~ful dnta for general structural desi.c;n and the determj.nation of conditions under ,·rhich ferro-cement methods may reasonably be used.

For these preliminary tests, the selection of materials will be limited to at most three cement mixes and three confj.8Ul'ations of "\-Tire m~sh and reinforcing, makinc; a total of nine possible combinations.

He '-Till arrange to have a number of p~ne1s of about 4 feet by 8 feet constructed to our spccificatjons by Mr. John Samson. These panels \·,ill then be cut. into test sections of the requir3d sizes. This procedure ,·Till ensure that each set of test sections has essentj.ally uniform characteristics. Before testing, the Height and volume of each section ,·rill be determined. 'l'he follmring tests \vill then be performed, for each confic;uration of mIx/reinforcinG.

1. Tensile

Two adjoinint; sCJ..uare samples of 12-inch edge length, cut at leAst 6 inches from the side of the original panel shall each b~ cut into 6 strips approxhilately 1-3/1+ inches in '<ddth by 12 inches in length, the strips from one sample beine; oriented at 90 de3rees to those from the other j.n respect to the "grain" direction of the original sample.

Each strip shall be tested to destruction in tension in accordance with A.S.T.M. Designations E8-61T, and A370-61T insofar as they apply.

2. Compressive

Two square samples similar to those of 1. above (12 in. by 12 in.) shall be cut in the same manner as required in 1. to produ.ce SIJccimens for compr~ssive tests.

Each specim<~n shall be tested in accordance ""ith the procedure for A.S.T.M. DesiGnation E9-61.

Foul' squ~trc s!3.r.lp1es sirnilar to those of 1. above shall each b::: cut into 2 Sl)ecimens appro::dmately 5 - 3/!~ inches in

" • 1t \dclth; t',ro r.amplcs are to be cut parallel to the e;raln, the Ot.ll·2~ t,",'iQ, Iterr.::ndicul::lr to ti'l2 "2:rninu"

Department of Fisheries February 9) 1968

Each specimen is to :be tested in bending, t'\vo longitudinal and tvTO cross sp~cimcns, face up, the remaining four specimens face dmTn. All tests are to be in accordance with the procedures of A.S.T.l~. DesiGnation A~-38-62 and Designation C293-64 insofar as applicable.

l~. Diaphragm or Flat Plate Bending

Four sql~re samples the same as required in 3. above are each to be .simply supported on a square fixture having cylindrical contact surfaces of 1/4 inch radius, and initial contact lene;ths of 10 inches for each side of the square. Two specimens' are to be tested face up and two face down. Each is to be loaded centrally on an area 1 inch in diameter.

Load is to start at 100 pounds, and is to be increased in 100-palmd incr~ments to 600 pounds, then in 200-pound increments to 1600 pounds, then in 400-pound increments to ultimate. The lea d is to be removed after each increase. Deflections loaded and unloaded for each step are to be observed and recorded.

5. Impact

Four square samples, similar to those of 3. above are to be tested for impact resistance while resting on the fixture of 4. above by dropping onto each a 'chilled-iron grinder-ball approxiwately 4 inches in diameter and of spherical shape, so as to strike the specimen ,\fith an energy of 150 foot-pounds. If no evidence of failure appears, successive impacts each 50 foot-pounds greater than its predecessor shall be applied until evidence of failure appears.

6. Freeze -Tha'\-T

Eight specimens 4 inches by 16 inches shall be cut and tested in accordance with A.S.T.M. Designation C29l-61T and Designation C215-60.

APPENDIX 2

Reprinted from: Proceedings of the Conference on Fishing Vessel Construction Materials, Montreal, Canada, October 1 - 3, 1968.

Ferro-Cement as a Fishing Vessel

Construction

Material

by

A. M. Kelly and T. W. Mouat British Columbia Research Council,

Vancouver, B.C. Mr. Kelly Mr. Mouat

Mr. Kelly was born in St. John's, Newfoundland, in 1930. He earned his diploma in engineering and his B.Sc. in mathematics at St. Francis Xavier University, Antigonish, N.s., in 1957. He obtained his M.Sc. in geology and geophysics at the Massachusetts Institute of Technology, Cambridge, Mass., in 1963. He did further post-graduate study at McGill University, Montreal, from 1964 to 1966. From 1951 to 1956 Mr. Kelly served in the Canadian Army. Between 1957 and 1964 he was Lecturer and Assistant Professor at St. Francis Xavier University ; in 1966 and 1967 he was with the Unica Research Company, Montreal, and from 1967 to date he has been Assistant Head of Operations Research at the British Columbia Research Council. He has had a lifelong interest in boats and naval architecture is his hobby.

Mr. Mouat was born in Nelson, B.C, in 1912. He obtained his B.Sc. degree in mechanical engineering from the University of British Columbia in 1934, and his M.Sc. degree in electrical engineering from the California Institute of Technology in 1939. From 1934 to 1938·he was employed by Cemco Manufacturing Company; from 1940 to 1946 he was with the Electrical Engineering Section of the National Research Council, heading the section before he left to become Project Engineer at the University oJ British Columbia, a position he held until 1949, when he assumed his present duties with the Division of Engineering of the British Columbia Research Council. Since 1949 Mr. Mouat has done a considerable amount of materials research and testing, including work on wood, metals, soils and concrete.

ABSTRACT

The material is described and a brief history of its usage given, including the results of some of the research which has been performed in the past. The current "state of the art" is then surveyed, with emphasis on three points: Costs of Construction; Strength and durability, and Design considerations. Finally, the results of a series of strength tests, made on flat panels of various confIgurations, are presented.

INTRODUCTION

"Ferro-Cement" is the name given by Dr. P. L. Nervi, of Italy, to a material consisting essentially of a number of layers of wire mesh impregnated with a mortar made of frne sand and Portland cement. Nervi (I956) showed that the resulting material did not behave like ordinary reinforced concrete but, in his words, "exhibited all the mechanical properties of a new material". The reasons for this behaviour appear to depend fundamentally on two things:

136

1. TIle ratio of reinforcement to mortar, by weight,

2. The dissemination of the reinforcement through­out the matrix of mortar.

\ The material is easy to fabricate into complex shapes without the use of fonns or moulds; it has good strength to weight and stiffness to weight ratios; it is waterproof; it is corrosion resistant, and it is relatively inexpensive. These properties lead to the conclusion that it ought to be a useful material for marine applications; indeed, many such applications have been made. The increasing interest in the material on the Pacific Coast reached a level some months ago such that the Industrial Development Service of the Department of Fisheries of Canada commissioned the British Columbia Research Council to carry out a study of ferro-cement as a boatbuilding material. This report is the outcome of that study.

The stated aims of the project were:

1) To collect and collate as much as possible of currently available infonnation on the properties of ferro-cement and its use as a boatbuilding material, and

2) To carry out a limited program of testing to detennine the physical and mechanical properties of ferro-cement, as fabricated by conventional techniques.

HISTORY OF FERRO-CEMENT

The invention of ferro-cement, as defmed above, is generally credited to Nervi and dates from the work he did in the years 1942-43. It is of interest to note, however, that similar methods were in use by Lambot, in France, as early as 1849 (Cassie, 1967). In fact, Lambot took out French and Belgian Patents, on what he called "Fen;:iment" in 1856. He caused several rowing boats to be built of the material. One of these was apparently still afloat in 1949, nearly 1 00 years later. In 1955, this and another were found in the mud on the bottom of the pond where the first had been kept; the older one is currently on display in a museum in Brignoles, France. Cassie reports that it is still in surprisingly good condition.

In 1887, the year of Lambot's death, a similar boat was constructed in Holland. This vessel, now 81 years old, is still afloat on the Pelican Pond at Amsterdam Zoo (Morgan,

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

1968a). Gabellini, in Rome, also built boats by this method, around the turn of the century.

No evidence of true ferro-cement construction in the period 1888 to 1942 was found, although many reinforced ' concrete vessels were built in this period. In the United States alone, during World War II, 104 vessels, ranging in displacement from 4,000 tons to 12,750 tons were con­structed (Tuthill, 1945).

One of the first sea-going reinforced concrete :;hips was the 356 ton "Namsenfjord", launched in Norway in August 1917. In March 1919, the SS "Armistice", 1,150 tons, was launched in Great Britain (Taylor, 1961). Morgan (1968) reports that this vessel is still in active service, 49 years later. Nine old concrete vessels have been converted for use as a floating breakwater at Powell River, B.C. The oldest of these is the "Peralta", 6,065 gross tons, built in 1916. The first of these were installed in 1947 and 1948 and all are still in good condition.

In 1941-1943, Dr. P. L. Nervi, the noted Italian architect and engineer, began a series of experiments on what he christened "Ferro-cement". His work led to the acceptance of tlle material by the Italian Naval Registry and the Department of Marine Engineering of the Italian Navy. As a result, in 1943, construction was started on a 40().ton freighter and three 150-ton naval vessels, all of ferro­cement. The work was abandoned in September 1943 because of the exigencies of war. In 1945, a 165-ton motor sailer, "Irene", was built by the fmn of Nervi and Bartoli for their own use. Nervi reports that the total weight of this vessel was approximately 5% less than an equivalent wooden ship; its cost was 40% less (Nervi, 1951). This vessel was subsequently wrecked in 1957. However, Nervi (1951) stated "After five years of hard and regular use in the Mediterranean, the boat is as good as the day it was launched and has never required any maintenance what­ever". In the same paper, he reports that the vessel had two serious accidents during that period, but sustained only minor damage. In 1948, he had built for his own use a 38-foot ketch, the "Nennele". The vessel has a skin composed of seven layers of mesh with one layer in 1/4-inch reinforcing bars on 2-inch centers. The total skin thickness is only I/2-inch (Nervi, 1956). Morgan (1968) reports that this vessel is still in regular service and is in excellent condition.

There seems to have been little, if any, a«tivity from 1949 to 1960. In 1961, however, the renaissance of the

A. M. Kel~l' all(/ 7: HI. /IIoliat

method started in New Zealand and in England. In new Zealand, a Mr. Manning built a 24-foot yacht in that year; this started a boom ill amateur yacht building using ferro-cement, which is still going on. ]n the sallle year, Windboats Limited, of England, began producing motor .boats, 34 feet long. Tell of these were produced in the first 18 months of operation.

Shortly after this, interest spread to North America, where tlle metllod has been widely adopted. ]n British Columbia, for example, fishing vessels, work-boats, barges, yachts and otller marine structures are now being built of ferro-cement. In fact, the material has become the basis of a thriving industry in the province-there are now four firms engaged full time in the construction of ferro-cement vessels, together with a finn specializing in their design. In addition, at least threc prominent naval architects are now producing designs for this medium.

Comparable activity is taking place in the United States, mostly in California and Florida. An interesting develop­ment is the Wusih factory in China, not far from Shanghai, which has been producing ferro-cement boats since 1963. The plant employed 600 people in 1 %6, 20 per cent of whom are women. They produce six different models, although most of their output consists of 3 and 5 tonners (Anon., 1966). The article cited does not give production figures; however, one of the accompanying photographs shows a part of a production line, with more than 25 boats under construction.

THE MATERIAL

As outlined in the introduction, ferro-cement consists of a number of layers of wire mesh impregnated with a rich mortar made of of Portland cement and fine sand. As Nervi has pOinted out (1956), the principle involved is that concrete can wit hstand large strains in the neighbourhood of the reinforcement and that the magnitude of these strains is proportional to the distribution and subdivision of the reinforcement throughout the mass of concrete. Specifically, when the amout of reinforcing material ex­ceeds about 15% of the total weight of the material, the strength increases dramatically compares to unreinforced mortar. This percentage amounts to about 30 to 40 pounds of reinforcement per cubic foot.

In order to avoid having to use forms, the usual practice is to construct an armatu re of reinforcing bars to which the mesh is attached. Conventional practice is to use eight

]37

layers of 20 gauge, I/2-inch hexagonal mesh, four on each side of the reinforcing bars, which are usually 1/4-inch maid or hard-drawn steel. This will be explained in greater dctail in the next section.

The mesh covered arn13ture is then impregnated with mortar. The mortar is made with a sand-cement ratio varying from 1.5:1 to 2:1, dependiJlg on the builder. Type 5 Portland cement .. an alkali resistant type, is commonly used, although some builders prefer the so-called "high­early" cement, which requires less curing time. Five to fifteen percent of tlle cement is replaced by pozzolan, again depending on tlle builder. This substance absorbs· the free lime produced by the setting reaction of the cement and also makes the resulting mortar more dense. The sand used is a sharp, fine grade. Grading curves vary, but in general all sand passes a number 8 sieve, willi 10 to 15% passing a number 100 sieve. Between these two, the grades are uniformly distributed. The aim here is to have a dense, impenneable mortar, with the grains of aggregate well packed and evenly coated with cement. The amount of water added should, in the opinion of most builders, be just sufficient to make the mix workable. ApprOximately 4 to 4 1/2 gallons per bag of cement is often used.

After the mesh has been thoroughly impregnated the surfaces which will be left exposed can be given quite a smooth finish by trowelling. This is best done by a professional plasterer or swimming pool finisher. The trowelling has the effect of floating some of tlle filler materials to the surface, which becomes, after curing, almost as smooth as a finished plaster wall. It must be done with care, however, as too much separation of the aggregate will weaken tlle ferro-cement. This procedure also ensures that no mesh remains exposed where it could corrode.

The material is then allowed to set until it becomes hard enough for grinding and sanding; this process takes about eight to twelve hours. At the end of this time, surfaces which require finishing are ground, using carborundum stones and carborundum sandpaper. This smoothing process done, the material is then cured for 21 to 28 days. During this period, tlle structure is kept uniformly wet at all times. The temperature should be maintained well above freezing and the stmcture should not be exposed to draughts or direct sunlight, which would cause uneven evaporation or uneven temperature distribution or both.

On completion of the curing process, exposed surfaces can be etched with muriatic acid and neutralized with

138

caustic soda to provide a good key for the fmal finish. Most builders then apply several coats of epoxy based paint. The paint is used solely to improve the appearance, as the ferro-cement is waterproof and corrosion-resistant by itself.

\ The resulting material varies from 3/4" to 1 1/4" in thickness, depending on the armature, and has a density of about 1 SO Ibs/cu. ft; this is equivalent to a weight/unit area of 9.5 to IS p.s.f.

The specific gravity of 2.4 seems high when compared to 1.6 for fibre glass and 0.9 for wood (including fastenings) (James, 1967). However, the absence of heavy internal frames reduces the weight of a ferro-cement hull sufficient­ly that for boats over about 30 feet long, the weigllt is 5 to 15% less than an equivalent wooden hull. In addition a gain of 11 % in internal volume is realized (James, 1967).

Some of the foregoing figures are general and imprecise, because of the numerous lay-up methods and mortar mixes in current use. Each of the manufacturers believes his product to be superior; understandably, none would divulge their specific sand/cement or water/cement ratios or their sand grading curves. However, in a later section of this report, specific values will be given for the test panels which were made. These are representative of typical amateur construction, and specify a useful point of departure for future work.

The few strength figures which are reported in the literature are mentioned only casually. The methods of arriving at these figures are not given. However, these sources plus verbal infornlation from local builders plus the results of our own tests (given later in detail) indicate compressive strength in excess of 6000 p.s.i. and tensile strengths between 500 p.s.i. and better than 10,000 p.s.i.

We have so far been unable to explain this seemingly excessive range of tensile strengths. No informa tion was available on the type of tests perfonned other lhan our own, which gave results of 450 to 900 p.s.i. These lower figures are consistent with the reports of Nervi (1956) and Byrne and Wright (1961) but are an order of magnitude less. than those reported by James (1967) and by several British Columbia builders who prefer not to be identified. It may be that the higher figures are derived from flexure tests; calculations based on our own flexure tests indicate strengths ranging from 2000 to 3000 p.s.i. James (1967) also reports on two other interesting tests. First, test panels were subjected to temperatures of 1,700 degrees centigrade

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

for 1 1/2 hours, with no effect. * Second, a sample strip 21 5/8 inches x 5 inches x 5/8 inches was tested for fatigue in flexure. A stress alternating between 600 and 700 psi was applied 8 1/2 inches from one support point; the sample survived 2 million cycles without fracture.

BOA TBUILDING METHODS

There are three methods of boat construction in current use. They will be referred to as the "pipe-frame" method, the "welded armature" method and the "wooden plug" method.

1. The Pipe-Frame Method

This is the oldest method. In its basic fonn, it appears to date back to the earliest use of ferro-cement. As is usual for all boat building, it starts with the lofting of the lines. At this point, station moulds are construted of iron pipe, bent to conform to the station shapes, instead of wood. Usually, 1/2-inch i.d. pipe is used. The stem, keel, stern post, tran­som and deck beams are Similarly made of pipe. These parts are' then assembled and welded together after the usual plumbling; levelling, squaring and fairing. This structure is supported by being hung from an overhead framework. The keel is shored up - this is the only support from below.

After the pipe-frame structure has been {aired, longitu­dinal reinforcing bars, usually 1/4-inch diameter, are attached on 2 to 3 inch centers. If required, transverse reinforcing, on 3 to 6 inch centers is also installed. These members are usually tied to the pipe frame and each other, as welding is said to disturb the structure.

The wire mesh is then fastened to the framework. Eight layers of 20 gauge, 1/2 inch hexagonal mesh (four inside, four outside) is the general practice. The mesh is pulled tight and attached by wire ties or "hog-ring" type staples. Some builders also lace the mesh in such a way as to pull the outer and inner layers together in the interstices between reinforcing bars. This practice is questionable on theoretical grounds, as it tends to concentrate the mesh on the neutral axis of the section, where it is least necessary. In addition, it leads to a "quilted" surface on the finished product if the plastering technique is imperfect.

* (This is probably Ilame temperature and not panei'temperature, as 1700

0 C is above the melting point of most steels and many sands).

A . /II. KellyallCI T. W. Moltat

The resul ting structure is then plastered from the inside, with the mortar being forced through and trowelled from the outside to give a smooth finish. It is then cured as described earlier. The finished hull thickness is from % -inch to 1 ¥. -inches, with the pipe frames, covered by mesh and mortar, standing proud inside the vessel.

\

2. The Welded Armatllre Method

After lofting, wooden moulds are fabricated and erected in the nomlal manner. They stand on a keel section made of channel iron. The false work is faired as usual. The next step has several variations. In one, longitudinal reinforce­ment, on 2-inch centers, is attached temporarily to the false work and welded to a prefabricated stem and transom, the fonner being of pipe or steel rod. Transverse reinforcing, appropriately spaced, is then installed by welding to the longitudinal bars, usually on the inside. Deck beams (tee-section) are welded in place, as well as floors, flanges for bulkheads, etc. The false work is then removed, leaving a strong but elastic armature. The fairness of the annature is checked; if necessary welds can be broken or individual members cut and re-welded to make the armature fair. The mesh is installed as before and the hull plastered and cured in the conventional manner.

The second approach is to fasten wooden ba ttens to the station moulds, followed by installation of the transverse reinforcing, outside the battens. The longitudinal rein­forcing is then welded on, outside the transverse. Propo­nents of this method claim that the resulting armature does not Have to be faired after assembly. The false work is then removed. Installation of mesh and plastering is carried out as before.

Although there are no data to substantiate it, it would appear that the welded annature method is superior, as the welding of the reinforcing into a monolithic structure should result in a great areal distribu tion of stresses. Oberti (1968), who has been working with ferro-cement since 1943, concurs with this opinion.

3. The Wooden Plug Method

This method also requires wooden station moulds. In this case, they are erected upside down. After fairing, the structure is sheathed with cedar or some such soft wood. A mortar barrier of plastic or tar paper is applied to the resulting plug. Four layers of mesh, transverse reinforcing, longitudinal reinforcing and fmally four more layers of

139

mesh are nailed and/or stapled to the plug. The mortar is then applied and cured. After curing, the hull must be turned over and the falsework stripped out.

The advantages claimed for this method are that the resulting hull is fairer and more quickly constructed, the latter being because the reinforcing bars and mesh can be put in place more rapidly. The first claim appears to have some validity, although proper bracing and dimensional control should ensure fairness with the welded armature method. The second appears a dubious advantage, as the tin1e and materials required to construct the plug could very easily offset any economic advantage gained by more rapid installation of mesh and reinforcement. In addition, as the reinforcing bars are not attached to each other, great stress concentrations could occur in the completed hull.

Precise measures of labour required were not available for any of the construction methods. Reliable estimates for the welded armature and wooden plug methods indicate that between 600 and 800 man hours are required to complete the hull and deck of a vessel between 40 and 45 feet overall.

In summary, the welded annature method seems superior, especially for the professional builder.

ECONOMICS

Materials lists were obtained for three different hulls constructed by different builders. The hulls were of comparable size, ranging from 42 to 45 feet overall, with displacements from 12 to 15 tons, approxima tely. The lists

Table I

Materials Lists For Three Sample Hulls, Including Decks

Hull A Hull B Hull C*

Pipe (Y.." I. D. Iron) 900 ft. 800 ft. Nil

Reinforcing Bar (¥.") 9000 ft . 12000 ft . 12000 ft.

Wire Mesh' (Y..", 20 gal 15750 sq. ft . 15000 sq. ft. 65000 sq. ft.

Cement (Portland 6500lbs (75 5100lb5 (58 (less than 7 Type 5) bags) bags) cu. yds. of

mortar) Sand 1 2000lbs (130 10200lbs (115

bags) bags) Angle or Strap

Iron 100 ft. Nil 700 ft. --

*Includes bulkheads and other internal structures.

140

are generally consistent, the variations being accounted for by differences in hull design and building techniques. Some of the builders are understandably reluctant to reveal precise details of costs; accordingly, the materials lists shown in Table I do not include identification of specific vessels. ..

Specific costs for these materials are not given, due to regional variation, differences between suppliers, wholesale and retail, and economies of scale realizable by larger commercial builders. However, as an indication of costs, these material lists, evaluated at average current Canadian prices, range from $1,400 to $2,000 approxinlately.

As mentioned before, the labour involved for hulls of this size varies from 600 to 800 man hours. Furthermore, this labour, according to the builders, is mostly of a relatively low level of skill and hence less costly than a skilled shipwright would be. If one estimates the average cost of tlus labour to be $5.00 per hour, including overhead, (tius is probably a high estimate), the labour costs would range from $3,000 to $4,000. The overall cost of a hull of comparable size to those mentioned would range then from a minimum ' of $4,400 to a maximum of $6,000, the average being $5,200. Although the cost of the hull is only one-tllird or less the cost of a completed vessel, it would appear that substantial savings can still be realized with the use of ferro-cement, especially when one considers that these estimates include the deck and, in the higher ones, such interior structures as bulkheads, engine bearers, etc.

THE TESTING PROGRAM

Because of tile appeal of this material to amateur builders, the test panels were fabricated in a manner believed to be representative of what a relatively unskilled amateur would produce. No efforts were made to impose strict control on materials, mixtures or crafstmanship. The resulting strengths should then be the minimum that could be expected.

An exploratory program of tests was planned to obtain some preliminary experience with ferro-cement and to provide a firmer basis for tile planning of more comprehen­sive future tests. This program included tension, compres­sion, shear, and bending tests, membrane tests on square samples under compressive and under impact loading, and freeze-thaw tests.

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

In selecting these tests the intention was to produce, if possible, data wluch could be compared with corresponding known values for steel or aluntinum, and to set preliminary stress levels for use in designing willi ferro-cement. The compressive membrane tests were intended for comparison with similar tests on metals. The impact membrane tests were expected to provide qualitative insight only into the damage to be expected under accidental impact in use. The freeze-thaw tests were considered vital since Canada's eastern and western sea coasts are subjected to many cycles each winter of freezing and thawing weather which boat­building materials would have to withstand.

Description of Sample Material (Figures 1 to 4)

Panels measuring four feet in width, six feet in length and three-quarters inch in thickness (nominal dimensions) were made up following fabrication procedures that would presumably be used by amateur boat-builders. Four groups were prepared as follows:-

Group 1 Seven panels containing respectively 1,2,4,6,8, 10 and 12 layers of I/2-inch hexagonal galvanised wire mesh, each made in down-hand position on a 3/4-inch plywood backing. The mortar was trowelled on by hand and mechanically vibrated to ensure penetration. The top surface was smoothed by hand trowelling. Quantities of ingredients for each panel are detailed . in the appendix.

Group 2 One panel containing one layer of hardware cloth having No. 14 gauge wires on a one-inch by one-inch mesh overlayed on each side with four la~ers of I/2-inch hexagonal galvanised wire mesh, made in a down-hand position on a 3/4-inch plywood backing. The mortar was trowelled on by hand. A vibrator was used to ensure complete penetration. The top surface was smoothed by hand trowelling. The quantity of ingredients is detailed in tile appendix.

Group 3 One panel similar to that of Group 2 except that I/4-inch ntild steel reinforcing bars on 2-inch centers, running in the long direction of the panel only were substituted for the hardware CIOtll.

Group 4 No panel in this group was constructed. This group was intended to involve the "gunite" method of application and was deleted from the

A. M. Kelly and T. W. Mouat

\

experiment (it is a professional's method) and replaced by Group 5 which was considered more directly related to the other groups and con­sequently more meaningful for the purpose of this explora tory program.

Group 5 Two panels similar to Group 3 except made without plywood backing and consequently trowelled from both sides. One panel was plas­tered down-hand, the other in a vertical attitude. No vibrator was used. The panets were fmished on both sides by hand trowelling. Quantities of ingredients for each panel are detailed in the appendix.

All panels were kept moist by spraying for 21 days. Following the curing period the panels were surface dried, marked for identification and cut to provide test specimens according to the cutting schedule in the appendix. Each piece was numbered when cut to identify its source panel and its orientation in the structure of that panel.

In addition to the panels, from each batch of mortar used in making up Groups 1, 2, and 3, three 2-inch cubes were made for compressive tests.

Tension Tests

From each panel in Group 1, twelve sample pieces were tested in tension. Wedge grips were applied directly to the specimen in a way sinnlar to that used for testing of metals. A tensile load was applied and gradually increased. First indications of cracking were noted and the loading was continued until it appeared that further straining would not produce additional useful data.

Results

The specimens first developed a simple crack through the mortar, followed by elongation of the wires of the reinforcing mesh, followed by a second crack more or less parallel to the first, separated from it by a small distance, typically one-half inch. Further straining produced additional cracks. Four specin1ens showing tIns cracking appear in the photographs Al and A2 in the appendix. A chart giving the range of tensile strength values, as determined from these tests, appears in the appendix. It can be seen from the chart that tensile strength increases almost linearly with the number of layers of mesh.

14J

Compression Tests

From each panel in Group 1, twelve sample pieces were tested in compression. The end surfaces as cut were flat and reasonably smooth so they were not capped prior to testing. A self-aligning head was used in the testing machine to accommodate any lack of parallelism in the specimen ends. A compressive load was applied and increased gradually until either maximum load was reached and passed or it appeared that further crushlng would not produce additional useful data.

Results

Typical compressive failures occurred in nearly all cases. As can be seen from the photographs A3 and A4 in the appendix, one or two shear planes developed; if two, the resulting wedge then penetrated the opposing part of the specimen splitting it more or less cen trally. The presence of the wire mesh appears to have guided these splits but otherwise had little effect on the results of tl1e tests. A chart showing the range of compressive strengths as determined from these tests appears in the appendix.

Shear Tests

Twelve sample pieces from each panel in Group 1 were tested in double shear, six with the trowelled face upward, six with the trowelled face downward. Tests were made using the natural panel surfaces in contact with the anvils of the test apparatus. The shearing force was applied and continuously increased until shearing occurred. Overtravel was restricted to the minimum practicable amount.

Results

Photographs A5 and A6 in the appendix show the results of the shear test on specimens from panels with 2 layers of mesh and 10 layers respectively. In the testing of specimens having one layer of mesh, complete separation of parts occurred in some cases. For panels with two or more layers of mesh the photographs are typical of the appearance after testing. The shear strengths as calculated from the test results show increasing strength approximately linearly related to the number of layers of mesh.

Transverse Bending Tests

Eight samples from each panel were tested in transverse bending, four with trowelled face upward, four with

142

trowelled face downward. Tests were in accordance with ASTM Designations A438-62 and C293-64 insofar as applicable.

Results

\ In each case cracks fonned on the tension face near mid-length. Following formation of an initial crack a small decrease of load occurred, then the load built up to a greater value than that at which the crack formed. Next a second crack fonned with a decrease in load followed by a further increase, then by further cracking. In no case did the test result in breaking of a specimen into major components. Some crumbling occurred along the edges of the cracks. Some samples from Group 5 (trowelled from both sides - not vibrated) which showed incomplete penetration, particularly around the 1/4-inch diameter reinforcing rods, failed by shearing along the neutral axis.

The photographs A 7 and A8 in the appendix show typical results of the bending tests. The photograph A9 shows one of the test pieces which sheared longitudinally. A chart giving the range of values of modulus of rupture, as determined from the results of these tests appears in the appendix.

Panel Tests (Compression)

Four samples from each panel in Group I were tested as point loaded flat plates. Each panel was placed on a test fIXture in the fonn of a square of half-round bars of 1/2-inch diameter with a mean side length of ten inches. A one-inch diameter anvil was placed on top of the panel at its center and load was applied to the anvil by a testing machine.

Each panel was loaded and released repeatedly, with increasing values of load until a sudden increase in deflection was noted, when the panel was considered to have failed.

Results

Each panel reacted elastically to its initial loading, then as loads increased developed cracks and pennanent deflec­tion which increased with load. Finally a load was reached that caused a disproportionate increase in deflection which was taken as indication of failure.

Failure resulted in a type of punching shear beginning at the perimeter of the I-inch anvil and spreading as a shallow

CONfERENCE ON rISJIING VESSEL CONSTRUCTION MATERIALS

cone to 3 or 4 inches diameter on the underside of the panel. The material within the cone showed considerable fracturing, but was retained by the mesh. The photographs AIO, All, A12 and Al3, in the appendix show the front and rear appearance after testing of panels with eight and ten layers of mesh. A table of values of maximum applied load for each panel appears in the appendix.

Panel Tests (Impact)

Four samples from each panel in Group 1 were subjected to impact tests. Two of these four samples were impacted on the trowelled face, the other two on the reverse side. Each panel was supported on the square fIxture described under Panel Tests (Compression) and subjected to impact by a falling weight dropped through progressively increasing distances. Variability in resistance to impact and in the nature and extent of the resulting damage made recognition of the point of failure uncertain.

Results

Impact resistance was less than expected. As a result the frrst two specimens tested were completely shattered by their initia,! impacts of 30 ft. pounds and 8 ft. pounds respectively. The photographs A14 and AIS show typical cracking type failure that occurred in panels with four layers of mesh or less. Photographs A 16 and A 17 show the type of punching shear that occurred in panels having six or more layers of mesh. A tabulation in the appendix details the maximum impact applied to each panel. .

Freeze- Thaw Tests

Owing to the complex special equipment needed for freeze-thaw testing, arrangements have been made with University of Alberta, where test facilities were available. The test results are not yet available.

CONCLUSIONS

The variability in the test results demonstrates the importance of craftsmanship in working with ferro-cement. Ostensibly symmetrical samples produced widely differing results when tested in flexure face up and face down because the distribution of reinforcing mesh was non­unifonn.

The failure to reach and pass maximum strength to weight ratios as reported by Oberti (1949), even with use of

A. M. Kelly and T. W. Mouat

twelve layers of mesh, indicates that a heavier gauge mesh should be used. Multiple fractures of the matrix in tensile tests and on the tension face in flexure tests showed that bond strength between wire and mortar was adequate, indicating that larger diameter wire could be used without 4isadvantage. Compression tests showed very little con­tribution to the strength of the composite material by the steel. Larger diameter wires would be expected to be more effective in compression. On the other hand if the wire diameter is increased too much, the mesh would be difficult to handle and the area available for adhesion is diminished to the point of inadequacy.

Many of the compressive strength tests resulted in splitting of the specimen between the layers of mesh. This suggests that more attention should be given to cross­bonding of the meshes and possibly to development of another type of mesh having some inherent cross-bonding characteristic. Some type of expanded metal lath would serve this purpose.

It is. evident that each aspect of the materials, mixing, and application could be improved and that ferro-cement would become more attractive as a boat-building product as each improvement is made. .

RECOMMENDATIONS

There is considerable scope for improvement in ferro­cement as a boat construction material and in fabrication procedures in the use of ferro-cement for the building of boats. Both these fields need intensive development so that reasonable levels are reached before the reputation of ferro-cement is damaged.

In the field of amateur boat building, comprehensive instruction manuals are needed which will contain step-by­step operating procedures, suggestions for optimizing the results, and thorough background discussions explaining the

143

properties of ferro-cement, suitable methods of use, sources of difficul ty and ways to avoid them.

In conducting future development work and tests more attention should be given to:-

1) Craftsmanship - to ensure that products and test specimens will be as specified.

2) Control of Ingredients - sand particularly' should be of suitable grading and grading should be uniform throughout each test series.

3) Control of Mixture - the real water-cement, and cement-sand ratios must be maintened at the specified values.

4) Control of Testing - efforts must be made to avoid or at least explain all inconsistencies in tests. Methods of measurement, both for specimen dimensions and for deflection or distortion result­ing from testing, depend largely on the surface texture of samples. Excessive roughness and pro­jecting or loose particles must be given very special attention to minimize their influence on the test results.

5) Control of Mixing - considerable variation of final properties can result Jrom slight variations of mixing procedure, timing, ingredient condition, particularly water temperature, mixing time, and hold time between mixing and emplacement.

Finally, development work in the short term should be aimed at gaining appropriate government certification of this material for use in offshore fishing vessels of small and medium sizes. This is the major step required to give encouragement to professional builders who can then be depended upon to press forward with improvements to the material and the fabrication methods.

144

Figure 1

Figure 2

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

PanelS

PanelS Detail

A. M. Kelly and T. W. Mouat

Figure 3

" "."'.

Figure 4

Panel 9 Ready for Mortar

• • 4, (, ~ • • l'': .: !~ . " .

Panel 9 Detail

145

146

REFERENCES

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Morgan, R.G. (1968a) Letter to the Editor, Concrete, March, p. 128.

NOTE: The following list contains only those references cited in Nervi, P.L. (1951) "Ferro-Cement: Its Characteristics and Potentialities", Translated from the Italian; L 'Ingignere, No. I, S.L.A. Translation Center.

, this paper. An expanded bibliography, containing approx­imately 100 references, is in preparation and will be available to interested persons within a month.

Anon., (1966) "Chinese Build Concrete Boats", Concrete Products, vol. 69, No. 12, pp 36-37.

Nervi, P.L. (1956)

Oberti, G. (1949),

"Structures", F.W. Dodge Corpo­ration, New York, pp 50-62.

Byrne, J.G. & W. Wright (1961) "Reinforced Cement Mortar Con­struction - An Investigation of Ferro-<::ement Using Expanded Metal", Concrete and Construc­tional Engineering, vol. LXI, No. 12, pp 429-433.

Oberti, G. (1968)

Taylor, R. (1961)

"Experienze SuUa Deformabilita 'e Resistenza a Trazione di Provini in Ferro-<::ementato" ("Some Con­clusions about Deformability and Resistance in Tension of Ferro­Cement"), unpublished manuscript.

Personal Communication Cassie, W.F. (1967)

James, T.L. (1967)

Morgan, R.G. (1968)

Panel No.

"Lambot's Boats - A Personal Rediscovery", Concrete, No­vember, pp 380-382.

"A New Boat Building Material", Ship and Boat Builder Interna­tional, April, pp 34-36.

Personal Communication

Tuthill, L.H. (1945)

APPENDIX I

CUtting Schedule

"Concrete Ships", letter to the Editor, The Architect and Building News, June, p. 852.

"Concrete Operations in the Con­crete Ship Program", J. A mer. Cone. Inst., vol. 16, No.3, pp 137-177.

1. 12 pieces 1 3/4" by 12" long, cut with the 12" dimension in the direction of the panel's 6 'ft. length, 6 of these are for tensile test bearing identification numbers 100 to 105 incl., the other 6 numbered 106 to 111 incl. to be cut centrally to 5 3/4" length. Half for compressive tests and mating halves for double-shear tests.

2 to 7 incl.

8

12 pieces as above except cu t across the panels' 6 ft. length, tensile test pieces numbered 120 to 125 incl., others numbered 130 to 135 incl. re-cut for compressive and double-shear tests.

8 pieces,S 3/4" by 12" half with and half across the direction of the panel's 6 ft . dimension, numbered 140 to 143 incl., and 150 to 153 incl. respectively for transverse bending tests.

8 pieces 12" by 12" for plate tests, 4 for compression tests numbered 164 to 167 incl. and 4 for impact tests numbered 160 to 163.

8 pieces, 4" by 16" fOr freeze-thaw tests, numbered 170 to 177 incl.

Cut same as above. Identification numbers are similar except first digit of each number is same as panel number.

12 pieces, 1 3/4" Wide by 12" lo'ng, half with and half across the'direction of the panel',s 6 ft. length, for tensile tests.

Identification numbers 800 to 805 incl. and 810 to 815 incl.

8 pieces 5 3/4" Wide by 12" long half with and half across the direction of the panel's 6 ft. length, for transverse bending tests. Identification numbers 820 to 823 incl. and 830 to 833 incl.

9, 10, 11 8 pieces from each panelS 3/4" wide by 12 loilg, half with and half across the direction of the reinforcing bars, for transverse bending tests. Identification numbers 900 to 903 incl. and 910 to 913 incl., 1000 to 1003 incl. and 1010 to 1013 incl., and 1110 to 1113 incl.

Note: Cuts parallel to re-bars are to be approximately centered between adjacent bars.

A. M. Kelly and T. W. Mouat

Table of Ingredients

Panel Numbers 1 2 3 4 5 6 7 8 9 10 11

I Weight of Material in Pounds Sand 184 200 210 211 195 190 204 199 189 195 195 Cement 92 92 92 92 92 92 92 92 92 92 92

Pozzolan 13% 15 15 15 15 15 15 15 15 15 15 Water 40 49% 49 56 64 36 52% 53 52 56 56

Reinforcement, Nature and Quantity Number of Layers V ... in. galv. No. 22 ga 1 2 4 6 8 10 12 8 8 8 8 Hexagon mesh I-in. pitch No. 14 ga Hardware Goth. See x Note (a) ~-in. dia. mild steel rods on 2-in. centers. x x x See Note (b)

NOTES: (a) (b)

1 layer of hardware cloth, I-inch square mesh, No. 14 ga wires with 4 layers of galv. mesh on each side. In central plane, lengthwise of panel, mild steel rods ~-in. dia. on 2-in. centers, 4 layers of galv. mesh on each side.

Derived Data

Panel Number 1 2 3 4 5 6 7 8 9 10 11

Water/Cement Ratio 0.38 0.46 0.46 0.52 0.60 0.34 0.49 0.50 0.49 0.52 0.52 Cement/Sand Ratio 0.57 0.54 0.51 0.51 0.55 0.56 0.52 0.54 0.57 0.55 0.55 Average Compressive Strength 'Of 28 days

6910 7140 7300 6250 7210 7650 7560 7260 7690 - -from 2-in. cubes, pounds per sq. inch Weight in pounds of reinforcement per sq. 0.11 0.22 0.43 0.64 0.85 1.07 1.28 1.85 1.85 1.85 1.85 ft. of panel Average Density of panel material, pounds 131 145 147 145 148 154 165 152 151 - 140 per cubic foot

NOTES: 1) In calculating ratios above pozzo!an was included as cement. 2) Sand was reputed to be oven dry but moisture content was not tested. 3) A sand analysis from a sieve test of a 100-gram sample showed:-

Screen size 3/16" No.7 No. 14 No. 25 No. 50 No. 100 in Pan Percentage Retained 0 2 3 10 55 22 8

4) Compressive strength tests were made by Warnock-Hersey International Limited, Coast Eldridge Professional Services Division.

147

148 CONFFRF.NCE ON FISHING VESSEL CONSTRUCTION MATERIALS

o ~ RA~JGE OF TEST VALUES

Speclrra0ns cui ICfD@iht':1ise of pan~I---­o Sp~CimGH'S cut crosswise of panGI-aaCDD-o co

o o I'-

o o ~

o o I I

i

I I ~ I ,~

D

I I

I J . ) ~ .2 l

o ·· .. -~i--i---i--=~t" -§ ---r6= - T2 NUMBER OF MESHES

A. M. Kelly and T W. Mouat

5 A-I

A-2

Tensile Specimens After Test

Tensile Specimens After Test

149

150

0 0 0 m

0 0 0 OJ

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:1 ·1 I

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

- 36 -

I I I I ! I ~ ·a

I ,I I m

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~ .~ ~

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a ~ I I a D

I I I I •

RANGE OF TEST VALUES Specimens cut lengi;'t'Jise of panel ~ Specimens cut crosswise 01 panel--~-

~ . I ~ .~

~ B I Q

I I I I

'I

1." .... __ • .1.. Ai .. _._.J-.......-J ____ L.. ,..,...,t_. _J I 2 4 6 8 10 12

NUMBER OF MESHES

A. M. Kelly and T. W. Mouat

a

A-3

A-4

Compression Specimens After Test

Compression Specimens After Test

151

152

---

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o w

o ~

o N

. ;3 ,9 la

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

RANGE OF l-ES1' VALUES Spccimentl cut Icngiht"Jiso 01 panel-""''"'"' S~:){~Ci~1ens cut crosst"Jise or ponol C::~0'3_OD

lQ

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.~ ~ I , .

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A. M. Kelly and T. W. Mouat

A·S

A·6

Shear Specimens After Test

Shear Specimens After Test

153

154

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0 0

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0 en ::> ..J ::::> 0 00 ~o

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I

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

RANGE OF TEST VALUES Specimens cut lengtht"ise of panel- -Specimens cut crosst1ise of panel----

• I I I

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r

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NUMBER OF MESHES

A. M. Kelly and T. W. Mouat

A-7

A-8

Flexure Specimen After Test

Tension Side

Flexure Specimen After Test

Tension Side

155

156

A-9

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Flexure Specimen After Test

Sheared Longitudinally

A. M. Kelly and T. W. Mouat 157

Panel Tests - Compression

Layers Specimen Maximum Point Load Applied on

of Mesh Code Load Trowelled Face Back

164 630 x

1 165 563 x 166 570 x 167 300 x

264 1400 x

2 265 1080 x 266 765 x 267 567 x

364 1870 x

4 365 1850 x 366 650 x 367 490 x

464 1600 x

6 465 1410 x 466 1000 x 467 765 x

564 2050 x

8 565 1960 x 566 1000 x 567 1090 x

664 2240 x 10 665 1850 x • 666 1110 x

667 1100 x

764 1500 x

12 765 1750 x 766 1150 x 767 1260 x

158

A-lO

A-ll

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Panel Specimen Compression

After Test

Panel Specimen Compression

Mter Test

A. M. Kelly and T. W. Mouat

A-12

A-13

Panel Specimen Compression

After Test

Panel Specimen Compression

After Test

159

160 CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Panel Tests - Impact

Specimen Layers Impact on Max. Impact Remarks Code of Mesh Trowelled Face Back Inch - Pounds

160 1 x - Completely shattered by 30 ft.-lb. 161 x - Completely shattered by 8 ft.-lb. 162 x 20 Quartered; mesh intact 163 x 14 Halved; mesh intact 260 2 x 45 Halved; mesh intact 261 x 45 Quartered; mesh intact 262 x 36 Cracked in quarters to mesh 263 x 27 Cracked in quarters to mesh 360 4 x 205 Cracked in half to mesh 361 x 108 Quartered; mesh intact 362 x 27 Quartered; mesh intact 363 x 36 Quartered; mesh intact 460 6 x 73 Quartered; cracks follow mesh 461 x 215 Center punched through; cracks 462 x 143 Punching shear-type failure 463 x 63 Halved; crack opened progressively 560 8 x 215 Punching shear; quartered 561 x 54 Quartered; cracks opened progressively 562 x 215 Cracks follow mesh 563 x 45 Quartered; parallel cracks showed 660 10 x 332 Cracks follow mesh; opened slowly 661 x 89 Quartered 662 x 322 Center punched through; spalled 663 x 90 Cracks center to 3 edges 760 12 x 36 Cracks opened somewha~; spal\ed 761 x 322 Center punched; mesh bulged; spaJled 762 x 143 Cracks; center to 3 edges 763 x 322 Center punched; mesh bulged; spalled

NOTES: Tensile, Compressive, Shear, Flexure and Panel tests were performed by Golder, Brawner and Associates

A. M. Kelly and T. W. Mouat

A-14

A-I5

Panel Specimen Impact

After Test

Panel Specimen Impact

After Test

161

162

A-16

A-1?

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Panel Specimen Impact

After Test

Panel Specimen Impact

After Test

APPENDIX 3.

FREEZE-THAt-l TESTS ON FERRO-CEMENT SAHPLES: EFFECT OF REINFORCING RODS OR HEAVY MESH. (The method of making the samples is discussed in Appendix 2)

Freeze-Thaw Tests

Winter weather likely to affect the durability of concrete will be experienced along the entire length of Canada's sea coasts and on its inland waterways. A review of the literature reveals that the temperature at which destructive freezing of concrete begins may be assumed to be 15°F. It should be considered then that an exposed structure would experience a number of freeze-thaw cycles roughly equal to the number of times that a temperature of 15°F or colder is followed by a temperature of 32° or warmer. Only rarely will this exceed ten times a year. A reasonable average for design purposes would be half this number, or five cycles per year.

The United States Bureau of Reclamation in its Concrete Manual terminates the freeze-thaw test when 25 per cent of original weight has been lost from a specimen or when one thousand cycles of freezing and tha\o1ing have occurred. Material which survives five hundred cycles is considered acceptable.

The American Concrete Institute sets a limit of three hundred cycles for the test, but uses loss of physical properties as indicated by a vibration measurement, or by substantial disintegration, as criteria of failure. The Institute's Manual states that the test is more severe than is natural exposure. The three-hundred-cyc1e limit is basic also to the ASTM tests.

Specimens and Procedure

Eight samples from each panel in Group 1 were prepared for freeze-thaw tests. Because of equipment limitation and costs of testing, only the specimens from panels 1, 4 and 7 were tested. Tests were in accordance with ASTM C29l-67 as far as possible but the dimension of the specimen in the direction of the panel thickness was approximately 3/4 inch while the test equipment was intended for a test specimen dimension in the range of 3 to 5 inches. Consequently the electronic vibration equipment could not be used. The tests were conducted on the basis of weight loss. Measurements were taken at intervals of approx­imately 25 freeze-thaw cycles for a total of 309 cycles except for those specimens whose condition had deteriorated excessively before 300 cycles had been completed.

Results

The weight loss from each specimen was recorded on completion of 22, 44, 73, 103, 125, 156, 176, 205, 227, 257, 279, and 309 cycles of freezing and thawing except for samples numbered 170, 171, 172, 174, 175,

- 2 -

l76~ and 177 which did not survive to the end of the planned 300 cycles. The average weight loss as a percentage of initial weight was computed for surviving specimens and is shmvn in Fig. 1. The percentage weight loss is shown in Fig. 2 on a base of number of freeze-thaw cycles for the averages of the samples from each panel. A strong inverse relation­ship is evident between the number of reinforcing meshes and the loss of weight.

Significance of Test Results

Repeated freezing and tha\ving under the continuously wet conditions of testing results in water gradually filling the minute voids and cracks that are inherent to a concrete material. As the voids become filled the expansion of the contained water upon freezing exerts disruptive forces on the material causing extension of existing cracks and formation of new ones. When adjoining cracks merge~ some particles separate from the mass and falloff, initiating the weight loss indication.

The rate of weight loss relates to the control of crack propa­gation which has been shown to be affected by the reinforcing, and particularly by its dispersion. Also, the rate of weight loss has been shown to correlate with durability; more durable concrete in resistance to natural weathering shows a smaller loss when subjected to freeze-thaw testing.

On the basis of total weight loss at 300 cycles of freezing and thawing~ the material reinforced with 6 layers of mesh, and that with 12 layers, would be adequately durable. The beneficial effect of adequate reinforcing is strikingly evident from the attached plot of weight loss against number of freeze-thaw cycles, for three different amounts of reinforcing.

Transverse Bending Comparison Tests - Effect of Rods or Heavy Mesh

The panels of Groups 2, 3 and 5 were prepared to explore the effect of heavier reinforcing material, used in addition to the fine mesh, and also to get information on application procedure and trowelling. Each of these panels contained eight layers of fine mesh, the same number as in Panel 5 of Group 1.

Panels 5 of Group 1, 8 of Group 2, and 9 of Group 5 were mortared in the downhand position against a: 3/4-inch plywood backing. Panel 10 of Group 5 was mortared in the vertical position, and trowelled on both sides. Panel 11 of Group 5 was mortared from both sides; mortar was trowelled to about half depth from the underside and allowed to set for 7 days, follO\ved by thorough trO\velling of the mortar applied from the top to complete the build-up to the required thickness. No bonding agent was used between the two layers of the mortar.

- 3 -

Eight test specimens 5 3/4.inches by 16 inches were cut from each panel, half in the long dimension of the panel and half across it. All specimens were tested in transverse bending, half of the specimens of each orientation from each panel being loaded on one face, the other half, on the other. The results of these tests appear in Fig. 1.

Results

Considerably larger values of modulus of rupture were observed for the specimens containing rod or heavy mesh reinforcement on the mid-plane than for specimens with an equal number of layers of fine mesh but without additional reinforcement. As the heavier reinforcement was near the neutral axis, it could contribute relatively little to the bending strength directly. He believe that it acted to position the fine mesh in locations where it was more effective, by preventing the cross-tying from pulling it towards the neutral plane.

There is in virtually all the panels which ,olere mortared in the horizontal position, whether containing heavy reinforcement or not, a significantly greater resistance to loads applied to the top ("trowelled") face than to loads applied to the underside ("back").

We believe this to be caused by an assymetry in the reinforcement distribution - that is, more fine mesh and/or heavy reinforcement belmY' the median plane than above it, and not to a difference in the quality of the mortar. One panel (No. 11 of' Group 5) which was mortared horizontally in two stages (~Y'ithout any bonding agent) failed consistently along the boundary bet\Y'een the two layers, indicating that the bond was poor.

T.W. Mouat Division of Applied Physics

TWM/cz

Fig. 1. Loss of weight in freeze-thmv cycling.

Loss of Height - Grams

Initial Number of Freeze-Thaw Cycles Specimer. Height

Number ' Grams 22 44 73 103 125 156 176 205 227 257

170 1745 0 0 5 15 105 185 345 486 171 1696 0 2 6 57 125 168 256 304 172 1750 0 0 0 59 150 278 350 650 173 1900 0 0 0 71 99 163 255 292 311 524 174 1942 0 0 0 2 12 380 437 443 455 175 1715 0 7 13 63 150 286 395 500 515 591 176 1809 0 0 6 98 181 237 409 584 661 177 1923 0 0 0 142 203 363 443 560 669

Totals 14480 9 32 507 1025 2060 2885 3819 2611 1115 Average 1810 1 4 63 126 258 361 477 522 558 Percent Average ,3.5 7.0 14.3 20.0 26.4 28.8 30.8

470 1870 0 0 6 52 90 170 190 250 260 294 471 1895 0 0 23 71 75 104 147 173 235 275 472 1703 0 24 48 64 71 120 173 190 261 303 473 1825 0 13 15 50 73 95 120 187 205 246 474 1850 0 0 31 45 46 88 131 188 208 278 475 1642 6 7 22 44 72 203 . 237 262 310 329 476 1809 0 0 9 159 187 214 358 404 485 519 477 1832 0 0 4 32 33 93 203 272 290 363

Totals 14426 6 44 158 517 627 1087 1559 1926 2254 2607 Average 1803 1 5.5 20 65 78 136 195 241 282 326 Percent Average 1.1 3.6 4.3 7.5 10.8 13.4 15.6 18.1

770 1945 0 0 0 5 8 15 25 30 45 85 771 1830 0 0 0 .0 11 15 28 28 41 68 772 1758 0 0 0 0 0 0 0 18 28 33 773 1687 1 2 2 4 8 8 8 9 17 39 774 1659 8 1 2 10 10 10 21 31 39 66 775 1627 0 0 0 0 0 0 0 15 19 32 776 1618 0 0 6 0 0 0 0 18 38 42 777 1703 0 0 0 3 3 3 7 13 15 34

Totals 13827 9 3 4 22 40 51 89 162 242 399 Average 1728 1 0 0 3 5 6 11 20 30 50

Percent Average 0.2 0.3 0.3 0.6 1.2 1.7 2.9

Note: The 'first figure in the specimen n~lber is the 'pane1 number. Specimens 170 to 177, inclusive, contain a single reinforcing mesh; specimens 470 to 47~ inclusive, contain 6 layers of mesh; specimens 770 to 777,inc1usive, contain 12 layers of mesh. All specimens are in Group 1 (made in horizontal position on plywood backing, vibrated, and trowelled on top face).

,---- -

279 309

640 805

640 805 640 805

35.3 44.5 -

330 430 289 363 341 449 263 263 288 321 346 420 530 539 372 382

2759 2867 345 358

19.1 19.8

89 101 71 74 38 43 57 69 79 81 47 51 46 48 43 83

470 550 59 69

3.4 4.0

,.... ' ~

c: Cl) u ... Q)

Fig. 2.

Q.. 30 .........

en (f)

9 I- 20 :J: (!) -

Freeze-thaw cycling - average loss of weight of eight samples versus number of cycles.

v I layer of mesh o 6 layers of mesh x 12 layers of mesh

v

" o~ 0 -X"

~~4I" ,.-

':i~~ '~;:;s~

~v ~ -x-0' 5'o"'~~0 . 150 =x-" 2JX; 7- 250- I · 360 350

~IIIM'~~~ "I=" J:"~J:"J:"7 1=' - TWAW ~V(,!I F~

Fig. 3. Transverse bending comparison tests.

. . . Modulus of rupture (p s i )

Specimen a) Heavy reinforcement Specimen length Specimen length

code1 Group parallel to panel length across panel length b) Mortaring position Trowe11ed2 2 Trowelled2 Back2 Back

540 1 a) None 1470 541 1800 542 810 543 650 550 b) Horizontal, p1y- 2240 551 wood backed 2203 552 961 553 926

820 2 a) 1114 gauge I-in. 3260 821 square mesh on 2860 822 mid-plane 1430 823 1870 832 b) Horizontal, p1y- 666 833 wood backed 869

900 3 a) 1/4-in. dia. rods 4200 901 on 2-in. centres 4070 902 lengthwise of 2310 903 panel on mid- 2710 910 plane 2256 911 2135 912 b) Horizontal, ply- 1163 913 wood backed 1336

1000 5 a) Same as Group 3 2470 1001 3030 1002 2620 1003 2450 1010 1659 1011 b) Vertical, trow- 1905 1012 e1led both 1445 1013 sides 1232

1100 5 a) Same as Group 3 1750 1101 1380 1102 930 1103 1230 1110 b) Horizontal, mor- 1186 1111 tared from above, 1280 1112 trowelled both 933 1113 sides 865

---.--

1 The first figure in the code is the panel number.

2 Face to which bending load was applied. In 1100 series "back" is surface trmvelled from below. In 1000 series there is no "back".

APPENDIX 4.

BIBLIOGRAPIIT

The references are arranged in three lists as follows:

List 1 - The main references used. Virtually all of the really useful references which were co~sulted are contained in this list.

List 2 - Secondary references, some of which repeat or confirm the references of List 1, but many of which are of very limited value.

List 3 - References which could not be obtained in Vancouver, or from the National Research Council Library in Ottawa. Only a few of these would likely add anything to the information available in List 1. Some are mainly of historical interest.

Assistance in obtaining the references in Lists 1 and 2 can be furnished by the British Columbia Research Council.

- 2 -

Bibliography - List 1

Anon., "Seacrete Stern Trawlers", Fishing News International, May 1967.

Anon., "Plasterers Work Full Shift on Unique Concrete Boat", Plastering Industries, March 1967.

Anon., "Concrete Barges Hultip1y in Gulf", Concrete Products, January 1967.

Anon., "Chinese Build Concrete Boats", Concrete Products, December 1966.

Anon., "Concrete-Hulled Pilot Launch for Bahrain", Shipbuilding and Shipping Record, 29 September 1966.

Anon., "Ferro-Cement", Concrete Construction, September 1966.

Anon., "A Remarkable Concrete Boat", Building, 29 July 1966.

Anon., "The First New Zealand Made Concrete Boat", New Zealand Concrete Construction, 12 February 1963.

Anon., "Thin Shell Reinforced Concrete", Engineering, 8 February 1963.

Anon., "Ferro-Cement Boats", New Zealand Concrete Construction, 12 February 1963.

Anon., "Concrete Ahoy", Corrosion Technology, October 1961.

Anon., "Concrete Freighter Shows Amazing Durability", Concrete Products, September 1961.

Anon., "Concrete Ship to Bridge a Gap", The New Scientist, 24 July 1958.

Anon., "Une R~lique Retrouv~e: La Barque de Lambot", Batir, 47,- Page 9, 1955.

Anon, "Canadian Conference on Fishing Vessel Construction Materials Attracting \~or1d-Hide Interes t", Fisheries of Canada, August 1968.

Anon., "Ferro-Cement Boats", Concrete Information, Cement and Concrete Association of Australia, Leaflet C. 39.

Anon., "Progress in Ferro-Cement", Yachting Monthly (London), September 1967.

Anon., "Ferro-Cement Tug Hull is 110 Percent Cheaper", Wes tern Fisheries, January 1968.

Abner, "Reinforced Concrete Ship"', The Architect and Building News, June 1961.

- 3 -

Burgess, John, "Seacrete Ncthod Developed by Progressive British Yard", Fishing Nc\Vs Intcrnational, May 1968.

Cassie, W. Fisher, "Lambot's Boats", Concrete, November 1967.

Fondriest, F.F., and D.L. Birkimer, "Control of Cracking in Concrete", Battelle Technical Revie~v, Volume 17, September-October 1968.

GardJler., John, "\.Jide Interes t Shmvn in Ferro-Cement Boats", National Fisherman, September 1967.

Gardner, John, "Ferro-Cement is Hottest Thing in Boatbui1ding", Nationa1 'Fishcrman, June 1967.

Gardner, John, "Ferro-Cement makes Strong Hull: Microballoons Help Lick Resin Sag", National Fisherman, March 1967.

Gibson, Peter, "Fishboats in Ferro-Cement", 1.Jestern Fisheries, January 1968.

Harper, Ross, F. Carius and L. Chase, Boat Building in Ferro-Cement (Pamphlet) •

lorns, Martin, "Ferro-Cement Advice From an Expert", National Fisherman, June 1967.

lorns, Martin, "Cement Boatbuilding Problems Aired", National Fisherman, May 1967.

Morgan, Roland, "Lambot's Boats", Concrete, Page 128, March 1968.

Nervi, P.L., "II Ferro-Cemento e la Prefabbricazione Strutt:urale", In: Colonetti, G., Sciense Delle Costruzioni, Volume III, Page 13, Torino, Scientifica Einaudi, 1957.

Nervi, P.L., "Ferro-cemento", Structures, F.H. Dodge Corporation, 1956.

Nervi, P.L., "Concrete and Structural Form", Engineering, October 28, 1955.

Nervi, P.L., "Ferro-Cement: Its Characteristics and Potentialities", L'lngegnere, 1951, Number 1 (Translation).

Nervi, P.L., "Thin Reinforced Concrete Members Form Turin Exhibition Halls", Civil Engineering, January 1951.

Nervi, P.L., "Precast Concrete Offers Ne~v Possibilities for Design of Shell Structures", Journal of the American Concrete Institute, February 1953.

Oberti, Guido, "La Condotta Forzata di Castelbello", L'Energia Elettrica, Volume XXX, Number 5, 1953 (Translation available).

- 4 -

Oberti, Guido, "Some Conclusions about Deformability and Resistance in Tension of Ferro-Cement", Milan, December 1949 (unpublished manuscript) •

Rath, Dick, "Concrete Boats - Are They For Real?" Boating, October 1967.

Samson, John, and G. Wellens, A Manual of Ferro-Cement Boat Building, Samson Marine Design Enterprises Ltd., Ladner, B.C., Canada, 1968.

Stevenson, H.I., "Use of Concrete Ships for the Log Pond Breakwater at Powell River", September 1964 (unpublished manuscript).

raylor, R., "Concrete Ships", The Architect and Building Ne,vs, 28 June 1961.

Taylor, W.H., "Ferro-cement fabrication", In: Concrete Technology and Practice, New York, American Elsevier, 1965, pp. 552-554 .

. Tuthill, Lewis H., "Concrete Operations in the Concrete Ship Program", Journal of the American Concrete Institute, January 1945.

Tyson, John F., "Ferro-Cement Construction for Fishing Vessels", Fishing Ne\l1s International, June 1968.

Tyson, John F., "Ferro-Cement Construction for Fishing Vessels", Fishing News International, April· 1968.

- 5 -

Bibliography - List 2

Anon., "Concrete Boats", Machine Design, April 11, 1968.

Anon., "Ferro-Cement: Tomorrow's Homemade Boat Boom?" Boating Journal, February/March 1968.

Anon., "Cement For Sail", G.A.H. on Yachting, Ontario Edition, January 1968.

Anon., "Ferro-Cement Boats", The Boating Industry, September 1967.

Anon., "Cement Yacht is Lot of Boat for Honey", National Fisherman, June 1967.

Anon., "New Fiberstee1 for Docks and Boats", Bay and Delta Yachtsman, January - February 1966.

Anon., "Awahnee Makes History", Sea Spray, August 1965.

Anon., "Marire - A Matangi Design Built in Ferro-Cement", Sea Spray, April 1965.

Anon., "Featherstone Ahoy", Concrete Construction, July 1963.

Anon., "Concrete Racing Yawl", Mechanix Illustrated, July 1963.

Anon., "Rubb a Dubb Dubb - 3 Men in a Concrete Tub", Concrete Products, June 1963.

Anon., "A Ferro-Cement Boat", Concrete and Constructional ,Engineering, March 1962.

Anon., "Consolidation - In Concrete?" The Economist, January 6, 1962.

Anon., "Reinforced Concrete Hull for 34 Foot Boat", Engineering, 10 November 1961.

Anon., "Construction of an 18 M Ferro-Cement Hyperbolic Shell", U.S. Joint Publications Research Service, 8 November 1960 (Engineering Construction, Number 9, pp. 33-35, Peiping, May 15, 1960).

Anon., "Hearts of Concrete" for Russia", The New Scientist, 20 February 1958.

Anon., Cefer Designs Ltd. (Brochure), Vancouver.

'Anon., "Cement Boats - Building Instructions", Marine Design Enterprises Ltd., Vancouver.

- 6 -

Anon., "Cement Boats", Harine Design Enterprises Ltd., Vancouver.

Anon., "Three New Designs in Ferro-Cement", Marine Design Enterprises Ltd., Vancouver.

Anon., "Valeo, 55' Design Series for Ferro-cement Construction", Sea and Pacific Hotor Boat, Page' lf6, 1967.

Anon.,_ "Value of Boats Built in B.C.", D.B.S. Otta\-la Reports.

Chapin, William, "Out to Sea - In Cement", San Francisco Chronicle, March 18, 1968.

Gardner, John, "Fly Ash for Ferro-Cement Could Help Utilities", National Fisherman, December 1967.

Hacking, Norman, "After Subsidy, What?" The Province, Vancouver, January 16, 1968.

Hacking, Norman, "Tug Hade of Cement and Hire Launched by Lulu Island Yard", The Province, Vancouver.

Hacking, Norman,"Concrete Goes to Sea Quite Confidently", The Province, Vancouver.

Lysaght, John, "Shiver He Timbers - Nm-l Concrete Hulls for Private Yachts", The Atlantic Advocate, November 1967.

Nervi, P.L., "Precast Concrete Offers Ne\-l Possibilities in Design of Shell Structures", Civil Engincerin_&, February 1953.

Rath, Dick, "Ferro-Cement Details", Boatin&, February 1968.

Ross, Stanley, "Concrete Floats: Smooth Sailing Ahead", Concrete Products, Page 69, October 1963.

Samson, John, "Concrete Boats", Boating_, February 1968.

Tyrell, Don, "Dr. Bob Griffith", (Circumnavigation of Globe in Ferro­cement Boat), The Sun, Vancouver.

Wellens, Geoff., "Pioneer \-1ill Soon Be Rolling Stone", 111e Province, Page 18, May 10, 1968.

Wellens, Geoff., "Sailor of Fortune's Tales are Stranger than Fiction", The Province, Page 15, Vancouver, November 15, 1967.

Wellens, Geoff., "Builder in a Hurry", The Province, Vancouver, October 13, 1967.

Wellens, Geoff., "Paradise in a Trimaran", The ProvincC':, Vancouver •.

Wellens, Geoff., "The A\vahnee: ~.Jhen all the tvorld was a t.Jatery Stage", The Province, Vancouver.

- 7 -

Bibliography - List 3

Anon., "Progress in Ferro-Cement", 'Yachting 'H6nthly, London, September 1967.

Anon., "Building in Ferro-Cement", Yachting 'Monthly, London, April ' 1967.

Anon., "Ferro-Cement Boats", Concrete Construction, Vol. 10, No.9, page 159, New Zealand, 12 September 1966.

Anon., "The History of Windboats, Ltd." The East Anglia Life, England, May 1965.

Anon., "American Concrete Yacht, 'Featherstone', Proves Herself Sea­worthy", Concrete Construction, Vol. 7, No. 11, page 206, New Zealand, 12 November 1963.

Anon., "Shipbuilding in Concrete", The Blue ' Circle, Vol. 17, No.2, 1963, pages 8-9. ,

Anon., "Reinforced Concrete Ship", The Architect ' and Building News, Vol. 219, No. 24, page 779, 14 June 1961.

Anon., "Concrete Ships", The Architect ' and Building News, Vol. 219, No. 26, page 852, 28 June 1961.

Anon., "New Splash,for Concrete", Concrete Construction, Vol. 5, No. 11, page 326, November 1960.

Anon., "Making a Concrete Punt", The Sphere, Vol. 233, No. 3034, page 295, 24 May 1958.

Anon., "Concrete and Structural Form", Engineering, October 1955.

Anon., "Le Costruzioni Navali in Ferro-Cemento", Industria Italiana Del Cemento, No. 7-8, 1950.

Anon., "Pioneering Prestress", American Concrete Institute, pages 22-27, 1945.

Anon., Concrete Information - Ferro-Cement Boats, Ref. C. 39, Cement and Concrete Association of Australia.

Anon., "Notes in Regard to ' the Physical Properties of Seacrete", from Windboats Ltd., Wroxham, Norfolk, England.

Byrne, loG. and Wright, W., "Reinforced Cement Hortar Construction -An Investigation of Ferro-Cement Using Expanded Metal", Concrete and Constructional Engineering, Vol. LXI, No. 12, pages 429-433, December 1961.

- 8 -

Collen, L.D.G., "Some Experiments in Design and Construction with Ferro­Cement", Trans. Inst. C.E. of Ireland, Vol. 86, page 40.

Collen, L.D.G., and Kirwan, R.W., "Some Notes on the Characteristics of Ferro-Cement", Civil Engineering and Public Works Review, pages 195-196, February 1959.

Collen, L.D.G., and Kin·,ran, R.W., "The. Mechanical Properties of Ferro­Cement", Civil Engineering and Public Works Review, December 1958.

\

Colvin, T.E. "Colvin Tries Ferro-Cement: Describes Results", National Fisherman.

Cox, Eric, "It's an E'asier Way", Yachting Monthly, pages 294-295, London, December 1966.

Gardner, John, "John Gardner Lists Sources of Information", National Fisherman.

Gardner, John, "To Sea in a Stone", The Skipper, December 1967.

Huxtable, A.L., Pier Luigi Nervi, George Bragilleu, Inc., New York, 1960, 128 pages.

James, T.L., "A New Boat Building Material", Ship and Boat Builder International, pages 34-36, April'1967.

Manning, A., "The First New Zealand Made Concrete Boat", Concrete Construction, Vol. 7, No.2, page 23, Ne\17 Zealand, 12 February 1963.

Nervi, P.L., Aesthetics and Technology in Bui1din&, Howard University Press, Cambridge, Mass., 1965, 200 pages.

Rogers, Ernesti, The Works of Pier Luigi Nervi, Frederick A. Praeger, New York, 1957, 142 pages.

Salvadori, G.M. Structures by Pier Luigi Nervi, McGraw Hill, New York, 1956, 118 pages.

Verney, Michael, "Concrete Keels", Yachting Honth1y, pages 314-317, London, June 1963.

FERRO-CEMENT AS A FISHING VESSEL CONSTRUCTION MATERIAL

REPORT - PART II

to

Industrial Development Branch Fisheries. Service

Department of Fisheries and Forestry

March 31, 1970.

I N D E X

INTRODUCTION 1

OBJECTIVES 2

PREVIOUS WORK 2

PRESENT PROGRAM 3

FERRO-CEMENT MATERIALS USED 5

MIXING EQUIPMENT 9

PREPARATION AND· TESTING FERRO-CEMENT PANELS 10

INTERPRETATION OF TEST RESULTS 18

STRAIN MEASUREMENTS - PRELIMINARY CONSIDERATIONS 20

REPAIRS TO FERRO-CEMENT HULLS 21

SIGNIFICANCE OF THE RESULTS 33

THE PRESENT STATUS OF FERRO-CEMENT 35

REFERENCES 38

APPENDIX I - Tables 40

APPENDIX II - Tests on Ferro-cement Panels Report to Ferro Cement Industries Ltd., Nanaimo, B.C. Nov. 1969.

, I

B. C. RES EARC H ~ 3650 w •• b,ook C, •• cenl, Voncouve, 167, Canada.

. ~ PhOM (60""""" ' Cob" "'''''CHIC' • T ... , 0'"'0"<1

The Development of Ferro-Cement for Fishing Vessel Construction Final Report to

Industrial Development Branch Fisheries Service

Department of Fisheries and Forestry March 31, 1970

INTRODUCTION.

There has been a remarkable upsurge in the last two years of interest and activity in the use of the wir.e-mesh/cement material known as ferro-cement, for boat-building and other marine applications. This activity is, on two fronts - commercial building and "back-yard" , owner building. The commercial building, which is in small or meqium

' size yards, 'has, resulted in a ,considerable development of propriety 'methods and materials and also in ~ vigorous promotion of the supposed advantages of one method or formulation over another.

\ The commercial builders are now vitally interested in obtaining certification for ferro-cement vessels over 15 tons. The regulatory authority is faced with deciding what constitutes safe and acceptable construction in the almost complete absence of unbiased factual data on the properties of the material for ship-building purposes.

_ ,The individual fisherman-builder is in an even more c;1ifficult position, since he cannot afford to buy the "secrets" 'carefully guarded by the commercial builders, nor can he afford the experimentation necessary to sift out reliable information from the enthusi&~tic promotion literature and poorly documented advice available to him.

It is clear that the orderly, economic development of ferro~cement as a fishing vessel construction material requires the collectiQn and dissemination of factual data on best materials and fabrication techniques, and on the steps and precautions necessary to produce a sea-worthy durable hull at a reasonable cost.

'Technical Operation of 'h. BRITISH COLUMBIA RESEARCH COUN<;:ll, Q Non·profi, Indu.'riol R •• earch Soci,Iy

OBJECTIVES.

69-4125 - 2 -

The obj ectives of t ,he present program are:

(a) To accumulate infonnation for dissemination to the fishermen builders of ferro-cement boats the best advice possible on materials selection and construction methods for vessels to participate in Canada's fisheries.

(b) To establish recommended quality control criteria and acceptable construction procedures which will allow vessels constructed of this medium to receive certification by the Canadian Board of Steamship Inspection and other legislative requirements. This is especially important for vessels exceeding 15 gross tons.

The program fully recognizes the need of the fisherman­builder for simplicity in methods and economy in materials - but these must be such as to ensure a durable hull of adequate strength for use in Canada's fisheries.

PREVIOUS WORK.

The voluminous literature on ferro-cement was analyzed in the report "Ferro-Cement as a Fishing Vessel Construction Material" submitted on January 16, 1969. In addition to an extensive bibliography, the report covers an exploratory test program on eleven 6' x 4' x 3/4" panels containing from 1 to 12 layers of 1/2-inch #22 gauge hexagonal mesh galvanized aviary wire. Four panels contained, in addition, 1/4" diameter mild steel rods or #14 gauge heavy square mesh. Type 5 Portland cement, with 15% of the cement replaced by Pozzo1an, was used in all panels.

The most significant results of the exploratory tests were as follows:

(a) There was considerable ' variation between ostensibly identical and symmetrical panels. The positioning of the mesh in the panel is critical and careful control of fabrication is necessary to obtain quantitative comparison of difficult materials and methods.

69-4125 - 3 -

(b) Even the twelve layers of aviary mesh, which is close to the maximum which can be placed in a 3/4" sla?, failed to reach and pass the maximum strength to "weight ratio observed by Oberti (1949), in laboratory tests. It is clear that this type of mesh is not optimum.

(c) Cross-bonding between mesh layers is required if the compressive strength is to be raised appreciably above that of the cement its~lf.

(d) Panels containing six or more layers of mesh showed adequate resistance to freeze-thaw cycling.

The exploratory tests covered only one type of mesh, and one type of cement and sand.

PRESENT PROGRAM.

The overall plan of the present program covered virtually all aspects of ferro-cement under the following headings:

1. Mortar and Reinforcing. 2. Shell Quality. 3. Patches and Bonding. 4. Hull Construction. 5. Sea Testing of a Complete Hull. ' 6. Accelerated Environmental Testing.

In setting up an efficient test schedule, account had to be taken of the interdependence of many of the elements under the above main items. Our approach has been to systematically reduce the very large number of possible combinations of ingredients and methods, to manageable proportions. The 30-day curing t,ime of most cements precludes rapid reorientation of the direction of attack.

There are a few fundamental questions which must be answered before any realistic optimization of vessel construction is possible. The most obviou~ of these are: what kind of mesh, what kind of cement, and what kind of mortar mix. It is equally important to ask: what are we trying to optimize? "Strength" - which itself has many different aspects - is one characteristic; durability, with low up-keep, ' is equally important and much harder to measure. Unga1vanized high tensile mesh will certainly give greater strength than galvanized mild-

69-4125 - 4 -

steel mesh. c But if this added strength is gained at the expense of durability it could be a poor bargain.

The initial test schedule resulting from the above considerations was to compare six substantially different wire meshes, using the same mortar, then five different sands and five different cements using in each case the same wire mesh - #22 gauge 1/2" hexagonal mesh, galvanized. This mesh was chosen because of its ready availability everywhere, and its use in previous comparison tests. Meanwhile suitable testing procedures, both for the test panels and for ultimate use in controlling hull quality, were being evolved, and information from the literature was assembled on the other items of the program such as layup and fastening of reinforcement, glues and admixtures, ~train-gauging and possible methods of assessing durability.

A certain amount of information was obtained from local builders, but this was in most cases either incompl~te or contradictory. While the builders undoubtedly know a great deal about what will work in practice and what will not, their procedures and preferences are rarely documented and disinterested. Thus it was essential to prepare our own panels, under closely controlled conditions. With the results from these as a foundation, it will be possible to broaden the base of the study by using test results on panels made by others, even where all the details of the preparation are not available. One such series of tests is reported in Appendix II.

From the beginning we have been seeking a realistic and practical method of accelerated environmental testing. Three possible procedures have been devised, one of which looks very promising, but none have been able to yield results in the short time that cured panels have been available. The question of repairs and patching has been ,gone into fairly extensively, using the first samples broken in the bend and impact testing. This is a much more critical and complex subject that the brief references to it in the literature would sugges~.

In the sections which follow our fabrication and testing procedures and results are described in considerable detail, so that anyone interested can compare them on a quantitative basis with the results of his own tests. This is followed by a discussion of the significance of our results to fishing vessel construction, and by an indication of the gaps in knowledge which still exist.

FERRO-CEMENT MATERIALS USED.

THE MORTAR MIX.

69-4125 - 5 -

The possible combinations of cements, sands, water and additives are legion and only th~ ones considered important from a practical point of view have been covered. This part of the work was based on using easily available materials and proportions recognized as favouring an adequate c·ompromise of such properties as workability, strength, water-tightness, etc., for the purpose of assessing types of reinforcing materials and other attributes.

(a) Sands.

It was the intent to use combinations of "standard" sands of rather narrow mesh sizes but a strike in the industry forced a change of plans. A quantity of Evco Dry Mortar sand was available and became the "standard" sand for the tests. Other sands used included Evco Dry Concrete Sand and Del Monte ~ands No.8, ,No. 20, and No. 30. Typical screen sizes are provided in Table 1 of the Appendix.

Long experience with concrete and mortar has shown that changes of sand gradings over even an extreme range have no material effect on compressive strength of mortar specimens when the water­cement ratio and the slump are held constant. Changes in grading · under the above constant conditions will require the cement content to vary inversely with the fineness modulus of the sand. However, the effect of the fineness modulus of the sand on the cement content is known to be relatively small. Because of this, the cement/sand ratio by weight was maintained at 1:2 for the variou~ mixes used . to compare types of steel reinforcement and other variables. The grading of sand, however, affects the workability and finishing quality of the mortar and will be significant in hull plastering.

Trial tests using closely-packed layers of reinforcement to make "tile" specimens with the various sands showed that mortars containing "8-mesh" sands could penetrate the reinforcing layers. It is generally · considered by mortar and concrete authorities that a clean, strong, sharp sand carefully graded and passing 8-mesh is required.

(b) Cements.

North American Portland cements are produced in five major types (Types I to V) which are adapted for use under specific conditions. The types differ in their proportions of the four main chemical compounds, namely, tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium alumino-ferrite.

69--4125 - 6 -

Type I is used in general construction work when the special properties of the other kinds are not required. The U.S. Bureau of Reclamation "Concrete Handbook" states that Type I cement is as durable as Type II under freezing-thawing conditions it if is air-entrained. Some of the additives for Type I cement act to increase the air entrainment. Type II is a cement used where moderate sulphate attack may occur. Its low trica1cium silicate content provides good resistance to sulphate solutions. Type III cement develops high early strength which is an advantage in some applications. Type IV cement generates less heat and at a slower rate and finds its use in massive structures. This type would appear to have no application in the ferro-cement boat industry. Type V cement has much greater sulphate resistance than do the other types. All five types have approximately equal strengths after two months but after several years Types ' II, IV, and V seem to surpass Types I and III. In addition to the above five types, which have tricalcium silicate (or dicalcium silicate) as their chief component, there is another kind of cement known as aluminous cement. This cement has mono-calcium aluminate as its chief component and, since free lime is not present, has good resistance to attack by seawater and aggressive ground waters. Its strength in 24 hours is claimed to be as high as the strength developed with ordinary cement in 28 days.

Various cement/sand' mixes have been used in the manufacture of ferro-cement boats. Nervi himself is said to have used 50 to 60 lb cement to 1 cu ft sand. The following list gives some of the ratios reported by various sources:

Portland cement ' Association(l), cement/sand 1:1 1/2 or 2 by ,.,eight.

J.F. Fyson(2), cement/sand 1:1 3/4 ("parts")

Sampson and loJellens(3) , cement/sand 1:2 (by bags).

Hartley(4), cement/sand 1:2 by volume.

Hurd(5) , ' cement/sand 50 to 65 lb cement to 1 cu ft sand.

Kaiser Cement Special Report T-19(6), sand/cement 1:1 1/2 by weight.

"YM and Ferro,,(7), cement/sand 1:2 by volume.

(c) Water-Cement Ratio.

The most important constituents in concrete (and mortar) are the water and the cement. The sand-aggregate is a relatively

69-4125 - 7 -

inert filler. The function of the water is to form a solution of electrolytes and apply a coating of hydration products on the particles. Low water-cement ratios favour resistance of concrete and mortar to sulphate attack~ increased water-tightness, increased compressive strength, increased erosion resistance, lower permea­bility, and lower shrinkage on setting and drying. American Concrete Institute specifications require that the water-cement ratio for concrete which will be subject to potentially destructive exposure such as freezing and thawing, severe weathering, or chemicals, shall not exceed 0.5 by weight.

Tests done in the present study showed that mixes with a water-cement ratio of 0.4 could be satisfactorily worked into the layers of mesh reinforcement with the aid of a vibrating trowel. Some cements, notably Type III, required a slightly higher ratio (more water) for adequate workability. However, even though the weight proportions of sand, cement, and water were closely controlled, a considerable variation in "feel" and slump was observed. The cause of this variation may be attributed to variations in the sand and/or to differences in the amount of entrained air.

(d) Admixtures.

Admixtures (additives) have not been pursued at this time although it is recognized ' that admixtures can be of some benefit when used as air-entraining agents, set-retarders, accelerators, water-reducing agents, and workability improvers. The Division of Building Research NRC(8) points out, however, that these benefits are contingent on proper use and a knowledge of side effects which may be harmful. We conclude that if it is possible to do a first class job without the aid of admixtures that it is better to avoid them. This removes the necessity of speci­fying sometimes secret and propriet~ry formulations and simplifies the mortar making operation in areas where the admixture is not readily available. Pozzolan is one material in common use by makers of ferro-cement boats. Pozzolan combines with any free lime in the cement and is reported to reduce the water/cement ratio and to increase the workability. Its effect on the strength and durability of the ferro-cement has not yet been adequately documented.

TYPES OF REINFORCEMENT.

69-L1125 - 8 -

The kinds of steel ,reinforcement which it is possible to use are almost limitless. Mesh size, mesh shape, wire gauge, wire strength, expanded metal (both as-expanded and as-flattened), perforated metal, woven wire, welded wire, twisted wire, linked wire, galvanized before weaving, galvanized after weaving, black wire, bright wire, and plated wire, are some of the possible variations which may be encountered. Early in the study it was realized that only a few of the many combinations could be studied. It was therefore resolved to use a representative variety of kinds readily available which had a relatively similar mesh size, i.e., openings of about 1/2 inch. The kinds used in, the various test panels of this study are as follows:

1. 2.5 lblsq yd expanded metal lath galvanized before slitting.

2. 1/2-inch, #16 U.S. Steel W.G., (0.0625 in.), welded square mesh, galvanized after welding.

3. As in 2 above but with zinc coating removed. (Ungalvanized mesh not available locally.)

4. 1/2-inch, #22 gao (0.027'in.) hexagonal mesh (aviary wire) galvanized before weaving - wiped matte or possibly electrogalvanized finish.

5. l/2-inch, #22 gao (0.024 in.) hexagonal mesh (aviary wire) galvanized after weaving - bright hot-dip finish - Belgian or vJest German.

6. 1/2-inch, #22 gao (0.024 in.) hexagonal mesh (aviary wire) galvanized after ~~aving - grey to black flat finish - Japanese.

7. 1/2-inch, 1119 gao (0.033 in.) w~lded hardware cloth.

8. l/4-inch coil, #19 gao (0.036 in,) black and oiled firescreening (fireplace curtains) - oil removed in naphtha.

9.. As in 8 - oil not removed.

10. 3/8-inch, 1120 gao (0.034 in.) wc,1ded square mesh ungalvanized (type used in one r,oprietary construc­tion method).

...

.-

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It was not possible to purchase loose-woven 1/2-inch screening locally at the time of the study. High-tensile drawn or oil tempered woven screens were available but appeared too stiff and too expensive to be practical. Some 1/4-inch 1121 gao (USHG) welded square mesh was purchased but this material has not yet been used.

Larger mesh sizes and heavier gauges obviously impart properties to ferro-cement not obtainable from the smaller meshes used alone. Ho,~ever, the study at this stage concentrated on assessing and comparing the strengths of panels made with one kind of mesh reinforce­ment. The strength of panels with composite construction is a separate subject.

As mentioned earlier in this report, all mesh layers in a panel were oriented in the same direction so that any directionality characteristics would be made apparent.

With the exception of the firescreen mesh and the 3/8" #20 gao welded square mesh, it was not possible to obtain suitable material without a galvanized coating. For future comparison of corrosion attack, the welded square mesh sheets for one panel were stripped free of zinc in 50-percent hydrochloric acid, then thoroughly washed.

The breaking strengths of the wir~ in several of the reinforcements are shown in Table 2. Except for the square mesh material, the strength obtained from single wires from a mesh docs not represent the strength of the mesh itself, either alone or incorporated into mortar. This is because of the mesh geometry and interlocking and bonding characteristics.

MIXING EQUIPMENT.

A used H~bbard bread dough mixer (200 lb flour capacity) was modified for use as an economical mortar mixer. (Identical machines are used in a local iron foundry for mixing cold-set core sand and in a local pottery workshop for mixing clay.) The mixer speed was reduced from 59 to 30 rpm and a scraper attachment added to the mixer arms. Figures I and 2 show the mixer and the scraper attachment. The dough mixer performed very satisfactorily. The normal bat~h size was 75 lb of dry ingredients and 10 lb water but a 90-lb batch of dry ingredients plus water was mixed on one occasion without difficulty.

PREPAl~TION AND TESTING FERRO-CEMENT PANELS.

PANEL MOULDS.

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Four moulds were made from 32 x 32 inch sheets of 1/2-inch plywood. Stock 1 x 1 inch was nailed to each sheet to make a 30 x 30 inch panel mould. Each panel was lined with a sheet of 4 mil plastic 36 x 72 inches stapled into the form. The free portion of the plastic sheet was used to fold over the mould to prevent dirt falling into the reinforcement layers and to reduce moisture loss during the two-day period prior to stripping of the cast panel.

The gene~al procedure of panel mould preparation was as follows:

(a) The selected reinforcement material was cut into sheets measuring about 29 1/2 x 26 1/2 inches.

(b) The sheets of reinforcement material cut from rolls were passed through a 3-roll sheet metal former to straighten and flatten the sheets.

(c) The reinforcement sheets were laid layer upon layer until a thickness of 1/2 inch was obtained. Each layer was "randomly" staggered to avoid geometrical interlocking and channeling and impeded sidewise movement of the mortar. The 29 1/2 x 26 1/2 inch reinforcement was laid so as to leave a three-inch strip on one side of the panel without reinforcement. The orientation of each layer of the reinforcing material in the panel was the same with reference to directionality characteristics of the material, if any.

(d) The layers of reinforcing material were held in position in the bottom half of the mould by means of 7/B-inch roofing nails. The nails were spaced in such a way as to avoid critical areas in the several bending, impact, and corrosion specimens to be cut from the panels.

Figures 3 and 4 show a typical panel-making process with vibrating trowel and hand finishing.

"

METHOD OF MAKING PANELS.

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The following procedure, with minor modifications, was used for all test panels:

(a) Dry sand and cement were weighed out.

(b) Samples from the bags of sands and cements were taken from time to time for future use as required.

(c) Dry ingredients were mixed in the mixer for two minutes.

(d) A quantity of water weighed to the nearest 0.1 lb was added.

(e) Mixing was continued for an additional three minutes.

(f) A slump test was performed on each batch and three 2-inch cube specimens were made from most batches after the first few.

(g) The mortar was placed on the mould laid in a horizorttal position and was worked intq the reinforcement by means of a vibrating "trowel". (The trowel was a 5 x 12 inch piece of 1/4-inch plate with a rod weld~d to the plate. This welded rod was inserted into a small pneumatic chipping gun as shown in the photograph of Figure 3.) It required about five minutes to work _the mortar thoroughly into all parts of the panel.

(h) The panel was immediately smoothed by hand-trowelling and covered by the plastic sheet on cross-supports. No further trowelling was done.

(i) The surface was wetted .after 24 hours and the plastic sheet placed in contact with the panel surface.

(j) The panel was stripped after 48· hours, rewetted, placed in a rack, and wrapped in plastic sheeting.

(k) The panel was cured by rewetting every two or three days and keeping wrapped for one month in. the p.1astic sheeting. The room t~mperature was about 65°F.

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Table 3 in the Appendix lists the details of the reinforcement, mortar mix, slump values obtained, the 7- and 28-day compression strength test results on 2-inch cubes, and the modulus of rupture of the unreinforced edge test specimens. The slump values of mortar in all panels used for subsequent tests except Panels 25 and 26 ranged from 4 1/2 to 7 1/2. Panel 25 with Type II cement and Del Monte sand and Panel 26 with Type I cement and Evco Dry Mortar Sand had slump values of 3 1/2 inches. The average of all values was 5 1/2 inches.

The average 7-day compression strength value on Type II-Evco Dry Mortar Sand combinations obtained to date is 5,840 psi, and the average 28-day strength value is 8,175 psi. Other mixes generally provide single values and are also shown in Table 3. The average 28-day modulus of rupture value of 14 paneis of Type 11-Evco Dry Mortar Sand combinations obtained to date is 960 psi. The single values range from 705 to 1,300 psi.

It should be mentioned that t,~o of the panels, 8 and 16, developed large flat blisters and small gas holes during the setting period. See Figures 5 and 6. The cause of these defects is not definitely known. A chemical reaction between the mortar and the galvanized coating is considered to be a possible cause.

The test panels us~d to evaluate the various reinforce­ment materials are Type II Cement-Evco Mortar Sand combinations. These include Panels 2 to 16 inclusive, some of which are duplicates for control purposes.

The test panels used to evaluate the various cements are the 1/2 in. 22 gao hexagonal mesh panels Type II - 5, 14; Type I -17, 26; Type III - 18, 19, 22; Type V - 23; aluminous - 24, some of which are duplicate controls.

The test panels used to evaluate the various sands are Type II Cement - 1/2 in. 22 gao hexagonal mesh panels 5, 14, and 25.

The test panels for evaluation of the effect of a galvanized coating are the 1/2 in. 16 gao welded square mesh panels 4, 12, and 9. Additional panels are desirable to augment their comparison using galvanized and ungalvanized wire of finer gauge.

The first group is essentially a strength comparison. The other three groups chiefly pertain to the resistance of the mortar

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and reinforcement to corrosive attack but will provide strength compari­sons also.

METHODS OF TESTING PANELS - TEST RESULTS.

After a month curing time the panels were laid out, as shown in Figure 7, for test specimens. Specimens A and Bare 15-inch square specimens for drop-impact tests; Specimen C is for bend tests of unreinforced material; Specimens D and E are for longitudinal and transverse tests (depending on the directionality of the reinforcement material; and Specimens F and G are specimens for corrosion, exposure, and any other tests. The panels were sectioned by means of a diamond saw.

1.. Drop-Impact Tests.

Various investigators of ferro-cement and laminate hull materials have used various impact test methods. Nervi dropped a 550-lb weight from heights which were gradually increased up to about 10 ft (5,500 ft-1b). Nervi's slabs reportedly ranged in thickness from. 2.4 to 4 inches and contained. bars from 0.24 to 0.40 inch with many layers of mesh •.

The relative impact resistance of laminates with various reinforcements has been determined by Gibbs and Cox, Inc. (9) using a test to simulate actual service conditions as nearly as possible. A cylindrical impacter with a hemispherical head 3 inches in diameter was dropped down a smooth seamless tube 20 feet long. The impacter could be varied in weight from 7 to 150 lb. Damqge was evaluated by leakage tests. In another study by H.W. Wimmers~IO), an iron ball 25 cm in diameter, 61 kg in weight, suspended from a steel wire 5.80 M (19 ft) in length was lifted 5.00 M (16 ft-5 in.) from its bottom position and set free. The ball hit the 70 x 70 cm (27 x 27 in.) test panel on a bearing 62 x 62 cm clear .with an energy of 174 kg-M (1,280 ft-1b).

A Russian study(ll) compared the impact strength of reinforced concrete and "ferro concrete" plates 5 em thick. A 50-cm diameter sphere weighing 25 kg was dropped onto ribbed specimens 90 x 50 cm. The impact strength was considered to equal the sum of the products of the weight p times the height of fall H times the number of impacts n from the given height ·of fall, Le., EpHn, at the time of the appearance of developed cleavage cracks. The opening of cracks was then related to the value EpHn.

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In our assessment of the panels provided by Ferro-Cement Industries Ltd., Nanaimo, which is attached as Appendix II, comparative impact resistance was obtained by means of a drop test in which an almost spherical ball with a centre hole was dropped down a 1/2-inch pipe onto a panel specimen. The panels, about 15 inches square, were supported in a frame with a 10-inch hole in the centre. The weight of the ball was 26.4 lb and the dropping height was 20 feet. Several drops of the ball (528 ft lb per drop) were required to produce substantial damage to the panels. The panels tested were nearly two inches thick and contained two layers of 0.192 inch steel rods on two­inch centres in the centre of the panel. On each side of this centre reinforcement were laid two layers of 2-inch 12 gao galvanized welded square mesh, one layer of I-inch 16 gao hexagonal mesh, and four layers of l/2-inch 22 gao hexagonal mesh.

The present test panels are, of course, of much lighter construction. It was felt after careful consideration of the literature, and of our results in the Ferro-Cement Industries' tests that the best impact test would be a single blow impact of such force as to provide a quasi-quantitative comparison of the various reinforcements. Thus any test should just damage the strongest panel specimen and not completely destroy the weakest.

This kind of impact. test should reasonably simulate a collision with a "deadhead" at a typical ship speed (15 knots). It does not, however duplicate such factors as hull curvature, the energy absorption of a relatively large panel (membrane), the inertia effect of a "typical" deadhead, or the possible resilience of the "deadhead".

In the improved test the round bottom half (about 9-inch radius) of a 6 7/8-inch diameter oxygen tank of the kind used by divers was filled with steel balls to make a weight of 50 lb. A frame was constructed to guide the dropped weight to the target area of the 15-inch panel specimen which is supported on a 3/4-inch plywood frame with a centre hole of l2-inch diameter. A disc ·of 1/4-inch plywood 6 inches in diameter sits in the centre of the target area to cushion the impact very slightly. Figures 8, 9, and 10, show the set-up. The drop height in the present study was reduced to a 10-ft drop from the 20-ft drop formerly used. This substantially reduces the velocity of impact from about 36 fps to 25 fps, equivalent to a boat speed of about 15 knots. The energy absorbed per impact is 50 x 10 ~ 500 ft lb.

The damage sustained under the 500 ft-lb drop-impact load has been measured both quantitatively and qualitatively. The

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concavity of the top surface and the convexity of the bottom surface after impact was measured by means of a straight-edge. It \vas not meaningful to measure the v:idth of crack openings mving to the very great differences in failure characteristics, e.g., fine radial cracks, concentric cracks, spa11ing, and disintegration of the several kinds of meshes.

The photographs of the top and bottom surfaces of the panel specimens after being subjected to the 500 ft-lb drop-impact test are sho\.;rn in pgures 11 to 17 inclusive. Inspection of the panel specimens shown in·the photographs allowed a visual rating of impact resistance. The visual rating and the convexity-concavity displace­ment measurements are presented in Table 4. The panels containing the firescreening and expanded metal lath were very severely damaged. The panels containing the l/2-inch hexagonal mesh were moderately damaged. The l/2-in. #19 gao hardware cloth and, more especially, the l/2-in. #16 gao welded square mesh and t.he 3/8-in. /120 gao welded square mesh were only slightly damaged. The visual observations and the displacement measurements rate the panels for their impact resistance in the same order.

It should be noted that all panels had a standard half inch thickness of reinforcement. The weights of the reinforcements per square foot of panel varied considerably. Equal weights per square foot would tend to equalize the strengths of the several panels. However, this would result in thinner panels (and lower total panel weights) for the stronger reinforcements. Also, the effect of even one layer of heavy square mesh or rod reinforcement in the centre of the panels would likely effect a marked improvement and equalization of the impact resistance of the several panel constructions. These variations merit further consideration.

2. Flexural Strength - Modulus of Rupture.

The flexural strength as modulus of rupture is measured under third-point loading. The test specimens used \.;rere 2 1/2 to 3 inches wide, 12 inches long. The span used \vas 10 inches. One each of the bottom supports and the top loading points is a steel ball to ensure that forces applied to the beam \vill be vertical only and applied without eccentricity in the manner described in ASTM Designation C78-64: Flexural Strength of Concrete (Using Simple Beam with Third­Point Loading).

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The deflection. of the test specimen under load was measured at increasing load increments until the maximum load was attained. This allows a measure of work performed to ultimate failure to be determined. Figure 18 shows typical curves. The load at the first sign of cracking in the bottom.of the specimen and again at the first sign of a side crack was usually recorded. The use of a mirror under the specimen greatly facilitates observation of the first crack. The manner of failure and the presence of broken wires was also recorded. The modulus of rupture at the maximum load held was cal­culated on the basis of

where W = load, b = breadth and d = depth (thickness) of specimen.

The modulus of rupture values for the panels containing the various reinforcements in a "standard" Type II Cement-Evco Dry Mortar Sand mortar are provided in Table 5. The values for the longitudinal and transverse directions are listed separately.

The average value for the modulus of rupture obtained from three panels with 1/2-in. #16 gao welded square mesh as reinforce­mentis 6,580 psi. The single value for the 3/8-in. #20 gao welded square mesh is 5,000 psi. The average obtained from two panels of 1/2-in. #19 gao hardware cloth is 3,560 psi. The other reinforcements gave lower values or values that varied greatl"y with the orientation of the wire.

the modulus of rupture values for the several cement­sand combinations in panels containing the "standard" l/2-in. 1122 gao hexagonal mesh reinforcement are sho,Yn in Table 6.

The top and bottom views of typical specimens after loading to a deflection of at least 0.5 inch are shown in Figures 19 to 22 inclusive.

3. Exposure Tests.

Justifiable concern is felt for the long-term durability of ferro-cement boats in a salt water environment both inside the hull from brine refrigeration tanks in fishing boats and outside the h~ll from the seawater. Seawater is well known to attack some Portland cements and the reinforcing materials when not adequately covered with a thick layer of concrete. In fact recent evidence is that even the reinforcing covered with the recommended several inches of sound

*Modulus of Rupture R in bending is the be.nding moment at "fracture" divided by the section modulus.

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concrete will ultimately oxidize and damage the concrete. Some authorities claim that galvanized reinforcing materials should not be used in ferrocement boat construction. Others claim that all reinforcing should be galvanized. Certainly, 'galvanized steel is finding, increasing use in construction in certain corrosive environments. Zinc gives cathodic protection to steel under certain chloride ion concentrations and potentials. However it is known that zinc can be dissolved as zincate ion when galvanized steel is placed in fresh concrete. The galvanizing coating would then provide less cathodic protection to the steel. Chemical and electrochemical treatments have been tried to control the initial corrosion of the galvanized coatings under conditions of potentially high alkali content. The initial attack by the alkali released on hydration is not considered to be progressive.

It has been pointed out that corrosion of reinforcement can be prevented by producing truly impermeable concrete but that this is generally impractical. Ferro-cement mortar with 'properly graded sands and a trO\velled finish would be expected to be less permeable than poured foundations, piers, and the like. However, the depth of cover will be very much less. Any fine cracks and porosities will allow access of salt solution to the reinforcement mesh.

The case for not using galvanized reinforcement is sometimes stated to be that the mortar-reinforcement bond will be poorer. Work on plain galvanized and black bars(l3) suggests that the bond is not appreciably diminished by galvanizing. A reaction between the zinc and the alkaline liquid of freshly placed mortar will produce bubbles of hydrogen which can adversely affect the bond strength (a's may be the case in panels 8 and 16 of the present study). A chromate dip reportedly prevents the hydrogen-producing reaction.

The sulphate resistance of concrete and mortar made with various cements has been the subject of many investigations. The long time required to obtain significant results is a major problem. One authority(14) has developed automatic equipment in which concrete test cylinders are soaked in a 2.1 percent solution of sodium sulphate for 16 hours at 73 F and then dried for 8 hours at a temperature of 130 F. A I-year exposure in this equipment is equivalent to 6 years of continuous soaking at 73 F in an identical solution. Soaking in a la-percent solution of sodium sulphate at 73 F is reported to be approxi­mately equal in severity to that of the automatic testing equipment. Another authority(15) stores bars of mortar in a 5-percent sodium sulphate solution and periodically observes changes in length, modulus of elasticity, porosity, and comp,ressive strength. Many samples and treatment by statistical analysis is required.

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No exposure tests have been undertaken in this study to date although it is planned to use specimens from the panels already made. Even more accelerated tests are required for the assess­ment of the corrosion resistance of the ~einforcement imbedded in the various mortars and of the resistance of the mortars to the salt water or brine environments. When the test panels have all cured one month it is intended to immerse and dry on a cyclic basis small test specimens. An electro-chemical method of testing will also be used. These tests would apply chiefly to the possible corrosion of the reinforcement materials rather than to sulphate attack of the mortar itself. Comments by some authorities in regard to the preferred type of cement are interesting and useful. The Kaiser Cement Special Report T-19 states that Type V cement, manufactured especially to resist sulphate attack should be the builder's first choice and that Type II cement will provide moderate protection from seawater attack. The Portland Cement Association report Ferro-Cement Boats states that Type II should be used for boats to be used on salt water or any water with a high sulphate content. Type -I may be used for boats to be used on fresh water lakes and rivers with no dissolved sulphates (less than 150 ppm). Until further evidence is available, it would appear that the preference of most of the local builders for Type V cement is wise.

INTERPRETATION OF TEST RESULTS.

The ~irescreening which looked interesting because of its 3-dimensional property appears patently unsuitable as a reinforcing material. Its longitudinal and transverse properties are quite different. Its spring-like construction in one direction and its link-like construction in the other -direction allows none of its inherent strength to be utilized until very large deflections have occurred. The large deflections result in deep cracks in the mortar and the breaking of the mortar into coarse pebble-shaped pieces. A panel reinforced with firescreen mesh would probably offer substantial resistance to complete penetration by a striking object but serious leakage would result from the severe mortar damage. -

Expanded metal lath contributes considerable strength to the mortar in one direction but the properties are highly directional. It distributes the load over a fairly wide span in one direction but the strength of the panels in its weak direction is little better than the mortar itself. The metal lath material tears readily. The mortar tends to crumble into coarse pebbles. In addition, it was more difficult to obtain good penetration of the mortar into the metal lath reinforce­ment during plasteri~g. Although one California builder has been

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reported as using metal lath successfully, the general op~n~on of the local builders that it is unsuitable appears justified, at least as far as ordinary plaster lath is concerned.

The l/2-inch hexagonal mesh reinforcement contributes significantly to the strength of the panels and distributes the load over a fairly wide span. However it is much weaker in one direction than the other and laying the mesh alternately in its longitudinal and ·transverse direction would be necessary to develop uniform prop­erties in both directions. This mesh offered moderate resistance to impact loads. The failure under impact loads appears to be shear­type. Penetration of the mortar into the mesh during plastering is relatively easy.

The l/2-inch hardware cloth adds considerable strength to the panel. The strength in both directions is almost ·identical. Hardware cloth distributes the load and cracks in the mortar over a quite wide span. Penetration of the mortar into the mesh during plastering is relatively easy.

The 3lB-inch #20 gao welded square mesh used provided slightly higher strength than l/2-inch hardware cloth. The aistribution of load imparted by this reinforcement is also good. Plaster penetration is satisfactory.

The l/2-inch welded square mesh used provided the highest panel strength. In other respects, its behaviour was similar to the square meshes discussed above.

It is interesting to.note that the reinforcement meshes used, regardless of kind (with the exception of firescreening which exhibits unusual properties) show a fairly linear relationship between panel modulus of rupture (in the stronger direction) and weight of mesh packed into the half-inch thickness of reinforcement. This relation­ship is shown in Figure 23. A somewhat similar relationship holds between the modulus of rup~ure and the total breaking load for the wires per inch across the bend test specimen. This relationship accommodates differences in the tensile strength of the wires making up the various meshes.

STRAIN MEASUREMENTS - PRELIMINARY CONSIDERATIONS.

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In addition to the · strength performance tests carried out on ferro-concrete hulls while ·on land with artificial loading, actual tests while at sea will be necessary to complete the investi­gation of this type of load construction. Due to the possibility of unsymmetrical reinforcing about the centre line of the material section, and the need to separate and to determine both axial and bonding deformation, it will be necessary to measure strain on both surfaces of the section, both inboard and outboard. It is therefore essential that the strain measuring devices must operate continuously and accurately for reasonable periods of time while immersed in seawater and subject to the erosion effects of the relative water velocity.

Our experience in the laboratory has shown that quick setting adhesives such as Eastman 910, used whenever possible to bond electrical resistance type strain gauges to test pieces, are not suitable for immersion in water. While adequate water proofing may effectively seal off moisture from the outer surface of the gauge, migration of moisture through the outer part of the ferro concrete will bypass the water proofing on both inboard and outboard surfaces.

Some water resistance adhesives are available but the strain gauge mounting procedures are involved and the life of the gauges is uncertain. The major problem is holding the gauge correctly in position during the prolonged curing period and the correct controlling of the artificial heat needed complete the cure of the adhesive.

Another potential problem may be the need to measure separately both strain on the concrete material and on the steel reinforcing. When the reinforcing material becomes exposed on the surface of the concrete, but is undetected, different strain measurements may be recorded to the case where the reinforcing is well buried in the concrete.

One possibility is the sheathing of a resistance type gauge in a very ductile material so that it and its connection to the wires is completely water proof, then place them on the surface of the critical sections during the last stages of surfacing the concrete hull.

Another possibility may be the use of Linear Voltage Differential Transformers (LVDT) mounted between pairs of pins projecting out from the surface of the hull structure both inboard and outboard. If the distance between the LVDT centre line and the surface of the hull is accurately measured, measurement of strain by a pair of LVDT's will

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enable the axial and bonding stresses to be determined. However, this method will be a more costly installation than the normal electrical -resistance strain gauges.

It is clear that the problem of strain-gauging a ferro­cement hull is not simple and unless a suitable technique can be discovered in our continuing search of the ferro-cement and concrete literature, a fair amount of development work will be required to solve it.

REPAIRS TO FERRO-CEMENT HULLS.

A vital consideration in the appraisal of a material or construction method for boatbuilding is the problem of repair. The resistance of a hull to damage must be compared with the difficulty and cost of repair. These are major factors in establishing insurance rates and influence the availability of financing for a new boat construction.-

The cost and availability of repair materials, the cost of labour, the level of skill required, the permanence of the repair and any special conditions necessary for the repair will all influence the expense and ease of repair. Obviously, a hull that cannot be satisfactorily repaired, even though it may be very resistant- to damage~ is not acceptable.

Objectives of a Repair.

The principal objectives in repairing a hull are:

1. To restore a watertight condition. This is the first essential.

2. To restore strength.

3. To restore appearance.

4. To increase strength at weak or vulnerable points which may show up after continued use.

5. Preventative maintenance. This is frequently tied to point 3. Surface damage to the hull must be repaired to prevent water reaching the reinforcing steel and causing long-term deterioration.

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One repair undertaking may be required to satisfy more than one of the above objectives.

Classes of Repairs.

1. Repairs during manufacture.

These repairs are to correct flaws and mistakes discovered during construction, damage due to accidents, or to incorporate design changes. The hull is new and unexposed to salt water, the concrete may not be fully cured, and the environment can usually be varied over wide ranges to achieve optimum conditions. This class of repair would be expected to remain sound and trouble-free for the life of the vessel.

2. Temporary Repairs.

These are short-term repairs undertaken to enable the vessel to remain in service until more lasting repairs can be made, until better conditions prevail, or to prevent the loss of seasonal income. In the extreme case, emergency repairs may be required to prevent the loss of the vessel. The primary object of these repairs is to restore the hull to a watertight condition. The strength of the hull may be restored with temporary shores and braces or bolted on stiffeners.

Temporary repairs will be made under the most severe conditions of temperature and moisture (even under water) and must be made using readily available materials that are generally found on boats or which can be carried as an emergency repair kit. The last criterion eliminates materials with a limited shelf life.

Lastly it is to be preferred that the temporary repair does not increase the cost or difficulty of subsequent permanent repairs.

3. Permanent Repairs.

Repairs in this class are undertaken to restore the vessel to the "good as new" condition, and the repair should be expected to last for the life of the vessel with no maintenance other than that required by the undamaged hull.

Methods of affecting a permanent repair may require more skilled labour, more expensive materials and a longer time. It may

be necessary to take the vessel out of the water.

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The , hull will be well aged, have been exposed to sea water for an extended time, and sea water and marine growth may have penetrated all breaks and cracks.

The interior of the hull could have been exposed to any combination of water, oil, fish slime, cleaning solutions, and various paints and primers. However, some choice of environment is possible.

In some cases it will be preferable to attempt repairs entirely from the outside of the hull rather than remove obstructing machinery, insulation of special linings.

Types of Damage.

Three categories of damage will be considered.

1. Surface Damage.

This includes scrapes, ' gouges and spalling. Since the outer reinforcing is protected by only a thin skin it is essential that surface damage be repaired to keep water from attacking the reinforcing. The patching material must be at least as waterproof as the original cement, have good adhesion, and be able to withstand extremes of temperature and moisture without lifting, even when featheredged. The patching material must have a hardness and abrasion resistance comparable to the original hull surface.

2. Cracking.

This may occur on the inner surface from impact, the outer surface, or go completely through the skin. Cracks that are visible may not leak excessivly, or at all. However, any crack can allow water to penetrate to the steel, and neglect or poor repairs could subsequently result in more extensive repair being required.

Cracks can occur with only minimal damage to the reinforcing and in some cases it should be satisfactory to repair cracks by filling and sealing only.

If cracks occur in normal service, repair may include the provision of additional strengthening or stiffening to prevent further ' cracking.

3. Extensive Damage.

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The damage extends completely through the skin resulting in damaged reinforcing, massive leakage, permanent deformation or possibly large areas of weakened hull.

EVALUATION OF DAMAGE TO FERRO-CEMENT HULLS.

It is relatively easy to assess damage to a wood or steel hull • . Bent and broken framing can be visually detected and extensive damage to the skin shows on the interior. Unfortunately, with ferro-cement construction the main structural reinforcing is hidden in the skin and large areas without framing are common. Some general guidelines are essential to relate surface indications of damage to that suffered by the reinforcing material. Some evaluation of the condition of the steel will be possible from observations of the size, number and patterns of cracks, permanent distortions in the skin and rust streaking or corrosion products, possibly aided by tapping, hammering, or loading the suspect areas while observing deflections.

More sophisticated techniques such as ultrasonic inspection, radiography or dye penetrant inspection will give much more information but may not always be available· or usable.

An attempt will be made later to produce general rules to allow the boat O\-lner to safely estimate the seriousness of, damage and the extent of the necessary repairs without having to pay for an educated guess by an "expert". These rules will require revision as more documented experience with ferro-cement hull repairs is obtained.

PAST EXPERIENCE IN REPAIRING FERRO-CEMENT.

The majority of articles on ferro-cement construction cite ease of repair as an important characteristic of the material. Unfortunately, few sources give any description of repair procedures.

The following procedure was outlined by T.M. Hagenbach(l2) of Seacrete Ltd., Norfolk, England:

1. Chip away the damaged area until sound and undamaged material is reached.

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2. Hammer broken or damaged reinforcing back into its original position or in exceptional circumstances replace it.

3. Apply ferro-cement mix to both inside and outside, leaving the surface slightly proud.

4. Grind surface off flush.

Mr. Hagenbach makes no mention of any surface treatment or bonding agent, or of any special treatment during curing.

In the Russian publication "Ship Hulls made of Reinforced Concrete" by V.F. Bezuk1adov et a1(11), mention is made of two repairs. The first was a repair to a launch built by the British firm Windboats which uses the "Seacrete" process. In a collision, an area 30 x 24 inches was damaged, resulting in a permanent deformation of 1.6 inches. The publication states that the area was pushed out with a jack to its original shape, at which time "only minor cracking was found", and the damaged area was "repaired in 30 minutes with a cement-sand mixture".

The other mention was of the Russian yacht "Opyt" which had been driven onto rocks, left for the autumn, frozen into the ice over the winter, and finally recovered in the spring. Repairs were made in one day by four men. Both these accounts are sketchy, implying that no special care was taken, and no mention is made of the durability of the repairs. Until evidence on this vital aspect is produced, they would have to be classed as "temporary repairs".

Patching of Concrete Structures.

Virtually all modern building and structures involve the extensive use of concrete and many years experience in the repair of ordinary concrete is available. Much of the available informa­tion will apply in part to ferro-cement and a brief examination of the literature is warranted.

1. Surface Preparation.

All sources stress the need for adequate surface prepara­tion. All unsound and contaminated material must be removed leaving clean, sound. cement. This may be accomplished by pneumatic chipping tools, wire brushes (power preferred), sandblasting, or an etch with muriatic acid (10-15%) followed by brushing and flushing off with water. However, some authorities consider acid etching to be unre1iable(3) and advocate only mechanical cleaning methods.

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The dense reinforcing material in ferro-cement makes it difficult to remove the broken or contaminated concrete without producing further damage to the wires. Also, an acid etch may react with any galvanizing on the mesh, or corrode the reinforcing.

2. Repair of Cracks.

Many methods of crack repair in conventional concrete involves some form of routing out along the crack and sealing. The nearness of the reinforcing steel in ferro-cement limits the use of these techniques.

Another method which may be more useful is that of grouting the crack with cement or injecting with an epoxy cement. This method requires sealing the surface over the crack except for a few ports along its length. The crack may be flushed if necessary. Finally the grouting material or epbxy is injected under pressure into one port. When the material reaches the next port the first is sealed and injection started at the second. This procedure is carried out until all ports are sealed and the crack filled. After the grout sets the surface seal is removed and the surface may be ground flush. In ferro-cement the tendency appears to be to form many fine cracks rather than one or more large cracks. This may limit the use of the cracks injection since the cracks may be too fine for effective penetration and too many to allow attention to each individual crack. Also, if the crack is on the outside of the hull, the crack will have filled with seawater and drying without effective flushing may leave the salt behind. A description of epoxy injection to repair cracks is given in reference (17).

To penetrate fine cracks with an injector or trowel on cement mortar would probably require an excessively thin mix giving poor bonding.

3. Surface Defect Repairs and Bonding New Concrete to Old.

The American Concrete Institute Manual of Concrete Practice, Part 2, 1967, (ACI 301-66), specifies the following procedure for patching surface defects:

"902 - Defective areas.

"(a) All honeycombed and other removed down to sound concrete. The area at least 6 in. wide surrounding prevent absorption of water from the

defective concrete shall be area to be patched and an it shall be dampened to patching mortar. A bonding

69-4125 - 27 -

grout shall be prepared using a mix of approximately 1 part cement to 1 part fine sand passing a No. 30 mesh sieve, shall be mixed to the consistency of thick cream, and shall then be well brushed into the surface.

"(b) The patching mixture shall be made of the same material and of approximately the same proportions as used for the concrete, except that the coarse aggregate shall be omitted and the mortar shall consist of not more than 1 part cement to 2 1/2 parts sand by damp loose volume. White portland cement shall be substituted for , a part of the gray portland cement on exposed concrete in order to produce a color matching the color of the surrounding concrete, as determined by a trial patch.

"(c) The quantity of mixing water shall be no more than necessary for handling and placing. The patching mortar shall be mixed in advance and allowed to stand with frequent manipulation with ' a trowel, without addition of water, until it has reached the stiffest consistency that will permit placing.

"(d) After surface water has evaporated from the area to be patched, the bond coat shall be well brushed into the surface. When the bond coat begins to lose the water sheen, th,e premixed patching mortar shall be applied. The mortar shall be thoroughly consolidated into place and struck off so as to leave th~ patch slightly higher than the surrounding surface. To permit i,nitia1 shrinkage, it shall be left undisturbed for at least 1 hr before beinf finally finished. The patched area shall be kept damp for 7 days. Metal tools shall not be used in finishing a 'patch in a formed wall which will be exposed."

This method should be applicable to surface repairs or ferro-cement hulls, particularly if the concrete is fresh.

primarily and old. dependent the fresh

The bond between old concrete and new concrete is a mechanical bond depending on keying between the new Thus, the strength of the joint will be extremely on the preparation of the surface, the consistency of cement and the method of placement.

Concrete exhibits two types of shrinkage, setting shrinkage during the initial setting of the concrete, and drying shrinkage, a long-term shrinkage which occurs as a result of chemical reactions during hardening of the concrete. Shrinkage

69-4125 - 28 -

from any cause produces stresses when the fresh cement is restrained as in a patch. The well dispersed reinforcing wires used in fer-r·Q­cement construction would help prevent the formation of shrinkage cracks. On the other hand, there will be less drying shrinkage with a stiffer mix, but forcing the mortar into the mesh will be more difficult, and a reduction in contact between old and new material can be expected reducing keying and bond strength. Setting shrinkage can be reduced by allowing the patching mortar to sit as long as possible after mixing before placement.

Chemical bonds are generally of a much higher order than physical bonds. With Portland cement the chemical bond is of a very low order, but epoxy compounds show a very high order chemical bond and.are the basis for many of the strongest adhesives. Normally epoxies are considerably stronger than concrete and exhibit coefficients of thermal expansion many times higher. Patches made with these resins eventually fail from thermal stresses in the concrete near the bond. Fortunately, epoxy compounds modified by the addition of a polysulfide, polyamide or a coal tar have been developed. These additives make the resulting material more flexible, reducing the thermal stresses in the concrete. Polysu1fides and polyamides also reduce the susceptibility of the bond to moisture, a valuable feature for a boat repair material.

There are two methods of using epoxies in concrete repair~ First, the epoxy, which is a two component cement and therefore does not depend on air drying, can be painted onto the old concrete before a Portland cement patching mortar is applied. The epoxy must be slow curing to give the mortar time to set first. The epoxy then bonds the new cement to the old. Second, for small patches a mortar can be prepared by mixing sand with the epoxy and using this as the patching material. The expense of the epoxy material limits the use of epoxy mortars to small patches, but the resulting patch is considerably stronger than the original concrete. It should be noted that in surface patching the epoxy film acts as a vapour barrier which may produce curling in thin Portland cement mortar patches due to drying on one side only. One disadvantage of most of the commercially availa~le epoxy concrete bonding and patching materials is that the lower temperature limit at which these materials will successfully cure is around 60°F.

Other materials such as polyvinyl. acetate are sometimes used as a bonding agent or an additive to Portland cement mixes. These compounds are reported to improve workability of the mix, promoting better wetting of the old cement by the new ma~erial, allow the use of less water in the mix, and improve the prope'rties of the patch

69-4125 - 29 -

by reducing the effect of the relative humidity during the cure. No study of their advantages and disadvantages in patching a material such as ferro-cement has been found so far. They may well have an important role fo play, but as is pointed out by Swenson(8) the use of admixtures ("additives") in concrete can produce undesirable side effects, and those must be ascertained and controlled.

PRELIMINARY PATCHING - EXPERIMENTS AND RESULTS.

Preparation for Patching.

These preliminary experiments were made on broken samples which became available from "the mechanical tests.

The first sample, from an impact test, contained 1/4" dia. rods on 2 1/2 inch centres with layers of coarse hexagonal mesh on either side and layers of fine hexagonal mesh near the surface. The damaged area was approximately· 10 inches in diameter. It was observed that the cement was broken into pieces roughly the size of the mesh. This meant that the layer pieces were in the centre trapped by the finer outer mesh. Initially, attempts were made to break up the loose pieces with a hammer. This only resulted in shaking out the very fine debris and distorting the reinforcing. An air powered chipping tool was then tried, first with a blunt point to prevent unnecessary damage to the mesh and later with a chisel point. The object was to break up the coarse pieces so they could pass through the mesh. This was unsuccessful as most of the particles were free to bounce around and give with the blmV's. The chisel point resulted in cutting and weakening the reinforcement. Finally, the finer meshes were cut back close to the edge of the damage and the chisel point applied at a shallow angle between the layers of mesh to remove the broken and cracked material remaining. '~en the air tool reached sound cement only fine particles were produced which blew clear. Also, the broken pieces near the ~dge were held more firmly and were ,more easily picked up. The result was that sound cement was reached, the coarse reinforcing was intact, but only about one inch of the finer mesh was left around the edges. Replacement of the damaged mesh would be required.

The second sample contained only one size of hexagonal mesh. The result was that there was less trapping of the debris and preparation took less time with less damage to the reinforcing.

Patching Materials.

69-4125 - 30 -

Samples were obtained of materials readily available frQm local suppliers. Some further materials were available but could only be purchased in large quantities and it was felt that this would eliminate their use by the boat owner for all but very large repairs.

The materials obtained were:

1. A polyvinyl acetate emulsion. The manufacturer's directions recommended painting the broken surfaces before patching with a Portland cement mix and as an additive.

2. A n.aterial described by the manufacturer as a vinyl copolymer latex. It was to be used as a bonding agent and as an additive replacing part of the water for patches under 1/2 inch.

3. An epoxy-polysu'lfide bonding agent.

4. A "just add water" type concrete patching material. This was an extremely fast setting mix.

5. An epoxy base marine patching compound.

6. An epoxy floor patching material. of an epoxy and hardener. Sand was

. after ~ixing to produce a mortar.

The kit consisted to' be added

Preliminary tests were made with unreinforced cement to eliminate the effect of the reinforcement and become familiar with the material. The samples were beams cut from one slab and were broken in bending, the fresh break was patched, and the specimen re-broken. The loads required to break the original samples was extremely variable in spite of the fact that all were cut from one slab. Thereforei it was felt that the load at failure of the patched specimen was not significant compared to the location and type of failure.

Repairs were made with Portland cement mortar alone, using materials 1, 2, and 3, as a bonding agent for Portland cement mortar, and using materials in 5 and 6 as patching mortars, and also using material 3 mixed with sand as a mortar. All patches were

69-4125 - 31 -

allowed to sit at room temperature and humidity for 7 days before breaking.

All Portland cement patches and that done with material 4 were enclosed on three outside surfaces but were exposed to the air on the top. All showed fine cracks on the surface froln shrinkage. This was the compression side during bending.

With both materials 5 and 6 the break occurred in the original material.

The patch using material 3 mixed with sand as a mortar failed at the edge of the joint. A strong smell was evident on the broken surface. It is likely the material contained a solvent to reduce the viscosity. When the material was used as a bonding agent this solvent would evaporate, but was trapped in the larger volume of the patch.

The patch made with material 4 broke at the middle of the patch at a very low load.

The breaking load of all the remaining specimens was low with failure starting at the bond. The sample patched with just mortar using no bonding agents or additives broke. before it could be set up in the testing machine. It is realized that curing conditions for these samples were far from ideal but it would not always be easy to ensure better conditions for a boat repair. The reinforcing found in ferro­cement would have had a substantial influence on the success of these repairs, reducing shrinkage stresses and distributing the load.

The sample patched with material 3 failed at the bond. The break again had a strong smell although the manufacturer's recommendations about the length of time between painting the break and placing the mortar was adhered to.

Discussion.

The surface has only been scratched on the problem of repairing ferro-cement.

Some of the areas to be considered are:

1. The effect of the age of the material to be repaired.

2. The effect of exposure of the damaged area to sea water both above and below the waterline.

69-4125 - 32 -

3. The use of emergency repair materials including epoxy formulations which can be applied to wet surfaces, marine caulking compounds and tar or pitch.

4. Surface · cleaning and preparation prior to patching.

5. The use of a reinforced overlay on the inside of the hull as an alternative to breaking out and repairing severely damaged reinforcing.

6. The effect of various curing methods, including the use of additives.

7. The problem of shrinkage of the. patching material.

8. The performance of the patch un~er cycles of tempera­ture, load, and moisture.

9. The influence of the type of reinforcing on the repair method.

An effort ~hould be made to obtain case histories and to inspect patches or repairs on ferro-cement boats now in service. Since ferro-cement construction is relatively new to North America, many of the case histories will have to be obtained by correspondence without first-hand inspection. However, these records will give a valuable back-up to laboratory tests which will rely on artificial conditions and accelerated deterioration.

Test panels should be prepared for long-term exposure under natural conditions both under water and in the splash zone. Observation of these panels over the years will allow a continual up-dating of the value of different repair methods, and may give advance warning of problems to be encountered in hulls already repaired.

As stated at the beginning of this section, the difficulty and cost of repairs to ferro-cement hulls is a vital part of the cost­effectiveness picture for the material, and more factual information in this area is badly needed.

SIGNIFICANCE OF THE RESULTS.

69-4125 - 33 -

The present six-mo~th development program could not hope to·provide all the information needed by the fisherman-builder of a ferro-cement fishing vessel. What it has succeeded in doing is to provide, for the first time, carefully controlled and fully documented quantitative test data on the combinations of cement, reinforcing mesh and, to a lesser extent sand, which are likely to be used. Some preliminary data on glues and patching has been obtained, and considerable consideration has been given to impact testing, accelerated environmental testing, and strain gauging. This basic data will permit the interpre­tation of a considerable amount of other uncontrolled or incompletely specified test results, and by a judicious extrapolation some useful conclusions can be drawn, despite the gaps in know+edge which will be discussed in a later section. These conclusions, which will undoubtedly be subject to modification in the light of further testing and experience, are as follows: .

Reinforcing and Mortar.

Welded square mesh is superior to hexagonal mesh aviary wire from a strength point of view but the latter is satisfactory "for vessels under fifty feet, and probably, with suitable heavy reinforcement, for even larger vessels." The optimum number of mesh layers is the maximum number that can be accommodated in the panel. Suitable fastening is important here, and extens.l.ve cross bonding of meshes · is necessary if the compressive strellgth of the ferro-cement is to be raised appreciably above that of the mortar. Steel rods and heavy welded square mesh can be used i~terchangeably to increase the shell strength to the desired value. The bond strength between heavy reinforcing and the cement is small compared to the strength of the reinforcing, and at least four layers of mesh, preferably more, should be used on each side. The heavy reinforcing improves the effectiveness of the mesh when it keeps it out near the surfaces where it is most needed.

At the present state of knowledge galvanized mesh should be used sinc~ it seems to offer more potential advantages than disadvantages. The mesh should be free of oily residues. A preliminary small test panel should be made to test for chemical reaction between the galvanizing and the mortar, especially with new shiny wire. If gas is evolved the wire should be left to weather, or treated with a passivating agent such as chromic acid and tested again. One authority(13) claims that chromate-treated galvanized steel should be used with all cements.

69-4125 - 34 -

Type V sulphate resistant cement is recommended, with Type II as second choice. The sand should be a clean, sharp, well-graded, preferably dry, mortar sand with most of the sand passing through #8 mesh. It ~hould be ·tested for its effect on the workability ·of ·the mortar. The ratio of water to cement is of paramount importance since it largely controls strength and porosity. If the sand is not dry, this ratio is hard to determine with the necessary accuracy. Additives, with the possible exception of a small percentage of pozzolan, are not recommended. They can decrease the required water to cement ratio and effect improvements in workability and permeability but sufficient experience in possible side effects and long-term durability has not been acquired. Slump tests from each batch are very useful in checking mortar characteristics.

Shell Quality.

Several test panels at least 30 x 30 inches should be made during construction of the hull. These panels should be of the same materials and the lay-up, plastering, and curing, should be identical to that of the hull. A few test specimens should be made as attached coupons at convenient locations on the hull, to enable verification of satisfactory hull curing. These coupons should be about 3" x 12". The important tests to be carried out on the panels are for modulus of rupture (bending test) in two directions, impact resistance and resistance to environmental deterioration. The coupons should be tested in bending, to verify that the test panel is representative of the hull. Triplicate 2-inch cubes of mortar should be made from batches on a routine basis'. All tests will be performed after 30 days of curing, or as appropriate for quick setting cements.

Patches and Bonding.

Only very preliminary recommendations can be made in this area. The best guide is to follow the instructions in American Concrete Institute Manual of Concrete Practice, Part 2, 1967 (ACI 301-66) as far as possible and to make sure that damaged mesh and concrete is clean and that adequate reinforcing strength is provided, by adding new mesh or bars if necessary. In using proprietary compounds and additives, careful attention must be given to curing conditions and shrinkage effects, and test samples· should always be made if these are not clearly established. We are not able, at this stage, to recommend one preparation or class of compounds over another.

Hull Construction.

69-4125 - 35 -

It would be premature to attempt to deal with construction and quality control procedures, outside of the recommendations which have been made in the other sections.

Sea Testing.

Extensive experience in the strain gauging of a steel hull over the past year leads us to expect little difficulty in obtaining meaningful data on hull strains at sea, once the difficulties of applying the strain gauge to a pervious non­homogeneous material like ferro-cement have been resolved.

Accelerated Environmental Testing.

The lack of adequate, unbiased data·on the long-term (10-20 year) durability of ferro-cement and the difficulty of obtaining even comparative data in a reasonable time, has resulted in little attention being paid to this factor and most of the attent:i.on has been focussed on the more easily determined mechanical properties. We hope to reduce this deficiency by using one of several accelerated testing methods which we have devised, but have not yet proven.

There seems little point in trying to optimize ferro­cement for the other environmental parameters until the best way of making it highly resistant to deterioration by sea water, brine, fuel, etc., has been established.

THE PRESENT STATUS OF FERRO-CEMENT.

Ferro-cement is a complex chemical-mechanical system. It would be nice to know exactly how each element of the system reacts with every other, and how they combine to produce a useful construction material. But such a complete understanding is not feasible in terms of time or expense and is not necessary from a practical point of view. What is necessary is a body of knowledge on the mechanical properties of the material, and the possible changes in those properties under appropriate environmental conditions. Such a body of knowledge has been acquired for glass reinforced plastics and for aluminum alloys during the past decade or so, and those two materials are now firmly established as ship-building

materials. Ferro-cement must follow a similar path.

69-4125 - 36 -

Some remarks on the adequacy of present knowledge, under the headings covered by thi,s project, are given below:

, The Material.

The question of best mesh configuration, from a performance and from a cost-effectiveness point of view still requires some investigation, and whether it should be galvanized or not is still open. More work on sand selection is needed. The basic cement types have nm" been investigated to a reasonable degree, but a considerable amount of work needs to be done on admixtures or additives. In all future work, close attention must be paid to the durability factor, and not, just to short­term mechanical properties.

Shell Quality.

As soon as the basic parameters for the material have been established, a schedule of tests for hull specimens can be worked out in consultation with the regulatory authorities.

Patches and Bonding.

This neglected area needs to be intensively investi­gated. Proprietary bonding agents and additives will usually be involved, and usable information on how to choose between the great variety available, and how to apply them to ferro­cement, is badly needed. Here, even more than for the hull material itself, long-term durability must be given at least as much attention as high early strength.

Hull Construction.

The whole area of reinforcing, stress concentration and sound and economical construction requires a substantial amount of work, and consultation with builders and with regulatory authorities should be pursued.

Environmental Testing.

There is a need for mechanical testing, especially abrasion and impact testing, on reasonably large hull elements, and for strain gauging and other measurements on a vessel over

69-4125 - 37 -

50' long, at sea. This aspect of the resistance of ferro-cement to the environment it will encounter in a fishing vessel is important but relatively straightforward. The question of long­term corrosion and other deterioration resulting from continual exposure to sea water, brine solutions, fuel, fish juices, etc., is much harder to answer. As has been stated earlier, it must be answered, and the perfecting of accelerated testing methods should be given high priority.

/'l./0~ / '. ,(:n(,jJl(cK-~7tL~ .

W.N. English Head, Division of Applied Physics

AWG/mc

A.W. Greenius Division of Engineering

REFERENCES.

69-4125 - 38 -

1. Anon' J Ferro-Cement Boats (C~OlO.OlG)J Portland Cement Association, Skokie, Illinois, 1969.

2. Fyson, J.F., Ferro-cement Construction for Fishing Vessels, FAO Regional Office, Bangkok, Thailand, ca 1968.

3. Sampson, J. and G. Wellens, How to Build a Ferro-Cement Boat, Samson Marine Design Enterprises Ltd., Ladner, B.C., 1968.

4. Hartley, R.T., Boat Building with Hartley, 3rd Edit., Auk1and, N.Z., 1967.

5. Hurd, M.K., Ferro-Cement Boats, ACI Journal, pp 202-4, March 1969.

6. Anon., Ferro-Cement Sea-going Architectural Concrete, Kaiser Cement Special Report T-19, California, U.S.A., undated.

7. Anon., YM and Ferro, Yachting Monthly, undated.

8. Swenson, E.G., Admixtures in Concrete, Division of Building Research, N.R.C. Technical Paper No. 181, Ottawa, Canada.

9. Gibbs and Cox, Inc., Marine Design Manual for Fiberglass Re-inforced Plastics, McGraw~Hill Book Company, Inc., New York, 1960.

10. Wimmers, H.W., Consideration of the Design and Construction of Larger Glass Fibre Reinforced Polyester Ships, The 4th RFP Conference, London, 1964.

11. Bezukladov, V.F., et aI, Ship Hulls made of Reinforced Concrete, Design, Strength, and Construction Technology, Shipbuilding Publishing House, Leningrad, 1968, Navship translation #1148 (Clearinghouse AD 680042).

12. Hagenbach, T.M., Ferro Cement Boats. Canadian Fisheries Report #12, Procedings Conference on Fishing Vessel Construction Materials, Montreal, Canada, Oct 1968.

13. Anon., Zinc-coated Reinforcement for Concrete, Digest 109, Buildi~g Research Station, Watford, England, Sept 1969.

14. Bellport, B.P., Combating Sulphate Attack on Concrete on Bureau of Reclamation Projects, Perfonmance of Concrete, pp 77 to 92, University of Toronto Press, Toronto, Canada, 1968.

References (cont'd)

69-4125 - 39 -

15. Mather, B., Field and Laboratory Studies of the Sulphate Resistance of Concrete, Performance of Concrete, pp 66 to 76, University of Toronto Press, .Toronto, Canada, 1968.

16. Schutz, B.J., Epoxy Resin Adhesives for Bonding Concrete to Concrete, American Concrete Institute, Publication SP-2l, Paper SP 21-4.

17. Gaul, R.W., and E.D. Smith, Effective and Practical Repair of Cracked Concrete, Paper SP 21-5, American Concrete Institute, Publication SP-2I.

69-4125 APPENDIX I. - 40 -

TABLE 1. Typical Screen Analysis of Sands used in Test Panels.

Percent Passing Mesh Size

Evco Dry Evco Dry Del Monte Mesh Size Concrete Mortar Openings/in. Sand Sand "8" 1120" "30"

4 99 100 100 100 100

8 88 100 99 100 100

16 67 92 36 100 100

30 41 66 0.3 57 99

50 15 26 5 38

100 4 7 10

L 200 1

TABLE 2. Breaking Strength of Wires from Various Reinforcements

Breaking Strength of ,·]ires Wire dia 1b/in.

Reinforcement in. 1b psi access panel

I/2-in. 19 gao hardware cloth 0.033 58 68,000 1,050

l/2-in. 22 gao hexagonal mesh (galv. Belgian,

I \ves t German) 0.024 20 44,000 475

I I/2-in. 22 gao hexagonal mesh (galv. Japanese) 0.024 27 60,000 650

1/2-in. 16 gao welded square mesh 0.0624 219 70,000 2,150 Ditto (but across sheet) 175 58,000

3/8-in. 20 gao welded

I square mesh 0.034 58 64,000 1,080

TABLE 3. Summary of Test Panel Construction Data.

Cement-Sand

Panel Reinforcement. Weight No. Material Cement Sand ratio

l' 2.5 lb expanded metal Type II Evco Dry 1:2 lath, galvanized Concrete 8 layers Sand

2 2.5 lb expanded metal Type r;r Evco Dry 1:2 lath, galvanized ~1ortar

8 layers Sand

3 2.5 Ib expanded metal Type II Evco Dry 1:2 I lath, galvanized Mortar 5 layers Sand

4 1/2-in. 16 gao welded Type II Evco Dry 1:2 square mesh, Mortar galvanized, 5 layers Sand

5 1/2-in. gao hexagonal Type II Evco Dry 1:2 mesh-galvanized Mortar after weaving Sand 12 layers

I I 6· 1/2-in. gao hexagonal Type II Evco Dry 1:2 mesh-galvanized Mortar before weaving

Sa.nd 12 layers

7 1/4-in. gao fire- : Type II Evco Dry 1:2 s~reening, washed Mortar in naphtha Sand 2 layers

a 1/2-in. gao hardware Type II Evco Dry 1:2 cloth, galvanized Hortar 9 layers Sand

I

Water- Compression Cement Strength, 2-in. Iveight Slump cubes si ratio in. 7-day 28-day

0.37 1 1/2 no tests

0.38 2 " '.

0.40 "

0.40 6 1/2 "

0.40 7 1/2 "

0.40 5 1/2 "

0.40 5 1/2 "

0.40 4 1/2 "

Modulus of Rupture, psi (unreinforced)

no tests

" ,

1106 906

1060 978

1125 1100

742 I 890

865 810

10l.0 1120

69":'4125 - 41 -

Remarks...

Hesh not fully penetrated. Panel discarded.

n

Mortar appeared to work in well

" "

" "

" "

" "

" "

TABLE 3 (cont'd)

C w ater- I

Panel I Reinforcement

, I Sand I Cer:lent I ~vei~ht I ~-lei~ht

I\o. ,Material Cement Sand rat~o rat~o

9 · 1/2-in. 16 gao welded Type II Evco Dry 1:2 0.40 square mesh, Mortar galvanizing removed Sand 5 layers

10 I 3/8-in. 20 gao welded Type II Evco Dry 1:2 0.40 square mesh, Mortar galvanized Sand 7 layers

11 l/2-in. gao hardware Type II Evco Dry 1:2 0.40 cloth, galvanized

I Mortar

9 layers Sand

I 1/2-1n. 16 gao we1dedl 12 Type II Evco Dry 1:2 0.40 square mesh, Mortar I galvanized, 5 layers Sand

13 2.5 lb expanded metal Type II Evco Dry 1:2 0.40 lath, galvanized 110rtar

I 5 layers Sand

14 l/2-in. gao hexagonal Type II Evco Dry 1:'2 0.40 mesh, galvanized . I Mortar after ,.eaving

I . Sand

12 layers

15 I 1/4-in. gao fire- Type II Evco Dry 1:2 0·.40 , screening, oil coat Mortar not removed Sand 2 .layers

I I \ I I !

Compression Strength, 2-in.

Slump cubes, psi in. 7-day i 28-day

5 1/4 no testE

6 1/2 6050 7100 (11

, days)

7 1/2 no test 7420

7 1/4 5400 7950 I 9875

5 1/4 5950 7200 7500

6 1/2 6200 7600 7250

5 1/2. 5600 8150 7675

Modulus of Rupture, psi (unreinforced)

1300 1230

905 705

ll80 990

840 -895

725 792

890 -

830 960

69-4125 - 42 -

Remarks

IClam-like breathing holes and blisters appeared, mortar appeared to work in

,satisfactorily

" "

1 1 Mortar a?peared to work in well. Clam~

like holes and 'blisters appeared

Mo!tar appeared to Iwork in well

I " " I , I I

" "

I I " " I

*

TABLE 3 (cont'd)

p - In . -Cement-Sand

ane~ I ~e~nrorcement Weight ~o. I rfaterial Cement Sand ratio

I

16 l/2-in. gao hexagonall Type II Evco Dry 1:2 mesh, galvanized . Mortar before weaving Sand 12 layers

17 l/2-in. gao hexagonal Type I Evco Dry 1:2 I mesh, galvanized Mortar I

after ~.eaving Sand 12 layers

18 l/2-in: gao hexagonal Type III I Evco Dry 1:2 mesh, galvanized I Mortar

I I after weaving Sand I 12 layers

I I

19 1/2-in. 22 gao Type III Evco Dry 1:2 I hexagonal mesh, Mortar I galvanized after Sand I

t ,.eaving, 12 la~~rs I

20 I 1/2-in. gao Type III Evco Dry 1:2 I hexagonal mesh, Mortar

galvanized after Sand weaving, Japan

I 9 lavers

21 I l/2-in. 22 gao Type V Evco Dry 1:2 hexagonal mesh, Mortar galvanized after Sand weaving, Japan 9 layers

I

I I I

Water- I Compression Cement Strength, 2-in. Weight Slump cubes, psi ratio in. 7-day 28-day

0.40 6 1/2 5830 9450 9875

1

0.40 5 5040 5875 6175

0.45 4 1/2 6400 8325

I I

0.47 5 5150 8450 7750

0.47 5 1/2 6930 curing

0.44 7 1/2 5280 curing

I I

I

,

..

I

69-4125 - 43 -

Xodulus of I Rupture, psi I (unreinforced) Remarks

760 IMortar appeared to 820 work . in well

1050 " " 960

no tests made Difficult to work in mortar, incomplete

Ipenetration noted later

t

590 IMortar appeared to 560 work in well

I I I

: !

, .

I I

1

TABLE 3 (cont'd)

Panel Reinforcement ~o. Haterial Cement Sand

22 . l/2-in. 22 gao .. Type III Evco Dry

hexagonal mesh, Mortar galvanized after Sand weaving, West Germ. 12 layers

23 " " . Type V Evco Dry Mortar

·1

Sand ,

24 " " Aluminous Evco Dry Mortar Sand

25 " " Type II Del Monte 8: 20: 30:: 1:2:1

26 " " Type I Evco Dry - Mortar

Sand

\ I

cement-, \V'ater-Sand Cement Weight Weight Slump ratio ratio in.

1:2 0.45 5

1:2 0.41 5 1/4

1:2 0.36 4 1/2

1:2 0.40 3 1/2

1:2 · 0.41 3 1/2

Compression Strength, 2-in. Modulus of cubes. Dsi Rupture, psi 7-day 28-day (unreinforced)

curing curing

curing curing

curing curing

curing curing

curing curing

69-4125 - 44 -

Remarks

On stripping it was found that mortar had not penetrated well

Mortar penetrated well

Mortar penetrated well

. Slightly difficult Ito trowel smoothly - tears

" " ,

~

-

TABLE 4. Results of Drop-Impact Tests on Specimens Containing Various Kinds of Reinforcement (All specimens from panels made with Type II Cement and Evco Dry Mortar Sand)

69-4125 - 45 -

Reinforcement Displacement at Panel lb/ftZ centre of impact, 1116 in.

No. Kind of panel Top Bottom Description of Mode of Failure

3 2.5 lb expanded metal 1.23 14 16 Open major cracks in top surface. Major X-shaped lath, galvanized opening in bottom surface. Metal reinforcement torn. 5 layers

4 l/2-in. 16 gao welded 2.B5 5 7 No cracks observed in top surface. Fine star-shaped square mesh, c~acking in centre of bottom. Fine closed cracks galvanized - 5 layers radiating to edges.

5 l/2-in. 22 gao 1.35 11 11 Open major ring crack in top surface. Shear spa11ing hexagonal mesh, and open radial cracks in bottom surface. No broken galvanized after wires observed. weaving - 12 layers

6 l/2-in. 22 gao 1.29 13 13 Similar to No. 5 ab olle but more complete ring of shear hexagonal mesh, spalling in bottom _surface. galvanized before

I weaving - 12 layers

7 l/4-in. 20 gao fire- 1.20 19 19 Extremely severe major ring cracks in top surface. Wide screening, black - open radial cracks and mortar crumbling in bottom 2 layers surface.

10 3IB-in. 20 gao welded 1.59 6 6 Fine ring crack in top surface. Slightly open square mesh, not r -ectilinear cracks and fine radial cracking in bottom galvanized - 7 layers surface.

11 1/2-in. 19 gao hard- 1. 79 5 6 No cracks (other than clamp-down corner cracks) observed ware cloth, square in top surface. Slightly open rectilinear cracks in mesh, galvanized - bottom surface. 9 layers

--

I

I

I

I I

TABLE 5. Results of Flexural Bend Tests on Specimens containing Various Kinds of Reinforcement (All specimens from panels made with Type II Cement and Evco Dry Mortar Sand)

69-4125 - 46 -

Reinforcement Modulus of Rupture, psi I Panel lb/ft l Orientation of wire :io. Kind of panel longit. transv. Description of Mode of Failure

3 2.5 lb expanded metal 1.23 3730 830 Transverse specimens cracked with more or less single 13 lath - 5 layer 3650 870 crack whereas longitudinal specimens cracked over a Av. 3690 850 wider space. Mesh broke.

4 l/2-in. 16 gao welded 2.85 5900 6130 Both transverse and longitudinal specimens cracked at 12 square mesh - 6850 5700 II-inch intervals over wide span. ~o wires broke. Top

9 5 layers 7000 6300 surface showed considerable compression spalling. --- ; 6040 Av. 6580

5 l/2-in. 22 gao 1.35 2900 1360 Top surfaces did not contain an open crack. Transverse 14 hexagonal mesh, 2420 1610 specimens cracked with more or less single cracks

I

I

Av. galvanized after 2660 1485 whereas longitudinal specimens cracked over a wider span ,-leaving - 12 layers \.]ires broke.

6 1/2-in. 22 gao 1.29 2980 1280 As above. 16 hexagonal mesh, 3100 1270 I Av. galvanized before 3040 1275

i weaving - 12 layers

7 1/4-in. 20 gao fire- 1.20 1900 1000 Major crumbling in local zones in both transverse and 15 screening, black 890 900 longitudinal specimens. One or two major cracks. Av. - 2 layers 1395 950

I

8 l/2-in. 19 gao hard- 1. 79 3520 3530 Both transverse and longitudinal specimens cracked at 11 ware cloth, square 3600 3600 Ill-inch intervals over wide span. Slight spalling of Av. mesh, galvanized - 3560 3565 top surface. Wires broken in B.

9 layers I

10 3/8-in. 20 gao welQ.ed 1.59 5000 4460 Top surface showed some spalling. Both transverse and square mesh, not longitudinal specimens cracked at 3/8-inch intervals galvanized - 7 layers over wide span. No wires broken. I

TABLE 6. Results of Flexural Bend Tests on Specimens with Various Cements and Sands. (All specimens from panels having 12 layers of 12 in. 22 gao hexagonal mesh, galvanized after weaving 1.35 lb of mesh/sq ft of panel)

69-4125 - 47 -

Modulus of Rupture, psi Panel Cement Orientation of wire No. Type Sand longit. transv. Description of Mode of Failure

17 Type I Evco Dry 2910 1665 Both specimens showed single crack in top surface. Mortar Sand Longitudinal showed bottom cracking over wide span,

transverse less so. Wires broken in both.

5 Type II Evco Dry 2900 1360 ~ ~enera11Y as in 17. 14 Mortar Sand 2420 1610

18 Type III Evco Dry panel discarded 19 Mortar Sand 2430 I 1585 Spa11ing of top surface. Bottom cracking over wide 22 curing span. Wires broken.

23 Type V Evco Dry curing Mortar Sand

24 Aluminous Evco Dry. curing Mortar Sand

25 Type II Del Monte curing 8:20:30:: 1:2:1

26 Type I Evco Dry curing Mortar Sand

~-- --

69-4125

Fig. 1 Hubbard mixer used for mortar.

Fig. 2 Modified paddles in mixer.

Fig. 3

Fig. 4

Mortar placement in panel mould with vibrating trowel.

Finishing of panel by hand trowelling.

69-4125

Fig. 5

Fig. 6

View of blisters and cracking in Panel 8.

View of gas hole in Panel 8.

69-4125

SPECIMENS" A" &. "B·

SPECIMEN "e"

SPECIMENS ''0'' &. "E"

SPECIMENS .oF' &. "G"

D A

G

C

for ct.ro p - impQct tests

E

F

B·

5 I ,~II I" CQ e. /8 "

for flexural strength tests on unr-elnforced portion of panel.

for flexural sttengthstests on reinforced portion of panel

for other tests (exposure, durCibiLi ty, corros ion.)

FIG.7 LAYOUT OF PANEL FOR TEST SPECIMENS

Fig. 8 View of drop-impact test fixture.

69-4125

Fig. 9 Close-up view of drop­impact test fixture at point of impact.

50 It> drop wei9ht SLlspendecl __ (0 ft above tesi speci men.

I Gin. sq,.uQre frQme. of 4)( 4 Qngle iron with '0 in. diCl . hole. in centre

15 in. 5~UQre ferro cement test panel.------­

lOin. diQ. support pipe.

'-=~

II

II ..

II ..

II

o

II · . II · . II · . II

6uspending Rope

4- lin angle Iron guide frome I2.H hi9 h contained by weld rin9s at 4 ft Ihterva Is

Ir Y4 in plywood pod Gin. dlQ.

~in stee.l plate wi th

7'n. dio hole, welded to verlicQI guides.

~ 3/4 in. plywood.. .support ring with 12in.dia.hole

rU------.-.u... _____ 2 in. planking support ..- pad.

'----------'

FIG.fO SKETCH OF DROP-IMPACT TEST GUIDE FRAME ASSEMBLY.

, .

Fig. 11

Fig. 12

69-4125

Top and bottom views of impact test specimens containing 5 layers of 2.5 lb/sq yd expanded metal lath.

Top and bottom views of impact test specimens containing 5 layers of 1/2 x 16 gao galvanized welded square mesh.

Fig. 13

Fig. 14

69-4125

Top and bottom views of impact test specimens containing 12 layers of 1/2 in. 22 gao hexagonal mesh; galvanized after weaving.

,"

Top and bottom views of impact test specimens containing 12 layers of 1/2 in. 22 gao hexagonal mesh; galvanized before weaving.

Fig. 15

Fig. 16

69-4125

Top and bottom views of impact test specimens containing 2 layers of 1/2 in. 20 gao firescreening.

I,Of>

Top and bottom views of impact test specimens containing 7 layers of 3/8 in. 20 gao unga1vanized welded square mesh .

Fig. 17

69-4125

Top and bottom views of impact test specimens containing 9 layers of 1/2 in. 19 gao galvanized hardware cloth.

:0 .J

3000 ,...,---,-------

2500 =-~2. in.IG 9'" welded S~UC1re mesh.

__ -~ 120

2000

1500 ·-

.-:l 1000 '­

10 E 3/8 in. 20gQ. welded sq,uare mesh'

c:(

::> ..J

14D

ve in. 2290. heXQgonal mesh

==~~~=..zr."'-~l~;='~."''''''~''''!~ZIIII_''"'''' __ .....".,.=t''''''''''''''''''' ............. =J

o 0.1 0.2 0.3 0.4 0.5 0.6

DEFLECTION - INCHES

FIG.18 LOAD-DEFLECTION CURVES FROM

TYPICAL FLE)<URAL STRENGTH SPECIMENS ,

Fig. 19

Fig. 20

Top view of modulus of rupture specimens loaded longitudinally and transversely with respect to orientation of bottom wires •

.i£". 16 '1""

~. - 228\01",

HEXA4IIio..a M£'lM

Bottom view of specimens shown in Fig. 19 above.

69-4125

Fig. 21

Fig. %2

Top view of modulus of rupture specimens loaded longitudinally and transversely with respect to orientation of bottom wires.

2'i!"f9 'I".

H4~IlWAAE CurTH

Bottom view of specimens shown in Fig. 21 above.

69-4125

cI) a..

1000

6000

5000

.c +-' 0

(3 4-(l)

E-"0 Q)

" C 0 0.. )(. al

.n -\(l

•

-5) v E q) I.-C1

~ 11\

~ QJ :Y ~ ~

d (p

0 N

C .-~ If)

0

o o

• .r: I/)

QJ g

LU 0:: 4000 -

N

~ l-n. ~ r:r 0- 3000 0

cI) :> .J ~ o 2000 0 :;!

1000

0 0 c:

0 0

0 .c:: +-0

....: c (l)

E \)

• Q.l

Y '-(3

..r! ~ I/) -c1

Q) u .... ..g s::: IU J-

~ L

E 0 ..c

0 c

...... 0 (1

c: <:n 0 <1-t;1') 0 b X C ClJ

...c (\\ ti ~ en

N N t: .-~

2

REIN FORCEMENT LB./SQ,FT. PANEL

FIG. 23 RELATIONSHIP MODULUS OF -----RUPTURE vs WEIGHT OF VARIOUS REINFORCE­

MENT MATERIALS IN STRONGEST DIRECTION . -

•

APPENDIX II

. I

B.C. RESEARC~-> 3650 Wo.brook Cro,eenl, Vaneouver 167, Canada

I -> Phone (604) 224-4331 • Coble 'RESEARCHBC' • Telex 04·507748

PROJECT REPORT November 7, 1969

To: Ferro Cement Inpustries Ltd., P.O. Box 231, Nanaimo, B.C.

Subject: 1-4127 Tests on Ferro-cement Panels

A. OBJECT:

To perform such mechanical tests on ferro-cement panels as required by the Steamship Inspector with a view to provisional approval of ferro-c('ment hull construction for a commercial vess~l 54-foot length.

B. MATERIALS AND BACKGROUND:

The Sponsor submitted two panels for tests. One panel, marked C, was approximately 26 x 20-3/8 x 1-1/2 inches. The other, marked D, was approximately 26 x 20-3/8 x 2 inches. (Part of the extra thickness of D is reported to be due to an extra thi.ck facing layer of concrete.)

Other panels, identified as A, B, E, F and G, were submitted at the same time but are outside the scope of this test report.

The description of the structure, number and kinds of mesh and rod reinforcement cement mix, additive, and curing provided by the Sponsor, is included as Appendix 1.

Briefly, the construction is as follows:

Panel C.

Two layers of 6 gauge (0.192 in.) rods spaced at 2 inches laid at right angles in the centre of the panel section.

One layer of heavy (0.056 in.) galvanized.hexagon­mesh (1-in. menh) laid on each side of the 6 gauge rods.

Te~hniC(l1 Operation 01 Ihe BRITISH COlUMBIA RESEARCH COUN~ll. a Non-profit Industrial Reseorch SCKioly

1-4127 - 2 -

Four layers of light (0.025 in.) galvanized hexagon­mesh (l/2-inch mesh) laid on the I-inch mesh.

A trowelled top coat (lIB-inch thick) overlies the l/2-inch mesh on one side.

The panels are reporte~ to have been cured for 30 days at the time of receipt.

Panel D.

Two layers of 6-gauge (0.192 in.) rods spaced at 2 inches laid at right angles in the centre of the panel section.

Two layers of heavy 2-inch welded square mesh (12 gauge wire) laid on each side of the 6-gauge rods in such a manner that the mesh wires lie between the rods'.

One layer of heavy (0.056 in.) galvanized hexagon­mesh (l-lnch mesh) laid each side of the above square mesh.

Four layers of light (0.025 in.) galvanized hexagon­mesh (1/2-inch mesh) laid on the I-inch 6-gauge mesh.

A trowelled top coat (1/4-inch thick) overlies the l/2-inch mesh on one side.

The same cement mix was reportedly used in both panels and is described in Appendix 1.

C. TEST PROCEDURE:

The two panels were cut up with a diamond saw according to the plan shown in Figures 1 and 2. The following test specimens were obtained.

C-l, D-l Transverse bend tests with trowelled face in compression side of specimen. Mesh twist is in long direction of specimen. Width of specimens is 4 in. Span is 10 in. centre loading.

C-2, D-2 Transverse bend tests with trowelled face in tension side of specimen. Mesh twist is in long direction of specimen. Width of specimens is 4 in. Span is 10 in. centre loading.

C-3, D-3 Transverse bend tests with trowelled face in compression side of specimen. Mesh twist at right angle to long direction of specimen. Width of specimen is 4 in. Span is 10 in. centre loading.

C-4, D-4

C-5, D-5

C-6, D-6

C-7, D-7

C-8, D-8

1-4127 - 3 -

Compression tests with test load on cut faces of specimen and at right angle to mesh twist. Dimensions: width, 4 in.; height, 4 in.; thickness, 1-1/2 in., 2 in.

Compression tests with test load on cut faces of specimen and in line with direction of mesh twist. Dimensions: width, 4 in.~ height, 4 in.; thickness, 1-1/2 in., 2 in.

Impact tests in which 26.4 lb cylinder 5 inches in diameter with round ends was dropped from height of 20 feet onto the centre of IS-inch square panel specimen supported in frame with a centre hole 10 inches in diameter. The drops were repeated until failure from the point of view of water-tight integrity judged to have occurred. The weight/ height relationship was chosen on the basis of drop tests on a "2 x 6" board (1-5/8 x 5-5/8 in.). Two drops produced failure of a 2 x 6 board supported in the frame described above. Figure 3 shows the frame set-up.

Test specimens 4 x 6 inches, not used except for calculation of the density of panels.

Tensile specimens (width 2 in., length 15 in., thickness 1-1/2, 2 in.) were tested by clampjng gripping hanger plates to the specimens. The distance between the grips, the effective gauge length, was four inches. The loading direction was in line with.the twist of mesh. Each specimen had one rod down its centre axis. Specimen D-8 had four longi­tudinal strands from the 2-inch welded square-mesh screen.

The tensile strength of the 0.192-inch diameter spacing rod taken from test specimen C-8 was also determined.

D. TEST RESULTS:

1. Panel C.

(a) Modulus of Rupture - from transverse bend test.

Spec C-l (trowelled side up - mesh twist longit.) 3950 " C-2 (trowelled side down - mesh twist longit.) 3650 " C-3 (trowelled side up - mesh twist across) 2970

psi psi psi

1-4127 - 4 -

(b) Compression Strength.

Spec C-4 (load at right angles to mesh twist) " C-5 (load in lin,e with mesh twist)

4830 psi 7010 psi

(c) Impact Test-Drop Test - 26.4 lb ball dropped 20 feet onto IS-inch square panel C-6 supported over 10-inch diameter ring - 530 ft-Ib.

First drop

Second drop

Third drop

Fourth drop

- slight crack and depression in top surface. - cracking along line of mesh over a 5-inch

square in bottom surface.

- depression 1/4-inch deep over ball contact area.

- cement spalled from bottom surface over an area 9 inches in diameter.

- three layers of mesh exposed in bottom surface.

- depression 3/4-inch deep over ball contact area. four layers of mesh exposed in bottom surface.

- panel failure assumed.

- depression l-l/4-inch deep over ball contact area.

- no cracks observed outside of contact area in top surface.

- heavy hexagonal wire exposed in top surface and two top layers of mesh contained broken wires.

- heavy hexagonal wire exposed in bottom surface and outer two layers of mesh contained broken wires.

(d) Density - Specimen C-7 (Approx 4 x 6 x 1.5 inch and containing three rods in one direction and two rods in other direction) = 0.098 lb/cu in.

(e) Tensile Test - C-S.

First transverse crack observed at 675 psi. Maximum tensile load held 975 psi.

(f) Tensile Test - 0.192-inch diameter spacer rod from Specimen C-S.

Breaking load U.T.S •. Elong. % in 8 ,in. R.A.

2. Panel D.

(a) Modulus of Rupture.

Spec D-l (trowelled side

2650 Ib 90,800 psi 5.5 percent

61. 3 percent

up - mesh twist longit.)

1-4127 - 5 -

3690 " D-2 (trowelled side down - mesh twist (longit.) 3280 " D-3 (trowelled side up - mesh twist across) 3320

(b) Compression Strength.

psi psi psi

Spec D-4 (load at right angles to mesh twist) - " D-5 (load in line with mesh twist)

6650 psi 7280 psi*

*load limit of testing machine reached before ultimate failure.

(c) Impact Test - Drop Test - 26.4 lb ball dropped 20 feet onto IS-inch square panel D-6 supported over lQ-inch diameter ring.

First drop

Second drop

Third drop

Fourth drop

Fifth drop

- top surface barely marked. - cracking along line of mesh over as-inch

square in bottom surface.

- top surface barely marked. small portion of cement spalled from bottom­surface to expose mesh.

- slight depression in top surface. two to three layers of mesh exposed in bottom surface.

depression formed in top surface. - four layers of mesh exposed in bottom

surface.

top surface crumD~y in contact area. - depression about 3/4-inch deep. - Eenel failure assumed.

1-4127 - 6 -

Sixth drop - top surface depression 1-1/8-inch deep. - four mesh layers exposed in bottom.

(d) Density - specimen D-7 (approx 4 x 6 x 2 inch) and containing three rods in one direction and two ~ods in other direction) = 0.096 lb/cu in.

(e) Tensile Test - D-8

First transverse crack observed at 500 psi. Maximum tensile load held 995 psi.

D. DISCUSSION AND CONCLUSIONS:

1. The surfaces exposed by the diamond saw showed no significant voids or internal discontinuities in the cement matrix portion of the panels.

2. The rods, which are not galvanized, are rusted. There. is no significant bonding between rods and cement matrix but since the rods are on the neutral axis the lack of bond may be unimportant.

3. The modulus of rupture values in both panels range from about 3,000 to about 4,000 ps~.

4. The difference in the values of modulus of rupture found for Panels C and D is probably not significant.

5. The modulus of rupture values for Panel D calculated for a thickness of l-3/4-inch (that is, removing the stated extra l/4-inch surface trowelled coat) are much higher than the corresponding values for Panel C.

6. Co~pression strength values range from 4830 to 7300 psi. The compression strength of Panel D is superior to Panel C.

7. The tensile breaking strengths of the two specimens C-8 and D-8 are 975 psi and 995 psi, respectively.

8. The ultimate tensile strength of the spacing rod specimen is 90,800 psi. The rod did not contribute significantly to the ultimate breaking strength of the ferro-cement specimen because the bond between rod and cement matrix allowed the rod to slip before the ultimate load was applied. In the hull itself the rod has a long contact length and the ends are tied into the structure so that the ~trength of the rod will

contribute to the ultimate breaking strength of the composite matrix. How much it will contribute depends on the elastic modulus of the rod and on the "effective elastic modulus" of the mesh/concrete matrix.

9. Although some surface damage was sustained by both panels when subjected to two drops of the dropping ball (26.4 lb from a height of 20 feet, 530 ft-lb), the damage was much less serious than that sustained by a 2 x 6 inch (1-5/8 x 5-5/8) fir plank subjected to two drops of the ball. One drop deformed 0.2-inch thick checker floor plate to a depth of about 1/2-inch.

10. Estimated failure of Panel C was assumed after three drops of the ball and of Panel D after five drops of the ball.

11. The test results reported herein appear to warrant further development of this means of construction in shipbuilding such as is proposed by the Sponsor.

A~W. Greenius Division of Engineering

~/a:?~~ W.N. English Head, Division of Applied Physics

AWG/mc

•

APPENDIX 1.

Dr. EnSl j.sh B .0. He seD.rch

November 3, 1969 P.o. Box 231 Nane.imo, B.O.

RE: Description of Test Panels

All panels \,:ere cODstrlJ.cted by laying reinforcinc material on a flat surface and stapled in position. Ooncrete is then

B.C, Resear Notes.*

vibre.ted throuGh the panels froD the open surfo.,ce. ~--. -_ .. (1)

The concretel:1ix is ic1ent:ical for all p::.no15 "lith the ex­eception of panel (A) vhich has G. hi[;her \';ator c:Jntent. The r.lix . is as follo':.Js.

1 ba3 (94 Ibs.) type 5 Portland Cemont 1 7 :.::; ClJbl' c fe o +. ~c'l >"Ie-! - ... ---------.----... - .. ------------ .. ----.-.-- - -.--- -------.. - -- -• -" ~ v ~ ."" .

6 lbs Pozolen 4% water tJ cement by weicht

R9infor:cins m[lteria1 in thof:"e panels is of mild steel con­struction i'.'ith the exception of paneln 0 and D. Specifica.ti )~1S for E!ateri2.1s are as fol10',,;5.

Oornmon r'hterie,ls

1/2 inch hex3..~~ono.l 1118Sb, 22 cue.ge, galv<'''i.~1iz8d ---.-----. linch hezLl.{;onal mesh, 16 GU8.Ge, Go.lve.nized -.

IlL!· inch \·;ovon mesh, ILl· [uace (panel G only)

Panels 8 G D 0.192 inch hiSh tensile rod S.A.E. 10-10 carbon minimum 1000,OGO psi -_________ ._ . ___ . __________ . __ __ _ . o in '·11 "..." 1 0" rna o'n S" 1<' 10 - 1::" c" Y'b 'n ILl cu·· '--e L.. \.... dv __ .. ~, ..... 0, .... , . .......,. _'.J '. "A .... J, r 0 t....I.~:) ,

galv8.ni Led. ----~---.-------.--~- -- .~-- --_. _. --- _ .. . -- .,,"' - '-' .. --

Panels A o.nel :a are of identice.J. construction ~'iith the ex-ceptilHl of tl18 viator c =·nte:tt.

Note: Panel A 10 , ~ i·!C~ter Panel B J+;'; ','Tater

*See next page.

(2)

(5)

(6) , (7)

Appendix 1 (cont'd)(2)

November 3', 1969

Pa:lels C and D are of similo.r constructio~l dupllcat1ns sections of a hull presently under construction.

Panels E,F, and G are of the same size e.nd sha.pe \'lith different types of reinforcing mat~rial em,ployed.

!E) 1/2 inch hexagonal mesh 22 guase F) 1 inch hexaGonal mesh 16 gU2.5e

, G) 1/4 inch ';[oven lilesh l.l~ guclse

*B.C. Research Notes:

(1) Sponsor reported by telephone that Panels C and D cured more than 30 days under cover - open - kept moist.

(2) Sponsor reported by telephone that sand used is Ocean Cement coarse sand (Victoria sand). '

(3) Wire diameter stripped free of zinc measured 0.025 in. which is slightly smaller than 22 ga (Steel Wire Gauge).

(4) Wire diameter stripped free of zinc measured 0.056 in. which is slightly smaller than 16 ga (Steel Wire Gauge).

(5) Should read 100,000 psi. The value determined by test is 90,800

(6) Only Panel D contained 2-inch weld mesh. Panel C did not contain 2-inch weld mesh.

(7) Wire diameter stripped free of zinc measured 0,104 in. which is close to 12 ga (Steel Wire Gauge).

psi~

(6)

t.J • "I (I :::~

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69-4127

G ." ~i .2

Figure 2. Layout of Panel Specimens after Tests •

. .

Figure 3. Frame and Ball used in Impact Test.

I

B.C. RESEARC~---> I>

3650 Wesbrook Crescent, Vancouver 167, Canada.

Phone (604) 224-4331 • Cable 'RESEARCH8C' • Telex 04-507748

TIlE DEVELOPHENT OF FERRO-CEt1ENT FOR FISHING VESSEL CONSTRUCTION

TECHNICAL SUPPLEl1ENT to PART II

This is a technical supplement to the Final Report presented to the Industrial Developmc=nt Branch of the Fisheries Service. At the time of writing the final report" certain test results were incomplete because some test panels were still curing. The panels have since cured and additional hend, impact, short­term exposure, and patching tests have now been co~pletcd. In addi.tion, 'ole have taken advantage of the opportunity to observe and comment on some of the practical problems encountered in the conf,truction of a 45-foot ferro-cement boat under back-yard construction near our laboratory.

These tests and observations comprise this Technical Supplement to our Final Report dated March" 31, 1970. Some of the tables of the March 31 report have now been updated by the inclusion of new material, and we have identified these tables by their original number plus the letter S, e.g. Table 3-S, to indicate that they are to be found in the Supplement. We refer to tables \\Thich have not been affected by the new work by their original number, e.g. Table 4, and such tables are to be found in the Harch 31, 1970 report.

INDEX

Technical Supplement.

Mesh Reinforcement' •...••..•.••.•.•.•• ...................... Cement and Sand ............................................. Water/Cement ratio •••••••••••••••••••••••••••••• II •••••••••••

Bond Strength between Mortar and Mesh .•... ~ .•••. . ......... , Exposure Tests ................................... .

Patching Ferro-cement ....................................... Observations of ~ Hull under Construction ................... General Conclusions and Recommendations

References. ............................... . . . . . . . . . . . . . . . . . . .. Appendix III (Tables of Test Results) ........................

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1

3

5

6

8

9

15

18

22

23

MESH REINFORCEHENT.

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This supplement contains additional tests on reinforce­ment materials previously reported. The additional drop-impact test results are included in Table 4-S. The drop-impact tests on inch­thick panel specimens containing a half-inch total thickness of the several reinforcement meshes rate them in decreasing order of impact resistance as follows:

1. l/2-in. 16 gao welded sq mesh (5 layers, 2.S5 lb/ft2 panel) .

2. 3/S-in. 20 gao welded sq mesh (7 layers, 1. 59 lb/ft2 panel) •

, 1. 79 1b/ft2

3. l/2-in. 19 gao hardware cloth (9 layers, panel) •

4. l/2-in. 22 gao hexagonal mesh (12 layers, 1.35 lb/ft2 panel).

S. 2.5 1b expanded metal lath (5 " 2

layers, 1.23 lb/ft panel).

6. l/4-in. 20 gao firescreening (2 layers, 1.20 1b/ft2 panel).

The values for modulus of rupture in bending, as shown in Table 5, rate the panels with the several reinforcements in the same relative order.

It will be noted in the above rating that although the total thickness of mesh in all one-inch thick panels is approxi­mately one-half inch, the weights of reinforcement per square foot of panel vary from 1.20 to 2.S5 lb per sq ft panel.

Four panels 30-inch square (Panels 27 to 30 incl) were made with approximately equal weights of reinforcement mesh, viz. 1.15 lb per sq ft. The mortared thickness of these panels was about l/2-inch, a small variation being caused by the springiness of some of the meshes. The four panels respectively contained 3 layers of l/2-in. 22 gao hexagonal mesh above and 2 layers below I layer of

"1/2-in. 16 gao welded square mesh, 10 layers of l/2-in. hexagonal mesh, 2 layers of l/2-in. 16 gao welded square mesh, and 6 layers of l/2-in. 19 gao hardware cloth. Type II cement and "Del Monte" sand were used in the four panels. (Cement/sand ratio 1:2) The drop­impact. tests (50 lb from a height of 5 feet) for the four panels are shown in Table 7-S. The panel with 2 layers of l/2-in. 16 gao welded square mesh was markedly superior to the other panels in drop­impact resistance. Figures 24 to 27 inclusive show the top and bottom surfaces after testing.

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The values of modulus of rupture for the longitudinal and transverse directions of these same panels are shown in Table 8-S. The panel reinforced with 2 layers of 1/2-in. 16 gao welded square mesh has a higher modulus of rupture than the other panels tested and a markedly higher modulus of rupture than the panel containing 1/2-in. 22 gao hexagonal mesh alone. The test specimens from the combination mesh panel (Panel 27) and from the hardware cloth panel (Panel 30) gave more uniform cracking on the bottom tensi.on side of the specimens and both held the load over a much greater deflection than did the test specimens from Panel 29 (2 layers of 1/2-in. 16 gao weld mesh). The specimen from Panel 28 (hexagonal mesh reinforcement) also held its load over a much greater deflection but, of course, at a much lm-ler level. The load-deflection curves of Figure 18 shmv the two characteristic conditions described.

Comparison of the modulus of rupture values of these panels does not give a completely fair assessment of the panels. The rather abrupt drop in load at ~mal1 deflection in the case of Panel 29 (2 layers 1/2-in. 16 gao welded square mesh) is caused by compression failure of the mortar before there is any yielding of the steel reillforcement. Within the limitations imposed by the non-uniform distribution of the mesh this type of failure may be classified as an over-reinforced beam. A detailed explanation of this is outside the scope of this study but Muhlert(18) provides a good analysis of bending failures in botll over-reinforced arid under-reinforced beams.

Panels reinforced with 1/2-in. 16 gao welded square mesh have been shmvn to be markedly stronge'): in drop-impact resistance and marginally stronger in flexure than panels reinforced with an equal weight of 1/2-in. 19 gao hardware cloth and with an equal wei~ht of the 1/2-in. 16 gao welded square mesh/1/2-in. 22 gao hexagonal mesh combination. Hmvever, the effect of spacer rods in the panel has not yet been assessed. Undoubtedly rods, in either a common hot-rolled grade or a high tensile grade, should substantially increase the drop-impact resistance of any panel.

It is interesting to note that the cost of reinforcement for the four panels 27 to 30, containing equal welBhts of the three different meshes and one tl>lo-mesh. combina.tion, :.:-angccl from ahout 60 to 70 cents per square foot of panel. The reinforcement materials used in this study were bought through both retail Dnd wholesale channels in small quantities and in some instances the price included federal sales tax. The costs are_therefore only approximate h'lt do indicate that the difference between the several reinforcements is not great on an equal-",eight basis. (The 3/B-in. 19 gao material 'vas supplied gratis and the cost was not availahie.)

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It is recognized that high stresses may also occur in the diagonal direction of boat hulls. As shown in Table 5, some of the reinforcement meshes tested showed a considerable difference between longitudinal and transversa strengths in bending. Diagonal test specimens ,,,rere therefore prepared from Panels 4, 5, 8, and 10 (1/2-in. 16 gao welded square mesh, 1/2-in. 22 gao hexagonal mesh, 1/2-in. 19 gao hardware cloth, and 3/8-in. 20 gao welded square mesh, respectively). Figure 7-S shm"rs specimen location.

The values of the modulus of rupture are shown in Table 9-S with the corresponding values from the longitudinal and transverse tests. It will be observed that the modulus of rupture of specimens in the diagonal direc~ion is somewhat lm"rer than that for specimens in either the longitudinal or transverse direction for reinforcement mesh of square construction. The value of the modulus of rupture in the diagonal specimen from the 1/2-in. hexagonal mesh panel lies between the longitudinal -and transverse values.

The characteristic directional properties were further assessed by "slmV' impact" tests which also sho,V'ed the effect of the velocity of impact on the mode of failure. The tup (striking head) from the drop-impact tests was used in a compression machine to load IS-inch square specimens supported on I-inch plywood with a l2-inch hoie (as in the drop-impact tests): The maximum load held and the mode of failure were recorded in Table 10-S. There is a good straight-line relationship between these slow-impact values and the average of the longitudinal and transverse values for the modulus of rupture of the panels as shown in Table 9-S. The characteristic modes of failure are not very different to those obtained in the 50-lb 10 ft drop-impact tests.

CEMENT AND SAND.

The curing and subsequent testing of panels 23 to 26, inclusive, since the Final Report have provided additional test results on the effect of the various cements and sands on the strength of ferro-cement panels. The additional drop-impa2t displacement values for specimens cured at least 28 days and the description as to the mode of failure are presented in Table 4-S. Drop-impact test results for comparison of various cements and sands are presented in Table ll-S. The additional modulus of rupture values of the unreinforced portions of the panels are shown in ~able 3-S and of the reinforced portions in Table 6-S. A direct comparison of the

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values of the modulus of rupture for the unreinforced specimens made with the several cements is provided in Table l2-S. The calculated modulus of rupture values are undoubtedly affected by such factors as the speed of applying the bending load; unevenness of bearing surfaces; inherent variation in the sand, cement, and mixing; and the sensitivity of the equation M = ~ to small differences in the thickness lid". bd

It should be noted that only the panels made with Type II cement offer a reasonable repl,ication of specimens for a valid comparison, viz. 14 panels with 27 values. The other test specimens with Types I, III, V and aluminous cement are from only one or two panels. The values for modulus of rupture of specimens with Type II cement range from 705 ,to 1300 psi and average 946 psi.

It will be observed in Table '12-8 that the average values for the modulus of rupture for unreinforced specimens from panels made with Types I, III, V, and aluminous cements do not appear to differ greatly from the average value of the specimens made with Type II cement. It should also be noted here that a cement/ sand ratio of 1:2 and a water/cement ratio of about 0.4 have been used for all panels. These ratios may not be the optimum ratio to produce the strongest mortar with all cements but we do not feel that significant improvement is to be expected from such optimization.

The values for the modulus of rupture of the reinforced specimens ma.de with the several cements are shown in Table 13-8. The modulus of rupture of aluminous cement specimen in the longitudinal direction was higher than that of the other specimens but the value for the transverse specimen· was not markedly different.

The one "standard" panel in 'vhich Del Monte sand was used showed a value for the modulus of rupture of the unreinforced specimen within the range determined for the unreinforced specimens of the naturally graded dry mortar sand used. The value 'vas, hO\vever, considerably below the average value of these specimens as shown in the lower portion of Table l2-S. The values of the modulus of rupture obtained with Del Monte sand in the reinforced specimens are similar to the corresponding values obtained with the Evc~ Dry Mortar Sand.

As before, cognizance should be taken of the points presented above as to the effect of several variables on the test results obtained. Also, the present test with Del Monte sand used 8-mesh, 20- mesh, and 30-mesh sand'in the ratio of 1:2:1 by weir,ht. This ratio, the cement/sand ratio of 1:2, and the water/cement ratio

of 0.4 may not yield a mortar of maximum strength.

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The grading of the sands is known to have an important effect on mortar strength and other properties. The Evco Dry Mortar Sand is reported to have a natural particle size gradation as obtained from the pit with the exception that the +8 mesh material is scalped off. The particle size gradation and the angularity of the grains are shown in Figure 28. Figures 29, 30, and 31, respectively, show the 8-mesh, 20-mesh, and 30-mesh Del Monte sands used in Panel 25. The sharper nature 'of the grains may be observed in the photographs at a printed magnification of about 4 times. It is generally agreed that sharp sands make a better mortar than do rounded sands for applications of this kind. Sands of an angularity or sharpness similar to the Evco Dry Mortar Sand used should be satisfactory for ferro­cement work provided the contents of clay, silt, and other constituents are acceptably lm-l.

\-TATER/ CEMENT RATIO.

No further tests have been undertaken as to the effect of the wat~r/cement ratio and slump on workability of the mortar. Experience in making the 30 panels showed that variations in slump and workability were obtained 'vith the water/cement ratio held at 0.4. Even though dry sand was used and sand, cement and water '-lere carefully weighed, differences in sand fineness, mixing variations, wetting of the mixer, and other unknown factors produced variations in the mixture. Larger batches should tend to minimize the effect of some of the variables but field conditions in general would be less conducive to accuracy and control of the components and would tend to allow wider variations in the mortar. For the controlled cement/sand ratio used throughout this study, the slump test provided a good guide to the 'vorkability of the mortar. A slight amount of additional '-later '-las sometimes required to obtain a slump of about 3 1/2 inches, the minimum slump , found necessary for adequate workability. One experienced builder in New Zealand(l9) considers that the slump should not be much greater than 2 1/2 inches but 've believe that the critical slump 'must be established for the raw materials used. It is worth mentioning that a U.S. Naval Civil Engineering Laboratory report(20) on ferro­cement panels states that slump is not a reliable control to use with mortar. We have found it is a useful aid to achieving consistency between batches.

A test was conducted to see how much of the total \-later addition could be contributed by wet sand. A I-kg sample of dry mortar sand thoroughly wetted, drained, weighed, and subsequently

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dried and reweighed was found to hold 150 gm of wAter. The total water requirement witll a cement/sand ratio of 1:2 and a water/cement ratio of 0.4 is 0.4 x 500 = 200 gm. It is evident that wet sand could provide up to three-quarters of the total water requirement in the present tests. Attention is also dra\vn to the hulking effect of damp sand which makes batching on a volume basi s Jess sati.sfactory than batching on a weight basis and making due allowance for the moisture content of the sand. Bagged dry sand has considerable virtue and should be used where possible.

BOND STRENGTH BEn-mEN HORTAR AND HESll.

No rigorous tests hqve yet been undertaken to determining whether galvanized or ungalvanized reinforcement provides the better bond. There may be no simple answer to tIle question. If galvanized, the reinforcement may also have a protective phosphate or chromate conversion coating to prevent whi.te rust storage stains. If the reinforcement is not galvanized, it may be covered with a black scale, in various stages of flaking and rusting, or it may be pickled clean with a partial coating of light rust. Testing of the effect of the galvanized zinc coating on the bond has been confined to a comparative qualitative examination of specimens from a panel containing galvanized 1/2-in. 16 gao welded square mesh and from a panel containing the same 1/2-in. 16 gao square mesh with its galvanized coating removed in 50-percent hydrochloric acid. First it may be poinled out that no significant difference in the modulus of rupture values was obtained from galvanized and stripped 1/2-in. 16 gao reinforced panels -compare Panel 9 with Panels 4 and 12 in Table 5. Secondly, separation of the lower layer of mesh from the specimens from Panels 9 and 4 was accomplished \-lith substantially equal difficulty. Examination of the wire grooves in the mortar lying immediately above the wire did, hmvever, shm·J a textural difference. The grooves of the Panel 4 specimen containing galvanized wire mesh had a somewhat spongy appearance whereas tJIOSC of the Panel 9 specimen containing stripped ~ire mesh had a smooth appearance. It has not bt'!en established whether or not the spongy appearance is the result of a zinc-cement-water reaction, but this is a possibility.

There is no conclusive evidence to show that the bond strength between wire mesh and mortar in the early life of the panel (before being subjected to a corrosive environment) is dependent on whether i.t is gAlvanized or not. In any case, the mechanical keying at the wire cross-overs will provide a satisfactory bond to prevent differential Hire/mortar movemenL under tensile stresses. Even in

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the absence of cross-over point keying it seems likely that even a few inches of wire/mortar bond will be enough to break the wire in tension.

The strength of the bond between wire mesh and mortar after exposure of the' mortared reinforcement to an aggressive environment is another question. The benefit of galvanized coatings on the reinforcement is considered in the section on Exposure Tests.

The 'surface areas of the reinforcing mesh (the bond areas) have been computed for several panels with various reinforcement meshes to look for a relationship between bond area and specimen strength. The bond areas per square inch of panel surface for four panels with a half-fnch thick packi,ng of reinforcement and the corresponding values of modulus of rupture are as follows:

5 layers 1/2-in. 16 gao welded square mesh 4.2 sq in. 6300 psi 9 layers 1/2-in. 19 gao hard't-lare cloth 4.3 sq in. 3560 psi 7 layers 3/8-in. 20 gao welded square mesh 4.2 sq in. 4700 psi

12 layers 1/2-in. 22 gao hexagonal mesh 4.8 sq in. 2000 psi

The above panels show no clear relationship.

Panels 27 to 30 with equal weights of reinforcement showed an inverse relationship between the.computed bond area and the average modulus of rupture as fol1mvs:

Panel 27 - 3 layers 1/2-in. 22 gao hexagonal mesh 1 layer l/2-in. 16 gao welded sq mesh

Panel 28 Panel 29 Panel 30

2 layers 1/2-in. 22 gao hexagonal mesh 10 layers 1/2-in. 22 gao hexagonal mesh

2 layers 1/2-in. 16 gao welded sq mesh 6 layers l/2-in. 19 gao hardware cloth

2.8 sq in. 3850

4.0 sq in. 2150 1.8 sq in. 4930 2.8 sq in. 3230

It is believed that this apparent in-verse relationship 'reflects the inter-relationships bet'veen wire diameter, wire flexibility, and modulus of rupture in bending rather than between bond area and strength. Variations in the strength of the several kinds of wire in the meshes, mechanical keying bond at twists and cross-over joints, uneven load-carrying by the mesh layers at various distances from the neutral axis, and bond areas much greater than the critical minimum bond area to prevent slipping obscure any significant bond areal strength relationship.

psi

psi psi psi

EXPOSURE TESTS.

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Coupons, approximately 3 x.4 inches, were cut as shown in Figure 7-S, from piece F of 11 panels for exposure tests. The Sa\VD edges and any edge spalling \vere coated with two layers of a two-component epoxy floor patching material to prevent ingress of corrodents through the cut edges.

Duplicate coupons -F-l, and -F-6 from the panels listed in Table lLf":"S \vere immersed in a plastic tank (5-ga1. capacity) of filtered sea\vater (obtained from the Vancouver Public Aquarium). A small flow of air from a submerged air hose aerated and gently circulated the sea\vater. The temperature was ambient about 68°F. The pH of the sea\,,"ater at the start of the test was 7.85. Measurements during the tests showed little change. The exposure cycle was 8 hours immersion follmved by 16 hours (overnight) of drying in an exhaust­hooded fume cupboard. Changes in appearance were noted during the IS-cycle periods completed at the time of writing .. The "observations are recorded in Table l4-S. In brief, the coupons reinforced with 1/2-in. 16 gao ungalvanized welded wire mesh (original galvanized coating had been removed with HCl) (9-F-l, 9-F-6) showed evidence of red rust ori the bottom surface after two exposure cycles, the rusting becoming more severe as the number of cycles increased. The coupons with 1/2-in. 22 gao hexagonal mesh galvanized before weaving (6-F-l, 6-F-6) shoued rust staining after 10 exposure cycles. The rest of the coupons still shmved no rust after 15 cycles. None of the coupons shmved any evidence of rusting through the top side which is protected bi the thicker layer (up to about 1/2-inch) of mortar. Figure 32 shows the bottom surface of one of each pair of coupons exposed in the seawater.

A single coupon -F-3 from the panels listed in Table l5-S were immersed in a 5-percent solution of sodium sulphate, a . standard accelerated test medium to assess the resistance of concrete to sea,.,ater. No aeration or circulation was used. The exposure cycling was otherwise as described for the seawater tests. The observations made during the 15 exposure cycles completed are presented 'in Table 15-S. In brief, the drying of the first cycle produced a white effluorescence on the top surface of several coupons, presumably from seepage of the solution from a porous surface. The aluminous cement coupon (24-F-3) had the heaviest coating. The effluorescence did not reappear after the first few cycles. The bottom surface of several coupons exhibited a white effluorescence which outlined the mesh pattern, presumably from-seepage of the solution from microcracks. Coupon 2 l l-F-3 (aluminous cement) showed the most prominent outline. Subsequent cyclings diminished the amount of

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effluorescence outlining the mesh pattern. Figure 33 shows the bottom surfaces of the exposed coupons after 15 cycles of immersion and drying.

Scratch testing of ' exposed and control coupons indicated no detectable softening or deterioration of the coupons after 15 cycles of exposure.

It may be argued that the corrosion of the mesh lying just below the bottom surface of the test coupon is more vulnerable to attack than the top layer which is covered with a mortar layer and thus protected from the corrosive environment encountered by the exterior of the hull. In practice, however, it is not possible to place a uniformly thick cover coat of mortar over the top layer of reinforcement because of lack of fairness in the mesh. Grinding of the finished mortar to improve fairness and surface finish can expose the reinforcing mesh. Figures 34 and 35 show exposed mesh on the hull of a boat built by an amateur but plastered by a professional cre,.,. Heavy white rust of the galvanie:ed coating and red rust of the steel wire is evident. In addition to exposure of mesh from the finishing operation, fine cracks in the hull appear to be unavoidable. Such cracks will allow access of corrodents into the hull skin. The interior of the hulls plastered over a mould or frames will also have exposed mesh where complete mortar penetration is difficult or impossible. Uncovered mesh, whether in fishing craft o~ in pleasure craft, will be subjected to various corrodents.

To date it has not been proved that galvanized mesh will in fact extend the life of a hull but it is believed that the use of galvanized material is good practice, both on general electro­chemical grounds, and because it is recognized to be beneficial in reinforced concrete exposed to seawater. Galvanized coatings appear to provide an adequate bond betvleen reinforcement and mortar and to delay the onset of unsightly and perhaps dangerous corrosion.

PATCHING FERRO-CEMENT.

In this phase of the investigation all experiments used clean, dry ferro-cement specimens, patches were done under ideal conditions, and all patches were cured under moist conditions.

While these conditions were idealized and would only be found with a very ne,., boat, it was felt that the experiments would yield a practical upper limit to the strengths attainable by the patching techniques employed. Also, the results would give a

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basis for comparison when experiments are carried out with specimens which have been soaked in seawater or otherwise contaminated.

of three types: The specimens used in these patching experiments were

(a) Bend test specimens, nominally 1" x 2 1/2" xlI". (b) Impact specimens, 15" x 15". (c) Impact specimens, 30" x 30".

All specimens \V'ere reinforced with either hexagonal mesh or rectangular steel mesh.

Only one 15" x 15" impact panel. was repaired, Panel 4-B (1/2-in. 16 gao welded square mesh), as ~t was 'found that the damage in the hexagonal mesh panels of this size extended to the edges and cleaning and patching was very difficult.

Three 30" x 30" panels with mesh were repaired, Panels 20, 21, and 22. had major cracks running to the edges.

1/2-in. 22 gao hexagonal Even this size of panel

The most effective device tried for cleaning out broken ferro-cement, opening out cracks, and roughening the surface was the . pneumatic needle gun. This device is similar to the air-powered chipping and scaling tools, but uses a bundle of small diameter steel rods. The tool used here has two interchangeable sets of rods; one containing 29 flat ended rods of 2 mm diameter, the other 13 chisel pointed rods of 3 mm diameter. The needle gun with the small rods in place is shmm in Figures 36 and 37.

The rods easily penetrated the opening in the mesh with a minimum of damage to the wires. Also, the rods will break up the mortar around a crack without seriously attacking sound mortar. The smallest rods were the most effective in this respect. The result is that the tool will selectively open out cracks and remove broken mortar. This is also illustrated in Figures 36 and 37. In Figure 36 the horizontal crack and the circular cracks have been opened out with the tool. Before patching, the cracks were opened up further until mesh was exposed to help anchor the patch. Figure 37 shows the back of the same panel. On the right side of the damaged area a crack has been cleaned out to below the first layer of mesh. Most of the loose fragments at the location of the major impact damage have been broken out. Note that the mesh is relatively undamaged at this stage.

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It was possible to clean all the broken material out of the specimens reinforced with the 1/2-in. 16 gao square mesh without causing excessive wire damage. Also, the wires were generally intact after failure of the panel.

On' the other hand, the specimens with 1/2-in. 22 gao hexagonal mesh sustained damage to the mesh and further distortion and damage resulted during preparation for patc~ing. It was necessary to compromise between leaving some debris in the mesh and causing further damage to the wires. For the specimens it was somewhat easier to clean out the damaged area of the impact panel than the breaks in the bend test specimens.

The preparation of ~he bend test specimens varied from attempts to completely remove all mortar fro~ the ?amaged area to only widening out the cracks.

Two types of patches were made. In the majority of specimens the patch was made using only a Portland cement mortar. Five bend test s'pecimens were repaired using epoxy-base patching materials.

The Portland cement mortar used a mix of one part cement, two parts sand and 0.4 pa~ts water by weight. The first patches were made using ' Evco Dry mortar sand. It was discovered that the larger particles prevented trowelling out the patch to a feather edge. Later patches were made using a 1:1 mixture of Del Monte 20 and 30 sand.

Whenever possible a vibrator was used to force the mortar through the mesh. The area around the patch was wetted down prior to patching, the mortar being applied while the surface was damp but not wet.

The specimens patched with Portland cement mortar were covered with damp paper towels and cured under plastic sheets.

Two types of epoxy patching materials were tried, materials 5 and 6, page 30 of the Final Report. One material was an epoxy marine patching compound. The resin came with all fillers mixed in and only required the addition of the hardener.

The other material was an epoxy floor patching compound. The resin and hardener were mixed -together, then sand was added to form a mortar. ' Some of the mixed resin, without 'sand, was applied to the old concrete before forcing in the mortar.

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All bend test specimens patched with epoxy base materials received the minimum of preparation. Three specimens were only chipped out along the cracks enough to allow the patching material to penetrate easily> Hhile t,.,o received no preparation at all. For these the epoxy \lIas forced into the open cracks before straightening. After the epoxy had set the other side of each specimen was patched with the marine patching compound without added filler or the epoxy floor patch containing Del Monte 30 sand> \lIhichever had been used on the first side.

After a suitable curing time of about 21 days for the mortar patches and 7 days for the epoxy patches the specimens were retested to compare the strength of the patched specimen and the type of failure with the results for an intact specimen. The patching experiments are summarized in Table l6-S.

1. Specimens patched \.Ji th Portland cement' mortar.

The bend test specimens reinforced with 1/2-in. 16 gao welded square mesh typically failed at 80% or better of their original strengths. The type of failure was generally the same for the patched specimen as for the original. Figure 38 shO\IIS specimen 9-E after patching and retesting. This should be compared 'llith specimen Lf-E sho\Yl.'l. in Figures 19 and 20. The failure is identical for both and is characterized by the fine transverse cracks on the tension face and failure of the mortar in compression on the compression side.

One specimen, 12-E, shown in Figure 39, failed in shear between a loading point and end support.

Specimen 9-E-2 was prepared for patching by only chipping out around the cracks. On the other hand, specimen 9-E from the same panel was prepared by removing all the mortar from the damaged area. The patched strength of 9-E was significantly higher.

The bend test specimens reinforced with 1/2-in. 22 gao hexagonal mesh only regained between 50 and 70 percent of their original strength. This lower strength is attributed to two causes. These specimens shm17ed more reinforcement damage during the original failure, it was almost impossible to remove the broken mortar without causing further damage and distortion to the reinforcement.

It should be noted that specimen 5-E-2 which had most of tIle loose mortar clesned out regained approximately 50 percent

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of its original strength, while 6-E-2 ,.,hich received the minimum of chipping out regained approximately 70 percent of its original strength. Specimen 6-E-2 is shmvn in Figure 40 after patching and retes~ing.

The only 1/2-in. 16 gao square mesh impact specimen patched is shown in Figure 41 after retesting ,.,hile the same panel after its original impact test is shown in Figure 12. The behaviour under impact was the same in both cases. It should be mentioned that the p~nel was subjected to a second impact after the first test to increase the amount of damage before patching.

All impact panels reinforced with 1/2-in. 22 ga •. hexagonal mesh were extensively damaged in the original impact, with cracking extending to the edges. After cleaning out the broken cement and patching, the panels tended to crack along the original breaks ,.,hen retested. The cra'cks in the patched panels were more open and more visible damage resulted than in the original test. Panel 21 is shown in Figures 36 and 37 during preparation for patching, and Figure 43 after patching and retesting. In all cases the deflections were greater than those in the original tests. The bond between the old material and the 'patch generally seemed to be good with little spalling around the edges of the patch. However, ,.,here the patch was feathered out the new mortar could be spalled off with a hammer, although this was not easily done.

2. Specimens patched with epoxy materials.

All the epoxy-patched specimens contained welded square mesh; one was reinforced with 1/2-in. 16 gao welded square mesh, two with J/8-in. 20 gao welded square mesh, and two with 1/2-in. 19 gao hardware cloth.

The specimen with the 1/2-in. 16 gao mesh (Figure 44) reached its full original strength before it failed in shear between a loading point and an end support in a similar fashion to l2-E (Figure 39). Except for specimen" ll-E, which along with ll~~ had received no preparation before patching, all the epoxy-patched specimens regained virtu'ally all their original strength with failure occurring outside the epoxy material. The lower strength of ll-E appeared to be due to a lack of penetration intb a crack.

The failures in all the lighter reinforcement (19 and 20 ga.) resulted in the breakage of most of the reinforcement wires.

l I

.69-4125 - 14 -

In summary, the specimens reinforced with 1/2-in. 16 gao welded square mesh were much easier to clean out and patch than those with 1/2-in. 22 gao hexagonal mesh, and regained a greater percentage of their ,original strength when ~o repair to the reinforcement was attempted for either type. With the heavier gauge wire the mortar failed before the wire was damaged and the wire withstood the abuse of mechanically removing the damaged mortar.

The smaller wires of the hexagonal mesh are easily damaged and if extensive chipping out .is required the results would indicate the repair of the reinforcement is required if most of the original strength is to be regained.

None of the specimens tested contained heavier rods. If rods were included it is possible that the los~ in strength from the damage to the light gauge mesh would be "masked somewhat by the rods.

Under the conditions of the experiment the Portland cement mortar performed well as a patching material. It is indicated that a patch with this material should not be feather edged. Perhaps if feather edging cannot be avoided, an epoxy filler could be used on the feather edge to avoid spalling.

Although the literature indicates that the bond between old mortar' and new mortar is weaker than either material, this weakness did not appear to contribute greatly to the failure of the specimens. Where the failure after patching occurred along the line of the original this could be attributed to damage to the reinforce­ment both from the first fa~lure and from mechanically removing the broken and cracked mortar. The weakness at the bond may have less effect than the hairline cracks shown in Figures 34 and 35.

Both epoxy materials were able to make very stro~g repairs and neither \-1as obviously superior to the other. The marine patching compound was the most expensive but could be trowelled out to a feather edge due to the fact that the filler was finer than the 30-mesh Del Honte sand used \-1ith the epoxy floor patch material., It also gave a smoother surface and according to the label could be sanded. The floor patching compound containing sand could be difficult to grind or finish.

Although two bend test specimens were patched with no preparation, it is obvious that some preparation would be required in practice to remove dirt from the cracks. The high strength of one specimen and the relatively 10\-1 strength of the other ltl0ulcl indicate that chipping out is required for reliable patching.

69-4125 - 15 -

The idealized conditions under which all patches were made must be kept in mind. It is expected that repairs to older, more contaminated ferro-cement under less than ideal conditions would not be as successful. Also, further testing must be done to evaluate the long-term performance of these patching materials under severe weathering, cyclic loading, repeated impact loads, and chemical and biological attack.

There are many more materials and combinations of materials still to be tried as well as-methods of repairing reinforcing to be investigated.

Tests must also be done with panels containing larger rods and, in the case of the light~r hexagonal mesh, with reinforced edges to prevent the spreading of cracks.

OBSERVATIONS OF A HULL UNDER CONSTRUCTION.

The construction of a 45-ft ferro-cement vessel nearby presented a valuable opportunity to observe some of the problems associated with this type of construction.

The frames and supports were set up and the reinforcing was placed by the boat owner. The actual mixing and plastering were done by a crew of professionals ,.,ho have plastered many of the backyard-constructed boats in Vancouver. Subsequent finishing is to be done by the boat owner. The plastering was done with the hull inverted, allowing the deck. to be plastered over a mould at the same time as the hull.

Temporary wood frames, supports and stringers were set up first. This provided a frame'-1ork to hold the first layers of 1/2-in. 22 gao hexagonal reinforcing mesh and a form over which the vertic~l 1/4-in. diameter reinforcing rods could be bent. The stringers were removed after all reinforcement was in place and tested together. Wooden forms were set up at the location of the built-in ferro-cement frames. These frames were plastered the same time as the hull and deck. The transom and bow sections were 'plastered over wooden moulds.

The hull was examined after it had been cured and turned over, and the wooden frames and fQrms stripped out.

There were numerous areas where the reinforcing mesh was exposed on the surface. Typical areas are shown in Figures 34 and 35. The branching white lines seen in Figure 35 follow very fine

69-4125 - 16 -

cracks in the cement. These hairline cracks seemed to be along the lines of the vertical reinforcing rods.

In the interior of the hull it was evident that there was poor penetration against the forms for the integral frames where the temporary supports touched the hull and in areas not easily accessible. Figure 46 shows a typical frame as seen from the form side. The exposed reinforcing rods and mesh are clearly visible. The lines running around the hull are where the temporary supports were located. One of these is shown in Figure 47.

The bottom of another frame and the top of the keel are shown in Figure 48. Again a lack of penetration is evident. Also, note the exposed mesh in the hull just over the top of the keel as shown in the close-up photograph of" Figur~ 49. Up to 5 layers of exposed mesh are visible. This photograph gives an indication of the excess cement over the mesh in some areas of the hull. The owner felt that there was generally an excessive thickness of mortar over the reinforcing on the inside of the hull and that there were probably several areas of poor penetration \l7hich had been plastered over leaving voids.

Lack of penetration appeared to be a problem mostly on vertical surfaces where one side was inaccessible. The deck, which was plastered over a form,showed adequate penetration. Possibly the plasterers could use a mix with greater slump on horizontal surfaces thus ensuring more complete penetration.

The owner penetration with mortar. The patches were covered curing.

h~s been filling in the areas of poor No special bonding agents were employed.

with plastic taped down at the edges during

In this case the poor penetration in the frames themselves may not be very critical as their function seems to be mainly to provide attachment points for the wooden bulkheads. The hull is well rounded and the frames are few in number and light in comparison to the hull so their effect on stiffness would be small. Ho\l7ev~r, on a hull having relatively flat areas the framing would be much more important. Of

"greater importance is the effect of the poor penetration in the hull at the junction of the frames and the hull, and at the locations of the temporary supporting frames. Weaknesses at these points could produce a notch effect and be a logical place for cracks to start. The reinforcing from the frames runs into the hull and the resulting extra steel may adequately strengthen this spot. There is no extra reinforcement at the locations of the temporary frames. Moreover,

69-4125 - 17 -

it can be seen that the temporary frame has been used as a convenient spot to locate a joint in one layer of mesh. These areas will be closely observed to spot early any sign of trouble. Since not all temporary frames showed such a lack of penetration, it must be concluded that sufficient care during plastering and improved methods of quality control are necessary and could be effective.

The preceding comments also apply to the areas in the hull just above the keel as shown in Figure 49. The problem is mostly evident on one side indicating that greater care during plastering is required. In this area the mesh from both sides appears to be overlapped resulting in a greater number of layers of mesh and more difficulty in obtaining comp1~te penetration and therefore requiring more attention and inspection. .

Figure 50 shows one of the fo·rward engine mounts. The engine is connected by a resilient mount to a short piece of heavy steel angle. This angle is bolted to a ferro-cement longitudinal plate with a steel washer plate under the nuts. There is a similar ferro-cement plate on the other side of the engine. The spaces between the plates, and the plates and the hull are filled with concrete. This concrete anchors the plates to the keel and the hull.

One of the propeller shaft bearings is shown in Figure 51. This is a self-aligning pillow block bolted to a steel angle which is in turn bolted to a ferro-cement web approximately 1/2-inch thick. The shaft passes through a hole in the web.

In both the above cases it is essential to prevent any motion of the bolts or plates. Any slack which a11mved the bolts to move in their holes due to engine or shaft vibration could result in the gradual wearing and enlargement of the holes. Also, the area of ferro-cement under the angles and washer plates must be strong enough to carry loads. Some unanswered questions include:

1. Can shear loads be considered as carried by friction between the plates and the ferro-cement if the bolts are sufficiently tight, or must they be considered carried by the bearing area of the bolt itself?

2. Is the answer the same for ·static and dyn.;l.mic loads?

3. Is epoxy bonding between the plates and the ferro-cement an advantage?

4. What size of washer plate is required for a given bolt size?

CONCLUSIONS AND RECONHENDATIONS.

Mesh Reinforcement.

69-4125 - 18 -

The tests undertaken to date indicate that welded square mesh (including hardware cloth) has much to recommend it as a reinforce­ment material for ferro-cement boat construction. On an equal-weight basis the square mesh reinforcements provide higher strengths in flexure and greater resistance to impact forces than does 1/2-inch hexagonal mesh. Welded square mesh allows greater ease in cleaning out the broken mortar from areas damaged under the conditions of impact and bending of this study. The wires, especially the heavier 16 gao wires, are less liable to breakage, both under load and during removal of broken mortar. Also there appears to be no great difference in the cost of the meshes incorporated into the mortar on an "equal­weight" basis. On an "equal-strength" basis', the 'l/2-inch "7elded square mesh would be cheaper than 1/2-inch hexagonal wire. The effect of using rods (approximately 1/4-inch diameter) int'o the structure has not yet been tested. It seems likely that the rods will carry most of the loads applied to the panels or hull so that the main function of the mesh will then be to hold the mortar together. The necessary load-carrying capacity of the mesh should therefore be small and 1/2-inch hexagonal mesh should be adequate. On the other hand, the use of 16 gao square mesh should allow greater rod spacings or make rods unnecessary. In the event that cracks or damage allmoJ' corrodents to come in contact with the reinforcing mesh, the thicker wire of the 16 gao welded square mesh will not fail so quickly. The number of layers of mesh and the degree of isolation or separation of the layers will likely also affect the seriousness of corrosion attack. Hexagonal mesh is easy to shape and form but is more difficult to hold flat and rigidly in place especially when mortar is being vibrated into the structure.

Galvanized vs Ungalvanized Mesh.

Galvanized coating is recognized as an effective way of protecting steel from corrosion. The present tests showed that mesh with no galvanized coating or only a very thin galvanized coating rusted quickly in semoJ'ater producing an unsightly 'stain. Long-term tests are required to show whether galvanizing will extend the life of a hull appreciably but it would appear to be good practice to use galvanized steel. Any difference in bond between mortar and galvanized or ungalvanized material appears unimportant.

Cement and Sand.

69-4125 - 19 -

The tests to date have not shmm any real differences in the strength of mortar made with the various types of cement or in the resistance of the various 'types of cement to seawater and sodium sulphate solution. However, the use of Type II cement, with its resistance to moderate sulphate action, or Type V which has somewhat more resistance, is advised for seawater environments in accordance with the recommendations of such authorities as the Portland Cement Association.

The masonry mortar sand used in this study produced a mortar of good strength. It does not appear necessary to use a very sharp, highly angular sand to·get adequate strength. A masonry mortar sand conforming to ASTM Designation C144-66T and obtainable from reputable producers across the country 'should be acceptable. The main criteria are that the sand should be washed, clean, well graded with nearly all passing a No. 8 sieve and l~ss than 10 percent passing a No. 200 sieve. Purchase of dry bagged sand is recommended to facilitate control of the water content. If this is not obtainable the water content of the sand must be allowed for •

. Patching.

Provided the reinforcement mesh is not badly damaged both cement/sand mortar and epoxy-base materials can substantially restore the strength of a damaged area under ideal conditions. No patching tests on damaged areas contaminated by a marine environment have yet been undertaken. Cleaning of broken mortar from the mesh and enlarging cracks can be' effectively accomplished with a pneumatic needle-gun equipped with a bundle of needle-rods (2 and 3 mm diameter).

Shell Quality.

Based on the tests which we have carried out, the many references which we have consulted, and on the discussions we have had with others, our recommendations for the steps to be taken to ensure shell quality are as follows:

1. The mesh and reinforcing structure should be inspected before plastering to ascertain that:

the mesh is securely fastened (about every 4 inches) so that it will not move-during plastering or cause excessive thickness, and that all heavier reinforcing is welded or securely tied at all intersections to give a rigid structure that will not deflect and lose its fairness under the heavy load of mortar which is to be applied.

, (This weight is seven tons on a local 45-foot boat.)

69-lll25 - 20 -

the mesh is free of any oily or greasy contamination.

adequate provision has been made to allow the plasterers to get at all parts of the hull without straining the plastered structure or working in unnecessarily awkward positions. This is particularly important in such areas as the keel and bow \-lhich can be difficult areas to reach.

the \-lho1e structure is on a foundation that will not settle when the weight of the mortar is added.

2. The mortaring should be dane by an experienced crew of an adequate number of men with whom the mix ,to be used has been discussed and agreed upon. It is recommended that a panel l-lith a mesh construction identical with that of the hull be p1as~ered before the hull plastering is started so that adequate 'workability of the mortar is verified. The ingredients should be proportioned by weight and the sand should be dry or else have had its moisture content measured and allowed for. During plastering the closest possible inspection for voids and poor penetration should be continuously carried out so that these faults can be made good before the mortar sets. An ultrasonic void detector would be very useful but as far as we know a suitable one has not yet been developed. The inspection of the work in progress should be done by at least one person whose sole function is to check the work as it is done. Another inspector should be employed to continuously monitor the weighing and mixing 'of the mortar, oversee the preparation of test samples; and perform tests (such as slump test) on the mortar before it is applied.

3. The following samples should be made for later tests:

a representative sample of the sand used of at least 25 lb from each batch of sand. Where bagged sand is used a handful should be taken from each bag. This should be visually inspected to ensure that all bags are the same type of sand.

one unopened bag of the Portland cement used.

three test panels 30w x 30" with construction to be identical to the hull. These panels should be made at the beginning, middle, and end of plastering and should be left in the hull for curing.

69- 4125 - 21 -

three mortar cubes 2 x 2 x 2 inches should be made at the time 01; each of the above test panels.

at least 4" "coupons 3" x 12" or larger made as part of the hull and cut off ~fter curing is complete. These can be projections at edges or can be made in openings such as hatches and deadlights. These should be ma~e at widely spaced areas of the hull.

A slump test (or equivalent) should be done on each batch of mortar to aid in detectini mixing errors and to ensure uniformity.

4. The follmving tests should be made on the ferro-cement samples after the hull has cured:

30" x 30" Panels.

Impact tests on 24" x 24" sample from first and last panels.

Bend test to determine modulus of rupture and observe mode of failure on 3" x 12" (or 6" x 24" depending on panel thickne"ss) samples cut from the above panels in two directions at right angles;

The third panel would only be tested in case of dubious or conflicting results from the other two.

Hull Coupons.

Bend tests on approximately 3" x 12" samples for comparison with panel samples.

Mortar Cubes.

Compression tests on all nine cubes.

Sand and Cement Samples.

These would be used to" make test batches of mortar in the event that the other tests showed possible problems in this area.

W.N. English Head, Division of Applied Physics

J.D. Smith, Consultant to Division of Applied Physics

/~ -: " ; ~; """.""-" . < ~ ~"-A.W. Creenius Division of Engineering

REFERENCES.

69-4125 - 22 -

18. Muhlert, H.F., Analysis of Ferro-cment in Bending, The University of Michigan, Paper No. 043, January 1970.

19. Jackson, G.W. and W. Morley Sutherland, Concrete Boatbui1ding, George Allen and Unwin Ltd., London, 1969.

20. Lin, T.Y. and Associates, Consulting Engineers, Ferro Cement Panels, Vol. 1, Naval Civil Engineering Laboratory, U.S. Department of the Navy, Port. Hueneme, California, November 1968.

69-4125

APPENDIX III

(Tables of Test Results)

TABLE 3-S.-;1 · Summary of Test Panel Construction Data.

?a:l.el I Rein:force~e:l.t No. I Hateria1 Cement

1 . 2.5 Ib e>..-panded metal I TyPe II lath, galvanized 8 layers

2 2.5 1b expanded metal I Type I~ lath, galvanized

3'

4

5

6 ,

7

a

8 layers

2.5 1b expanded metal I Type II

I

lath, galvanized 5 layers

I 1/2-in. 16 gao welded I square mesh, galvanized, 5 1a~ers I l/2-in. 22 gao hexagonal mash­ga1vanized ' after weaving '12 layers

.1

Type II

Type II

l1/2-in. 42 gao hexagonal ~esh~' galvanized be~ore

"' . Type II

weaving 12 layers

1/4-in. 20 gao fire:-. r Type II s~reening, washed in naphtha 2.1ayers

Il/2-in. 19 ga. ' . Type II hard.~~are cloth,

I galvanized 9 layers

I

I I

I

Sand

Cement­Sand Weight ratio

Evco Dry 11;2 Concrete Sand

. Evco ,Dry 11;2 Mortar Sand

I Evco Dry 11;2 l10rtar

, Sand

Evco Dry I 1;2 Mortar Sand

Evco Dry I 1;2 Mortar Sa:l.d

1

Eveo Dry I l:2 Mortar Sand

I Evco DrY I 1:2 Mortar Sand '

Evco Dryj 1:2 Hortar Sand

·1

Water­Cement rleignt ratio

0.37

0.38

-.

0'. '40

'0.40

0.40

0.40

0.40

0.40 , '

ICe '" -13::: ' ·1

Slump .IS.:':.? .-l.·n' 17- .... ", . T --.- .. ~

I 1 1/2 ! Q:) ." .-

2

6 1/2

7 1/2 ' I

:,

I I

5 1/21 i , I I

5 1/21 I

. ! 4 1/2 '

I ! I , I ,I

'~

69':'4125 - 23 -

"

~ , .~. . IMOdUIUS of " Rupture, psj. =:':~I (unreinfor~c) 1 Re~arks

no' tests' ~ IHesh not f\11'l-y

"

1106 ·906

lQ60 978

11125

' , 1100

I

742 890

865 810.

11010 1120

. i

F' etra.ze<i. ...Panel " carc.ecl..

'1 " Mortar ap~eared to . tork in ven

I " "

1 I ' " II

I I,

I II ..

II II

" II

CABLE 3-S (cont'd)

'a~el ~ei~:o~ca=~~t

:0. ::2. ::G~:'al

9 .

LO

Ll

L2

13

! weldedl l/2-in. 16 ga.

square mesh, g~lvail:'zi:1g re~oved

5 layers

I I

I 3/~:~n.~2~. gao welded,' squ~_e •.. e",n, not galva:1ized 7 laye:-s

1/2-i.:1. 19 gao care,Jare cloth, ga1v,anized 9 layers,

I I I

! i

! ! I

1/2-i:1. 16 gao welded! square r:;.ash, ! galvanized, 5 layers I

• I

2.5 10 expaildeci metall lath, galvanized I 5 layers

C~:::e:1t

Type II

Type, II

Type II

Type II

T¥pe II

L4 1/2-in. 2,2 ga; ~exago:lal cash, galva!"'.izec. after ,Jeav:':1.g 12 layers

.j Type II

~5 1/ £.-i"::,. 20 ~a.! fi-re­screening, oil coat r.o:: re:::oved 2 .1ayers

I

Type II

Sand.

I EVco Dryj ! Mortar I ! Sand . . I I

I I I I I ., I I

I

I I i

I i I

Evco Dry! Mortar I Sand . I

! i

Evco Dry 'I Mortar Sand

Evco Dry Mortar Sand

Evco Dry Hortar Sand

Evco Dry Mortar Sand

,

cer:;.ent-I Sand Height I ~atio I

Wat.e'!:"­Canent ~·]eig!"lt

ratio

1:2

1:2

1:2

1:2

1:2

1:'2

I. 0.40

0.40

1. 0•40

I I 0.40 I

I 0.40

I ·1

0.40

I I I

Evco Dryj 1:2 ~1ortar I

0·.40

Sand

I I '

I ICo:::p~ession I Strength, 2-~r..

IS1uwp • cubes, ~si in. 17-cay I 28-cay

I i 5 1/4 InO tests; I

6 1/2 16050 7100 (11 days)

7 1/21no test I 7420

7 1/415400 7950

5 1/4i~950 I .·1

6 1/216200

5 1/2.15600

9375

7200 7500

7600. 7250

8150 7675'

69.;..4125 - 24 -

I •

"

""0';·,1"5 0: I ..1 ......... _\06 _

I RU?i:ure, psi. 1

•• ~~.;.,....: .,.. 0 ...... ,. -,"c (Yn_~_~_o_ced), R~_~_~_

11300 I Cla:::-l:'ke b:::-ec:.th:'ng

l1230 l~ole~ a~ci ~l::~~=S I~ppe~rec, _o_~~_ 'RnneR¥~t -0 vo¥~ ~-1 c.~. Co._ II,,;. I.,. ..... ~ ........

isatisfactorily

'<90S 1 II II

705 !

1180 990

840 895

725 792

890

830 960

<

1 J

I~O-_R- --n--¥-c' -0 . .... _ ~c. .. c:;..",;r-c:~~ e · I,.

!wor~ i~ Well. C1£= llike holes a:-.c j~lis~ers £J?eared ~ . j ~io:::-tar a.??ea-=e~ to

lwo~k in wall

j i II

i j , 1 II I

j

1

! II

I I I !

II

II

II

TABLE 3-5 (cont'd)

?a::.el X~.

, r _0

17

18

19

20

21

3.~i:1.':o~ce=en:

:~a~e~ial

1/2-in. 22 gao nexago:J.a1 mesh, . galvanized before weaving 12 layers

1/2-in. 22 g'a. .' 1 . r.l.~xc.go:1.a ::lesC"..., galvan:'zed after weaving ~2 layers

1/2-in: 22 gao hexagonal mas~" . galvanized after >-leaving 12 layers

1/2-in. 22 gao hexagonal :::esn, galvanized after weav:'ng, 12 1ay~rs

l/2-in. 22 gao ne:-::ag o:'..al :::es:-., galva::.:'zed after vleavi::.g, Japan 9 ,layers

1/2-:'n. 22 gao nexa6ona1 !:lesh, galva:-.:'zed after 'iJeavi:J.g, Japa:J. 9 layers

Ce:':lent 'Sand

-_I Type II

I Type I 'I -: I I I 1 Type III I ! I i I

Evco Dry Mortar Sand

EVCO'Dry / Xortar Sand ·1

I I

Evco Dryi )for tar Sand

I I I·

I Type III Evco Dry

'j , ~~~~ar I I

I " I , I

! Type III I Evco Dry I

I I ~~~~ar I

I 'I' I ; . ! 'I Type V Evco Dry!

Mortar I I Sand i • 1

i I ! I

I

I , !

Ce:::ent­Sand Weight ratio

1:2

1:2

1:2

1:2

1:2

1:2

I-I",,:er­Ce::.ent Weight ratio

0.40

0.40 '

! 0.45

I j'

0.47

0.47

0.44

I Co:::nression

I· Strengtn, 2-in. Sl~~p cubes, usi in. I 7-day ! 28-day

61/2!15830 9450 9875

5

1

5040

4 1/216400

5 (5150

I 5 1/2 16930

1

7 1/215280

I

1

' /

5875 6175

8325

8450 7750

9900 11400

9175 10975

V • " - i,

I .. oa~.l.':ls 0: Rupt~re, psi I

I ( •· ........ e.;.,;: .,..~e.,) I 1..-..... .... .... _0 ... '- "- I

,

69-4125 - 25 -

Re:::arks

760 820

Ivo ... t-.,.. -~-e-"'ed -0 , .... ~ G. ... Gr~ G.... ...

1050 960

11320 I "1280 . !

590 560

;work in well ! ! , I I II "

i 1 1 I jDif:ic~lt to work

I;n -0"'--"-.-.. ;,~, .. ~c;.._ J

i inco::1p1e te lpar.etration no~eG 'JIater 1 1 1 lV.o"'~-- -~~e-"'ec -0 , ............. Q ... 0.... G.. ~

i~ork in well ·1 1 ! ! , ,

INot determined ~ Incomplete (whole panel 11 penet'ra~ion

iused for-a mortar

I drop-impac t " test)

of the

I

(as above) (as above)

TABLE 3-5 (cont'd)

! I

-.)~-al I "'a"'-'·:o--:o.-en-... co. .... _ I :.... _ ... _ .... ,,-c.;;... ..I.-

Xo. I

I ::a:arial Ce!:'.ent

22 _ I/2-in. 22 gao Type III hexagonal :::ash, galvanized after ,-leaving, West Germ. 12 layers

23 " " Type_ V

-, 24 ! " " Aluminous

I

! i i i I

25 I " " I Type II

I

I

I - I

26 I " " I. Type I I I I I

I ,-

I-I

-I I I

I

cerr.ant-I Wa~er- I

Sand Cer:ent I Co:::pression 1 !

69-4125 - 26- ~

I Strength, 2-in. y;ai~h1: I Wei~ht Slump Icu~ep ~~; \

MOdulus of I J> Rupture) psi !

I (unreinforced) I Ra:::arks Sand. ra1:1.O :-at1.0 in. !7-day.

I 0.45 I

Evco Dry! 1:2 5 I 8000 Mortar I i

I I

Sand

I" I I

Evco Dry I 1:2 I 0.41 5 1/4·1 7575 }10rtar I

Sand

Evco D=y1 1:2 I 4 1/21 0.36 9150

Hortar I Sand

I Del : 1:2 I 0.40 3 1/21 5700 Honte I 8: 20: 30::

I 1:2:1

Evco D~ j 1:2 j- 0.41 3 1/2j- 6850 Hortar Sand

\.

I Lb-ca I 7000 i

I 7800

10000 10700

7250 6280

1

'6390 5780

8110 9450

I - i not determined'l~n sCri?ping it was

1 (whole panel 'I~o~nd t~at :::ortar used for a droPlnaa not penetrated impact test) - lwell

I -I

932 843

1028 '792

635 78~

855 738

i I !xortar penetrated Iwe11 i

~ j

jXortar penetrated iwell

! i 1Sligh:ly difficult jto trowel s~oothly i- tears j I I

I " " I

j I

I I

I I I ! I

! I I

TA3LE 4-S. Co~parison of results of drop-icpact tests on IS-in. square specimens contain~ng various kinds of reinforcements. (All specimens from panels made with Type II cerr.ent and Evco Dry Mortar Sand. Drop 50 Ib from 10 ft.)

69-4125 - 27 -

)= -:: -: I '~;~-I

3

1 ~ -oJ

4

9

12

5

14

7

'..5

3.21 .. : o:-ce::.en-:

:(:"~i

2.5 Ib expanded metal lati, galvanized, 5 layers

. .l..s in 3 above

1/2-in. 16 gao welded sc,uare :::esh, galvanized, 5 layers

As in 4 above but galvanized coating scri?ped

.:..s in 4 above

1/2-in. 22 gao taxagonal mesh, galva~ized after ~eavir:g, 12 layers

As in 5 above

l/ ~ -i~. 20 gao fire­scrcc~i~;, blac~,

2 layers

.':"'s i~ 7 a.bova

? Ib/;;t-of oanel 1. 23

1.23

2.85

"

"

1.35

"

1. 20

11

Displace:::ent at centre of impact, 1/16

I To':)~- I 30::0::1

14 16

20 24

5 7

2 3

3 3

11 11

. 19 21

19 i9

24 26

in. Descrintion of YLoce 0: Fa~lure

Open major cracks in top surface. Kajor X-s~aped opening in bottom surface. Metal reinforcemant torn.

Open ring and transverse cracks in top surfa~e. Larbe diagonal cracks and broken mesh in bottom surface.

So cracks observed in to? surface. Fine sta:- shaped cracking in centre of bottom. Fine closed cracks radiating to edges.

No cracks o~served in top surface. Slight rectilinear cracking in bottom surface.

No cracks observed in top ?urface. Slight rectilinear cracking in bottom surface.

Open major ring crack in top surface. Snear spalling and open · radial cracks in bottom surface. :~o broken T,yire's observed.

Large open ring cracks. Snear spalling, radial crac~s, exposed mesh, and broken wires in bottom surface.

Extre~ely severe major ring crac~s in to? suriace. ~i6i

open radial cracks and mortar crumbling in botto~ surface.

Large open ring, spalling, and sr.atter in to? s~r:ace. Large diagonal cracks, s~acte;i~g i~ botto= s~r:a~e.

TABLE 4-S. (cont'd)

p~::.ell Rainrorcer:.a:lt

~o. I 6

I !

8

;ci~d

l/2-in. 22 gao hexagonal mesh, galvanized before vleaving, 12 layers

galvanized, 7 l 'ayers

~/2-in. 19 gao nard':.:are cloth, galvanized, 9 layers

li ' As in 8 above

I 11:l/.~t2 of nanel 1.29

I 1.59 I I

1. 79

II

_ _ Displacement at centre of i~nact. 1/16 in. Top Botto:n

13 .

13

I !

I 6 6 I

12 13

5 6

I :

69-4125 - 28 -

Descrintion of Mode of Failure ! Similar to No. 5 above, but more complete ring of shear ! spalling in bottom surface. I

; I --j \ , 1 Fine ring crack in top surface. Slightly open 1 rectilinear cracking and fine radia1 cracking -in bottom

surface.

Moderately open ring in top. Moderate rectilinear cracking in bottom.

No cracks (other than clamp-down corner cracks) observed in top surface. Slightly open rectilinear cracks in bottom surface.

:ASLE 6-S. :.\e.Si.:l:s 0: Flexi.:ra1 Bend' Tests on SoeciDens ~.;ith Various CeDents and Sar.ds. (A:l s?2ci~ens fro~ panels having 12 layers of 12 in. 22 gao hexagonal ~esh, g~lva~ized after weaving 1.35 Ib of cesh/sq it of panel)

69-4125 - 29 -

~ _ ...... ~ , I -~ .... \,;;;- : x.:;.

17

:;

::.s, 22

, . -~

2t,.

25

?,. _0

I Xodulus of Rupture, psi Ce~ent I Orientation of wire :'y?e S2~d , longi t. I transv.

:'y?e I

:y?e

':j"?e :~!

:":/?2 V

.. !.::'-..:.= .. :':"' .. o~s

:y?c. ~.!.

'::'J?e I

~vco Jry ::or-:ar Sar..d

E~oDry

Xortar Sand

Eveo Dry ::o-:-:a~ Sand

Evco Jry :':o=-~a:- Sane

:::vco Jry :·:c::~a.:: Sa.::c

Jel ~-:o:1:a 8:28:30:: ::2:1

Zvco Dry ::o:-:a::.- Sand

i .,

2910

2900 2420

1665

1360 1610

·panel ciisca=ded 2430 1585

~ot determined

2960 1735

3500 1810

2490 1660

2700 1830

Description of Xo~e of ":'- ~ -: ... ". ~ ...c::. ___ ,-_\.::;.

Bot~ sPeci~ens s~owec s~r.~le crac~ in to? si.:r:ace. Longitudinal showed hotto~ crae~ing over wi~e s?ar., transverse leSS so. WireS brc~en in bo-:~.

/

in 17. ' ~ Generally as

Spalling of to? surface. Eotto~ crae~ir.g over w~~e span. r..!ires broKe;:-••

Sli~ht co;npression spalling en to? surfaCe. Crac~in; over wide span. Wires bre~en.

Bot~oc cracking over 3 to 4 inches with a s~ng~2 ~aior crack. ~ires broken.

Slight co~?reSSion spalli~6 0: ~op SU~:~Ce. C~~C~~~; cainly over 2 to 3-inch spEn bu~ lonsi~u~~nal S?ec~=2~ failed Eai~ly un~er one support. ~i=es b=c~e~

Slight spalling of 3 to 4-inch span.

top surface. I-!ires bro~en.

Bot tOi.; c:,~c..cki:-.g OV2::"

TABLE 7-S. Comparison of results of drop-impact tests on IS-in. square specimens containing equal weights of reinforcement mesh. (All panels made with Type II cement, Del Monte sand (8:20:30::1:2:1)). Drop 50 lb from 5 ft.

69-4125 - 30 -

Reinforcement I

I lb/ft2 Displacement

Panel at centre of ~o. Kind of panel impact, 1116 in. ! Description of Mode of Failure

I 3 layers of l/2-in. 22 gao I

27 1.14 14 1 Top - moderate ring cracking. I hexagonal mesh above and 2 layers

1 Bottom - radial cracking over about l2-inch area, I below 1 layer of l/2-in. 16 gao exposed mesh, broken wires.

I welded square mesh. i J ~

28 I 10 layers of l/2-in. 22 gao 1.15 16 i Top - moderately severe ring cracking. '. ! hexagonal mesh.

'; Bottom - some shear spalling, radial cracking ove

I , l2-inch area, broken wires.

29 I 2 layers of l/2-in. 16 gao I 1.14 7 I

Top - fine part ring crack. [

! welded square mesh. .

I I Bottom - moderate rectilinear cracking over about j

I I 3-inch area. i ,

i Top - moderate ring cracking. 30 I 6 layers l/2-in. 20 gao 1.19 15 I ! hardware cloth. I Bottom - radial and rectilinear cracking over

I 1'8 to l2-inch area. --.

TA3L:: 8-S. Co~?arison of results of values of modulus of rupture on specimens from panels containi~g equal weights of reinforcement mesh. (All panels made with Type II cerr.2.nt, Del :lonte sand (8: 20: 30: : 1: 2: 1))

69-4125 - 31 -

I Reinforcenent Modulus of Rupture, psi

I , .. ~~ I lb/ft2 :> .......... ~ , Orientation of Wire _ c.. .... ~ ..

::0. I of nanel I Lon~it. Transv. ! Description of Xoie of Failure I ~l,.~ I

I I I ?"' I 3 layer3 of 1/2-in. 22 gao I 1.14 4130 3600 I Longit. - bottom cracks over 4-incn s?an. -I

I hexagonal =es~ above and I Transv. - bottom cracks over 4-incn s?an. I I I 2 layers jelow 1 layer of ! I

j l/l-in. 16 gao welded square i ! , :::esh. I I

j I I ;

?C •• v 18 l&yers of 1/2-in. 22 gao 1.15 2640 1650 Longit. - botto~ crac~s over 4-incn s~a~. :1axa:;onal :::esn. Transv. concentrated cracki~g in joc:c:::.

')0 -.-' 2 layers of 1/2-in. 16 gao 1.14 5350 4520 Lo::gi t. - single ~ajor crack in bo:t~:::.

~el~e~ square ~esh. Transv. - single ~ajor crack in Dot:C:::.

30 ! 6 layers of 1/2-in. 20 gao 1.19 3460 2990 Longit. botto::: cracks over 3-incn s?a::. narc.';lare clo th. Transv. botto~ cracks oVer 2-inc~ s?an.

69-1.125 - 32 -

TABLE 9-S. Comparison of values for modulus of rupture in the diaeonal, longitudinal, and transverse directions (Type II cement, Eveo Dry Mortar Sand).

Panel Modulus of Rupture, ]lsi No. Reinforcement Diagonal Longitudinal Transverse

4 1/2-in. 16 gao welded 4700 5900 6130 square mesh, 5 layers.

5 1/2-in. 22 gao hexagonal 1950 2900 1360 mesh, 12 layers.

8 1/2-in. 19 gao hardware 3140 3520 3530 cloth, 9 layers.

10 3/8-in. 20 gao welded 3720 5000 4460 square mesh, 7 layers.

l , I

/ r

I

I

T . .:.B:E 10-S. Cooparison of "Slow-Impact" load tests on 15-in. square specimens of differing ~esh constructions. (Type II cement. Evco Dry Mortar Sand)

69-4125 - 33 -

f I Rei!:l.force:nent:

? a::al ~:o. ~~:ta

!;

5

... .::.

10

liZ-in. 16 gao welded square . -, :::e5.:1.. :l ... ayers.

::'/2-:'n.. 22 gao hexagonal mesh, 12 layers.

1/2-b . 19 gao hardware cloth, 9 layers.

3/3-b. 2C ;;a. welded square :::<:5h, 7 layers.

lb/ft2

of panel

2.85

1.35

1. 79

1.59

:!ax load held. lb

8600

4000

6560

6870

Description of ;:{oce of Failure

Ring shear spalling 12-in. dia. on botto~, lig~t rectilinear cracking in ce~tre of botto::: surface. :op surface showed a centre crus~ u~der tup.

Part ring shear l2-in. dia. on botto~, ~oderate crac~i~g in hexagonal pattern in centre of bot~o:::. O?en ri~g cracking in top surface.

Ring shear spalling 12 in. dia. on botto:::, ~od€ra~e rectilinear cracking in centre of bott03 sur£&ce, To? surface showed .a ce~tre crusn ~.der tU?

Ring shear spalli~g 12 i~. dia. on botto:::, ~oderate rectinli~ear cracking in Ce~tre of botto::: surface. :O? surface showed a centre crush uneer tU?

'ABLE ll-S.

'anell Type of No. I Cement , 17 I I

I 26

I 11

!

5 i i II I i

14 i " I

19 III

, 23 I V

I I t

Comparison of results of drop-impact tests on l5-inch square specimens made from various cements and sands. (All reinforcement is 12 layers of 1/2-in. 22 gao hexagonal mesh.)

69-4125

- 34 -

Displacement of Centre ~

Type of of ImEact, 1/16 in. l

Sand Top Bottom , Description of Mode of Failure ~

Evco Dry 16 19 ~

Large open ring crack in top. Shear spalling, radial cracking, Mortar I exposed mesh, and broken wires in bottom surface. , Sand !

I " 24 26 I Severe shattering of top surface. Severe diagonal cracking I I , and many broken wires in bottom surface.

I i I " I I

I 11

I 11 I Open major ring crack in top surface. Shear spalling a~d open

i I i radial cracks in bottom 'surface. No broken wires observed. I

I I t

I 11 19 21 i Large open ring cracks in top surface. Shear spa1ling, radial

I i cracks, exposed mesh, and broken wires in pottom surface. I !

I 11 22 23 I Open ring crack in top surface. Shear spalling and open radial 1 I I cracks in bottom surface. Broken 'vires. I I I

1 I 11 11 9 Open ring crack in top surface. Shear spalling and open radial

I cracking in bottom surface. Broken wires. I

i I I - -------- _._----_. -- -_._-- ----- --- -----

24 Aluminous 11 18 26 Moderate shattering of top surface. Moderately severe diagonal cracking and many broken wires in bottom surface.

I

5 II ' I

I I I , I

25 II

Evco Dry }iortar Sand

Del Monte i 8:30:30 mesh I 1:2:1 ratio !

11

13

11 Open major ring crack in top surface. Shear spalling and open radial cracks in bottom surface. No broken wires observed.

15 . I Open major ring and radial crack in top surface. Shear spallin~

radial cracking to specimen edge, and broken wires in bottom , surface.

,

I I

TABLE 12-5. Comparison of the modulus of rupture values obtained from unreinforced bend test specimens made with various cements and with various sands.

Type of Type of I No. of Tests Panels Cement Sand Panels I Specimens

17, 26 I Evco Dry 2 4 Mortar Sand

3, 4, 5, 6, 7, 8, 9, 10, II " 14 27 11, 12, 13, 14, 15, 16

18, 19 III " 2 4

23 V . " 1 2

24 Aluminous " 1 2 I

I 3, 4, 5, 6, 7, 8, 9, 10, II Evco Dry 14 I 27 11, 12, 13, 14, 15, 16 Mortar Sand I

I

I 25 II Del Monte 1 I 2

Sand - . !

69-4125 - 35 -

Modulus of Rupture, psi I Range Average I 738-1060 901

705-1300 946

.-

560-1320 940

843-932 890

792-1028 910

!

705-1300 946

635-782 708 --- - - .- - .- ------

TABLE l3-S.

Type of I Cement

I

II

III

V ,

Comparison of modulus of rupture values of bend test specimens from reinforced panels made with various cements and sanels. (12 layers of 1/2-in. 22 gao hexagonal mesh. Evco Dry Mortar Sand.)

69-4125 - 36 -

Panel Modulus of Rupture, psi r Type of Sand No. Longitudinal TransverS"el

Evco Dry 17 2910 1665 Mortar Sand 26 2700 1830

" 5 2900 1360 14 2420 1610

" 19 2430 1585

" 23 2960 1735

Aluminous I " 2/. 3500 1810

II Eveo Dry 5 2900 1360 Mortar Sand 14 2420 1610

II Del Monte Sand

I

25 2700 1830 8:20:30:1:2:1

7A3~: 14-S. ~esults of exposure tests in seayater.

?~::c._

CC;"':?O:: Xo.

, - , -6 :.,-=--,

5-?-1,-6

6-=- 1 ,-5

... -.. ".

.j-.--..l,-0

9-?-1,-v

17-:-1,-6

19-=-l,-6

23-::-1,-6

2L.-:-1,-6

2~-F-:!.,-6

26-;-1,-6

Jescription

1/2-in. gao welded cesh, galvanized, Ty?e. II ce:::.a:1.:.

:'/2-:"-: .. 22 gao hex. :::esh, galvanize~-a::c~ wa~vi~g, Ty?a II ce~e~t.

!/2-~~. 22 ga. heX. ~esh, galvanized ~c=o~e. ~eaving, ~ype II ce.:::ent.

:/2-:"n. 19 gao ~a~dware. cloth, ga:va~~za~, Typa II Ce~e~~.

~s :"n 4, ~~: ga:vanized coat stri?ped, ':y?e I:.

As ~~ 5, ~~: Ty?a I ca=er.t.

As :":1. 5, bu~ Type ITT .. ce::e:lt .

' -r.::. in .5, but Type V ce:::ent.

As ~n j, but Aluwinous. cecant.

As in .5, but Del ~onte Sand.

As :...:. 17.

Observatior:s

69-4125 - 37 -

After 2 Cycles____ IA£~e::: 10 fycle_s__ I Af:e~ 15 Cyc:.ss

Ho change No Significant change XO significant ch~:-.. ~a •

Slight outlining of I fine botto~ crac~s.

"

Slight greying exposed mesh in

of !s~all rust spots bottoml

,. .;.~o change

Perce?tible rusting of wire. in bottom

Slig~t outli~ing of fine bottom cracks

No c~ange

I I INo significant change

I IConsiderable rusting jof wire in bottom ! iKO significant change

I I I

It

Slight greying of ! exposed mesr. in botto~ i

II

Sli;nt outlining of fine bottom cracks

Slight greying of exposed mesh in bottom

11

I I I II

I , !

i II

II

"

:-lore rust S?ots

Xo significant cJ-.a:"'.I.;2.

Consider~ble =~S~~~6

of \vi.re in bo t to::-.

Xo signi:iccut C~~~6e

"

It

"

"

II

TABLE 15-S. Results of exposure tests in 5-percent sodium sulphate. 69-4125 - 38 -

Pa:lel Coupon

4-F-3

5-F-3

6-F-3

8-F-3

9-F-3

17-F-3

'19-F-3

23-F-3

24-F-3

2.5-F-3

26-F-3

~o.l Description

1/2-in. gao welded mesh, galvanized, Type II ce:uent.

1/2-in. 22 gao hex. mesh, galvanized after weaving, Type II cement.

1/2-in. 22 gao hex. mesh, galvanized befora 't-leaving, Type II cement.

1/2-i:l. 19 gao hardware cloth, galvanized, Type II cement.

.4.s in 4, but galvaniz'ed coat stripped, Type II.

As in 5, but Type I cement.

As in 5, but Type III cement.

As in 5, but Type V cement.

As .in 5, but Aluminous cement.

As in 5, but Del Monte Sand.

As in 17.

Observatior.s After 2 Cy<::l_es__ ~l\.fter 10 S;ycle:_s_ After 15 Cycles Mesh cracks in bottom IMesh pattern outlined on bottom surface, outlined in white little effluorescence.

I with top

As in 4

t [

II

I effluorescence f

[ t t I I

Similar to 4

I 4 Sim-ilar t ,o , I

As in 5 lMesh pattern !surface.

I clearly

i outlined on bottom

Little change

As in 5

As in 5

Slight effluorescence on top and bottom

Heavy effluorescence on top ~nd bottom

As in 5

As in 5

i I

I

I l i

I

Similar to 8 I ! I

Similar to 4

I Similar ~o 4

I Similar

I to 4

Similar I to 4

Similar I to 4

Similar to 8

':ADL~ 16-S. Summary of rerro-cement patchi~g tests. 69-4125 - 39 -

)~cioen In. _ I Original ~o. , ~e~nrorce~ent Mortar

El..

~!1d

~s c:

md ,st

~~

,nd ,st

~E2..

/ 1/2-i6 gao I tveldeci sq ; ;;!esh,0alv 'd., 1 5 layers

I

"

"

,1]) ! :nd I " ,SI:

-2-1 ad st

i !

"

I i Type II I Evco dry

I ~'lortar

Sand

I

,I !

"

"

"

"

Preparation and Condition

I, Patch Material

" and !Cure (days)

Chipped out below first i As layer of mesh for surface; 21 patch. Mesh distorted i but unbroken I

original days

Some distortion of mesh. ~o broken wires. Chipped out.

Chipped out around cracks only

All loose mortar removed. Wires distorted. No breaks

i I

l As i 23 j , i I

! I i

original days

"

': As original f 21 days

Test on Patching Technioue jPatch

Test Res"Jlts ecicen ?atched Speci~en

Mortar tamped and trowe11e4. Kept moist during cure

Vibrating trowel. Kept moist during cure.

"I Mortar tamped and trowelled. Kept

lAS I A-E-l Mod. of

lorig ina1 i Rupture = 5900 psi

Ibend test! Top - compression

. spalling. I i ~ottom - crac:dng I ' •

I " ! over w~de ,span. ~o , I broken wires.

" IMod. of rupture 1= 6300 psi I Top - ) as

Bottom -) above

"

~od. of rupture -4695 psi. Top - compression spalling. Eottcc - patch separated from mes~.

~od. of rupture = 5985 psi. Top - compression spalling. Bottom - tension cracking, some spa11ing of patch. Fig. 33

Mod. of rupture = 4630 psi.

moist during' curing.

Hod. of rupture "\ = 5700 psi Top": ) as Top - compression

spalling.

" "

1 Bottom -) above Bottom - transverse ct'acking. I

Mod. of rupture Mod. of rupture -= 6850 psi 5630 psi Top - ) as Top - compression

"jBottom -) above spalling. I Bottom - break at edge I of patch - broken i wires - perhaps due

to cleaning. I

Loose mortar removed. A . 'na1 Vibrating trowel. " I Mod. of rupture , s or~gl. ' . d ' Wires distorted - one 23 days KeP7 mOl.st url.ng I - 5700 ~si longit. wire and one cUrl.ng. Top _ ) as transverse wire broken. I Bottom -) above

I

}!od. of ru,? tu:-e 5340 psi Failure outside of patched area. Fig. 39.

I

:~a~z 16-S. (co~t'd)

\ I

.. :)~.:.:'::.~::. : Original. . ::.:>. ! ~ei::'::lrce:::e::.t: Xorcar rE!.

i 1/'1-'1'1 "'a :ype I! .-J - -- ;:> •

.5c::,i : hex~gonal, I ~vco dry ::~!:it , ::lesn, galv d'i ,',ortar.

. 12 lay_ers Sand • '" ;z.

" i :'e::.d I

~~s:: I ,

" i

4 -6 ; 1/2-16 gao 5 x 15" i Ivelced sC;

.Jro?-i:::?act est

2.0

30 x 3i)" ::lro?-.::l?a.c~

,.;anel

:::esh 5 layers

1/2-22 C;a. hexagonal :::es~, 'galv'd, 9 layers

I I i 11

I I I i

I :ype · ~I!

Sand

Type I! Evco dry :!ort.ar Sand

Type III E:vco dry ~10rtar

Sand

Preparation and Condition

Most loose cortar removed - some lumps trapped. ~esh not repaired.

I I ~ortar chipped out around two main

I breaks.

I :·fesh ba~ly. dist~rted

ttempt to repair mesh.

!.fortar chipped out to 5-incn cia. Some radial crac~s left. Little d~age to wires.

Badly cracked and loose mortar chipped out but stopped before mesh badly damaged.

I I. I I I

. i I

.j I I I

Patch Material

69-4125 - 40 -

and Test on Test Res".llts Cure (days) Patching Technique Patch Original Soeci:::e::.

As original :10rtar tamped and I As I 5-E-1 Mod. of 21 days trowelled. Kept original i rupture = 2900 psi

1Ol0ist during I bend test: Bottom cracks over curing. I span. \hres·broken.!

As original II II ~ 6-E-l Mod. of . 21 days I rupture oz 2980 psi.

I As in 5-E-l above. .

I I

I !

Type II Vibrating trowel. - .. - ..

sand. i during cure. (equal. partsl 20,'30 mesh) I 23 days .

I I --~-------.--

As original I Mortar t&~ped and! As iTop - no cracks 21 days '1 trowelled. Kept 'original i Bottom - fine radial

. d . I d I k i mo~st ur~ng cure. I rop-. ! crac S.

I impact I Deflection - 5/16" I test I

Type II! Del! Monte sand 1 (equal parts!1 20,30 mesh) 16 days· I

Vibrating trowel. Kept moist during cure.

i 50 Ib- I 110 ft

I

I Broke across panel. Deflection - 21/32"

"

I

?atcheci Speci.;;-.e::.

~'fod . of rupture '" 1380 psi. Ero;-e at original location. ~.Tires badly da:::a .. ec.

'·:od. 0: rupture z

2025 ?si. Broke at edge of patch. 'Fig. 40.

p broken.

Top - no cracks Bo~tom - fine radial cracks. ;)eflection - 5/16" Fig. 41

Top - Major cracks. Some fine cracks oefore impact cid :1.01.: c.pen <.;? further. Bo teom - So!::!: ?atc:~

material broke out i but patch see~ec walL

___ L__ bonded to old !::.:>r:ar.

' • .-.BLE 16-S. (cont I d)

I, IJ

:!l I

12 "

1.

n

>peCi::len Xv. 11

o x 30" :op-"pact anel

~

() x 30" rop-npact anel

.;-:::-1 ' end est

Original Preparation and Rei::force:::ent ~lortar Condition

1/2-22 gao Type V I Loose mortar chipped hexagonal Evco dry out but stopped before mesh, ga1v ' d, Mortar I mesh badly damaged.

o 9 layers Sand I

1 I I •

I I ! I ! 1 1/2-22 gao I Type III I hexagonal , I Evco dry ! mesh, ga1v l d' i ~lortar i 12 layers I Sand 1 ~ 0

1/2-16 gao I "elded sq

4.lesh. 5 layers

1

Type II Evco dry 110rtar Sand

: Original mortar had I poor penetration. Host ; loose mortar in 6 in. \ dia. removed. Cracks I chipped out 1/8-3/16"

~linin:um chipping with needle gun to open up cracks and remove loose mortar

i ~ O_D 3/8-20 gao end ,,,elded sq

.. est nesn

.:end 'test

, ~ E

7 layers

Patch Material and Cure (days) Patchin!/; Technique As original Vibrating trowel. 23 days Kept moist

during cure.

Type III De~ " Monte Sand (equal partsl 20.30 mesh) I

16 days I I

patching cracks by

Test on Patch As original drop-

I impact test 50 1b-10 ft

I "

I I I

69-4125 - 41 -

Test Results Original Speci::len Patched Speci~en Broke across pa~e1. Top - ring cracks mesh exposed in with major radial bottom. crack. Deflection - 9/16" Bottom - centre pushed

l Fig. 42 out, fine radial cracks. Fig. 43. I

I

i Deflection - 11/16"'1 Top - ring cracks. i ! Botton - radial cracks I I fro::: centre (sone ! large) hut no patch I i mortar spal1ed out.

: Deflection - 7,/4"

I As Xod. of rupture -Harine epoxyl' Forced into

compound , trowelling I original I 5900 psi , bend test Top - compression I 0 spalling.

:~od. of rupture -5995 psi. Broke out­side of patch area. Fig. 44 7 days j ,

Epoxy floor patch material 7 days

Marine epoxy! patching compound 7 days

Bottom - cracking over wide span. No broken wires.

Mod. of rupture ~ 5000 psi. Cracking over wide span.

I Mod. of rupture -446~ psi. Cracking over wide span.

~Iod. of rupture -4520 psi. Broke at ne", site. I,ires broke.

Mod. of rupture -4430 psi. Broke in mortar - not in epoxy. :10st wires broken.

,sLE 16-5. (cont' d)

).;!ci:r:en ! Patch Xaterial

Original Preparation and and ~o. ! Reinforce:nent ,~fortar Condition Cure (days) Patching Technique

-D I 1/2-19 gao Type II I No preparation Epoxy floor Epoxy forced into .nd I hardware Evco dry patch bottom cracks .sc i cloth, :1ortar I material before straighten-

I

I galv'd, Sand ! 7 days ing. Specimen 9 layers i straightened, set.

I

I ! Top side then I filled with epoxy/ ! ! I sand mix.

-2 I " I " j " I Marine epoxy\ " nd I I I patching st I i compound ,

I I 7 days ! 0 0 I i ! I !

I " 0 I i I - -----~

Test on Patch

As original bend tes

I

I I

!'

I I I

69-4125 - 42 -

Test Results Original Specimen I Patched Speci~en

Mod. of rupture,= Xod. of rupture = 3560 psi. 3754 psi. Top - compression Break not in epoxy. spalling. Fig. 45 Bottom - cracks . over wide span.

Mod. of rupture = ~fod. of rupture = 3600 psi. 2030 psi. Top - compression ' Crack not in patching spalling. I material.

I Bottom - cracks over wide span.

-

I~ -_. E _ ...

D t-?·

'/ ---- --1 --~~-- --~ :_>

SPEC!t,,1ENS ~ A" &. -B"

SPECI MEN "C"

'~A~ .:'-. '

G

C

B

~

5 I l.l" ," co e /8 •

for cLrop- impQct tests ("11- diClqoI'l0'/ +a .... ,A·"'"

for flexural strength tests on unr-eJnforced portion of panel.

SPECIMENS ''0'' &. -E" for flexural strengthstests on reinforced portion of panel

SPEC I M ENS .oF" &. -G II for other tests (exposure, durQbiLi ty. corros ion.)

FIG. 7-5. L/-\YOUT ()F PANEL FOR TEST SPECIMENS

Fig. 24 Top and bottom surfaces of 1/2-inch thick specimen from Panel 27 containing 3 layers of 1/2-in. 22 gao hexagonal mesh above and 2 layers below 1 layer of 1/2-in. 16 gao welded square mesh. After drop-impact test.

Fig. 25 Top and bottom surfaces of 1/2-inch thick specimen from Panel 28 containing 10 layers of 1/2-in. 22 gao hexagonal mesh. Af ter

drop-impact test.

Fig. 26 Top and bottom surfaces of l/2-inch thick specimen from Panel 29 containing 2 layers of l/2-in. 16 gao welded square mesh. After drop-impact test.

Fig. 27 Top and bottom surfaces of l/2-inch thick specimens from Panel 30 containing 6 layers of l/2-in. 19 gao hardware cloth. After drop-impact test.

69-4125

Fig. 28 Natural particle size gradation of Evco Dry Mortar Sand. Mag. 4X.

Fig. 29 Del Monte 8 Sand. Mag. 4X.

69-4125

Fig. 30 Del Monte 20 Sand. Mag. 4X

"

Fig. 31 Del Monte 30 Sand. Mag. 4X

Fig. 32

Fig. 33

Bottom sur·face of coupons after 15 8-hr cycles immersion in seawater.

Bottom surface of coupons after 15 8-hr cycles immersion in 5-percent sodium sulphate solution.

69-4125

Fig. 34 Exposed rusted mesh in hull over rod stringers and water creeping from fine cracking at the stringers.

Fig. 35 Exposed mesh near keel with white and red rust.

69-4125

69-4125

Fig. 36 Opening crack and cleaning loose mortar from mesh with pneumatic chisel.

Fig. 37 Cleaning loose mortar from mesh with pneumatic chisel.

Fig. 38

Fig. 39

Top and bottom view of 9-E patched with mortar and retested.

. '.

Bottom and side view of 12-E patched with mortar and retested.

69-4125

. .. " .. ,

.~. ' .

Fig. 40 Top and bottom of 6-E-2 patched with mortar and retested.

69-4125

Fig. 41 Top and bottom of 15-inch impact specimen 4B patched with mortar and retested.

Fig. 42 Top and bottom surface of 30-inch Panel 21 after impact test.

69-4125

Fig. 43 Top and bottom of 30-inch Panel 21 patched with mortar and retested.

69-4125

Fig. 44

Fig. 45

Bottom and side view of 4-E patched with an epoxy­base marine patching compound and retested.

Top of 11-D patched with sand/epoxy mix and bottom patched with epoxy only and retested.

69-4125

Fig. 46 Typical frame-web in hull . ...--~-----

Fig. 47 Exposed mesh at location of temporary supporting frame.

69-4125

69-4125

Fig. 48 Exposed mesh in frames in bilge aft of engine.

Fig. 49 Close-up of exposed mesh in bilge.

69-4125

Fig. 50 Engine bed from forward end.

Fig. 51 Shaft bearing and bracket.

THE FOLLOWING SECTION ILLUSTRATES'

SOME OF THE DIFFERENT TYPES OF

STEEL REINFORCING THAT HAVE BEEN

INVESTIGATED FOR SUITABILITY IN

FERRO-CEMENT CONSTRUCTION

1/2" 22 GA. HEXAGONAL MESH· - GALVANIZED AFTER WEAVING

1/2" 22 GA. HEXAGONAL MESH - GALVANIZED BEFORE WEAVING

1/2" 20 GA. FIRESCREENING

1/2" 19 GA. HARDWARE CLOTH

J

I '0 ..

I

I ,

,

- -

1/2" 16 GA. WELDED SQUARE MESH (GALVANIZED)

T -.

3/8" 20 GA. WELDED SQUARE MESH (NOT GALVANIZED)

7 lIlllllllllll ! 1,1 111 11 , III,! IIIIJ I! ! 1IIIjlllllllJ [ 11I1I1I1I1I1I !J 111I111I11II ! IIJ 1[1'1111]111111

2.5 LB/SQ. YD. EXPANDED METAL LATH (GALVANIZED)

1 I .I l J. J J.

1]11111

4

7 8 l8F 1I!!i!!!fIi.ljl!!l!!illyt!' .. 11IIi' g"'!fi'I','liIg Ifpn;I!IIHI!l!i fll P"l"i

INDICATION OF COMPARATIVE SIZE OF VARIOUS MESH TESTED

The Regulatory Aspect~ of Ferro-Cement

Part I - Regulatory Aspects of Traditional and New Construction Materials -W.E. Bonn. Ministry of Transport. Ottawa.

Part II - Tentative Requirements for the Construction of Yachts and Small Craft in Ferro-Cement -Lloyds Register of Shipping.

,

Reprinted from: Proceedings of the Conference on Fishing Vessel Construction Materials, Montreal, Canada, October r - 3, 1968.

Regulatory Aspects of Traditional

and New Construction

Materials

by

Warren E. Bonn, Superintendent, Hulls and Equipment Division,

Marine Regulations Branch. Mr. Bonn Department of Transport, Ottawa

Mr. Bonn matriculated from Dartmouth High School in 1940. He joined Halifax Shipyards Limited and received diplomas in mechanical engineering in 1944 and Naval Architecture in 1946, from Nova Scotia Technical College and M.l. T. respectively.

He held various positions of responsibility with Halifax Shipwards, Limited, including Chief Draftsman. Estimator and Ship Manager.

He joined the Steamship Inspection Service of the Department of Transport in 1955 and served on the Headquarters Technical Staff for two years. He then moved to Toronto, surveying ships on the Great Lakes for a period of some 5 years. In 1961 he was promoted to Senior Inspector, Montreal, which post he held until 1964 when he moved to Halifax to the position of Divisional Supervisor in charge of the Atlantic Division.

In 1964 he moved to Headquarters in Ottawa to assume the duties of Supervisor, Hulls and Equipment and was later appointed Projects Officer. He was then promoted to a position heading the Hulls and Equipment Section entitled Superintendent, HuUs and Equipment.

Mr. Bonn is a member of the Society of Naval Architects and Marine Engineers. He is Chainnan of their HS-1-1 Panel on Great Lakes Waves and serves on a number of their other technical committees.

He is also a member of the American Boat and Yacht Council and several other professional groups associated with the Marine Industry.

ABSTRACT

This paper describes the broad outline of the Steamship Inspection Service's approach to plan approval, inspection and certification of fishing vessels, with the emphasis on safety of life at sea.

All the necessary steps to be observed by owners, naval architects, builders and operating personnel are clearly

pointed out to satisfy whatever aspects of the inspection process are involved.

Scantlings for structural parts and advice on good building practice are also highlighted in this presentation. In addition, the Steamship Inspection Service offers recommendations in respect of non-traditional construction materials, which are still essentially in a developmental stage.

74

INTRODUCTION

In today's world we see new materials being introduced in all aspects of life, especially in the construction and engineedng fields.

\. Most of us at this Conference are of the marine fraternity and I think we all feel that as far as the building of commercial ships and boats is concerned our approach is very traditional and conservative. Indeed our only accepted major "breakthroughs" in the past three decades have been the change over from riveting to welding in the construction of steel vessels and the introduction, mainly on large vessels, of aluminum deckhouses.

This often leads one to sit back and wonder "how can I assist in developing modem and new approaches to the ship and boat building industry?"

As expressed by a number of our associates we find new construction materials have already been tested on smaller type boats with great success. These materials will, I am sure, inevitably find their place in the construction of large and small fishing vessels and eventually on large vessels of all types. .

With the above in mind I feel that regulatory bodies must play their part and keep an open mind on new developments within our industry. As a member of the Department of Transport, I can say that the Government is most anxious to provide as much encouragement as possible to the progress and development of new materials and building techniques in the shipbUilding and marine engi­neering field. As the Government's regulatory body, the Board of Steamship Inspection will give full consideration to all proposals submitted to them.

The object of this paper is not to explain how to build vessels of new or traditional materials; this area of the Conference is admirably covered by a number of experts. It is merely an attempt to give a broad outline of the Steamship Inspection Service approach to the approval, inspection and certification of fishing vessels from the point of view of safety of life at sea.

REGULATORY ASPECTS

In the preparation of this section on "Regulatory Aspects" the paper is divided into six parts which are as follows:

1. GENERAL REQUIREMENTS APPLICABLE TO ALL FISHING VESSELS.

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

2. REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF WOOD.

3. REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF STEEL.

4. REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF ALUMINUM.

5. REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF GLASS RE-INFORCED PLASTIC.

6. REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF FERRO-CEMENT.

, PART 1- GENERAL REQUIREMENTS APPLICABLE TO ALL FISHING VESSELS

Notification of Proposed Construction

The owner or the builder of the vessel should advise the Steamship Inspection Service of the proposed con­struction, size of vessel, nature of service, type of material of which it is to be built and the extent of the voyages for which it is required.

Submission of Plans

Prior to commencement of construction the plans and information listed in Appendix I of this paper should be submitted to the nearest Steamship Inspection Service Office for approval and should the owner or builder require any particular infonnation relative to requireme.nts for the type of construction he is proposing the Board will be pleased to provide all possible advice and assistance within their jurisdiction.

Inspection During Construction

During construction a Steamship Inspector will carry out regular inspections to check that the vessel is being built in accordance with the approved plans and that the materials and workmanship are to the required standards. In addition to the hull construction he will witness aU necessary hose testing and tank testing and will examine and test the machinery installation, piping installations and steering arrangements. He will also check the life­saving, firefighting and navigating appliances and other statutory requirements.

Sea Trials

On completion of construction the Steamship In­spector shall be present during the sea trials to ensure

,

Warren E. Bonn

that the machinery and all essential services are function­ing properly and that the vessel is operating in a safe and satisfactory manner.

Certification

On completion of the "First Inspection" the Steamship Inspector will issue an appropriate Inspection Certificate for the voyages on which the vessel will be engaged. The period of validity of the certificate will normally be

(i) one year for vessels of more than 150 gross tons, (ii) one year for vessels that are steam driven, regard­

less of their tonnage, or (iii) four years for vessels that are not steam driven

and not more than 150 gross tons.

Periodical Inspection and Certification

Periodical inspections will be carried out by a Steam­ship Inspector when renewal of an Inspection Certificate is required and in accordance with the requirements of the Large and Small Fishing Vessel Inspection Regulations, the appropriate sections of which are added as Appendix II to this Paper.

It should always be remembered that it is the respon­sibility of the owner, operator or master to have his vessel inspected and certificated in accordance with the require­ments of the Canada Shipping Act. That is to say he should advise the local Steamship Inspection Office when the vessel is due and ready for inspection and in the case of new construction, the builder should advise when he wants any particular inspection or test etc. carried out.

PART 2 - REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF WOOD

Shipbuilder

The builders, past standards of construction and the physical conditions under which the vessels are built are considered by the Steamship Inspector and the Board when approval of a vessel is given. Acceptable ship­building practice must be followed in all aspects of construction and selection of materials to be used.

Strength

Although strength standards for wooden vessels are not laid down "hard and fast" each vessel shall have s'trength characteristics acceptable to the Board.

75

These are based on the type of construction with particular attention being given to good detail design and the use of local area building materials.

The following scantling tables have been compiled over the years and have proved satisfactory in service. They are provided as a guide to designers and builders and they are acceptable to the Board.

Periodic Inspection

Periodic inspection of the hull structure will be carried out at intervals specified in the Large and Small Fishing

. Vessel Inspection Regulations, the appropriate sections of which are added as Appendix II to this paper.

At the underwater inspection visual examination will normally give the Inspector a good idea of the areas where deficiencies can be expected. Distorted planking, pulled butts, cracking, wetness or weeping are likely indications of deteriora tion.

Where rotting is suspected internal ceiling may have to be removed, core drilling carried out to check the condition of the wood and fastenings, joints, fittings and caulking wilt" be all carefully examined.

PART 3 - REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF STEEL

Shipbuilder

Close attention is given to the building plant and conditions under which steel vessels, especially the larger type vessels, are constructed.

Construction should be carried out in accordance with acceptable shipbuilding practice and care must be taken with all facets of the operation such as preparation of material, burning, fitting, fairing, welding, riveting, etc.

Strength

The strength requirements for a steel vessel are that the modulus of the midship section and the stresses in the structural mcmbers shall be acceptable to the Board.

Calculations for the scantlings may be carried out from fIrst principles or the Board will normally accept scantlings derived from acceptable Classification Society Rules.

GUIDE TO SCANTLINGS FOR EAST COAST FISHING VESSELS

<M:R 10 OVER 15 OVER 20 pVER 25 !oVER 30 CM:R 35 TONNAGE 10 UP TO 15 UP TO 20 UP TO 25 UP TO 30 UP TO 35 UP TO 40

SOG MLD SOG MLO SOG MLO SOG MLO SOG AlLO SOG AlLO SOG AlLO

STEM Hi 7' 5' 7'h.' 5'. B' 5~ If 6' <5' 6'/1; 8)( 6'12' 8'1z'

KEEL 4r,' 7' 5' 7Y; 51>' 8' 5-¥." 8' 6' 8' 6~' BY; 6V; 81"

STERN POST 'tY' 7' 5' 7'1-, 51>' 8' 5'!, S' 6' B" 6Y, 8Y'; 6'12' ay,'

KEELSON 't'h' +'Iz' 5" 5" 5'1'; Sy,' 5'" 5~ 6' 6' 6',. 6'!-z' 6'h' l'

SISTER KEELSON

FRAMES (SAWN) 2' 3' 2'h )'12' !I' ,,' 3~ +~ 3'h' 't"l 't' s· 4' 5'

PLANKING I' IYa I:t.' I 'It- l'f. I"a' Z'

CElUNG >f8' r IY6 1'/. IY' I.,., 1'1 .. '

BILGE CEIUNG 1'/1: If I'/t' 16' I'li IB' I'V. 20' Pfi 20' Z· 2z" Z' 22'

Nt OF STRAKES 2 - 2011 3 3 - 3 - 3 - 3 - 3 -CLAMPS I'h' 57. rl/~' 6' 2' 71z' 2'1. S· ZY. 10' Z'iz' 11' Zy,' W

Nt OF STRAKES I - I - I - I - I - lo,f Z lOll 2

SHELF 2Y':' 4" 2'''' "'Iz' l' .'1:. 3:4' ~,,- 3~' ~~ 3)2' 5- 3"", 5'" Nt OF STRAKES ,. - I - I - I -

I I - I - I -

BEAMS 2' 2"i 2'1i z~ 2~' 3'~' 3" 4-' 3'" +~ 3'lz' 4'11' ".- H\.

SPACING CR, TO CII 3D' 3D' 30' 30' 30' lQ' 30'

DECKING, THKS. 1'1. l'Iz' 1'1. ' 1'1,' Z' Z· Z'4"

FRAME SPACING II' IZ' 1+" 1Hz' /5' 16' n" '-- -'---- ~- - - -~-

NOTE, SCANTLINGS ARE BASED ON VESSEL'S UNDER DECK TONNAGE

COMPUTED FROM '!liE FORMULA LIB. D I ,7lI

100

..

PIER 40 <M:R 45

UP TO 45 UP TO 50

SOG AlLO SOG MLO

7' 8' 7" 8'

T S· r 8'

T 8' l' 8'

6"'. 7r~' 6"'. 7'h'

't'h' Sl'l 4'!' 5t. Z'/8' 2'/8'

I~'+' I'ls'

Z.,.' 2~' 2',1; 2~"

~ - + -2"'; It;' 2". 16"

IIX t 2 -+' 4-~' H. ~~ I - I -

"ill.' 5' 'ti'z.' 5 .... •

30' 30'

Zy .. ' ZY'

n", lB'

OVER 50 OVER 55 OVER 60 OVER 65 OVER 70 lOVER 75 OVER eo UP TO 55 UPTO 60 UP 65 UPTO 70 UP TO 75 UP TO 80 UP TO 85

SOG MLO SDG AlLO SOG MLO SDG MLO SOG AlLO SOG MLO SOG AlLD

7Y,' g' 7'h.' g'lz' 7ft' 9'/,' 7'1'.- 9f' 8' 10' s' 10' s~' II'

7'1i 9' 7r.' 9)\' 71,: 9Jr ]f.

9f: S' 10' a' /0' ar; I/"

ni g' 7r; 9'12' TN 9'12' 7'1. 9'1. 8' /0' B' 10' 8'l' I/"

7' 7'1; 7'1l 8' 7'n B'/i 7Yt" BY,' 8' g' B' g' B'''' 9 'h.'

It,,' 7Y; S'fz' BY,' Sif 8'12' 6' 9' 6" 9' 6'1t' g'

S' 6" S' 6' 5'/0.' 6'1z' S'h' 6'/, 5'h' 6!i' SY1' 6,y,' 6' 6'/i

ZY<: Zr.; lY' ZlIa' a' Z'It' Z",'

z' 2" Z' 2' 2Yi 2'10' 11.

2'h' Zt,.' 27,' 2t,.· 2'1i 2t,.' 2~~ 26' 3' 26' 3'/i'- 2&' 3'l~ 28'

~ - 4- - ~ - 4- - ~ ,- ~ - ~ -3' IB 3' IS' 37;' 20' 3'12' 22" 3V.' Z2' 3J~' 2¥' Jr. 2'1'

Z - Z - 2 - 3 - 3 - 3 - 3 -+l'.' 5" s- 5'/; 5' 6- s· o· 5'; 6'11' $'1. 6~' S'lz' G¥.'

I - I - I - , - I - I - I -.. 14 51'!' \olj; S'h' 5' 5'1>' $" 6" 5'h.· 6'1>' 5'1z' 6'lz' sw r.?f.'

3D' 3D' 35' 35' 4-0' 4-0' 4,5'

2~' t'l'

IB'Il' I~" 19'1z' 20' ZO'll' 21' V'll"

L • LENGTH IN FEET OF VESSEL ON LOAD WATERUNE.

B' BREADTH AMIDSHIPS IN FEET INSIDE CEILING,

OVER 85 ~90 ,0000H SO

~_T090 ~T095 UP TO 100

SOG MLD SOG MlD SOG MLD

BY,' lI'l 8¥t" 11'1; 9' 12'

s'li II!I.' B'Y' 1I'f. 9' 12'

BY; 1I'h' 8l' "". g' 11'

8Y; 9~'I.· g' 10' g' 10'

6'12' g'/:' 6>).' 9"" 7' 10'

6' 6:r, 6Y: 7' 6Y; T

Zff; zsli Zl'

2Y4' 2Y~' 2'1,

~:e' 26' 3Yi 2B' 3i11 28'

~ - It - ~ -)r. 2'.- ' .. H' ~" 2.'

:3 - 3 - :5 -s'li 61'. s~ 6l" sr.' 6".:1 I - I - I "

5"; 6~ 5~' 7- S~ 7'

"5' +5" ,"S'

Z2' ZZy,' 23'

D • DEPTH AMIDSHIPS IN FEET FROM TOP OF BEAM AT CENTRE LINE TO TOP OF CEILING

ON FLAT BOTTOM,

--J 0\

8 z "!"l W ::0 r:; Z (') r:; o Z "!"l v.; ::c Z Cl < r:; en en r:; r (') o Z en ~ :;0 c:: ~ o z :: > ~ r:; ::0 ): r en

Warren E. /301111 77

GUIDE TO SCANTLINGS FOR WEST COAST FISHING VESSELS

LENGTH O.A. 421 481 541 601 651 69

1

I

~ - -

i~.~LMLO - ...

MLD SOG MLO SOG MLD SOG MLO SOG MLO 1--.

STEM 6" I 10" I 6. 'It" II '/z" 7" 11'/:" 7~f" 12" a· 12" 9'/z' /3' -

KEEL 7- 8' 7'/z' 9'1z- 8'/z" 10" 9" 1/. 91z· /I 'h· II· 13"

STERNPOST 7" 9" r 9· I 7 'Iz' 9'/z " 8" 9~2' 9" /0" 9'1t' 11 ~2" -

KEELSON S' 7" 6- 9" 7- /0' 7'11.' 1/" B" 11'1:" 9" 13'/t' --

SISTER KEELSON 7'h..- IIYt" a '1/ /3"

FRAMES (BENT) I /318" 2'1z' /7JIl" 2%' 2" 3'A" 2' 3'11' 2]/8" 3)/,,,- 23/,,' )7/8'

PLANKING £..t~ ~ II',· 5tCo. -/0 ~ ~-:;;.. r:!5~" I¥ .. ~~. -to ~. 5 '1?;::;d /- -tD" ~" ~d 3:/i- !:Z--10'

CEILING /" 6' ,'/s" 6" 1'/,,: 6" ,~~' 5" I.'/t" G: ,!l11J " G"

BILGE CEILING l»flt" 5" 2'1,..' sYz" 27a· 5'1," 2'1. 5'/%" 2-'1,.." 572· 3" 5 '/z"

W! OF STRAKES 3 4- + 6 6· 6

CLAMPS, 1ST STRAKE 13/,. • 7' 2" 7" 2'1. B· 2 '/z" a" 3" s" .3'1," 9"

CLAMPS, ~STRAKE - - 1-'".· 7' 2' 7" 2 '/ .... ,. 2'/z' a· 3" a"

SHELF 10/.' 5" Z'/,,· li" Z'l,· T 2:1/+ " 7" Y 7" 3!'z" 8'

HATCH BEAMS 4-'12 " 4-" 5'1,' 4-1/ .. " 6'/2" 4-0/". 7Y.t" 5'1"," a" 5·/~" s'lz· 6'

BEAMS 3" 4-" 30/ .. • + 0/ .. " ~ '/I." 4-~+ • f.~' 5';'" 5'!z' s~+" 6" 6·

SPACING CR. TO CR. 20' z," zz· 2·2' 23" 2"'"

ce:CKING, THKS. 13/8" I 'It" 1% •

FRAME SPACING /0· /0. /0·

Materials

The Board requires that steel used in the construction shall be of an approved shipbuilding grade for which mill certificates should be available.

Although to date the new high strength steels have not been used for fishing vessel construction in Canada these steels ~re acceptahle to the Board who will consider a corresponding reduction in the vessel's scantlings.

Connections

Connections of welding and riveting are acceptable to the Board and details of all main hull connections should be submitted for approval before construction is started.

Where a vessel is to be of welded construction a "Welding Schedule" should be prepared to ensure that locked-in stresses are minimized. Modem welding tech­niques are encouraged and only qualified welders should

/9a· /If". • 2·

JI" /z- /2"

be employed. During inclement weather adequate pro­tection as far as reasonable and practicable should be prOVided for the welding operation - i.e. the work should be protected against rain, snow and also chilling winds during freezing temperatures. The welding rods used must be suitable for the materials being connected and proper protected storage facilities shall be provided for these rods.

First Inspection Procedures

In addition to the general requirements of Part I the Steamship I nspector, during his regular inspections, will give particular attention to main hull connections and local high stress areas.

Where a vessel is of welded construction he will check that the approved "Welding Schedule" is being followed. Visual" examination of the welding will be carried out but the inspector may request that non-destructive testing methods, such as X-rays, be employed in way of main hull connections.

78

In certain cases weld samples may be requested for mechanical testing and in way of local high stress areas such as around the bossings and stem of a vessel pre-heat­ing may also be required. The Inspector will also ensure that welded lugs used for prefabrication, fairing and staging, etc., are removed in a manner that will not produce stress raisers or cause damage to the structure.

Periodic Inspection

Periodic inspections of the hull structure will be carried out at intervals specified in the Large and Small Fishing Vessel Inspection Regulations, the appropriate sections of which are added as Appendix II to this paper.

At underwater inspections the external and internal condition of the hull will be examined by the Inspector and where he notes heavy corrosion he may require that drill testing be carried out. He may also call for internal examination and hydrostatic testing of tanks where he feels this is required.

Where repairs are necessary these must be completed to the satisfaction of the Inspector.

PART 4 - REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF ALUMINUM

ShipbUilder

Construction of aluminum vessels shall be carried out at a plant where the personnel are properly trained and familiar with the type of work which they are to perform and close attention will be given to the conditions under which the vessels are being constructed.

Strength

An aluminum vessel is required to have an equivalent factor of safety to that of a steel vessel of similar size and design and the modulus of the midship section and the stresses in the structural members shall be acceptable to the Board.

Calculations for the required scantlings may be carried out from first principles or the Board will normally accept scantlings derived from acceptable Classification Society Rules for steel vessels that are converted to equivalent strength aluminum alloy ~ections.

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

When carrying out structural design calculations the following general conversion formulae are usually ade­quate:

PLATING: tal = Fst X tst FaJ

STlfFENERS(I) =(1) X F BEAMS Y al Y st ~ GIRDERS Fal PILLARS AND MEMBERS SUBJECT Ial = 3 X 1st TO BUCKLING

Material

where tal = thickness aluminum

tst = thickness steel Fal = yield stress aluminum F st = yield stress steel

( I) = section mod. alum. Yal

(I) = section mod. steel Y st

Ial = Inertia aluminum 1st = Inertia steel

All materials used in the main structure of the vessel must be of an approved grade aluminum alloy for which mill certificates should be available. Pure aluminum is not strong enough to be used to structural advantage, therefore careful attention must be given to the selection of a suitable aluminum alloy.

The alloying elements affect the physical and mechanical properties· of the aluminum and cause the alloys to fall into two distinct groups.

The first group, which is commonly referred to as heat treatable alloys, contains alloys that obtain their strength from heat treatment and therefore are generally not recommended for welded structures; however, these may be incorporated into welded structures, in which case the Board will consider each specific application.

The second group, known as non-heat-treatable alloys, contains alloys that obtain their strength from the alloying elements and strain hardening and are suitable for welding and other types of fastenings.

The aluminum companies have developed a wide range .of alloys that are suitable for a variety of applications; however, construction alloys containing magnesium have been found most useful for marine structures due to their

- adequate strength qualities and their resistance to corro­sion.

The following tables contain details of some marine alloys manufactured in Canada and the United States, all of which are acceptable to the Board. Other grades of aluminum alloys will be considered by the Board on receipt

Warren E. Bonn 79

Table of Mechanical Properties of Aluminum Alloys

A1can Tensile Strength Shear Strength U.S.A. Description Temper

Alloy ULT.(K) Yield (K) % Elong. ULT.(K) Yield (K) Equivt.

-50s Heat-Treatable T5 22 17 8 13 10

A1um-Magnesium- T6, T6c 26 21 8 16 13 6063 -Silicon Alloy. Welded 17 10 ]0 6

Non-Heat-Treat. HIlA 32 18 8 19 7 B53s A1um.-Magnesium H32 36 26 8 22 16 5454

Alloy with H34 39 29 6 23 17 Manganese Added Welded 30 15 18 9

Non-Heat-Treat. HllA 40 24 12 24 13 0545 Alum-Magnesium HUB, H31A 44 31 10 26 19

Alloy with H32 45 34 8 27 20 5083 Manganese Added H34 50 39 6 30 23

Welded 38 18 23 11

Non-Heat-Treat. H32 31 23 7 19 14 575 Alum-Magnesium H24, H34 34 26 6 20 15 5052

Alloy. Welded 25 10 15 6

Heat Treatable T4 26 16 16 16 10 658 Alum-Magnesium- T6 38 35 10 23 21 6061

Silicon Alloy. Welded 24 16 15 10

Heat-Treatable T4A 42 26 10 25 16 74s Alum-Zinc- T6A 47 40 8 28 24 X7004

Magnesium Alloy T6 47 40 8 28 24 Welded 40 24 25 16

Table of Temperature Effects on Aluminum Alloys

Approx. Effect of Temperature on the Mechanical Properties of Aluminum Alloy - Given as a Percentage of the Room Temperature Values

A1can Approx. Melting - 300°F -lOOoF + 200°F + 300°F + 400°F + 600°F

Alloy Range OF

50s 1110 - 1200 Ultimate Strength 130 110 95 65 20 10 Yield Strength 115 105 95 65 20 10

B538 1110 - 1190 Ultimate Strength 150 110 100 80 65 25 Yield Strength 115 105 95 85 70 20

D54s 1075 - 1180 Ultimate Strength ]40 115 95 70 50 20 Yield Strength 120 115 95 70 55 10

57s 1100 - 1200 Ultimate Strength 140 105 95 80 60 20 Yield Strenl:(th 115 100 95 80 40 15

65s 1075 - 1200 Ultimate Strength 130 110 95 70 40 10 Yield Strength 135 105 95 75 40 5

All Above Elastic Modulus 110 105 100 95 90 70 Alloys

8()

of full particulars of proposed use, strength and chemical properties, etc.

Connections

" The strength of any structure is directly related to the efficiency of the connection provided, therefore it is essential that all connections be carefully considered when choosing the type of alloy to be used.

Welding, riveting and bolting are acceptable but details of all main connections must be submitted for approval before construction is started.

In way of bi-metallic connections riveting and bolting are acceptable and care must be taken with the design of the connection to prevent galvanic corrosion being set up. This is usually accomplished with adequate gasketing arrangements and stainless steel bolts. Aluminum bolts or rivets are not recommended as, should they be fitted, frequent replacement will most likely be necessary.

A recent development for connecting aluminum deck­houses to steel decks, is the use of a vertical glass re-inforced plastic strip separating the steel foundation bar and aluminum deckhouse plating.

Concerning welding of aluminum, this in itself is a subject on which a lengthy paper can be written and I do not propose to deal with it in this presentation. The aluminum companies have published many excellent man­uals that are readily available and the methods described are acceptable to the Board. Included in these manuals are the MIG & TIG welding procedures that should be adopted for the various grades of aluminum and the type of preparation required.

Fire Protection

One of the disadvantages of using aluminum for main hull structures is its low melting point and the adverse effect of heat on its strength characteristics.

With this in mind the Board has decided that for fishing vessels constructed of aluminum and operating on exposed voyages the following A-30 standard structural fire insulation should be provided:

(i) in machinery spaces: all shell plating from the deckhead to the light waterline,

CONFERENCE ON FISIIING VESSEL CONSTRUCTION MATERIALS

all deckheads and supporting structure, boundary bulkheads on the machinery space side for the full height, oil tank bulkheads.

(ii) outside machinery spaces: oil tank bulkheads adjacent to spaces, such as a galJey or paint locker, where a fire hazard exists.

When using insulation on aluminum structures care should be taken by the builder to ensure that a suitable type of insulation is chosen that is compatible with aluminum. In way of bilges suitable protection against oil

, and water seepage shall be provided for the insulation.

First Inspection

TIle inspector will carry out regular inspections throughout the bUildit1g of the vessel with careful atten­tion being given to connections, especially to the details and gasketing arrangements in way of bi-metallic con­nections.

In way of welded construction the inspector will ensure that the approved "Welding Schedule" is being followed .. Visual examination of the welding will be carried out but the inspector may request that non-de­structive testing methods, such as X-rays, be employed in way of main hull connections.

In certain cases, especially when prototype vessels are being constructed weld samples may be required for mechanical testing.

Periodical Inspection

Following completion of the sea trials and the "First Inspection" special attention will be given to the vessel at each subsequent inspection. The underwater inspection periods will normally be the same as the requirements laid down in the Large and Small Fishing Vessel Regulations, the appropriate sections of which are added in Appendix II to this paper. However, should accelerated corrosion be noted, then more frequent inspections may be required.

PART 5 - REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF GLASS

RE-INFORCED PLASTIC

Shipbuilder

Glass reinforced plastic moulding is a specialized chemi­cal process and must be carried out at an approved establislunen t.

Warren E. Bonn

Approval of the establishment necessitates that the personnel engaged in the construction must be properly trained for the type of work which they arc to perform.

Workshops used for the moulding should be

(a) protected from the weather, adequately lighted and ventilated but free from draughts and direct sun­light,

(b) maintained in the temperature range 60°F - 70°F at a low humidity level, both readings being recorded regularly,

(c) clean and dust free, and

(d) provided with adequate dry and draught free storage spaces for the raw materials.

Strength

The modulus of the midship section and the stresses in the structural members shall be acceptable to the Board.

Calculations for the required scantlings may be carried out from first principles or the Board will generally approve scantlings derived from acceptable Classification Society Rules.

Materials

The resins and glass fibre reinforcements lIsed in the moulding processes should be of types recommended by the manufacturers for marine use and atc td be approved by the Board.

The resins should be suitable for laminates that may be stressed when in a temperature range of -22°F to + 150°F and formulated to have a gel time of generally less than 1 hour.

Surfaces of the moulding that will be exposed to the atmosphere or to liquids must be provided with a gel coat and surfaces that may be walked upon shall have a good non-slip finish.

Laminate must be free of voids, air bubblcs or other similar faults that may effect their strength and details of wood or metal inserts should be submitted to the Board for approval.

81

Connections

Care should be takcn in the design of all connections throughout the construction and special attention should be given to the main huU connectIOns such as the decks to the shell, bulkhead bOllndaries, deckhouses to the main hull etc.

The following methods of connection are acceptable to the Board:

(a) Bonding: the surfaces must be rou~hened and thoroughly cleaned, the gel coat shall be removed in way of the surface and the total thickness of fillet bonding strips should be approximately equal to the thickness of the thinner parts being joined.

(b) Riveting: Rivets should be cold driven and dipped in resin or other' suitable sealant to seal the fibres within the hole. Washers or metal strips should be fitted in way of the heads and points to prevent damage to the laminate. The minimum distance between the centre of the rivet hole and the edge of the laminate should be three times the diameter of the rivet; the holes are to be drilled neat. Where a joint is required to be watertight a suitable sealant should be used.

(c) Bo/ting: Bolts should be of non-corrodible metal, other than copper or its alloys, and should be dipped in resin or other suitable sealant to seal the fibres within the holes. To prevent damage to the laminate, washers or metal strips should be fitted in way of the heads and points. Bolt holes are to be drilled neat . and the minimum distance between the centre of ~he bolt hole and thc edge of the laminate should be three times the diameter of the bolt.

(d) Screwing: Screwing is lIcce~fable only for the connections of items of relatively truhot ittlpottll11ce and only where a bettcr type of connection cllhiidt be readily used.

COl1stmction of Tanks

Tanks for oil or water may be COllstructed as independ­ent units or moulded as an integral part of the vessel's structure.

Adequate supporting structure is to be provided in way of all tanks and through bolting and riveting should be avoided wherever possible. Longitudinal divisions shall be

82

fitted in wide tanks to reduce the effect of free surface liquids.

Machinery Seatings

Due to induced stresses from the vibrations and weight of the machinery special attention should be given to the design and construction of machinery seatings and the adjacent structure.

Fire Protection

Ordinary polyester resins will bum even when the source of ignition is removed leaving the glass reinforce­ment limp and unsupported. With this in mind, and with a view to the probable growth of the G.R.P. boatbuilding industry, the Board is investigating the effect of elevated temperatures on plastic laminates.

Pending the completion of these investigations the Board requires that within the machinery space and galley, and other similar spaces where there exists a fire hazard, the shell, decks, bulkheads, and load bearing structures should be constructed of approved fire retardant resins and insulated to A-30 standards.

Fire Inspection

Althougll, in Canada, a large number of small G.R.P. pleasure craft are manufactured each year only a few commercial vessels have been constructed in fibreglass. For this reason G.R.P. is still considered to be a new method of construction in this country. This being the case the inspector will carry out more than the usual n umber of inspections during all phases of the construction and random checks will be made of the resins, the lamination reinforcement materials and also the readings for the temperature and humidity in the building sheds.

The inspector will check the gel coat prior to the lay-up of the laminations and he will be present during at least part of the lay-up of the main hull. He will also check attachments of all main stiffening members and will be present when the mould is removed. Special attention will be given to the joining of main sections of the hull such as the deck to the shell, bulkheads boundaries, deckhouses to the main hull etc.

During the course of construction test specimens should be prepared for main hull materials. These are to

CONFERENCE ON FISIIING VESSEL CONSTRUCTION MATERIALS

be prepared concurren t with the building of the hull and at a time when the inspector is present.

The number of test specimens and the tests that are to be conducted will be decided upon by the Board for each individual vessel depending upon its size, design character­istics and other relevant features. Tests will generally be made for tensile and compressive qualities, flexural stress, water absolption etc. These tests may be carried out at a testing laboratory recognized by the Board and they should be witnessed by an inspector.

Provisional Requirements for Inspection and Certification

The Board has decided that for vessels constructed of G.R.P. the following provisional requirements shall apply for periodical inspection and certification:

(a) the vessel will be inspected externally and inter­nally after the first year of operation, and

(b) following the fust underwater and internal inspection, and provided the vessel is found in satisfactory condition, then normal inspections will be carried out in accordance with the requirements of either the Large or Small Fishing Vessel Inspection Regulations as applicable.

PART 6 - REQUIREMENTS APPLICABLE TO VESSELS CONSTRUCTED OF FERRO-CEMENT

Shipbuilder

Construction should be carried out at an approved builders, where the personnel are properly trained and familiar with the type of work which they are to perform.

Strength

The modulus of the midship section and the stresses in the structural members should be acceptable to the Board. Calculations for the reinforcements should be made from fust principles.

Care should be taken to ensure that the reinforcements - form continuous strength members and discontinuities and

that local high stress areas are avoided.

Materials

The strength of the ferro-cement hull is obtained from the homogeneous qualities of the cement and the grid

Warren E. Bonn

re-inforcements which bind together to form a solid structurc. The requirements [or the materials are as folIows:

(a) Cement - The cement although contributing to the strength of the vessel's hull hns the primary function of giving rigidity to the re-infon:ements. For the cement the 130ard stipula tes the following require­ments:

(i) it should be of the Portland or equivalent­type, should be recommended by the manu­facturer for marine use and should be appro­ved by the Board.

(n) the water used for mixing should be clean fresh water and free of impurities and chemi­cals that may effect the concrete mix,

(ill) the aggregate of the mix should be of a

suitable type and as recommended by the manufacturer and approved by the 130ard. The water/cement ratio should be controlled as low as possible to give a good quality and workable material.

(b) Reinforcements - The reinforcing pipes, rods, bars and wire mesh used are to be of an approved grade of steel for which certificates should be available. The steel should be clean and free of scale, oil, grease or other similar con tamination.

Connections

Welding, lacing and clipping of all main hull re-inforce­ments should be cHrried out with care and completed to the satisfaction of the Steamship Inspector.

Constmction of Tanks

Tanks for oil or water may be constructed of steel or ferro-cement that has been treated with a suitable sealer.

Adequate supporting structure should be provided in way of all tanks and through bolting should be avoided wherever possible. Longitudinal divisions shall be fitted in wide tanks to reduce the effect of free surface liquids.

Machinery Seatings

Due to induced stresses from the vibrations and weight of the machinery special attention should be given to the design and construction of machincIY seatings. Carc should be taken that hard notches and corners are eliminated and the continuity o[ strength maintained.

83

inspectioll Proc(!duf(~s

During the construction regular inspections will be carried out by a Steamship Inspector with particular attention being given to the following stages:

(a) whcn the steelwork re·inforcement is half complete, (b) when the steelwork re-inforcement is completc, (c) during the application of the cement m.ixture, (d) at the removal offorms or moulds, (e) at completion of the huH prior to curing, (f) at completion of the hull after curing, and (g) on completion of the vessel and during the running

of the sea trials.

Testing Procedures

At the present time the 130ard of Steanlship Inspection is participating in a research program, instituted by the Industrial Development Service of the federal Department of Fisheries and being underta.ken by the British Columbia Research Council, to determine the qualities and suitability of ferro-cement as a shipbuilding material. We hope that results will be forthcoming from tllis program in the near future that will provide clear guidelines into the construc­tion, testing and inspection procedures wllich we should follow.

However, pending the completion of the above men· tioned research program the Board has decided that the following testing procedures should be adopted:

(a) During the course of construction the Steamship Inspector will cany out standard slump tests on the concre te mix to ensure that the mixture is a good quality and workable material.

(b) There should be prepared, concurrent with the hull plastering, test specimens of the main hull struc­tures, the preparation of which should be witnessed by the Steamship Inspector.

(c) Tests will be required for tensile, compressive, flexural and impact strengths. These tests should be carried out a t a recogn izcd laboratory and witnessed by the Steamship InsJlector. For vessels built in Canada to datc these tests have been carried out at the Department of Public Works testing laboratories in Ottawa.

(d) The number of test spccimens will be decided upon by the Board for individual vessels gellerally depcnd­ing upon their size, type of construction and whether the vessel is or a prototype design.

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Provisiollal Requirements for Periodical Inspections and Certification

Special attention wiIl be given to a vessel of ferro-cement construction for the fIrst four years of operation and provisional inspection and certification will be as follows:

(a) the vessel will be limited to Home Trade Class III Voyages - i.e. not more than 20 miles off shore and not more than 100 miles between ports of refuge,

(b) inspection will be made of the vessel afloat every six months, and

(c) underwater inspection will be carried out annually.

CONFERENCE ON [-lSI liNG VESSEL CONSTRUCTION MATERIALS

Following the fIrst four-year period and provided the vessel is found in satisfactory condition, the normal inspections will be carried out in accordance with the Large or Small Fishing Vessel Inspection Regulations as appli­cable.

ACKNOWLEDGEMENTS

The author wishes to acknowledge the use of publica­tions issued by L10yds Register of Shipping, The Aluminum Company of Canada and The Society of Naval Architects and Marine Engineers.

APPENDIX I

Submission and Approval of Plans and Data

The information contained in this Appendix is extracted directly from:

(a) The Small Fishing Vessel Inspection Regulations that are applicable to fishing vessels not exceeding 80 feet registered length that do not exceed 150 tons, gross tonnage; and

(b) The Large Fishing Vessel impection Regulatiolls that arc applicable to fishing vessels exceeding 80 feet registered length or 150 tons, gross tonnage.

The section numbers referred to are those of the Small or Large Fishing Vessel Inspection Regulations.

CANADA SHIPPING ACT.

Small Fishing Vessel Inspection Regulations.

FISHING VESSELS EXCEEDING FIFTEEN TONS,

GROSS TONNAGE Submission and Approval of Plans, etc.

5. (1) Subject to section 6, before construction of any fishing vessel is begun, the owner thereof sllllll submit in triplicate to the steamship inspection office for the arca where it is proposed to construct the fishing vessel the scantlings, information and data set forth in Schedule A concerning propelling machinery, pumps, piping, fuel tanks, steering arrangcments and the hull of the vessel.

(2) Before construction of a subsidized vcssel is begun, the owner thereof shall submit in triplicate a lines plan of the hull to thc steamship inspection office for the arca where it is proposed to construct the fishing vessel.

(3) Before construction of any fishing vessel is begun, the owner thereof shall submit to the steamship inspection office for the area where it is proposed to construct the fishing vessel detailed plans and data of any of the following equipment with which it is equipped, namely : its main, auxiliary and heating boilers (other than hcating boilers having a working pressure not exceeding fifteen pounds per square inch), steam pipes, boiler mountings and air receivers.

6 . (1) Where, under subsection (I) or (2) of section 5, any scantlings, infonnation, data or plans are submitted to a steamship inspection office, an Inspector may approve them if, in his opinion,

(0) the scantlings, infonllation, data or plans conform with the requirements of sections 8 to 26 where those sections are applicable; and

(b) the vessel, if constructcd in accordance with those scant­lings, informa tion, data or plans, will be :;afe and suitable for the voyages for which it is intended.

(2) Where, under subsection (3) of section 5, plans and data are submitted to a steamship inspection office respecting any equip­ment mentioned in that subsection, that office shall send them to the Chainnan who may approve or reject them.

7. No inspection certificate shall be issued in respect of a fishing vessel unless

(a) the scantlings, information, data and plans required to be submitted under section 5 have been suhmitted under that section and have becn approved under section 6;

(b) the vessel is constructed in accordance with

(i) such scantlings, infonnation, data and plans, and

(ii) the requirements of these Regulations; and

(c) the vessel is in the opinion of an Inspector safe and suitable for the voyages for which it is intended.

Warren E. Bonn

Small Fishing Vessel Inspection Regulations

Schedule A.

The scantlings, infonnation and data respecting machinery and hull required to be submittcd in accordance with section 5 are as follows:

(a) Propelling Machinery.

Number of engines Manufacturer's name Diesel, gasoline or steam Cycle Number of cylinders, diameter and stroke (if diesel or steam) Brake or indicated horsepower at continuous rating Engine revolutions per minute at continuous rating Maximum indicated pressure (if diesel) Mean indicated pressure (if diesel) Weight of flywheel (if diesel or steam) Diameter of flywheel (if diesel or steam) Reduction gear manufacturer Reduction gear ratio Diameter and material of intermediate shaft Diameter and material of tailshaft Particulars of tailshaft liner Propeller diameter Propeller pitch Type of stern bearing

(b) Air Receivers.

(c)

(d)

Manufacturer's name Number on board Intemal diameter Type of construction Shell thickness Head thickness Radius of heads of circular section Depth of heads of semi-elliptical section Are heads dished in or out? Is a safety valve or fusible plug fitted on each receiver? Working pressure

Bilge Pumps and Pipi'lg.

Number and capacities of bilge pumps driven by (i) main engine,

(il) auxiliary engine, and (iii) hand

Number of suctions in (i) machinery space,

(ii) hold spaces, and (iii) crew and other spaces Internal diameter of bilge piping

Fire.Pumpsand Pipi1lg.

Number and capacities of Cue pumps Internal diameter of hydrant piping Number of outlets

(e)

(f)

Number of tanks Description

Fuel Tanks.

Capacity of each in gallons Thickness of plate

Steering Gear.

Steam, hydraulic, electric or hand Diameter of chain, wire or rod Diametcr of rudder stock Area of rudder Average distance between trailing edge of rudder and

centre line of rudder stock

, (g) Hull.

Name of ship and official num ber Year built Name and address of builder Name and address of owner Type ofvesscl (open or closed construction) Type of fishing for which vessel is designed Material (wood or steel)

85

Registered length (that is to say. the length from the fore­most part of the stem of a fishing vessel to the after side of the head of its stern post, or if it has no stern post, to the forward side of the rudder stock at the deck)

Breadth (extreme over planking) Depth (top of beam at side amidships to rabbet line on keel) Number and location of watertight bulkheads Length and height of deck-houses Location of engine room Number and sizes of engine room entrance and emergency

exits Location of crew accommodation and total number of crew Height of bulwarks Height of sills of doors giving access to main hull Hatches, number and size Hatch coamings, height and thickness Hatch fore and aCters, vertical and horizontal dimensions Hatch covers, type and thickness

(hI Details of Materials

Item Finished Material Spacing Details of dimensions (centres) fastenings

Keel Stem Sternpost Keelson Frames Deck beams Hanging knees Lodging knees Hatch carlings Clamps Shelfs Bilge ceiling Floors Plank o~ plate Deck Engine Foundations

NOTE: the above information and scantlings may be submitted as a list, or in the form of plans, or as 8 combination of both methods.

86

CANADA SHIPPING ACT

Large Fishing Vessel Inspection Regulations

Submission and Approval of Plans, etc.

\ "6. (1) Subject to subsections (2) and (3), before construction of any fishing vessel is begun, the owner shall submit for approval, in triplicate, the plans and data set forth in Schedule A con­cerning boilers, superheaters, economizers, air receivers, propclling m3chinery, pumps, piping, fuel tanks, steering gear, rudder and hull."

(2) Plans of the following are not required to be submitted:

(a) heating boilers having a pressure not over 15 pounds per square inch,

(b) diesel engines not exceeding 75 brake horse power, con­tinuous rating, unless of unusual design,

(c) gearing for main engines and electric pr.opulsion motors not over 300 brake horse power, continuous rating,

(d) gasoline engines unless of unusual design, or

(e) parts that are found by an Inspector to agree wHh plans already approved .by the Chairman.

(3) Notwithstanding subsection (2) the Board may require t,hat plans and data of parts not listed in Schedule A shall be submitted.

"(4) Where under this section plans and data are submitted to a Divisional Supervisor, one copy of each submission approved by the Divisional Supervisor for the Chairman shall be forwarded to the Chairman by the Divisional Supervisor."

(5) No inspection certificate shall be issued in respect of a fishing vessel unless

(0) The plans and data submitted under this section have been approved by the Chairman,

(b) the vessel is constructed in accordance 0) with such plans and data, and

(ii) with the requirements of these regulations, and

(c) the vessel is in the opinion of an Inspector safe for the voyages for which it is intended.

Large Fishing Vessel Inspection Regulations

"Schedule A

I. The plans and data respecting machinery and hu\1 required to be submitted for approval in accordance with section 6 are as set out in this Schedule.

"2. (1) Where a fishing vessel does not exceed 100 feet in length

(a) The plans for the following equipment and parts of the vessel shall be submitted to the Board: (i) new air receivers,

(ii) boilers having a working pressure of 15 pounds or over per square inch,

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

(iii) diesel engines over 500 B.H.P., (iv) gearing for all engines over 500 B.H.P., (v) lifeboats, life rafts and buoyant apparatus, and

(vi) aluminum superstructures; and

(b) the plans for the following equipment and parts of the ves­sel shall be submitted to the Divisional Supervisor who may approve those plans for the Board or forward them to the Board for approval:

(i) new boiler mountings, (ii) steam turbines over 500 B.H.P.,

(iii) reciprocating steam engines over 500 B.H.P., (iv) general arrangemcnt of ship, (v) midship section,

(vi) longitudinal section and deck plans, (vii) rudder,

(viii) electric circuits and protective devices, and (ix) such other equipment and parts of the vessel as the

Divisional Supervisor may consider necessary.

(2) Where a fishing vessel exceeds 100 feet in length

(a) the plans for the following equipment and parts of the vessel shall be submitted to the Board:

(i) (ii)

(iii)

(iv) (v)

(vi) (vii)

(viii) (ix) (x)

(xi) (xii)

(xiii) (xiv) (xv)

(xvi) (xvii)

(xviii)

new air receivers, sprinkler and foam pressure tanks, boilers, main, auxiliary and heating, superheaters and economizers, boiler mountings, electric circuits and protective devices,

. steam turbines over 500 B.H.P., diesel engines over 500 B.H.P., reciprocating steam engines over 500 B.H.P., gearing for aU engines over 500 B.H.P., general arrangement of ship, midship section, longitudinal section and deck plans, subdivision details and data if required by owner, unusual cargo gear, sprinkler system if required by owner, fire-resistant bulkheads if required by owner, lifeboats, life rafts and buoyant apparatus, and aluminum superstructures; and

(b) the plans for the following equipment and parts of the ves­sel shall be submitted to the Divisional Supervisor, who may approve those plans for the Board or forward them to the Board for approval:

(i) (ii) (iii)

(iv)

(v) (vi)

(vii) (viii) (ix) (x)

(xi) (xii)

general arrangement of machinery, stern tube, stcrn bu~h or bearing, shafting, including thrust, propeller, intermediate shafting and couplings, diagram arrangement of feed water, oil fuel and cooling system s, compressed air systems, existing boiler mountings, existing air receivers, arrangement of steam pipes, propane gas installations, bilge and ballast pumping and piping, fuel oil tanks separate from hull, main and auxiliary steering arrangements with details of quadrant and tiller,

Warren E. Bonn

(xiii)

(xiv) (xv)

(xvi) (xvii)

(xviii) (xix) (xx) (xxi)

(xxii) (xxiii) (xxiv) (xxv)

(xxvi) (xxvii)

(xxviii)

fixed fire extinguishing equipment as outlined in section 6 of the Fire Detection and Extinguishing Equipment Regulations, rudder stem, sternpost or sternframe, pillars and girders, shell expansion, \V.T. and D.T. bulkheads, engine and boiler seatings, shaft brackets and bossing, schemes of riveting and welding, list of fastenings in the case of wooden ships, sea chests, boat arrangement, natural and mechanical ventilation, usual cargo gear, fresh and salt water systems, and scuppers and dischargers."

3. In the case of reciprocating steam engines, the fonowing data shall be supplied with the plans:

(1) Designed indicated horsepower (2) Revolutions per minu te (3) Number of cylinders, diameter and stroke of pistons (4) Diameter and weight of flywheel (if fitted)

87

(5) Diameter of propeller (6) Physical properties of principal forgings and castings.

4. In the case of diesel engines, the fonowing data shall be supplied with the plans:

(1) Designed brake horsepower (2) Revolutions pcr minute (3) Two or four cycle (4) Maximum and mean indicated pressure (5) Balance weights (weight and number) and radius of gyration (6) Number of cylinders, diameter and stroke of pistons (7) Diameter and weight of flywheel (8) Diameter of propeller (9) Physical properties of principal forgings and castings.

5. In the case of gears in excess of 300 brake horsepower, the , following data shall be supplied with the plans:

(1) Designed shaft horsepower (2) Revolutions of each pinion and gear (3) Number of teeth, pitch and pitch circle diameter in each gear

and pinion . (4) Length and thickness of teeth (5) Helix and pressure angles (6) Physical properties of principal forgings and castings.

APPENDIX II

First and Periodic Inspections

The infonnation contained in this Appendix is extracted directly from:

(a) The Small Fishing Vessel Inspection Regulations that are applicable to fishing vessels not exceeding 80 feet registered length that do not exceed 150 tons, gross tonnage; and

(b) The large Fishing Vessel Inspection Regulations that are applicable to fishing vessels exceeding 80 feet registered length or 150 tons, gross tonnage.

The section numbers referred to are those of the Small or Large Fishing Vessel Inspection Regulations.

CANADA SHIPPING ACT.

Small Fishing Vessel Inspection Regulations.

FISHING VESSELS EXCEEDING FlrTEEN TONS,

GROSS TONNAGE First Inspection of New Construction.

41. (1) Every fishing vessel shall be inspected during construc­tion at such times as the Inspector deems advisable.

(2) The owner of a fishing vessel shall notify the Inspector at least one week in advance of

(a) the commenccment of framing; (b) the commenccment of planking or plating; (c) the launching; and (d) the dock and sea trials.

(3) An Inspector may accept machinery in respect of which plans are not required to be submitted under these Regulations even though it has not been inspected during construction without its

being opened for inspection if he is satisfied that it is safe and suitable for the purpose for which it is intended.

(4) Inspection and construction of boilers. steam pipes, boiler mountings and air rcceivers of fishing vessels for which plans are required to be submitted under these Regulations shall be in accordance with the Steamship Machillery Inspection Regulations and the Steamship Machinery Construction-Regulations.

(5) Dock trials and sea trials of a fishing vessel shall be held in the presence of an Inspector, at which time the bilge and fire pumps shall be tested, the speed in knots estimated, the stcering and stopping powers of the vessel tested and the launching arrangcments

- for the lifeboats, boats, dories or skiffs tried out, and sueh further tests shall be made as the Inspector considers necessary to satisfy himsclf that the vessel is safe and suitable for the purpose for which it is intended.

Periodic Inspection.

42. Every fishing vessel propelled by stcam shall havc the following parts inspected annually by an Inspector :

88

(a) boilers, boiler mountings and steam pipes; (b) life saving equipment; and (c) fIre extinguishing equipment.

. 43. (1) Subject to subsection (2), every fishing vessel shall be inspected once evcry four years as follows:

(a) Air reccivcrs shall be tested by hydraulic pressure to one and one-half times the working pressure but the Inspector may waive this test if the air receiver has a manhole or other opening that permits a thorough examination of the interior and he is satisfied that it is in a safe and sound condition;

(b) an engine trial shall be held and if the engine is found in good operating condition the Inspector may accept it without opening it up for inspection; but where the running trial is not to the satisfaction of the Inspector he may require that the engine, or any part thereof, be opened up for inspection; the owner shall notify the Inspector when­ever the engine is opened up for overhaul so that the Inspector may have an opportunity of examining the engine;

(c) the hull shall be examined inside and out by the Inspector while the vessel is in dry dock or while beached;

(d) fire and bilge pumps shall be tested by trial and overhauled if necessary;

(e) the rudder shall be examined in place, the weardown of the taUshaft measured and all sea connections opened up for inspection;

(j) all life saving, fire extinguishing and navigating equipment shall be inspected;

(g) tailshafts shall be inspected in accordance with section 44; and

(II) air compressor relief valves and air receiver relief valves shall be set to blow off at the assigned working pressure.

(2) The periodic inspection required by paragraph (a) of subsection (1) in respect of a new air receiver shall commence eight years after the date of the first inspection of the air receiver.

44. Tailshafts of a fishing vessel shall be inspected as follows:

(a) carbon steel tailshafts, where used in salt water, shall be completely withdrawn for inspection and the propellor removed at least once every four years; in order to facilitate such inspection the owner shall notify the Inspector when­ever the tailshart is withdrawn and the propellor removed; and

(b) bronze, monel, stainless steel or other non-corrosive tail-. shafts used in salt or fresh water and carbon steel tailshafts used in fresh water shall, if considered necessary by the Inspector, be partially or completely withdrawn for inspec­tion once every four years and the propellor shall, if considered necessary by the Inspector, be removed once every four years; in order to facilitate such inspection the owner shall notify the Inspector whenever the tailshaft is withdrawn.

45. An Inspector may, in addition to any inspection or test required by these Regulations, conduct any inspection or require any test to be made to satisfy himself that anything on a fishing vessel that may affect its seaworthiness is safe and suitable for the purpose for which it is intended.

46. (1) Notwithstanding the requirements for periodic inspec­. tion prescribed in this Part, an Inspector may issue or extend an inspection certificate for a period not exceeding

(a) two months beyond the due date of periodic inspection; or (b) five months beyond the due date of periodic inspection if

authorized to do so by the Divisional Supervisor.

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

(2) Prior to issuing or extending an inspection certificate under this section the Inspector shall satisfy himself from such inspection of the hull, machinery and equipment, as is possible afloat, and without opening up any machinery except boilers and boiler mountings, that the fishing vessel is in a seaworthy condition.

(3) An inspection certificate issued or extended to the maxi­mum period allowed under this section shall not be renewed or further extended without the permission of the Board.

47. Any alterations affecting the seaworthiness of a fishing vessel shall be equivalent to the standards of these Regulations and to the satisfaction of an Inspector.

CANADA SHIPPING ACf

Large Fishing Vessel Inspection Regulations,

First Inspection of New Construction

23. (1) Every fishing vessel shall be inspected during construc­tion at such times as the Inspector deems advisable.

(2) The owner of a fIshing vessel shall notify the Inspector at least one week in advance of

(a) the commencement of framing, (b) the commencement of planking or plating, (c) the launching, and (d) the dock and sea trials.

(3) Dock trials and sea trials of a fishing vessel shall be held in the presence of an Inspector, at which time the bilge and fire pumps shall . be tested, the speed in knots estimated, the steering and stopping powers of the vessel tested and the launching arrangements for the lifeboats, boats, dories or skiffs tried out, and such further tests shall be made as the Inspector considers necessary to satisfy himself that the vessel is safe and suitable for the voyages intended.

Periodic Inspection of Hulls of Wooden Fishing Vessels

31. (1) Every wooden fishing vessel over 150 tons, gross tonnage, if operating in salt water, shall be dry docked and inspected every two years.

(2) Every wooden fishing vessel over 150 tons, gross tonnage, if operating in fresh water, shall be dry docked and inspected quadrennially.

(3) Every wooden fishing vessel not over 150 tons, gross tonnage, shall be dry docked and inspected quadrennially.

(4) The hull inspection shall be carried out as follows:

(a) the Inspector shall examine the hull externally and inter­nally in order to satisfy himself as to the condition; such parts of the ceiling shall be removed as the Inspector may require in order that the condition of the hull, timbers, floors, etc. may ' be ascertained; fastenings and sheathing shall be removed where considered necessary by the In­spectator; boring shall be carried out where and as consi­dered necessary by the Inspector;

(b) hatchways, ventilators, doorways and other deck openings with their closing and opening appliances, superstructure bulkheads with their closing appliances, hatch coamings and door sills shall be inspected;

(c) such further opening up shall be done as the Inspector may require in order to satisfy himself that the hull is in good condition;

Warren E. Bonn

(d) all repairs and renewals shall be carried out to the satisfac­tion of the Inspector; and

(e) any alterations made to the vessel since the previous inspection shall be reported in detail by the Inspector to the Chainnan.

Periodic Inspection of Hillis of Steel Fishing Vessels

32. (1) Every steel fishing vessel over 150 tons, gross tonnage, if operating in salt water, shall be dry docked and inspected every two years.

(2) Every steel fishing vessel over 150 tons, gross tonnage, if operating in fresh water, shall be dry docked and inspected quadrennially.

(3) Every steel fishing vessel not over 150 tons, gross tonnage, shall be dry docked and inspected quadrennially.

(4) The hulls of steel fishing vessels not over 145 feet in length shall be inspected as follows:

(a) the Inspector shall examine the hull externally and internally in order to satisfy himself as to the condition; such parts of the ceiling shall be removed as the Inspector may require in order that the condition of plating, frames, floors, tank tops etc., may be ascertained; drill testing of the plates shall be carried out where and as considered necessary by the Inspector;

(b) hatchways, ventilators, doorways and other deck openings with their closing and opening appliances, superstructure bulkheads with their closing appliances, hatch coamings and door sills shall be inspected;

(c) where considered necessary by the Inspector fore and after peaks, bunkers, double bottom tanks and bilges shall be cleaned and examined;

(d) steel ~ork shall be cleaned and exposed for exam~nation where considered necessary by the Inspector;

(e) where considered necessary by the Inspector double bottom tanks shall be tested by a head of water at least to the light waterline but not less than 8 feet above the inner bottom, and peak tanks used for water ballast shall be tested to a head of water not le.~s than 8 feet above the crown of the tank;

(j) such further opening up shall be done as the Inspector may require in order to satisfy himself that the hull is in good condition;

(g) all repairs and renewals shall be carried out to the satisfaction of the Inspector; and

(h) any alterations made to the vessel since the previous inspection shall be reported in detail by the Inspector to the Chairman.

(5) The hulls of steel fishing vessels over 145 feet in length shall be inspected as required by the Hull Inspection Regulations.

Periodic Inspection of Sea Connections, Windlass, Rudder, Steering Gear, Anchors and Anchor Cables

33. (1) All sea suction and discharge valves and cocks situated below the load water line or which exceed 2 inches in internal diameter shall be opened up for inspection at least every four years.

89

(2) On every occasion that a fishing vessel is dry docked in compliance with these regula tions the sca connection fastenings, windlass, rudder, steering gear and anchors shall be given a general examination by the Inspector, who may request any opening up that he deems to be necessary.

(3) Anchor cables shall be ranged eight years after construction of the vessel and every four years thereafter; where the chain is so worn that the mean diameter at any part is reduced to the mininmm size shown in Schedule E as requiring renewal, that part shall be renewed.

(4) Steering chains so wom that the mean diameter at any part is reduced to the minimum size shown in Schedule E as requiring renewal shall be renewed at that part.

Periodic Inspectioll of Screw S/lOftsand Tube Shafts

34. (1) Fishing vessels over 150 tons, gross tonnage, making voyages in salt water, shall have the screw shafts and the tube shafts withdrawn for inspection at least once every two years, except that shafts of the foUowing types need be withdrawn for inspection only once every three years in the case of single Sl.TeW fishing vessels, and one every four years in the case of fishing vesscls having two or more screws:

(a) shafts fitted with a continuous liner in way of the stern tube, and in way of outside bearings where fitted;

(b) shafts fitted with approved glands or other approved appliance~ at the after end to permit of their being effic.iently lubricated;

(c) shafts of bronze, monel metal, or other approved non-cor­rosive material;

(d) shafts that are fitted with non-<:ontinuous liners and that are completely covered between the liners with rubber or neoprene that has been applied and bonded by an approved method.

"(la) Notwithstanding subsection (1), where a single screw fishing vessel has a shaft of a type described in any of paragraphs (a) to (d) of SUbsection (1), the shaft need only be d~awn for inspection once every four years if

(a) the by way, if fitted, has well rounded ends or is of the sled type, has an adequate root radius and has rounded edges at the shaft surface; and

(b) at each inspection, the shaft between the after end of the liner, or the after end of the stern tube if no liner is fitted, and a position one third of the length of the taper from the large end, is examined by an efficient crack detection method and found free from defects."

(2) Fishing vessels not over 150 tons, gross tonnage, making voyages in salt water, shall have the screw shafts and the tube shafts withdrawn for inspection at least once every four years.

(3) Fishing vessels making voyages in fresh water shall have the screw shafts and the tube shafts withdrawn for inspection at least once every four years.

(4) When a screw shaft Or tube shaft is withdrawn for the inspection required by this section it shall be completely removed from the stern tube and bearings and the propeller shall be taken off the shaft.

90

(5) When a fishing vessel is inspected in dry dock and the shafts are not withdrawn for periodic inspection, the propellers and stern bearings shall be examined in place and the wear-<lown of the stern bearings shall be noted and reported.

Postponement of Inspection

35. (1) The Board may authorize the requirements of the quadrennial inspection of the machinery and hulls of fishing vessels over 150 tons, gross tonnage, to be postponed from the due date, either wholly or in part, for a period not exceeding twelve months from the due date if the annual inspection requirements have been carried out.

(2) The Board may authorize the requirements of the annual or quadrennial inspection of the hulls of all fishing vessels to be postponed from the due date, either wholly or in part, for a period not exceeding six months from the due date.

"(3) Notwithstanding the requirements for the periodic inspec­tion of hull and machinery prescribed in these Regulations, an Inspector may issue or extend an inspection certificate for a period not exceeding

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

(0) two months beyond the due date of periodic inspection; or

(b) five months beyond the due date of periodic inspection if authorized to do so by the Divisional Supervisor.

(4) Prior to issuing or extending an inspection certificate under this section the Inspector shall satisfy himself from such inspection of the hull, machinery and equipment, as is possible anoat, and without opening up any machinery except boilers and boiler mountings, that the fishing vessel is in a seaworthy conditon.

(5) An inspection certificate issued or extended up to the maximum period allowed under subsection (3) shall not be renewed or further extended without the permission of the Board."

Continuous Inspection

36. The quadrennial inspections may be carried out on a continuous basis if all parts subject to inspection are inspected at least once every four years; where this method of inspection is adopted the owner shall furnish a chart for recording the inspections carried out; this method of inspection, however, shall not exempt any fishing vessel from the annual inspection required by these regulations.

LLOYDS REGISTER OF SHIPPING Yacht Technical Office

Tech. Note: FC/REQ/l

Date: January 2, 1967.

Tentative Requirements for the Construction of Yachts and Small Craft in Ferro-Cement

Part 1 - GENERAL REQUIREMENTS

Survey During Construction

101. Where ferro-cement is used in yachts and small craft proposed for classification or to b~ built under supervision, it shall comply with these requirements.

All new boats intended for classification are to be built under the Society's Special Survey and when classed will be entitled to the distinguish­ing mark inserted before the character of classification in the Register of Yachts or the Register of Ships, as appropriate. In the case of boats wholly or mainly constructed of this material, the class shall have the notation "Experimental - Ferro-Cement Hull", and shall be subject to annual survey.

Works

102. The boat is to be constructed under the survey of a Surveyor to the Society in an establishment where the facilities, equipment, etc., are such that acceptable standards can be obtained both for the construction of the hull and for the installation of any machinery and/or electrical equipment to be fitted.

The boatyard should be staffed by competent tradesmen and supervised by a management familiar with this material, and capable of carrying out the production of high quality work.

Inspection

103. The boat is to be built under a rigid inspection system employed by the builder, the inspection being made at regular intervals and stages of construction by a responsible official of the firm. A satisfactory record of these inspections is to be maintained for the Surveyor's inspection.

The construction will normally be inspected by the Surveyor at the following main stages:

1. When the steel reinforcement is half completed.

2. When the steel reinforcement is completed.

3. During the application and compaction of the mortar.

4. At the stripping of any major formwork.

5. At the end of the curing period.

- 2 -

The above visits are intended only as a general guide and the actual number will depend on the size of the construction and the degree to which ferro-cement is being used, and will be arranged between the boatyard and the Surveyor. The boatyard are to keep the Surveyor advised as to the progress of the construction.

Part 2 - MATERIALS

Cement

201. The cement is to be Ordinary Portland Cement of a type complying with a suitable specification, such as B.S. 12, and is to have good water­tightness properties. Other types of cement will be considered but no mixing of the various types should be carried out.

The cement is to be of the type specified, and is to be fresh and of uniform consistency; material containing lumps and foreign matter is not to be used. The cement is to be held in storage for as, short a period as possible, under dry conditions and properly organized as regards turnover of material, etc.

Aggregates

202. The aggregates are to be of suitable types with regard to strength, durability and freedom from harmful properties. The material is to be of uniform and of a grade which will readily give a satisfactory minimum cover of the reinforcement without risk of segregation and use of excessive water.

Water

203. The water used in the m1x1ng is to be fresh and free from harmful materials in solution which will affect the strength and resistance of the mortar. Salt water is not to be used.

Batching and Mixing of the Concrete Materials

204. The proportions of cement and aggregates are to concrete equivalent to the basis material (see para. of the materials are normally to be determined by weight, aggregates may be determined by volume where so desired.

be such as to give ). The quantities although the

The water/cement ratio is to be controlled as low as possible to give a material consistent in quality and workability. '

Reinforcement

205. The rods, bars and wires are to be ,of steel ,having a satisfactory yield stress, ductility, tensile strength and other essent~al properties and complying with a suitable specification such as B.S. 18 or B.S. 785.

The wire mesh is to be formed of a suitable diameter steel wire, ' laid up in such a manner as to preserve as much of the strength properties of the basic wire as possible. A sample of the mesh is to be submitted along with the material data.

- 3 -

The reinforcement is to be clean and free of millscale, oil, grease, paint or other contamination.

Part 3 - DESIGN ~~D CONSTRUCTION

Scantlings

301. These requirements envisage the hull and other structures built in ferro-cement, being a form of reinforced concrete in which a high steel content is sub-divided widely throughout the material that the structures will act when under stress as though produced from a homogenous material.

In view of only a limited number of builders at present using this material and also until such times as a common practice is established, the scantlings of the structures will be based on the representative strength figures referred to below, and on an examination of the design and construc­tion methods to be employed. Each case will be examined individually and considered on its merits.

Basis strength properties of representative panels laid up using the same mix and mesh reinforcement as are proposed for the structures, are to be determined as given in Part 4. However, where such representative properties have been previously established by an acceptable authority, these may be considered by the Society and the need for these tests may be dispensed with.

Submission of Plans and Data

302. Plans, in triplicate, are to be submitted for approval for each design before construction is commenced. These plans shall show the arrange­ment and detail of the reinforcement of the hull and other structures. Such other plans as may be necessary to define the structural arrangements are to be submitted.

A data sheet is to be submitted giving details of the materials, mixes, curing procedure, etc. of the ferro-cement construction.

Steel Reinforcement

303. The steel content of the ferro-cement is to be as high as practicable, and the disposition of the rods and mesh to be consistent with the production of void-free material. The rods and mesh are to be correctly disposed and shaped to form, with sufficient transverse members to maintain the form of the hull, and to be securely wired and welded to avoid movement during the placement of the mortar.

The keel centreline member, longitudinal girders, floors, etc., are to be formed with rods and mesh and may incorporate rolled steel sections, but the build-up of reinforcement should not prevent satisfactory penetration of the mortar. Two or more layers of mesh forming the member are to be worked into the hull form, due regard being paid to the sharpness of curvature to avoid large voids within the base of the member.

- 4 -

Any discontinuities in the strength of the reinforcement are to be avoided and the ends of members are to be properly faired into the adjoining structure. The wires of the mesh layers can be orientated to suit the arrangement of lay-up but should not unduly affect the panel strength and pre­vent penetration of the mortar. The'edges of the mesh layers forming the overlaps along the hull centreline, transom boundary, etc., are to be staggered back to permit the reinforcement to be neatly formed and allow satisfactory mortar penetration. Butts in the mesh reinforcement should be correctly arranged and suitably staggered.

The welding of rods and bars is to be carried out by a skilled operator, care being taken to avoid the burning through of the reinforcement on account of excessive heat generation.

Formwork

304. The structures are assumed to be normally built-up by the application of mortar to one side of the reinforcement and trowelled to a finish on the other, however, production using formwork can be employed provided void-free material can be achieved.

Where formwork is used, it should be dimensionally accurate and have adequate stability and strength to resist the weight of the pour. The panelling should be well fitting and free from joints and cracks liable to leak. Free water and debris are to be remove~ before a pour commences. The forms may be hosed down prior to pouring to remove any settled dust.

Concrete

305. The various practices for the mixing, handling, compaction and curing of the concrete should be consistent and closely supervised to ensure high quality material. The practices should comply with paragraphs 306 - 308 and the builder should be guided by established Codes of Practice, such as CP 114 (1957) of the B.S.I.

Handling

306. The mortar should normally be placed within 1-1/2 hours of adding the mixing water, and with continual agitation during the waiting period. During handling and placing of the mortar, care is to be taken to avoid segregation of the mix and if this is seen to be occurring, remedial steps are to be taken.

If the mortar is transported in barrows or skips, these are to be clean and smooth inside and free from leaks.

Compaction

307. ' The material must be thoroughly compacted during placing to ensure the absence of voids around reinforcements and in the corners of any forms. Formless ferro-cement shells are to be compacted by applying the mortar from o~e side of the reinforcement only and then hand trowelling the opposite side. V1brators and hand rodding are to be used in the thicker sections between forms.

- 5 -

Although the m1n1mum amount of mortar coverage over the reinforcement is desirable, this amount is not to be less than that consistent with the satisfactory protection for the steel.

Curing

308. The various structures are to be properly cured and the set concrete is to be kept wet for a period which will depend on the type of cement being used and the ambient conditions. The method of cur:i.ng should normally be by water spray but other methods which prevent evaporation of the residual water will be considered.

Where formwork has been used, it should be kept in position for as long as practicable. Due regaFd is to be paid to the ambient conditions, the type of concrete and the position of the structure before the formwork is stripped.

Items not particularly Specified

309. If the decks, deckhouse, superstructure, bulkheads etc., are of materials other than ferro-cement, the construction is to be in accordance with the Society's Rules applicable to the particular material being used.

Where special reference is not made ~erein to specific requirements, the construction is to be efficient for the intended service and is to conform to good practice.

Part 4 - TESTING

General Requirements

401. The following tests, or equivalent tests as agreed by the Surveyor, are to be carried out on sample panels, the mortar mix and the placed concrete structure. Other tests may be required as necessary at the discretion of the Surveyor.

Sample Representative Panels

402. Sample panels laid up from the same materials and mix, and reinforced with the same number of layers of wire mesh as are proposed for the hull, are to be prepared and tested to determine the typical mechanical properties of the ferro-cel'lent. The ·tests are to be carried out by a recognized laboratory and the results submitted to the Society, however, in certain circumstances, test results by the builder may be considered.

The flexural and the impact strengths are to be. determined on reinforced panels, but the tensile and the compressive strengths may be otained from the un-reinforced material.

Slump Testing of the Concrete Mixes

403. A selection of mixes are to be tested in the standard slump

- 6 -

cone for workability and water content and are to show a minimum slump consistent with reasonable workability.

Compression Testing of Concrete Samples

404. A suitable number of standard test cubes or cylinders are to be taken during the course of application of the concrete as representative of the material being used in the construction. The samples are to be selected and filled in the presence of the Surveyor and are to be suitably indentified.

The samples are to be cured under standard conditions (such as given in B.S. 1881) and the compressive strength determined after 7 days and 28 days' cure. The tests are to be witnessed by the Surveyor, or if done by a testing laboratory, the certified results are to be submitted to the Surveyor.

Watertightness of the Structure

405. The hull and other surfaces which are intended to be watertight, are to be closely inspected for surface faults after completion of trowelling, or when formwork is first stripped when applicable. A smooth, sound appearing surface will normally be presumed watertight until tested by hose, by filling or afloat. Spot checking by air testing may require to be done at the discretion of the Surveyor.

Papers and Discussions on Ferro-Cement

from the

Conference on Fishing Vessel Construction Materials

Montreal, 1968

I . New Thinking on the Use of Materials in the Construction of Fishing Vessels -Traung & Gulbrandsen

I I. Ferro-Cement Boat Construction -Samson

III. Ferro-Cement Boats -Hagenbach

IV. Comments - Muh1ert

V. Estimated Hull Work and Material Content for 100 Ft. Combination Fishing Vessel in Different Materials - Fraser

Reprinted from: Proceedings o/the Conference on Fishing Vessel Construction Materials, Montreal, Canada, October r - 3, 1968.

New Thinking on the Use of Materials

Mr. Traung

in the

Construction

of Fishing Vessels

by

Jan-Olof Traung Assistant to the Director,

Fishery ResouJCes and Exploitation Division, Department of Fisheries,

Food and Agricultural Organization of the United Nations, Rome

and

(/)yvind Gulbrandsen Naval Atchitect, Fishing Vessel Section,

Mr. Gulbrandsen

Fishing Vessels and Engineering Branch, I Fishery ResouJCes and Exploitation Division,

Food and Agriculture Organization of the United Nations, Rome.

Mr. Traung was born in 1919 in Goteborg, Sweden, and started his career as a naval architect in 1940 in a boatyard at Sverre. During his time at Sverre, until he joined FAO, he designed and supervised the construction of some 60 fishing vessels for Sweden, Iceland, France and Colombia, as well as hundreds of yachts and small working boats.

In 1947 he organized and acted as Secretary for the Nordic Countries Fishing Boat Congress in Goteborg, Sweden, and in 1948 received a fellowship to study fishing vessels and fishing methods in the U.S.A. From 1948 to 1950 Mr. Traung acted as Consultant Naval Architect to the Royal Swedish Board of Fisheries in connection with research vessels. He joined the Food and Agriculture Organization of the United Nations in Rome in 1950.

During his time with FAO, he has supervised technical assistance projects in the boat, harbour and fisheries engineering fields in Chile, Dahomey, India, Iraq, Pakistan, Senegal, Thailand, Togo, Tunisia, Turkey, UAR and the West Indies. He is the author of many papers on fishing vessels and fishing methods.

He organized and was Secretary of the 1953 FAO 1nternational Fishing Boat Congress in Paris and Miami, the FAO Second World Fishing Boat Congress in 1959 in Rome and the Third FAO Technical Meeting on Fishing Boats in Goteborg in 1965, and edited the proceedings "Fishing Boats of the World" ( 1955), "Fishing Boats of the World: 2" (1960) and "Fishing Boats of the World: 3" (1967).

6 CONfERENCE ON fiSHING VESSEL CONSTRUCTION MATERIALS

Mr. Gulbrandsen graduated from the Technical University of Norway, Trondheim, as q Naval Architect and Marine Engineer in 1961. He spent two months working as a fisherman on board a purse seiner off the coast of Norway during the herring season in February-March 1962. From April of that year he worked under the Norwegian Naval Architect, Jan Herman Linge, on designs of small power boats, sail boats, and fast marine craft ill wood and fibreglass.

In October 1962 the Norwegian Agency for International Development initiated an associate expert scheme similar to the ones operated by several other European countries. Mr. Gulbrandsen applied and was accepted as one of the first five Norwegian associate experts to be sent out. He started working for FAO on September 15, 1963.

Mr. Gulbralldsen worked for four years and two months as an associate expert under the trust fund arrangement set up between NORAD and FAO until his contract expired on November 15, 1967. From that date he has been employed by FAO and is at present working at its headquarters in Rome.

Jall-()fo/ Trilling ami fjJ)'JIilld Gulhralldsen

ABSTRACT

The cost of material plays a rather minor role in the total cost of flShing enterprises, and very large differences in hull costs are necessary to show up as profit. The wise selection of constmction methods might make possible the choice between more space, more carrying capacity, lower construction cost, higher speed or less fuel consumption. Some materials have specific qualities, e.g., wood and steel pennit a greater amount of versatility. As yet little is known abou t strength requirements for fishing vessels and about the optimum distribution of materials.

The general conclusion is that the choice of material is not so important in the economy as a reduction in the number of crew or the selection of a material which increases the efficiency of acoustic fish-detection instru­ments. Perhaps the ideal fishing vessel will not be construct­ed of a single material, but a combination of materials suitable for variolls places in the hull. Much should also be expected in the future from new materials, such as rubber.

INTRODUCTION

The success of fishing operations is becoming increasing­ly dependent upon the quick detection, catching and keeping of fish. Indeed, one important trend in the design of modem fishing vessels is to improve facilities for the location and detection of fish. At the same time larger and heavier nets are being developed for more effective catch­ing. These nets in tum require more sophisticated winches and other handling arrangements to save labour and to make work easier. In fact, so much has been happening in the fields of fishing methods and gear lately that any astute investor in new fishing craft will be most careful to have the craft designed so that it can easily be adapted for new developments in methods of catching. Further, since the costs of labour are rising more quickly than fish prices, difficulties are encountered in attracting clever and intel­ligent men of the type so necessary for the efficient conduct of fishing operations. More attention to crew comfort is therefore necessary - in particular, appoint­ments of crew quarters, seakindly motions of the ship, protection against weather, and the hazards of deck machinery. With the increasing complications of modern fishing vessles, the whole unit has to be made more reliable since the breakdown of only one small component due to a fault in design or materials could lead to a loss rather than a profit over the whole operation.

7

The traditional way to look upon materials for fishing vessels is frrst expenditure for material, labour cost, depreciation time and maintenance costs, thus arriving at a quasi-economic efficiency of hull cost per value fish landed. Most people recognize, in addition, that the various materials have specific advantages for certain sizes of vessel. Often it is suggested that a diagram be developed, like Fig. 1, from which one could easily select the most advantage­ous material for a given size - and, for example, for a given locality. The diagram given is only a hypothetical one -and both the slope of the curves and their magnitude arc selected at random. It is difficult in itself to develop a tme diagram since it would require many studies for various

. sizes of fishing vessels like the one for lOO-ft vessels which it is anticipated that Fraser will present to this Conference. However, the point is that this traditional way to look upon materials would not ne~essarily produce the most efficient vessel for harvesting fish from the waters.

The new thinking necessary is to consider the fishing craft much more as a complicated machine comprising many integrated components of very specialized functions, requiring careful tuning in order to work with maximum efficiency and effectiveness.

Quite apart from the instmmentation aspect, considera­tion must be given to the constmction of the vessel itself. A hull material transmitting so much noise that it is scaring fish away or is limiting the range of acoustic fish-detection instruments is certainly not economical, however low· its initial cost - or upkeep - happens to be.

CONSTRUCTION OF FISHING VESSELS

Size distribution

In 1965 Canada caught some 1.2 million tons of fish. This quantity of fish was landed by about 40,000 boats ranging in length from 25 to 160-ft. and representing a total value of around $100 million. Most of these vessels were small (Fig. 2, prepared from Proskie's [1965] data) . The "value distribution" (Le ., the number of boats multiplied

- by the mean value of each boat) has its peak somewhat toward5 the bigger boats, but perhaps not as much as could be expected . The most important size range, as regards investn;ents in fishing vessels, is still from 20 to 60-ft. The same pattern of fishing boat size and value distribution would probably be found if investigated on a world-wide scale . Although there has been a tremendous development

8

during the last tcn years towards bigger and more sophisti­ca ted fish ing vessles, those below 60-ft. are still the most important producers of fish.

Bllilding costs

The approximate cost of longliners and small trawlers built of wood in Canada is shown in Fig. 3 (Proskie, 1965). Whcn comparing building costs in other countries (Hamlin, 1967), as in Fig. 4, it seems that Canadian-built wooden vessels compete favourably with steel vessels built else­where. This is in contrast to the relatively high costs for larger steel vessels built in Canada. Fig. 5 (prepared from Proskie's [1966] data) shows percentage distribution of average capital investment in fishing boats from the Nova Scotia area, and a similar distribution is found in other provinces. As the size of vessel increases, so does the importance of hull cost, which varies between 45 per cent for the smallest to 77 per cent for the largest. As an average it can be said that 60 per cent of the total vessel cost can be attributed to the hull. Well worth noting, however, is that the hull cost is low when there is a choice of building materials, but high when steel is the only possible material.

If by various means one could reduce the cost of hull construction by 50 per cent - a rather drastic amount and hardly possible - it would represent a saving of 30 per cent in the total cost of the fully equipped vessel. What is the inlportance of such a saving? How would it influence the early expenditure of the fishing vessel? Proskie (1967) has given the average distribution of total expenditure of no less than 102 vessels and this is shown in a graphical form in Fig. 6. The parts influenced by cost of construction are the fIxed charges (assuming that the hull maintenance will be unchanged). A 30 per cent reduction in cost of construc­tion will correspond to about the same reduction in fixed charges. Since the fixed charges are approxima tely 18 per cent of the total yearly expenditure, cutting the cost of hull construction in half would, therefore, result in a 6 per cent reduction in total yearly expenditure. While a reduction of this amount in a profitable fishing operation means comparatively little, it makes a lot of difference in a marginal case. If the profit is 3 per cent, a 6 per cent reduction in expenditure means a three fold increase in profit. A 6 per cent reduction in yearly expenditure cannot therefore be neglected but it requires that there must be a rather drastic reduction in the hull cost before it appreci­ably influences the total yearly expenditure. Although an effort to decrease building costs is still worthwhile, it is evident that a variation of the order of 10 per cent in the

CONrERENCE ON FISIIING VESSEL CONSTRUCTION MATERIALS

cost of hull material wiII have only a very low effect on the yearly running costs.

Volume or weigIJt?

Fig. 7 shows panels of a 55-ft. fishing vessel built of various materials, and the corresponding weight per square foot. The reduction in wood volume between the sawn frame and the laminated frame is considerable and the low material volume of the bent frame version is also remark­able.

All fishing vessels have some kind of inner lining in the 'fish.holds, which is placed inside the frames to make a surface which can be ·c1eaned easily. In metal craft some kind of insulation must also be provided, otherwise the heat transfer from the sea w.ould be too great. Larger wooden vessels have a ceiling running along the entire length. Therefore, in comparing the space required by various types of construction, one has to add to the thickness of the planking or plating and the height of the frames, the thickness of the lining or ceiling and the possible insulation. On the matter of insulation, materials like wood have advantages over metal. The total wall thickness of various constructions do, in fact, influence to an appreciable extent the hold capacity, and often a construction with bent frames turns out to be far more space-saving than one with laminated frames, even if bilge stringers are required, because they can be built into the lining (ceiling).

While the height of frames influences the space available in holds for fish and the determination of how far aft or forward machinery can be placed, the cost of frames is certainly only a very small part of the cost of the fishing unit. Therefore, the frequent proposals to mass-produce frames for fishing vessels in a central place and ship them to local builders have very little chance of leading to greater economy. In cases where the volume of the fishhold is a limiting factor, space-saving should be considered. A vol­ume-saving construction means a smaller boat and, there­fore, less investment for the same capacity. The gain can be measured in lower fixed charges but, once again, the economic outcome does not show any remarkable varia-

- tions without drastic changes in the volume.

The same argument applies to weight in cases where weight is the limiting factor,. but economy can be obtained in other ways. A glance at the weight figures in Fig. 7 shows that fibreglass gives very low hull weight. (Aluminium would give an even lower figure but since very few fishing

Jall-Olo[ Trallllg and (/)YIJilld Glllbrandscll

boats of this size arc built of alull1iJiium, it has been left out of this comparison) . A fibreglass hull can be about half the weight of a steel or ferro-wncrete hull. Since the weight of machinery and equipment remains the same, the total weight saving is in the range of 30 per cent. Such a saving in the case of a 55-ft steel fishing boat of 47 tons displace­ment would, with the same engine, result in an increase in speed of about 4 per cent (Fig. 8). If speed were kept constant, the corresponding savings in fuel consumption would be about 30 per cent, as shown in Fig. 9.

If the catching capacity is assumed to be directly proportionate to the fishing time, Le., total length of the trip less the steaming time, the increase in catch due to higher speed as a function of the ratio between steaming and trip length varies according to the curves in Fig. 10. A similar curve can also be drawn in the case where the speed is kept constant and a smaller engine is installed, thus showing the savings in fuel costs. It is believed, although without verifying data, that it is more favourable to have increased speed than a low fuel consumption in cases when the steaming time is long compared with fishing time, since the ratio fuel cost to total cost is relatively stable. The main point thus is that reduction in weight can either be utilized for higher speed or for lower engine power, but the choice depends on the type of fishery.

USE OF MATERIALS

Which material?

The basic constructional materials are limited to fishing vessels of certain lengths (Fig. II). No single material can be said to offer distinct advantages over the others. Each material has its advantages and disadvantages and it would be a waste of time to become involved in heated discussions about what is the only or most economic boatbuilding material. More important is a summary of the recent development that has taken place in each of the five main boatbuilding materials and an investigation of the possibili­ties for an even more rapid development in the future . It is necessary to know all the fundamental characteristics of these materials and how they most economically can be shaped into a boat hull. Since most fisheries are changing constantly, fishing vessels are continually being modified and rebuilt. Winches are replaced by more modern types, net drums and cleats are added, bollards and blocks are shifted about on the deck to make fishing operations as

9

practical and less back-breaking as possible. Certain materi­als are more suitable than others for changes which generally take place on deck. Wood has the advantage of being easily screwed and nailed into and, with the ease of welding, steel also is an easy material to deal with for modifications and changes. Similar changes are far more difficult to achieve with materials such as fibreglass reinforced plastic anti ferro-concrete.

In Europe few fishing boats above 80-ft. are built of wood, and the fact that in Canada wooden boats up to 120-f1. compete very favourably with steel shows that it is necessary to be very careful when generalizing on a ,world-wide scale on the preference of one material to another. The cost of material and labour differs so much from one country to a'nother that no grounds for a general conclusion exist .

In wooden boat construction the manufacturing tech­niques of lamination should be studied in order to cut down present high labour costs. Possibly labour savings could be made by using newly developed types of 'marine glue which give good quality laminations without too strict requirements as to pressure and temperature. Parallel with tltis analysis of strength requirements, there must be an analysis o( the labour required to put a wooden boat together. Complicated and technically sophisticated struc­tures often require too much skilled labour. The additional investment in yard machinery might be offset by reduction in labour costs.

The introduction of new fibreglass reinforced plastic (FRP) has been the greatest breakthrough in small plea­sure-boat construction since the war. Its popularity can be noticed at the annual boat shows in such centres as London, Paris and New York, where FRP boats increasingly outnumber boats made of wood and aluminium. FRP will certainly be used more and more for fishing boats below 40-ft. which can be standardized and produced in very great numbers, but it is still not clear to what extent it will be used for bigger boats.

In the 40 to 70-ft. range FRP wiII probably meet hard competition from ferro-concrete, another newcomer in the boatbuilding field . Use of ferro-concrete can result in , a major reduction in building costs and the material. has already proved itself in strength and longevity, so the road seems open for a basic change in fishing boat construction. Here again there is a great lack of research on the best use of this material. Fyson (1968) and many others have given descriptions of basic manufacturing me thods.

10

What strength?

Although the task is difficult, it is necessary to establish how much strength is really required in a fishing boat. Boats obviously have to be strong enough but the question is - how strong? The surveys made by Gnanadoss (1960) and Pedersen (1967) show that there are discrepancies between the regulations of different Classification Societies as to how strong wooden boats have to be. These regulations are the result of age-old practices and do not rest on a scientific basis. The same can be said for many of the regulations for steel fishing vessels.

There are some encouraging signs that successful re­search is being undertaken towards a rational assessment of the strength of wooden boats. The Technical University of Norway, in co-operation with Det norske Veritas, has, by means of a computer, calculated the stresses in a 55-ft. wooden boat and also made practical full-scale tests of construction details (Fredriksen, Moe, 1967; Fredriksen, Pedersen, Moe, 1967). Considerable saving in materials has been achieved while maintaining the same strength.

For a fishing vessel of length under 1 OO-ft., travelling on a sea influenced by wave action, the longitudinal bending moments are negligible. What has to be detennined under these conditions is the pressure on the shell in various places along the hull and the stresses set up. Very few actual stress measurements on fishing boats have been made, and here is a field which should attract much attention in the future. With knowledge of the stresses, material can be distributed in the most efficient way. More tests will be required to obtain data regarding various types of fastenings and how the shear stresses between the planks can best be managed. In this respect the traditional caulking method for wooden boats is far from satisfactory, and new methods have to be evolved in order to give maximum contact between the planks while retaining the ease to change planks needing repair. What is known of the influ­ence of vibration from those large oversized engines used in fishing vessels on ferro-concrete and FRP structures?

NEW THINKING

Rational [actors

In previous sections it was noted that the various measures for improving the construction or design by choice of building material have only a small effect on the economy of the fishing operation. Fig. 6 gives the relative

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

importance of the different cost items. It appears that a much more marked change in the magnitude of expenditure can be achieved by the reduction in the number of the crew rather than by a change in the cost of the material. Considerable work is being done by makers of fishing winches and designers of fishing vessels to reduce the number of crew by increasing automation. The powered blocks and synthetic twines, combined with acoustic fish-detection instruments, have certainly revived purse seining which, not many years ago, was dying out as a fishing method due to its high crew costs. The introduction of pre-cooked food, as on aircraft, caused laughter during the 1966 Montreal Fishing Vessel Conference but could .easily make more difference to the total expenditure than any possible changes in materials. Also such a thing as improving the hull fonn towards less resistance, giving higher speed or lower fuel costs, might be more profitable than a practically possible reduction of construction cost. TItis, of course, does not mean that one should neglect the possible reductions in fixed charges but merely emphasizes that these are only a part of the total cost. One should also remember that the aim is to produce economical boats and that different materials and construction methods are the means to achieve this. A true picture of the influence of materials and methods can be obtained only if it is 'studied in a complete cost model.

The qualities of different materials and ways of utiliza­tion can be expressed in costs, volumes and weights. Together with known factors such as relations between speed and power, distance to fishing grounds and assumed catch rates, a complete cost analysis will give the most favourable combination. The results will vary with country, area and type of fishery and in one case one might get a light and expensive vessel and, in another, a cheap and heavy one, and the speed could be either low or high.

Studies of this kind, of which so far there have been too few, will put the fishennan in a better position to select the right material for his boat. It would also clean the market of quasi-economic and misleading cost calculattons now provided by manufacturers of materials and boats, who always claim that their own product is universally superior to all others.

Irrational [actors

Unfortunately, the choice of material can seldom be made on the bases of entirely rational or fairly well-known factors. TlIere are many aspects that require good predic­tions and guesses to get good economic operations. Such a

fan-Olof Traung and f/Jyvind Gulbrandsen

factor is the versatility mentioned above, while another problem, steadily increasing in importance, is that of the production of noise. It has lately been established that noise does scare away certain fish by causing them to dive and escape the fishing gear. It has also been established that noise reduces the range of acoustic fish-detection instru­£nents, such as asdic. It has been stated that comparatively small reductions in noise level might double the range of such instruments.

What creates noise? Certain propellers (particularly controllable pitch ones when not working at designed pitch) are great generators of noise but it should be possible to choose blade profiles of propellers which create less noise than others. TIle uneven wake field behind a ship creates unsteady propeller forces which are also sources of noise, especially if propeller and rudder shaft bearings do not have the correct tolerances. A small propeller, perhaps driven by the trawl winch motor, placed on top of the main propeller shaft and in front of the main propeller, helps to equalize the wake field - and will decrease noise and vibrations at the same time as it increases propulsion efficiency (Munk, Prohaska, 1968). A further important source of noise is reciprocating machinery, especially if unbalanced and directly bolted to the hull. The way to minimize machinery noise is to isolate the engine from the hull shell by installing it on flexible mountings. While much airborne noise can be absorbed and damped by felt-type materials or perforated plates, the transmission of noise to water can really only be stopped by such dense materials as lead plates or stone. Recently a Canadian journal reported that the machinery of a small fishing boat was isolated by lead plates and the machinery noise then became very "comfortable" for the crew. In future the same type of isolation of engine noise might have to be used in order to protect the fish and the fish-detection instruments rather than tlle fishermen from the noise. Here also heavy materials, such as ferro-concrete, might play an important role.

Further causes of noise might be hull generated and while it is likely that a hull with comparatively little wave resistance may have less noise than one having much, this has by no means been established. Strictly, hull generated noise has little to do with the choice of materials - but designs involving materials like wood and steel often result in unfaired stems and keels which create turbulence. Similarly scoops for water inlets and transducers for echo sounders increase the noise level.

11

Unfortunately, in spite of the research which has been done by the navies in various countries, the results are considered so secret that very little has been published about underwater noise. This is somewhat surprising be­cause there does exist quite considerable interchange of technical information in the hydrodynamics field between navies of the world and between navies and the merchant marine. However, this is not so when it comes to the problem of noise and the possibilities of increasing fish production might be enhanced if such available information could be released.

Future

Any country striving to increase its fish production needs inexpensive and'longlasting fishing craft which can be built locally by unskilled people and modified easily for future needs. In many countries the fish industry is experiencing heavy depression, due partly to unduly high labour costs and partly to high investment in their craft. Millions of dollars are spent on developing new materials such as petrochemicals (plastics), while the research on traditional materials, such as wood, for fishing craft is comparatively non-existent. However, research resulting in new paint-$ystems might do much to revive the importance of wood for fishing craft.

Ferro-concrete seems to offer great advantages in cutti down costs, and it seems a matter of the utmost urgency to clarify all its technical problems so that it can be introduced on a large scale. It should not be necessary' to wait another 20 years for a complete answer concerning the longevity because Nervi's first boat is still intact after 24 years. A research program involving accelerated testing of new materials for fishing craft construction, similar to the testing made with new aircraft, when the whole lifespan of the aircraft can be compressed into a short period of time, is still called for.

Some years ago a firm on the U.S. West Coast was building boats with the midship section of steel, and wooden ends. While perhaps not so successful in its frrst attempt, it revealed' a considerable amount of logical

_ thinking in order to use material to its best advantage in various places in the hulL In the future one must decide whether it is really necessary to make a fishing vessel hull of one material only. Certainly many materials which nobody has thought of to-day will, be used for fishing craft in the future. Couldn't small fishing boats be built like Greenland kayaks of some kind of wooden framing with nylon cloth

12

sheeting (instead of sldn), and why should not rubber be used more? The sllccess during the last ten years of Zodiak·type rubber rafts certainly proves that with rubber one can create a sturdy, reliable, seakindly and fast craft. For mother ships, one could probably well consider the use of inflatable catcher craft.

In order to stimulate discussion, why not consider a fishing vessel with a wooden bow for ease of construction, lead plating under the machinery and lead engine bulkheads

This paper reflects the authors' views and not necessarily those of FAO.

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

to suppress engine noise, steel plating in the midship section for ease of construction and in the stem for best water flow to the propeller, aluminium top sides for stability, steel deck for ease of welding, and aluminium for the superstructure again to ensure stability? The new thinking could extend to equipment also. Various types of rubber containers could be used for holding water, fuel and catches. Perhaps even inflatable fishholds could be con­structed; they could be shipped or towed home as soon as full - and new ones created by inflation!

Jan-Olof Trallng and f/Jyvind Gulbrandsen

Fredriksen, K.E. 1967

Fredriksen, K.E. 1967

Fyson, J. 1968

REFERENCES

and J. Moe StyrkeunderS<j>kelser av Trefartcpyer Del I. Trondheim, Norges Tekniske Hcpgskole.

G. Pedersen and J. Moe. Strength of Wooden Ships Part II. Trondheim, Norges Tekniske Hq,gskole.

Ferro-cement Construction for Fishing Vessels. Fishg News illt. 7(4)(5)(6).

Gnanadoss, D.A.S. Comparison of Wooden Scantlings Regulations. 1960 Fishing Boats of the World: 2. London, Fishing

News (Books) Ltd.

Hamlin, C. 1967

Fishing Vessel Construction Costs and the U.S. Fishing Vessel Construction Differential Sub­sidy. Kennebunk, Maine, Ocean Research Cor­poration.

Munk, T. 1968

Pedersen, G. 1967

Proskie, J. 1965

Proskie, J. 1966

j>roski e, J. 1967

Ridgely-Nevitt, C. 1967

13

and C.W. Prohaska. Unusual Two-propeller Ar­rangements. 7th Symposium on Naval Hydro­dynamics, Rome.

Wood for Fishing Vessels. Fishing Boats of the World: 3. London, Fishing News (Books) Ltd.

Economic Aspects of Small-Boat Fishing. Con­ference on the Design, Construction and Opera­tion of Small Fishing Vessels. St. John's, Newfoundland, College of Fisheries, Navigation, Marine Engineering and Electronics.

Some Economic Considerations Relating to Canadian Atlantic Offshore Fishing Vessels. Proceedings Canadian Atlantic Offshore Fishing Vessel Conference. Ottawa, Department of Fisheries of Canada.

Costs and Earnings of Selected Fishing Enter­prises Atlantic Provinces 1964. Ottawa, Depart­ment .of Fisheries of Canada.

The Resistance of a High Displacement-Length Ratio Trawler Series. New York, Trans. SNAME Vol. 75".

14

4

/ • ... ____ 3

--h """ .... .---..... . ........... ... .. ___ _ _______ 2 '. ---::;::0-......... ------ -

--.~:.:..

Figure I - If one makes 5 or 6 designs of fishing vessels of various sizes and calculates the cost of hulls built out of various materials, such as wood, steel, fibreglass reinforced plastic and ferro-concrete, and calculates the factor of the hull cost (depreciation cost + main­tenance + interest) per value of fish landed, one might get a number of curves with quite different characteristics, some of them showing specific mini­mum costs. It would seem simple from such a diagram to select the most economical material for a given size but unfortunately this type of calculation would not take into account the tishing effectiveness, versa­tility, reliability and crew comfort of the individual materials.

CONFERENCE ON fiSHING VESSEL CONSTRUCTION MATERIALS

t I o

j . z

NUMBER OF VESSELS

TOTAL VALUE OF VESSELS

o

Loa jft It -.....

Figure 2. - Approximate distribution of number and value of fishing vessels in Canada (Proskie, 1965)_

Jan-Olof Trallll~ alld $Yl'ind Gulbrandsen

en '-~ (5 "U

.... 0

en "U c 0 11/ ';:) 0 £ c -en 0 U

120-r--------------.---------------r-------------~~------------_,

110

100~--------------4---------------+---------------~----~~~--_4

90

80

70

60

50

40

30

20~--------------~----~~~~~~------------~------------~

10

O-r--------------~------------_r--------------~------------~ 30 40 50

Loo in ft ~

Figure 3. Building costs in Canada (proskie, 1965).

60 10

15

16

lit ... .!! '0 "0

15 .. "0 c: 0 lOt ::)

2 -.!: -.. 0 U

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

1.000-r--------------,---------------~------------_,--------------~--~

900

800~------------~------------4_------------+_--~~--~~~_4

700

STEEL SIDE TRAWLERS

CANADA

600 STEEL STERN

TRAWLERS STEEL VESSELS CANADA

US

~OO

400 GERMANY NORWAY UK HOLLAND

300

WOODEN SIDE TRAWLERS

CANADA

200

100

0~----~-----4~----r_----~----1I----_+----~------r_~

70 80 90 100 110 120 130 140 I~O

Loa in ft.----.

Figure 4. Building costs in Canada according to Proskie (1965) compared with building costs in U.S.A. and elsewhere (Hamlin. 1967).

DANISH STERN SCALLOP WOODEN STEEL VESSEL SEINERS DRAGGERS DRAGGERS TRAWLERS TRAWLERS

AVERAGE LOA 60 57 96 115 120

AVERAGE COST $ 31.348 57.604 166.179 300.868 547.209

Per cent

1v"v'Vr- ENGINE

80-+-----1

I- HULL 40-1-----1

30-+-----1 .

20-+-----1

10-1-----1

O~ ___ ~ __ ~ ______ ~ ______ ~ __ L_ ___ ----&------A--~

Figure S. Distribution of average capital investment in fishing vessels of Nova Scotia (proskie, 1966). The figure indicates that the proportion of the hun cost is larger for larger vessels and thus, for larger vessels when steel is the only possible material, there are slight possibilities of getting large changes in total expenditure due to material selection.

17

18 CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Per cent

100 HULL

ENGINE MAINTENANCE

90 EQUIPMENT AND

REPAIR GEAR

80

FUEL

70 OTHER

OPERATING ICE

EXPENSES PROVISIONS

60 WHARFAGE MISC.

INSURANCE

50 TAXES INTEREST. FIXED

CHARGES DEPRECIATION

40

~o

20 CREW SHARE

10

O~----~------L---------______ ~_ Figure 6. Average distribution of total expenditwe of 102 vessels, Atlantic Coast, -Canada (Proskie,

1967). The figure indicates that compared with the cost for the hull and fixed charges relating to the hull cost, the crew share is considerable and that a reduction of one man of the crew might mean considerably more than a large difference in hull cost.

Ja1l-Olo/ Troung and f/Jyvind Gulbrandsen

TRADITIONAL DNV

Rules 1957

LAMINATED

Proposed D N V

Fir

Fir

31/8" X 5 I/Z"

16"--~~

. 21/4"x4"

BENT FRAME I Nr' U.S. WEST COAST o~~ ~ (Bilge stringer .2$~~::::=-=---

essential) " _ I ~ Fir ~'IO~ '"

STEEL U.S. WEST COAST

FRP

LLOYD'S

[ IE

c: 15" ~

3"x 2"x 1/4"

i ~f

FERROCONCRETE {!'ZZXZZZZZZZ2/ZXz i 7ZZY.z~~

WEIGHT

14,5 1b/ft 2

8 l%t 2

12.5 1 bitt 2

Figure 7. Shell panel proposals for a 55-ft fishing vessel built of various materials. When studying these sketches one should rem em ber that a lining is necessary in the fishhold for all vessels, that larger wooden vessels have to have a ceiling and that steel vessels 1nave to be insulated in the fishhold. Thus the insulating properties of wood have a certain advantage over metal construction.

19

20

, 10 ' ...... " ... ,, ~ , ... , ... :--... ... ,

:--...::-..... ' ... " ..... ~~

~ ' ... ...... .................. <D.

.........

A •• , t.". _______ Til ..... _ . _ a "not. ___ ellftO"

Figure 8. - The necessary power to drive a 55-ft. vessel with various displacements was calculated and this diagram was plotted, using the displacement of 47 tons as a basis. If the displacement is reduced by, say, 30 percent, the speed will increase by about 4 per cent in the 8 to 9 knots range, and if the displacement is increased by 25 per cent, the speed loss will be about 3.5 per cent. This diagram then shows that large differences in displacement mean comparatively small differences in speed. The dia­gram was calculated from Ridgely-Nevitt (1967).

+ 20'1\.

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

910

J j'O I 0

1 '0

i<D1O • So

J

h-L~~ ~~

,~~

L ,~'

,~/

~ ~/ " .. -':.?..-"

o :::r_'/'" 00

eo .50\1, .... '1\. 0.47 tOM

_______ 7 kIlO" __ eknot. ___ 1 knot.

Figure 9. - If the displacement of the 55-ft vessel in Fig. 8 were modified and the speed kept constant one would obtain larger or smaller fuel consumption. Thus, if the displacement were decreased by 30 per cent, the change in .fuel consumption would amount to about the same value. Similarly, it would increase by 25 per cent if the displacement were increased by this amount.

Jan-O/o! Troung and (/JYJlilld Gu/brandsell 21

'" :J C

'" > '" '-

.= CII II> o :! u .5

CII 00 o C CII

~ CII

Cl.

25

20

1<:1-- sptl«! incIVos,d by 5~

15

10

5

o 10 20 30 40 50 70 eo

Percentage steaming of the entire fishing trip

Figure 10. - The preceding Figs. 8 and 9 show that one could choose between a comparatively small increase in speed or a large decrease in fuel consumption, if one is changing the displacement. For cases where the steaming time is comparatively long, a reduction in steaming time might mean that the fishing vessel can spend more time on the fishing grounds and thus a small speed increase might mean comparatively large increase in revenue.

22 CONFERENCE ON FISHING Y ESSEL CONSTRUCTION MATERIALS

WOOD ........ ------.... ------.... --.... ----.... ----.... ----.............. .. STEEL ........ ____ .. __ a. ______ .... __ .............. ______ .... __________ .... ____ .... ..

ALUMINIUM -----------------------------

FRP -------.. _------------------------FERROCONCRETE

o Boot lenath ___ ft .

Figure 11. - Approximate sizes when some typical boat building materials are used to advantage.

Reprinted from: Proceedings of the Conference on Fishing Vessel Construction Materials, Montreal, Canada, October 1 - 3, 1968.

Ferro-Cement Boat Construction

by

John Samson, President, Samson Marine Design Enterprises Ltd.,

Vancouver, B.C.

Mr. Samson

Mr. Samson was born on the Canadian prairies in 1937 and joined the Royal Canadian Navy when he was 17. He later spent six years overseas working in various boatyards around the Pacific. He started his own boatyard in Richmond, British Columbia, in 1966. Mr. Samson has made several trans-Pacific crossings in sail boats and power boats. Much of his boat yard work has been on the building, repair and mailltenance of fishing boats.

ABSTRACT

In this paper Mr. Samson, a pioneer of ferro-cement boat construction, discusses in detail the construction of a ferro-cement hull through from lofting to completion of plastering. He does not touch on the merits or dis­advantages of this relatively new medium, but rather confines himself to construction techniques.

He takes as an example the construction of a 44-foot salmon troller designed in the S.M.D.E. office specifically for ferro-cement.

Mr. Samson covers the recently developed building technique which involves web frame construction, and this is probably the technique which will be used in the construction of fishing vessels up to the 100-foot mark.

The paper contains the latest information on bUilding materials and mixtures, etc.

OUTLINE OF METHOD

Any description of ferro-cement boat construction could run into lengthy chapters but the follOWing is a concise outline of the method which will most probably be adopted in the building of a fishing vessel.

We will refer to this method as the web framework technique - a method which should be found to be most suitable for medium to large size fisl>ing vessels. Other techniques now being Widely used in the industry are the pipe framework and cedar mold methods. Many im­provements in ferro-cement building technique lie ahead and this web framework method serves as an example of this. The many refinements it presents would not have been possible without the earlier efforts.

At the outset it must be made clear that the web framework technique is for one-off construction. It was evolved to bring about improvements in structural con­struction techniques, and not to illustrate production methods. And, while it does streamline construction, the end product is the same, the building materials are the s$l1l1e. The basics of wire mesh, reinforcing bar and mortar have not been cast aside.

A 44-foot West Coast troller, recently designed by Samson Marine Design Enterprises in Vancouver, will serve as the demonstration vehicle in this discussion. Construction of this vessel is taken through from the very first stages.

The first consideration is the structure which will support the hull throughout construction - and this can

268

also serve as the structure which will shelter the hull. Too much emphasis cannot be placed on this structure and l11ustration No. 111 details a suitable type of building in which lofting can be carried out under good conditions.

It should also be pOinted out at this stage that in this 44-foot troller design the fish pens and bulkheads have all been designed on stations for ease of construction (see Illustration No. 1104).

After the lofting is complete 1/4-inch plywood pat­terns are cut for the webs and bulkheads and on these are carefully marked the waterlines, diagonals and buttocks. This will aid in setting up the hull.

Two layers of 1/2-inch 22 gauge chicken wire are now lightly stapled to one face of the plywood patterns. The inside edges are neatly trimmed off with shears while the outside edge is allowed to run wild for 6 inches. This overlap will later join into the hull and to achieve this on the curved areas darts must be cut at 6-inch intervals on the overlap.

While the patterns are still lying on the workshop floor one-inch by one-eighth-inch strap iron should be attached to the neatly trimmed inside edges and to any edges which will not later mate with mortar. These strap edges will give a neat finish and can be attached in position with nails..

The strap edges are applied where bulwark stanchions, access cut-outs and fish pens occur together with all areas of framing which are not joined with the hull. These form screeds which give the plasterer a landing for his trowel.

A length of 1/4-inch cold-rolled reinforcing bar is now spot welded into the corner formed by the strap edge and the mesh-covered plywood pattern. A second length of 1/4-inch reinforcing bar is now stapled to the outside edge of the mesh-covered pattern, giving a true outline of the mold. Continuous lengths of re-bar are then filled in on the pattern on approximately 2-inch centres with shorts welded into areas which form the keel, bulwark braces and engine bed braces.

Short lengths of the 1/4-inch reinforcing bar are cut in readiness for positioning across these continuous lcngths of rod. They are welded in place on 6-inch centres and odd ones should be attached at 45-deg. anglcs for bracing.

CONFERENCE ON F1SIHNG VESSEL CONSTRUCTION MATERIALS

These shorts are allowed to protrude for about one foot beyond the outside edge (see Drawing No. 106).

Two more layers of the 1/2-inch 22 gauge chicken wire are now stapled on top of this re-bar framework with the inside edge again trimmed off neatly with the shears. And again, darts must be cut into the outside edge at 6-inch centres, the outside again being allowed to overlap for 6 inches.

In the medium-sized fishing vessel, these' now pre­formed webs would not be plastered at this stage. In the larger vessel, however, it might be considered advisable to

. plaster at this point and provide stiffening for the vessel during the remainder .of the construction. In this case, the strap iron screeds would be replaced by three-quarter-inch by one-inch wooden .screeds or whatever thickness of bulkhead is designed into the vessel. These web patterns would then 'be plastered right on the workshop floor.

Returning now, however, to our 44-foot troller we are ready to commence the setting-up of the vessel. Using waterline "A" as our guide, lengths of 2 x 12" lumber are attached to the frame patterns, and these are hung in position as' shown in II1ostration No. Ill.

The next step is to shore-up a length of channel iron which will run along the straight length of the keel. This serves a number of purposes and provides an ideal ground­ing shoe. Sharp corners of mortar are inclined to chip and the channel iron eliminates this danger. The bottom of the keel has also proven a difficult area in which to achieve perfect penetration. The channel, iron helps pro­vide the finish and is further a good stiff member to assist in the set-up and reduce movement throughout con­struction. When shored-up in place this channel iron is welded to the web frames to ensure against shifting during construction (Diagram No. 108).

The channel iron is used along the straight length of the keel and where the sweep of the bow commences a length of one-inch cold rolled steel rod is substituted. This is allowed to run wild beyond the sheer line and can be secured overhead for further stiffening.

The shaft log is now set-up as shown in Illustration No. 119 and when this is complete the stem assembly can be set up.

After ensuring the hull is fair the task of welding in place the longitudinal lengths of l/4-inch reinforcing rod

Johll SalllSOIl

can begin. It will be found silllple~t to spot weld the longitudinals first along the water lines and then fill in with lengths on 2-inch centres. Quarter-inch re-bar ribs C:.lI1 now be spot-welded into place vertically on 6-inch centres. Extra rods should be pl:Jced in the stem area, parallel to the stem and about one-inch apart for re­inforcement.

Short rods arc bent around the inside of the stem and welded in place as shown in Illustration No. 111.

The wire Illesh which was left protruding frum the web frames '.""ill now of course have becn bent over to allow placemclll of the longitudinais, two layers in each direc­tion and the short rods protrud ing from these frames can also now be bent at right angles and welded into place. These should all be bent longitudinally, fore and aft alternately.

It should perhaps also be pointed out at this stage that as the deck is constructed in the same llJanner as the hull the vertical rods fonning ribs in the hull should be lapped in and welded to rods running athwartships on the deck. The re-bar on the deck should follow the contour on two-inch centres. All beds and joints should have a minimum of a five-inch radius.

I-latch coamings, etc. should also be finished off at this stage and edged with one-inch strap iron screeds.

While the over-all thickness of the hull and deck will ideally va!)' little over three-quarters of an inch, the one-inch screed is used to ensure that all stray ends of mesh can be well buried in the mortar.

The engine beds are next framed up before the 2 x 12 lumber braces are removed. These lumber braces are removed one at a time and transferred to an overhead position, see Illustration No. 111. The hull is then braced to these lengths of lumber by lengths of re-bar attached to the deck.

The hull is now ready to receive the wire mesh - eight layers of the 1/2-inch 22 gauge chicken wirc. Four layers are attached to each side of the rods. Mesh obtained in lengths 3' x 150' will be found the ea'.lest to work with. Desired lengths can be doubled and suspended from the sheer, ensuring that the joints are lapped. On the inside, the wire mesh must lap over the mesh on the web frame.

269

The llIesh must be laced as tightly as possible, using tic wires or hog ring fasteners.

When the mesh is tightly laced, the 1/4-inch wooden plywood pattems can be freed from the staples and the mesh secured on the webs. And, when the wire mesh is tightly laced all over, 3/4-inch plywood wooden blanks can be positioned for any through-hull fittings, deck fittings, limber holes etc.

Now is the time to put braces under the bilges to eliminate any danger of distortion when the wet mortar is

. applied. The hull framework can now be well hosed to oxydize the mill-scale off the reinforcing bars.

Scaffolding must nQw be rigged in preparation for the plastering.

The mix to be used on this hull is as follows:

200 Ibs. sand All sand must pass a No. 8 sieve with 10 per cent passing a No. 100 sieve. There must be an even grading curve of the inbetween sizes, see Illustration No. 451. The sand should be sharp and ingenious in origin ..

87 1/2 lbs. Type 5 Portland Cement. Sulphate resistant.

15 Ibs. Pozzolan or fly ash.

4 1/2 imperial gallons of water or sufficient to allow penetration.

The first part of the hull to be plastered is the keel, using a vibrator to ensure penetration. TIns is followed by the underside of the decks and the webs.

The mortar is then applied to the inside of the hull and is squeezed through as thoroughly as possible, with the finish applied from the outside.

The top of the deck should be plastered one week later using a latex bonding' agent. The coat applied to the underside will provide the necessa!), form for this.

It can normally be expected that a hull of this size will take 14-18 hours to plaster with an,eight to ten man crew. Two shifts would be advisable.

270

The outside of the hull should be given a trowel finish. The temperature for the plastering work should be between 50-80 degrees and the wetting dowll process should begin after 24 hours. This will be carried Ollt continuously for three weeks.

• After this curing period, the outside of the hull should be etched with muriatic acid and well rinsed. Two coats of a tar based epoxy are then troweled on to protect any stray ends of wire mesh which may be protruding. The hull can then of course be painted to suit, again using an epoxy paint on the topsides and vinyl anti-fouling.

The wooden cabin is to be through-bolted into position and aU deck-fittings wi.ll be bolted into place using hardwood backing blocks.

The fish hold will be insulated with sheet styrofoam glued onto the ,inside of the hull. One layer of wire mesh can be applied over this and plastered, allowing the inside of the hold to be easily cleaned.

The fuel tanks and water tanks will be constructed from mild steel.

The forepeak of the vessel can also be lined with the styrofoam covered with a white vinyl. Spruce sparring can be placed over this to provide a warm, clean foc'sle.

In summary, the fishing boat hulls already in service appear to withstand impact reasonably well. While damage has been encountered it has been quickly and inexpensively repaired. The damaged areas have been pounded out using a dolly on the inside and a pin mall outside. After pulverizing the area the rod and mesh is straightened and new plaster applied.

CONFERENCE ON nSIIING VESSEL CONSTRUCTION MATERIA

The hulls in service have to date reported no damage through electrolysis. Corrosion is minimal providing the hull exterior is well sealed and maintenance is low.

Seepage is nil and cement has proved a good material for absorbing engine vibration. Steel and cement have very compatible expansion co-efficients.

While all these factors point to the practicability of ferro-cement construction it should be pointed out that light high speed planing hulls are not suitable to the medium. However, large hulls are only limited in size by relation to the thickness of reinforcing through which the

, mortar can be successfully forced.

Another factor weighing in favor of ferro-cement is its ductability which is lower than steel, aluminum or fibre­glass. And of course, ferro-cement appears to improve with age. It should also be pointed out that the medium achieves its waterproofing properties from the high percentage of fines present in the mixture and not from additives.

As we said at the outset, this has been little more than a very brief outline of one construction method which can be used with the ferro-cement medium. There are other methods and other techniques which can be successfully applied in fishing boat construction. Now that more attention is being paid to the ferro-cement medium it is almost a certainty that even more improvements will be made-probably quite rapidly.

Perhaps it is well to remember the words of one leading ship builder who said: "It is a matter of economics. When initial construction and maintenance become too expensive, new materials will be found to take their place".

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Reprinted from: Proceedings of the Conference 011 Fishing Vessel Construction Materials, Montreal, Canada, October 1 - 3, 1968.

Ferro-Cement Boats

Mr. Hagenbach

by

T.M. Hagenbach, Managing Director, Seacrete Ltd.,

Wroxham, Norfolk, England

Mr. Hagenbach (M.A. Cantab) the 58-year old Managing Director of Seacrete Ltd. and Windboats Ltd., Wroxham, Norfolk, England, took an honours degree in Law at Cambridge University and subsequently qualified and practised as a lawyer in the West Riding of Yorkshire. Feeling that "Boats were a more congenial way of making a living" he acquired a Norfolk Broads boatyard in 1946, which soon gained a national and later an international reputation. Starting the manufacture offerrocement (Seacrete) boats some nine years ago, his company is now regarded as the world leader in this sphere. (Editor'S Note: The author prefers the use of "ferrocement" as one word.)

ABSTRACT

After tracing the history and development of ferro­cement as a boatbuilding material and drawing comparisons with the physical properties of competitive materials, the author contends that ferro cement - of which "Sea crete" is a specialized form - is the logical material from which to build fIShing and commercial craft for the following main reasons:

1. The ability to build hull, decks, bulkheads, floors and engine bearers, fish tanks and bulwarks in one piece, resulting in a monolithic structure of immense strength which actually increases in strength with age.

2. Due to low cost of raw materials and the type of labour that can be employed, a ferro cement hull will generally cost less than an equivalent hull in other material.

3. Because it has great resistance to abrasion, will not corrode, has proven aging properties and is immune to marine borers, maintenance costs with a ferro­cement hull are less than any other.

4. The ease with which a ferrocement hull can, in the event of damage, be repaired by unskilled labour in any climatic conditions except freezing.

Brief details will be given in the paper of approximately 150 ferro cement craft built by the Seacrete company and acceptance of the material by Lloyds Register of Shipping, Bureau Veritas, the United Kingdom White Fish Authority and the Food and Agriculture Organization of the United Nations in Rome.

FERROCEMENTBOATS

It is my intention today to present to you the case for ferrocement boats. Whilst these are frequently and popular­ly referred to as "Concrete Boats" nothing is really further from the truth.

It is of course true that in both cases sand, cement, water and steel reinforcement are used, but beyond that there is a real and fundamental difference, which I will explain later.

First let me point out that using concrete in the marine field is certainly not new. Between 1917 and 1922, due to the shortage of steel during and just after World War I, over 150,000 tons of concrete shipping was built on both sides of the Atlantic. The vessels ranged in size from 7,500 ton oil tankers to small tugs and lighters, and the hull thickness was usually between 4 inches and 6 inches.

366

The main point that I wish to make in regard to these old concrete craft is that in the light of tests carried out recently on panels cut from them, it was found that they are stronger today than when they were built. This is a normal characteristic of almost any cement product - it increases in strength with age. \

The material that we shall discuss is ferrocement. Probably the inventor of the technique was M. Jean Louis Lambot, a Frenchman who was born in Montford in 1814. In the Museum at Brignoles, France, there is a ferrocement boat built by Lambot over 120 years ago. The boat is 11 feet 8 inches long and 4 feet 4 inches across the beam. The sides are approximately 1 3/8 inches thick and there is a bulwark of approximately 2 5/8 inches in breadth with an iron strip on top. It is still in fairly good condition and the metal pins to be used as rowlocks are still in position.

The name "ferrocement" was coined by Professor Pierre Luigi Nervi, to describe a new material consisting of cement mortar and reinforcement in multiple layers of light mild steel mesh.

Nervi showed that if there was a high percentage of mild steel evenly distributed throughout the cement mortar, the result was a marriage of the steel and mortar, resulting in a waterproof homogeneous material with a high degree of elasticity and a high resistance to cracking.

This is the vital difference between concrete and ferrocement. In the case of reinforced concrete there is no marriage of the metal to a concrete mix and nonnally reinforced concrete is not waterproof.

Nervi made slabs of up to 2 1/2 inches thick without losing any of the particular qualities of ferrocement. In 1943 ferrocement as a hull material was accepted by the Italian Naval Register and the Department of Marine Engineering of the Italian Navy.

Following this various craft were built in ferrocement in Italy, including a 165-ton motor yacht "Irene" - with a hull thickness of 1 3/8 inches, a 20-ton crane pontoon "Toscana", a trawler "S.Rita", and a 41-foot ketch "Nennele" .

So far as the marine field was concerned, the data and technique appeared to lie donnant until 1959 when Mr. Paul Hagenbach, D.I.C., A.M.I.C.E., A.M.LE.Aust., A.M.I.Struct.E., at Civil Engineer who had taken degrees

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

both in Zurich, Switzerland, and in London, England, persuaded me, his uncle, with the boatbuilding company of Windboats Ltd of Wroxham, Norfolk, England, to embark on ferrocement boat construction.

Many of you hearing this paper may be sceptical. Believe me, positively no-one was more sceptical than me. I regarded concrete as something that one used for making a garden path and which cracked if anything dropped on it. My nephew was a very persuasive young man, so we got underway.

With the knowledge that I now have, perhaps the most remarkable thing about ferrocement is the length of time that it has taken for interest in it on a worldwide scale to be aroused to its present pitch. However, to those who know the world of ships and, boats and the nature of the people who buy them, this is not altogether surprising.

A boat of any size represents to the buyer, particularly if he is a fishennan or commercial user, a sizeable long tenn investment. He is, therefore, naturally somewhat conserva­tive in his outlook, with a strong leaning towards materials with which he is familiar and whose qualities - even if some of them are undesirable - he knows well.

I confess that it took some time for me to become absolutely convinced that ferrocement was logically right. Immensely strong, maintenance free, easy to repair and economical to build. I realised however that there was bound to be incredible prejudice against it.

We developed our own specialised fonn offerrocement, called it "Seacrete" and fonned a company, Seacrete Ltd., especially to develop it. The first three hulls were made by Seacrete Ltd. for their parent company, Windboats Ltd, for use in Windboats' Fleet of Norfolk Broads hire craft. There were three reasons for this, apart, of course, from the fact that at that time it would have been practically impossible to find any other buyer.

The first was that a Norfolk Broads Holiday Hire Fleet is as good a testing ground as you will find for materials whose claims for attention include touglmess and durabili­ty. A cruiser let for 25 'Yeeks each season will have many holiday skippers, most of them inexperienced and liable to submit a boat to !llore ill-treatment in a week than a professional wQuld in a year.

The second was that it would enable us to compare the wear and tear suffered by the Seacrete boats with that to

T. M. Hagenbach

craft of traditional construction - including glass fibre - in exactly similar circumstances. Thirdly, we wished to gain firm first hand experience of the material in use, knowing that our chances of selling craft made of Sea crete would depend entirely on our ability to put before potential buyers irrefutable evidence of its properties.

Our first season with the Sea crete cruisers out on hire satisfied us that Sea crete was everything that we had hoped it would be and more followed into our holiday fleet. The boats had a tough time during those early years. One was rammed by a two ton yacht travelling at around 5 knots. Another was struck amidships by a 3 1/2 ton sloop travelling at around 10 1/2 knots. A third suffered an explosion which blew the cabin top 50 feet into the air and the mast 200 yards, while during the winter of 1962/3 two cruisers were locked in 18 inches of ice for over two months.

Whilst at the time we did not enjoy seeing our boats subjected to this sort of thing, we were delighted with the evidence the mishaps they suffered produced. The ice­bound boats suffered no damage at all; while those subjected to ramming and the explosion incurred damage so minor in character, compared with what would have happened to them 'had they been made of any other material, that the merits of Seacrete were proved beyond all doubt.

It is not by accident that the facts obtained during those early years, coupled with a straightforward statement of the physical properties of Sea crete as established by independent laboratories, still fonns the basis of our sales literature today.

A major breakthrough was obtaining the approval of Lloyds Register of Shipping - after two years of tests -and the building of a cruiser classed 100 A.I. by Lloyds. In January 1967 Lloyds produced their own rules for ferro­cement craft, thus giving the material international recogni­tion. Sea crete is now also approved by Bureau Veritas, is accepted for grants by the United Kingdom White Fish Authority and is approved by the Food and Agricultural Organisation of the World Health Organisation in Rome.

In the light of experience gained in building over 150 ferro cement hulls I make the contention that ferrocement -of which Seacrete is a specialised form - is the logical material from which to build fishing and commercial craft, for the following main reasons:

367

1. Monolithic Structure.

The ability to build hull, decks, bulkheads, floors, and engine bearers, fjsh tanks and bulwarks in one piece, resulting in a monolithic structure of immense strength which actually increases in strength with age.

This is only possible in ferrocement.

Photograph A shows a 46-ft. trawler with all those items listed built in one piece in Seacrete.

2. Ease of Construction.

Ferrocement craft can be built without highly skilled labour. This is 'not so in the case of timber or steel. No expensive plant is necessary, which is the case with steel constfuction and to a lesser extent with timber construction.

It is not necessary to use a mould for ferrocement construction, as in the case of building in glassfibre, and no temperature controlled shop is necessary.

The process and technique lends itself readily to "one off' construction and also to local manufacture in less sophisticated countries.

3. Raw Materials.

The raw materials necessary for ferrocement construction' (with the exception of the steel mesh) are cheap :md usually readily available in most countries. Ther~ is a dearth today of good quality seasoned boat building quality timber almost every­where. Many countries are without steel plants. The materials for glassfibre construction are relatively ex­pensive and sometimes require special storage facil­ities.

4. Initial Cost.

Much misleading data has been published, usually by amateurs, on ' the low cost of manufacturing ferrocement hulls. There is a vast gulf between an amateur bUilding a boat for himself and a commercial manufacturer bUilding and guaranteeing his product. Generalisations are always dangerous but a ferro­cement 11ull may be expected to cost 20 to 25 per cent less than a similar hull in timber or steel, but this is only half the story. The engine, stern gear equi~

368

ment and superstructure, of course, will cost the same.

Over-all saving may not be more than 4 to 7 per cent, but this is great because you also get a better boat.

To give an indication: the materials and man hours to construct the 46-ft. trawler in photograph A, inclu­ding hull, floors, engine bearers, bulkheads, fish tanks, decks and bulwarks were as follows:

Materials U.K. prices, cost £545

Man hours, 2752

Figures for the 30-ft. boat hull in photograph B were as follows:-

Materials, U.K. prices, cost £191

Average man hou rs, 1051

5. Maintenance.

Unlike steel, ferrocement is immune to rust and corro­sion. Unlike timber it will not rot and is immune to marine borers. Unlike glassfibre, ferrocement has proven ageing qualities. Ferrocement does not require painting except to enhance appearance.

6. Strength.

The ultimate tensile strength of Seacrete is 5340 psi, and because a mesh reinforcement is used it will have this tensile strength in all directions. The tensile strength of wood is approximately 4000/10,000 psi along the grain and negligible across the grain. The tensile strength of a wooden hull is also diminished considerably by the fastenings and the fact that the grain often runs out. In ferrocement hulls there are no fastenings and the tensile strength is accordingly unifonn.

Compressive strength of the material without rein­forcement is about 7200 psi after 7 days, and 12,225 psi after 28 days, and continues to increase with age far in excess of wood.

Any fishing vessel must be strong enough to with­stand rough treatment in harbour, where it will

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

inevitably be subjected to buffeting by and rubbing against neighbouring craft or the quayside.

Seacrete craft being used off the beach in Kenya have demonstrated the material's enormous resistance to abrasion. This would appear to be the great weakness of glass fibre.

7. Weight.

The specific gravity of the ferrocement is 2.6, that of glass reinforced plastic 1.6, and that of a wooden hull, including fastenings, 0.9. Whilst in craft of less than approximately 40-ft. length over-all, a ferro­cement hull with a 7/8 inch skin is generally heavier than a hull built in other materials. In the case of craft over 40-ft. over-all, when skin thickness of other materials must be'increased, a Seacrete hull compares favourably in over-all weight with most wooden, glass reinforced plastic and steel hulls, particularly because no heavy internal frames are required.

Photograph B shows a 30-ft. Seacrete hull with a beam of 13 ft. with engine installed, as supplied to Keny'a for completion locally into a shrimp trawler. Notice that the hull maintains shape without cross bracing.

Due to the built-in framing and inherent strength of the material, it is quite possible to obtain 11 per cent more useable space than in a similar sized craf~ witl! a hull constructed in some other material.

8. Ease of Repair.

Another advantage over other fonns of hull material is ease of repair. Should a hull be danlaged in a collision it can be repaired, in any climatic conditions except below freeZing, in much less time and with less tools than in the case of any other hull material.

Photograph C shows a 34-ft. Seacrete hulled cruiser after she had been struck amidships by a 3 1/2-ton sloop travelling at 10 1/2 knots. Notice that the hull is only damaged at the point of impact. The repair including repainting,' took 21 man hours.

The proct:dure is as follows:

The danlaged skin area is chipped away until the surrounding material is sound and undamaged. It

T. M. Hagenbach

should be remembered that damage to a Seacrete hull is completely localized and confined to the area where impact took place. Once the broken ferro­cement has been removed, any broken or damaged mesh reinforcement should be hammered back into its original position, and in exceptional circumstances replaced. Ferrocement mix can then be applied both to the interior and exterior of the damaged section. The exterior is left slightly proud and finally ground off. Normally a repair can be effected in one working day. Even in tropical conditions it is comparatively sin1ple to repair a ferrocement hull, humidity being a help rather than a hindrance.

9. Non-absorbent and Odourless.

Ferrocement hulls do not absorb moisture, and therefore there is no risk of contamination by fish in fishing boats. Moreover the material is a very good insulator having a thermal conductivity of 68.88 btu/sq.ft/deg/F/hr. Consequently there is little or no risk of condensation in such hulls which are in addition completely odourless.

May I, in conclusion, give brief details of over 150 ferrocement craft built by my company.

369

These have been exported to ten countries and have ranged in size from a 20-ft. dumb barge to be used in connection with oyster fishing, thirty-six 26-ft. cruisers for Norfolk Broads charter work, three 30-ft. open fishing boat hulls with a beam of 13 ft. for use in Kenya, nineteen 34-ft. hulls for use in Norfolk Broads charter work, five 35-ft. pilot boat hulls for use in the Arabian or Persian Gulf, thirteen houseboat hulls some 37 ft. in length, one 40-ft. tug for Guiana, one 45-ft. motor launch hull for use in the British Solomon Islands, and three 47-ft. fishing trawlers for use in Aden and Somalia.

Even this extensiye experience will be suppJemented in the very near future, as licensing agreements for the manufacture locally of "Sea crete" boats have been con­cluded with fim1s in the States of California, Maine and Washington in the U.S.A., British Columbia in Canada, Iran, South Africa and Spain, and there will be a complete pooling of knowledge between us and our licensees.

If you are not now convinced of the outstanding advan tages. of ferrocement for fishing and commercial craft, write me off as a poor advocate, but do not write off ferrocement; the demand will grow and grow world-wide -it is so logically right.

370 CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Photograph A. 46-ft. trawler in which the hull, decks, bulkheads, floors and engine bearers, fish tanks and bulwarks are built in one piece of Seacrete ferrocement.

Photograph B. A 30-ft. Seacrete ferrocement hull with engine installed, as supplied to Kenya for completion locally into shrimp trawler. The hull maintains shape without cross bracing.

T. M. Hagenbach

Photograph C. A 34-ft. Seacrete ferro cement hulled cruiser after she had been struck amidships by a 3~ton sloop travelling at IOYl knots. The hull is damaged only at the point of impact. The repair, including painting, took 21 man hours.

371

RC(Jrillfed from: PJ'Oceedillgs of the Conference 011 Fishing Vessel Constructioll Materia/s, Montreal, Canada, October r - 3, 1968.

Comm e nts by Han s F. Muhlert

iIIr. f1ans F Mult!ert, studcllf in the Department ()/N{[~'al Architectllre al/d Marine HI/gil/eering at the University of Michigan, pruvided the /ollolVillg written cumments un Mr. Hagel/bach's paper un ferro-cemel/t boats:

My principal criticism of th is paper, indeed of most papers Ull /erru-cet//ent that Illl/IIe encountered, is tile lack of qual/titatil'£' il/formatio/l. I ('{[I/I/ot help but belielle that, ulltil the properties ofIerro-cement arc accurately determillcd, and ul/til ratiunal ltllu(l'sis al/d syntllCsis methods fire discol'C'red or devised, tile desil(n of ferro-cemellt stn/ctl/res lVill be a haphazard and approximate l/ndertaking. We mllst begill to express 0111' knolVledge in terms 0/ nUllibers. '

The resllits of a lack of understanding of this particular material are tlear. Stnu..'tures designed by "experience" or "eyeball" are in danger of being either IInderdesigned and unsafe, or m'erdesigned and wastefid of manpower and materials. III either case, a poor irwestment is the result. Therefore, I suggest the following approach (figure 1):

First, the material properties of the components are to be determined. III this case these would be the mortar, the wire mesh, the rods, etc.

Then a rational method of synthesizing these components and of analysing any gh'en compositIon should be either adapted from existing techllology or devised from scratch

Having done the foregoing, one is in a position to design the stmcture. Then a feasibility study can be conducted and ultilllate(v tlte stn/cture can be fabricated.

It is my belief that all too often the foregoing flow diagram (figure I) is, in effect, entered somewhere in the middle rather than at tlte top, or that the steps are not taken in order.

For the first step, the following values were obtained from tests at The University of Michigan by N. Jergovich, J. Coleman, and myself'

The second step illpolves a rational analysis and synthesis techniqllc of the composition. The following technique is one that I am clIrrently investigating:

Two basic assumptions are made:

I) ferro-cement is a lIOn-homogeneous material 2) standard reillforced concrete techlliques are applicable

"Proceeding on these assumptions the cross section of ferro-cement member is studied in detail. rile neutral axis is foulld by assuming that the mortar is only effective in compression and by taking into account the exact location and amount of steel. Then, assuming strains are equal ill the mortar and steel at a given distance from the neutral axis, the stress can be found at any distance from the neutral axis both in the mortar and in the steel.

"Using this method, I predicted the stress for failllre for a number offerro-cement specimens to be that stress at which the outer steel Jlbers would fail in tension. Keeping in mind that the ultimate tensile stress of tlte wire mesh is 107, 000 psi please observe figure 3 showing the results oFthree bending tests.

"With this technique the stnlclural design can be approached. I feel that in this area milch can be learned from fiberglass construction techniques, for ferro-cement is I'ery similar to fiberglass. Both consist of a network offibers hc:/d together and made impervious to water with.an adhesive.

"The last two steps follow ill order, and there is no need to elaborate on them except to emphasize, as Mr. Hagenbach lias, that all costs, including labor alld ol'erhead, should be accollllted for in the feasibility study. Also the study should encompass the life of the vessel, not just its construction.

"In conc/usion, I want to say tltat I respect the time and effort that Mr. Hagenbach lias Pllt into this interesting paper, and that I acknowledge his authority on this SUbject, stemming from his extensive practical experience, which I, unfortunately, callI/at claim to have. "

DETERMINE MATERIAL PROPERTIES OF COMPONENTS

r

PRODUCE RATIONAL ANALYSIS AND

SYNTHESIS TECHNIQUES OF COMPOSITION

, DESIGN STRUCTURE

, STUDY FEASIBILITY

, BUILD STRUCTURE

FIGURE I

MATERIAL PROPERTIES OF COMPONENTS

Mortar Composition used:

cement. . . . . . . . . . . . . . . . .. 16.51bs pozzolan.. . . . . . . . . . . . . . . . . 4.51bs salld . . . .. ...... . . . . . . . .. 30.0 Ibs water .... . . . . . . . . . . . .. 3500.0 cc

Ultimate compressive stress: ° = 4,760 psi (after 7 days) p. .

Steel Rod Reinforcing 1/4 in. hot rolled steel rods (no deformations):

Yield stress: 0/JY 39,800 psi

Ultimate tensile stress: 0p.= 62,600 psi

3/16 in .. :old rolled steel rods (no deformations): Ultimate tensile stress:

° p. = 90,800 psi

Wire Mesh 19 gage 1/2 in. x 1/2 in. galvanized hardware cloth: Yield stress:

0p.= 91,800 psi

Ultimate tensile stress: 0p.= 107,000 psi

Figu're 2

413

120

100

~'? ...JQ ILl" 80 ILl -­... ·c fI),

3':~ ...... fI)

~ a: "0 a: ILl Q ... ~ fl)1L.

ILl ILl ...J2 -ILl fl)a: z ... ~ ~ 40

20

400

1·0" SPECIMEN

L ~~ OF WIRE MESH

------

SEPTEMBER 26. 1968 HANS F.MUHLERT

10185" SPECIMEN

TENSILE STRESS· IN STEEL AT

EXTREME FIBER PLOTTED AS

A FUNCTION OF CENTER POINT

FORCE ON BEAM

_t Rt.. 23·5" ~ R

600 800 1000 1200 1400 1600

CENTER POINT FORCE ON BEAM (lb •. )

FIGURE 3

~ -~

() o z

~ t'!'!

~ ~

o z Cii

== z Ci < t"l I:n I:n t"l'l r

8 z I:n

'"" :;:tl

R '"" (5 z 3: > '"" t"l'l :;:tl

;; r I:n

..

Reprinted from: Proceedings of the Conference on Fishing Vessel Construction Materials, Montreal, Canada, October 1 - 3, 1968 .

stimated Hull Work and Material

Content for 100 ft.

Combinat·on Fishing

Vessel in Different

Materials Mr. Fraser

by

D.l. Fraser, C. Eng., Naval Architect,

Commercial Marine Services Limited, Montreal

Mr. Fraser came to Canada in 1967 with the specific object of working in the gap between research and practical application. After military service he was for 13 years in the Commercial Branch of the Ship Divison, National Physical Laboratory, as an experimental officer, and undertook work on the hull form on powering of ships in general with special emphasis on fishing vessel development using statistical analysis and computer techniques to predict performances and economics.

In 1965 he was loaned to the Fishing Vessel Section of F.A .O. to join the editorial team for the Fishing Boat Conference and to work on "Fishing Boats of The World, III. "

Since coming to Canada Mr. Fraser has held a position as Naval Architect with Commercial Marine Services Limited, Montreal. He is an Associate Member of the Royal Institution of Naval Architects and a Member of the Society of Naval Architects and Marine Engineers.

ABSTRACT

The construction materials considered are steel, alumi­num, wood, plastic and concrete and the vessel is a 100 ft. LOA X 24 ft. breadth moulded X 13 ft. moulded depth. The general arrangement is for a typical one and half partial shelter deck combination vessel with bridge and engine room forward and fish hold aft.

Lloyd's Rules are used to derive the scantlings where applicable but the particular properties of each material are not ignored. It is considered that steel and aluminum are best suited to conic sections, whilst the other

materials as used require a conventional round bilge construction. The normal methods of construction employed in Eastern Canada are followed even though more advanced techniques are now available.

Any large differences in some of the other ship constructional items caused by the variation of the basic hull material are taken into account before carrying out an analysis of the hull structural weight, material costs and man hours required for the completion of the hull in each material. These estimates are adjusted as far as possible for geographical price variations.

306

INTRODUCTION

The construction materials considered are steel, alumi­num, wood, plastic and reinforced concrete for a 100 ft. LOA combination vessel. Lloyd's Rules are used to derive ·the scantlings where applicable but account is taken of the particular properties of each material. Each material is used for as much of the construction as possible even though the incorporation of another material may well have more advantages structurally and economically. The nomlal methods of construction employed, or easily feasible, at present in Canada are followed even though more advanced techniques are rapidly being introduced by many shipbuilders.

Differences in ship constructional items caused by the variation in the basic hull material are taken into account before estimating the hull structural weight, material costs and hours required for the completion of the basic hull. These estimates are for single geographical area so that the relative values may be compared.

·THE VESSEL

After surveying existing data, the vessel's main dimensions are taken as 87'-6" LBI' ; 24'- 0" Beam and 13' -0" Depth. These dimensions concur with the trend toward deeper and beamier vessels now considered good design practice. The fish hold capacity would be of the order of 6,500 Ft.3 for stowage of wet fish in ice, giving a displacement of approximately 500 tons loaded depar­ture from the grounds, and an all up equipped lightship weight in the order of 375 tons.

The engine room is forward, the fish hold aft with a shaft tunnel under to the propeller. There is a raised £' ' " 1.0 C s Ie and a partial shelter deck on the port side. The winch would be mounted to operate athwartships and the vessel is capable of undertaking most modes of fishing with minor changes in deck gear.

MATERIALS

The hulls are considered to the sanle standard, that is to basic classification with no adjustments for ice re­inforcement.

Steel

This vessel is constructed on the ring frame system (I) and the form is double chine, conic sectioned. The loss in

CONr EREN('E ON FISHING VESSEL CONSTRUCTION MATERIALS

hydrodynamic performance of this form is marginal and would be more than offset by permitting boat yards with limited facilities to undertake construction. The building costs for all yards would be reduced by keeping frame and plate bending to a minimum.

Aluminum

The hull form in this material is the sanle as for steel for the same reasons but also because great care must be exercised when attempting to bend aluminum, as cracking can easily occur and the accuracy of the overbending must be high because of the lower resilience of the alloys recommended for shipbuilding. The method of conversion of scantlings to give' an adequate strength level are those recommended in (2). Each member was isolated and an attempt made to ascertain the mode of loading each structural member is required to support.

Wood

In all fairness this material is considered as though using ave~age Canadian practice. That is, natural timbers have been used for the most part and not manufactured laminates. Much of the construction now undertaken is on a semi-professional basis with at times only semi­skilled labour. This does not imply that the vessels are poorly constructed but, due to the higher factor of safety required when using natural timber, they are heavily constructed and the techniques used are for ' straight forward construction , From the data contained herein the individual fisherman may be able to gauge the cost differential should he undertake some or all the construc­tion on a semi-skilled basis.

The hull form for this and the remaining materials considered is round biJge.

Reinforced Plastic

This is single skin fibrcglass reinforced construction layed up in a female mould and adheres as far as possible to the recommendations in (3). Certain alterations are incorporated over , and above the proposed regul~tions, additional 1011,gitudinal framing in the bottom and some modification and additional material in that most awkward constructional region in this material; the point attachment of the shell, deck framing, deck and bulwarks.

D. J. Fraser. C. Eng.

Fe/To-Cement

This material required quite a period of development being a comparatively recent innovation as a boat con­struction material for fishing vessel hulls. Entire reliance on shell strength members seemed rather unrealistic for a vessel of 100 Ft. in length when vessels presently built in tIns material are little more than half this length. It was considered that a shell thickness of about 1-1/4" and the addition of a reasonable number of ring frames and a substantial steel keel member is more in order. Certain amounts of pre-stressing of the reinforcement in the deck beams would also avoid excessive tensile stresses in the cement. The pre-cast ring fran1es when jigged up also act as supports for the reinforcing framework thus ensuring a good hull shape and a homogeneous construction.

l/Iustrations

Figures 1, 2, 3, 4 and 5 give details of the proposed midship sections which together with a shell expansion are the basis for the calculation of hull material content and weight. It was found easier to calculate the weights by dividing the hull into units as is shown in Table 1. This made a compariso ll of results easier to check and any large errors in a particular unit were eVident, thus reducing the checking.

Limits

Before proceeding to the results, the limits of the investigation undertaken must be stated:

(a) Deckhouses have not been considered because of the range of material and construction methods available.

(b) The engine seats have been constructed in a material suited and compatible with the main hull structure material.

(c) Sonic insulation or translation of vibration has not been considered.

(d) The powering and hence the engine room size and equipment is considered constant.

(e) The cost of the hull construction ONLY is given and the choice of a hull material should not be decided on this criterion alone.

WEIGHT

The total weight of the hull as constructed is illus­trated in Fig. 6 wInch shows the distribution of weight by

307

units. The units are basically the after end, fish-hold, engine room and forward end and they arc 20.7%, 33.3%, 27.0% and 19.(}OJ, of the length over all respectively. Four of the materia~ weight curves follow a similar line but the heavy engine seats in the wooden vessel in Unit 3 are evident.

When comparing published data the fibre-glass re­inforced plastic weight would seem somewhat low but most of the available data is for a hull in a more advanced constructional stage than is now envisaged.

MATERIAL COSTS

These are given in Tables 7-12. The ''wastage allowance", variable with each material is an estimate of the scrap material ba~d on Ref. 4,5 with modifications to fit good modern practice. With conic sections and a "ring frame" system of construction, the normal steel and aluminum allowance of 15% should be reduced to about 8%. The wood waste is taken as 20%. The wastage quoted by some sources for FRP construction can be as high as 20% but with a production method using such high quality and production control the factor has been taken as 10%. .

The cost per unit weight of material is the current cost from the manufacturer or supplying agent in the quantity specified, without cartage and the discount obtainable on the quantity required for a single vessel production. The material cost of the FRP mould is taken as an extra material cost and is estimated from that required for a 110 ft. stern trawler (Ref. 5).

HULL TOTAL COSTS

The hull cost is given in Tables 13A-13E and an overall comparison in Table 14. Great difficulty has been met in trying to establish a reasonable work-rate; if the work rates published are used, it is difficult to see how known vessels could have been constructed for their selling prices. There is also a marked interaction between work rate, pay rate, overheads and depreciation. Published costing systems are few. and are almost always estimates and not actually based on costing after the ship has been constructed.

Finally the' following method is proposed: that there should be two overheads, one applicable to material costs, the other labour overhead. The material overhead is that

308

portion of the material cost of loft moulds, templates, drawing office work, yard management, foremen, indirect and sundry labour, tank experiments, docking, travelling, tools, power, light, ironworker's stores, gas, water, oil, coke, coal and electrical sundries that may be allotted to the hull construction. This figure for steel construction is \

about 5% for a material cost of $2,000,000 decreasing to about 4% for the present vessel.

The labour overhead includes the labour involved in the items composing the material overhead plus a proportion of establislunen t charges, holiday pay, social insurance, etc. This is about 74% for a material cost of $2,000,000 and about 95% for the vessel now being considered. A work rate of 162 man hours/ton for steel is given in Ref. 7, but with good construction procedures, a flgtJre of 140 should be obtainable. The rate of working aluminum is difficult to assess as most yards are unfamiliar with it for large hull construction, but a total number of man hours equivalent to 90% of that for steel has been assumed. This gives a man hour/ton rate of 312.

The rate of working with wood is more obscure but for superstructures, figures of 100 man hours/ton are quoted therefore a figure of 120 is taken. The cost of direct labour for FRP construction is taken as 1/3 of the material cost which when converted is reasonably close to the 13 Ibs./man hour taken on large hull construction. This would give 172 man hours/ton. For ferro-cement construction the man hours required is taken the same as for steel. When considering these work rates, it has been borne in mind that these work rates are for the hull alone and would therefore be somewhat higher than for the overall ship where other items such as piping and electrics tend to have lower work rates.

The yard overhead is varied by 10% as the overheads are dependent on the yard equipment and the preparation necessary for production.

For single hull production, the ferro-cement hull is 88% and the FRP 143% of the steel hull cost. The cost of the wooden hull is very similar to that in steel and aluminum, some 35% more expensive. For a series production of 5 and 25 hulls, the percentage decrease in cost per number of ships is taken the same for all hulls but in the FRP hull, the cost of the mould is also divided between the number of ships built. This may be a little biased in favour of the FRP hull, but series production

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

certainly favours this mode of construction. These results are given in Table 13 and represented graphically in Fig. 7.

COMPARISON WITH PUBLISHED DATA

The comparison with published and other data is represented in Figs. 8 and 9. Both the hull weights and total costs are in reasonable agreement with those now obtained. Some of the cost data is somewhat higher being Naval and thus constructed to a higher standard than is usual in civil construction.

CONCLUSIONS

It must be remembered that the hull cost considered represents only about 35% of the total initial investment therefore the percentage cost range for total ship costs is approximately +15% to -4% of total ship cost for single hull production.

I'n days of rising borrowing interest rates, however, these variations are not to be ignored, steel and aluminum appear to have no further production cost reduction

-possibilities open to them that will not also be available to the other materials. Wood with the good use of laminates should close the gap with steel in this size of vessel.

FRP with its high quality control and production methods and at the moment at least constant raw material costs and improving techniques should be more than competitive on series production basis, but it is difficult to visualize a single production being so.

Ferro-cement, on paper looks extremely attractive price-wise, but scantlings can only be assessed. Too light or too heavy, who knows? Only by building, research and testing will its true economics be known.

Finally, the hull construction as presented is only one item in the economics of-fishing vessel design. Changes in fish hold insulation _ and capacity are directly affected and so is the fish weight carried because of the variation in the hull weight in what is a displacement limited regime. Economics can only be generated if a fair assessment of each component part is known and that has been the object of this paper.

D. J. Fraser. C. Eng.

REFERENCES

1. "The Design Construction. and Operation of a Close of Twin Screw Tugs" Corlett. Venus and Gibson R.I.N.A. May 1958.

2. "Strength of Aluminum". Aluminum Company of Canada Limited 2nd Edition 1965 .

3. "Provisional Rules for the Application of Glass Reinforced Plastics to Fishing Craft". Lloyd's Register of Shipping.

4. "Fibreglass - Reinforced Plastic Minesweepers" Spaulding and Della Rocca S.N.A.M.E. 1965.

5. "A 110 ft. Fibreglassed Reinforced Plastic Trawler" Della Rocca Fishing Boats of the World 3 1965.

6. "Comparision Between Plastic and Conventional Boat Building Materials" Verweij-Fishing Boats of the World 3 1965.

7. "An Analysis of U.S. Fishing Boats - Dimensions. Weights and Costs" Benford and Kossa-Fishing Boats of the World 2 1960.

ACKNOWLEDGEMENT

The author is considerably indebted to Mr, A.D. Milne for his contribution in this paper.

Table 1 Summary of Steel Weight

Unit No . & Weight (Tons) Item

I -

2 3 4

Keel & stern bar 0.11 0.35 0.29 0.25 Skeg 0.80 0.42 Rudder & stern frame 2.02 Shell Plating 6.56 10.74 8.36 5.00 Floor 0.98 1.80 1.45 0.19 Shaft Tunnel Plating 1.70 Shaft Tunnel Stiffeners 0.22 Store Flats Plating 1.43 0.34 Store Flats Beams 0.11 0.06 Store Flats Girders 0.06 Main Deck Plating 2.84 4.42 3.42 1.15 Main Deck Bca ms 0.50 0.92 0.70 0.20 Main Deck Girders 0.20 0 .58 0.47 0.10 Bottom Shell Stiffeners 0.18 0.29 0.32 Bulkheads Plating 3.85 1.58 2.60 1.40 Bulkhead Stiffeners 1.11 0.59 0.66 0.33 Main & Crant Frames 0.59 1.76 1.42 0.84 Chine & Transom Bar 0.63 0.64 0.52 0.15 Bulwark Rail 0.27 0.29 0.07 Fo'c's'le Deck Plating 0.80 2.95 1.72 Fo'c's'le Beams 0.13 0.54 0.37 Fo'c's'le Girders 0.06 0.15 Fo'c's'le Bulkheads Pit. 0.76 4.19 0.57 Fo'c's'le Stiffeners 0.07 0.61 0.09 Bkts, Brcasthooks etc. 0.64 0.32 0.34 0.31 Main & Aux. Engine scats 4.81

Tota I Weight 22.88 28.44 33.72 13.22

8% Allowances 24.71 30.72 36.42 14.28

-Weight Total Tons

1.00 1.22 2.02

30.66 4.42 1.70 0.22 1.77 0.17 0.06

11 .85 2.32 1.35 0.79 9.43 2.69 4.61 1.94 0.63 5.47 1.04 0.21 5.52 0.77 1.61 4.81

98.26

106.12

Table 2 Summary of Aluminum Weight

Unit No. & Weight (Tons) Item

1 2 3

Keel & Stem Bar 0.06 0.21 0 .17 Skeg 0.38 0.20 Rudder & Stern rramc 0.99 Shell Plating 2.97 4.78 3.84 Floors 0.54 0.99 0.69 Shaft Tunnel Plating 0.76 Shaft Tunnel Stiffeners 0.07 Store Flats Plating 0.64 Store Flats Beams 0.05 Store Flats Girders 0.02 Main Deck Plating 1.17 1.99 1.54 Main Deck Beams 0.23 0.45 0.34 Bottom Shell Stiffeners 0.06 0.10 0.11 Bulkheads Plating 1.76 0.71 1.16 Bulkheads Stiffeners 0.41 0.24 0.30 Main & Cant Frames 0.26 0.78 0.65 Chine & Transom Bar 0.22 0.23 0.19 Bulwark Rail 0.09 0.10 0.03 Fo'c's'le Deck Plating 0.35 1.28 Fo'c's'le Beams 0.05 0.19 Fo'c's'le Girders 0.02 Fo'c's'le Bulkheads PIt. 0.34 1.84 Fo'c~s'le Stiffeners 0.03 0.24 Bkts. Breasthooks etc. 0.29 0.14 0.16 Main & Aux. ·Engine Scats 2.25

Total Weight 10.21 12.74 15 .14

8% Allowa nces 11.03 13.76 16.35

Table 3 Summary of Wood Weight

4

0.15

2.75 0.11

0.15 0.03

0.53 0.10

0.62 0.16 0.38 0.05

0.79 0.18 0.05 0.25 0.04 0.15

6.03

6.51

Unit No. & Weight (Tons) Item

1 2 3 4

Decks 1.20 2.91 3.31 1.62 Shell and Keel 2.80 7.74 7.56 3.09 Bulkheads 4.18 0.46 1.34 0.46 Deck Beams 1.21 3.03 3.66 1.41 Rudder Steel 1.25 - - -Frames 1.02 . 3.78 9.73 3.69 Flats 0.65 - - -Flat Beams 0.20 - - -Stringers 0.17 0.30 0.24 -Stern Post 3.53 - - -Transom frames 0.35 - - -Cant Frames 0.26 - - -Bulkhead StiffCs. 0.36 0.21 2.16 0.23 Bulwark 'Stays 0.19 0.28 0.06 -Bulwark Rail 0.26 0.29 - -Whale 0.24 0.25 0.05 -Waist 0.46 0.48 0.15 -Bilge Ceiling 0.72 1.99 1.14 0.20

309

= Weight Total Tons

0.59 0.58 0.99

13 .84 2.33 0.76 0.07 0.79 0.08 0.D2 5.23 1.12 0.27 4.25 1.11 2.07 0.69 0.22 2.42 0.42 0.07 2.43 0.31 0.74 2.25

44.12

47 .65

Weight Total Tons

9.04 21.19 6.44 9.31 1.25

18.22 0.65 0.20 0 .71 3.53 0.35 0.26 2.96 0.53 0.55 0 .54 1.09 4.05

310

Table 3 (Cont'd)

Unit No. & Weight (Tons) Item

I 2 3 4

'Shelf, Clamp + Lodger 1.08 3.58 2.92 2.34 Shaft Tunnel - 1.54 - -F.O. Bunker - - 4.54 -Eng. Seat+ Keelson, Wood - 1.45 3.15 1.29 Chocks 0.04 0.04 0.04 0.04 Chain Locker Flat - - - 0.14 Fo'c's'le Bhds - - 1.47 -

Fastenings 5% 1.01 1.44 2.08 0.72

Weight 2l.l8 29.77 43.60 15.23

Table 4 Summary ofF.R.P. Weight

Unit No. & Weight (Tons) Item

1 2 3 4

Decks 1.24 3.02 3.80 1.76 Shell 3.24 5.34 5.47 2.33 Bulkheads 0.50 0.22 0.62 0.17 Deckbeams 0.22 1.18 1.40 0.46 C Girder+ Floors 0.39 - - 0.15 Frames 0.46 1.47 1.54 1.01 Flats Beams 0.24 - - -Transom Frames 0.14 - - -Cant Frames 0.06 - - -Beams+ Webframes 0.20 0.74 0.74 0.10 Bulkhead Stiffeners 0.66 0.31 2.19 0.45 Skeg+ Keel 0.95 - - -Rudder+ Stern Frame 1.61 - - -Girders 0.58 1.04 0.86 0.34 Bulwark Stays 0.08 0.26 0.04 -Bulwark Rail 0.09 0.10 0.02 -Stringer Angle 0.26 0.27 0.22 0.08 Angles 2.02 1.54 2.23 0.66 Shaft Tunnel+ Floors - 0.82 - -Stringer - 0.03 0.09 0.08 F.O. Bunker 0.98 - 0.54 -Double Skin Deck 1.29 - 0.76 0.57 Engine Scat - - 1.75 -Bulkheads (Accommod.) - - 0.44 -Wood Bottom Chain Locker - - - 0.13 Brackets 0.03 - - -Gel Coat 0.24 0.25 0.35 0.13 P.V.A. 0.05 0.05 0.07 0.D3 Epoxy-Grit 0.02 0.D3 0.04 :>.01

Total Weight 15.90 16.97 23.17 8.46

Weight Total Tons

9.91 1.54 4.54 5.89 0.16 0.14 1.47

5.25

109.78

Weight Total Tons

9.82 16.38

1.51 3.26

.0.54 0.46 0.24 0.14 0.06 1.78 3.61 0.95 1.61 2.82 0.38 0.21 0.83 6.45 0.82 0.20 1.52 2.62 1.75 0.44 0.13 0.D3 0.97 0.20 0.10

64.20

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Table 5

Summary of Ferro-Cement Weight Unit No. & Weight (Tons)

Item I 2 3

Keel and Stem Bar 0.07 0.24 0.20 Skeg 1.53 - -Rudder and Stern Frame 2.02 - -Shell Plating 8.63 12.93 10.64 Floors 0.78 0.89 1.72 Shaft Tunnel - 1.80 -Store Flats 1.17 - -Bottom Shell Stifers. - 0.51 0.47 Main Frames/Cant Frames 0.82 1.75 1.25 Intermediate Frames 0.06 0.13 0.11 Bulwark Rail 0.18 0.19 0.05 Main Deck 3.08 4.92 3.86 Fo'c'le Deck - 0.87 2.94 Bulkheads 6.97 3.11 4.35 Deck House Bulkds. - 0.83 4.80 Bkts., Breasthooks, etc. 0.18 0.41 0.73 Main Engine Seats - - 3.97 Aux. Engine Seats - - 1.68 Main Web Frames - 3.39 2.25

Total Weight 25.49 31.97 39.02

Table 6

COMPARISON OF WEIGHTS

4

0.32 --

6.31 0.17 -

0.15 -

0.63 0.05 -

1.40 1.56 2.17 0.66 0.42 ---

13.84

Weight Total Tons

0.83 1.53 2.02

38.51 3.56 1.80 1.32 0.98 4.45 0.35 0.42

13.26 5.37

16.60 6.29 1.74 3.97 1.68 5.64

110.32

Material Total Weight

Percentage of Steel Weight

Steel Aluminum Wood . F.R.P. Ferro-Cement

106.2 T 100% 47.65 T. ' 45%

109.78 T. 103% 64.20 T. 60.5%

110.32 T. 1'04% ---------' ------.-~.-.---

MATERIAL COSTS BREAKDOWN

Table 7 '

Ordered Steel.Weight + Material Cost

Material FOr/it Wastage Allowance Weight S/LBS. Cost S

Sections +8% 31.10 0.10 6,966 Plating +8% 75.50 0.08 13,530 Castings' - 1.50 0.15 504 Welding + Gas 5% of hull weight 5.00 0.21 2,361 Gas 1'h% total cost

S23,361

"\

D. J. Fraser, C. Eng.

Table 8

Ordered Aluminum Weight and Material Cost

Material Form Wastage Allowance Weight $/LBS.

Sections ., +8% 8.67 0.725 plating +8% 38.80 0.545 Welding + Gas 5% of hull weight 2.20 1.60

Table 9

Ordered Wood Weight and Material Cost

Material Form Wastage Allowance Weight $/LBS.

Steel Casting - 1.50 0.75 Steel Plate - 4.54 0.08 Fastenings - 5.31 0.25 Oak +20% 85.27 0.12 Fir +20% 25.75 0.20 Birch +20% 7.09 0.20

Table 10

Ordered FRP Weight and Material Cost

Wastage Material Form Allow- Weight $/LBS.

ance

FRP Mat 10% 7.89 0.46 FRP Woven Roving 10% 8.55 0.56 Poly Urethene 10% 1.06 1.00 Resin (Polyester) 10% 48.42 0.25 Wood (Oak) - 3.01 0.129 Gel Coats (2) - 0.97 0.39 P.Y.A. - 0.20 0.40 Epoxy-Grit - 0.10 10.00

Female Mould (Material Only)

Total Material (One Hull)

Table 11

Ferro-Cement Material Cost

Wastage Material Form Allow- Weight $/LBS.

ance

Cement + 10% 25.96 25/T. Aggregate +10% 46.86 0.65 T . Chickenwire + 10% 6.39 0.18 Hardward Cloth +10% 4.94 0.54 Reinforcing Rods + 5% 8.40 0.Q7 Pipes + 5% 12.84 0.16 Tying Wire

Cost $

14,080 47,367

7,885

$69,332

Cost $

504 814

2,974 22,921 11,536

3,172

$41,921

Cost $

8,130 10,725

2,374 27,116

· 809 847 179

2,240

$52,420

$45,330

$97,750

Cost $

674 30

2,576 5,975 1,317 4,602

100

$15,274

Steel

Aluminum

Wood

-PRP

HULL COSTS Table 12 (A)

Weight of Hull Man Hours at 140/ton Wages at $3/hr. Overhead 95% Ma terial Cost Material Overhead 4% Total Building Cost Profit 10% Purchase Price

Table 12 (B)

Weight of Hull Man Hours at 90% Steel Wages at $3/hr. Overhead 95% Material Cost Material Overhead 4% Total Building Cost Profit 10 % Purchase Price

Table 12 (e)

Weight of Hull Man Hrs. at 120/T. Wages at $ 3/hr. Overhead 85% Material Cost Material Overhead 3% Total Building Cost Profit 10% Purchase Price

Table 12 (0)

Weight of Hull' Wages at $3/hr. Overhead 85% Material Cost Material Overhead 3%

'Total Building Cost Profit 10% Purchase Price

3]]

106.2 tons 14,R68 Ius.

$44,604 42,374 23,361

934 $111,273

11 ,127 $122,400

47.65 tons 13,381 $40,143

38,136 69,332

2,573 $150,184

15,018 $165,202

109. 78 tons 13,174 39,522

$33,594 41,921

~ 116,295

11,630 127,925

64 .20 tons $31,758

26,994 97,750

2,933 $159,435

15,944 $175,379

312

Table 12 (E)

Ferro·Cement Weight of Hull Wages at $3/hr. Overhead 85% Material Cost Material Overhead 3% Total Building Cost Profit 10% Purchase Price

110.32 tons $44,604 (as steel) $37,914

15,274 458

$98,250

9.825 $108,075

CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

Material

Steel Aluminum Wood FRP. Ferro·

Cement

Table 13

Comparison of Purchase Prices

$ PURCHASE PRICE

1 Hull % 5 Hulls % 25 Hulls

122,400 100% 111 ,100 100% 97,500 165,202 135% 150,000 135% 131,200 127,925 104% 116,100 104% 101.200 175.379 143% 111,300 100% 87,720

108,075 88% 99,200 88% 86,000

%

100% 135% 104% 90%

88%

ADDENDUM

The following items have been revised anc incorporated in the text in the light of information and discussions since reading the paper.

Wood Construction

The construction suggested in the original text contained virtually an allowance in the scantings for ice reinforcement and a more accurate assessment is incorporated with the appropriate reduction in weight and cost.

Conclusion

On re-estimation of the huH cost as a percentage of the total ship cost a figure of 35% is substituted for the original 40%.

The Vessel

The displacement should be SOO tons.

Note:-

All weights are Long Tons (2240 lbs.)

All costs are Canadian Dollars.

r

BULWARK i V.· THK.

4" UPSTAND

SHELL t.T.

GARBOARD - 30·x 3/8· RE MAiNDER - 5/16·

DECK STRINGER I!! 24" x IV32" FOR .. L.. TO

9132· AT ENDS.

RE"AI.~ER OF OECK- 9/yr

CFTSHIP

z -c!

=:::::::I ~; ~ ~ -+-- ~- -A Et- --- ~ 6·CAM'BER - - -- 1 , _1_ -

DEPTH

t.t OU LDE D I'·· o· I

T 4-3"

BEAM KNEE I . vi' x 6 V2" x 9/Yt'

(LAp SIzE) If ~'X 2" xfl. O.A· SPACED IS·

MAIN FRAMES

3" x 2 V2" x SlI'" I .• A. SPACED .. " I

CHINE BAIIIS i' OIA· S_III •.

I

ALUMI!lWIII

5" x 3"x !V16M I.O.A. urTO SUIT

BOTTpJI! IrONGIt.

/--=- I ~ 6x~lI16 I.O.A.

<!{ROERS

(/'X 31/2"x ~6M I.

FISH Itt OLq I

CHIONI

MOULD E D HALF BREADTH J21·0~

I\)

~

SHAFT TUNNEL

5oIt,"1..' -STIFF.!!!.3"X2'~~"1.0A

WT. ~TABLE TOP R! IN SU ITABLE LENGTHS.

.. FIG.I-MIDSHIP SECTION FOR lod STEEL COMBINATION FISHING VESSEL.

!:' ~

~ s::a

~ f'l

~ ~

1M -1M

BULWARK I.' Ir- THK.

4" UPSTAND ---:"1

SH ELL FlT GAR BOARD _ 30"J,1 M

BOTTO'"' SHELL - ~ .. SIDE SHELL - i·

ALLOY-DATA PLATING: ALCAN 054 S EXTRUSIONS: ALCAN B 51 S

DEPTH

MOULDED

13' - 0-

T 4'-3" ,

Of t SHIP

DECK STRINGER I.' 24-.a- fOR '4L m TO·r AT

NOS. REMAINDER aF DECK 10

BEAM KNEE

.6fJ,6flll\" (LAP SIZE)

I I BEAM -I- -.1" "a3 ' .. I .O,A,

SPACED 18-MAX. SPAN ,'-3-

I I

z'-d' ----t

j FISH

ALUMINUM FI H HOLD

10 MAIN FRAMES I .4"J,3"J,'\ " I.O.A.

SPACED IS"

'" BKT.

HOLD

STANCHi:ONS PI) \()

SHAFT TUNNEL a" t ~ It. " .. ,L' STifF MI . 3 at l( .r.aA.

I W.T. PORTABLE TOP

R.' IN SUITABLE LENGTHS • .

I BASE LINE

")T' 24"

.L _ • b. r?'t""'= ---'---

MOULDED HALF BREADTH 12' - o·

FIG. 2- MIDSHIP SECTION FOR iOOD ALUMI NUM COMBINATION FISHING VESSEL

r

w ~

;) o Z ." ~ ;.:l r.l Z ('") m o Z or, v; ::; z Cl < ~ en en r.l t"" ('") o z ~ ;.:l c ~ (3 z :: ~ r.l ;.:l ;; t"' en

BULWARK STAY a -. BUlWMIC 1L'.-50- ---=-.1 :; -(5 lilt. + I M.l J .0 STRINeER AN6LE TYP£ (lZ·)(4 f.tatJ ... -

ABBREVIATIQHS t:M. - "FABMAT· ALTE_ATE

PLIES OF: 3+5". ·5rJ' I - 24 oz/SQ. YD. WOWN ~ (ef.y.+114.l 2 - Z QUsa. fT. MAT

N. - t.fAT:- 2 OZ./SQ. FT. MAT

p.u. - POLYURETl4N&£ FOAM 2 U$./Cu. FT.

OEJTH

ltOULOEO

131- 0"

T 4'_~ I

BULWARK RAIL OF~HlP REtatAIr400 OF DECK

·4,D C5f.K) ~~

~CAr~

~- .~-BEAMS SMCE 10-.-x zf. '38- f C£ nscs.T\- wtnt E a fAA!£S (2 F. M .• I fA). I ~AYER aI ~IOIRECTIONAL ROVI~ STRIPlitf FACE P.U. CORE 1

"'NUM fISH HOLD STANCHIONS

I tM9.t fRAME SIPACED IS- ~ISH ! HOLD 5"x3"x·..oN FAe THKS . .fIo-

(2F.1l+ IMJ +IEER OF \MOIRECTI AL ROVING STRIP IN FACE P.U. CORE I

~\ fRAMES. SPACING ,:..0- I

10· ... 7·x '50· F/tCE TtG(!!""L

\ INTERCOSTAL tOTTOY a SlOE LON'" td S"1L3"x·23· (2 F. • + I at.)

BASE LINE

+ I LAYER Of ~IOIRECTIONAl. ROVI,G STRIP IN FACE ~U.CORE

80 1''''<2# ($ I:Itt $/()£ S/Jo..

.,. '1Jt.) :S:J

DaJBl.E ANGLE TYPE (3")(2 F.M.+IM,) = ·23-

\.oJ o

SHAFT TlJNNEL

FACES ·21"THK. (2 F.IL+ 1M) WITH

2" THK.P.U.CORE

Ft.OOR ·41,1 (4 F.lt •• 1M.) Sf'ACED IS"

FIG.3- MIDSHI P SECTION FOR 100' FIBERGLASS COMBINATION FISt«NG VESSEL

~ ~

~ I:l

'" ~ ..... n tlj

~

w -VI

! RAIL STRINGER •• , at" OAK.

WNST PLAHlCING .. BU..WARI( STANCH OAK or BACH ._ .. II ..

2t OAK. 3'-3" S = 6 W: 1 at 0fC1( 5 at TOP. SLL _ OAK GALVQ. F. 8. "-4" S -5"

OF I SHIP

STEEL HATCH COAMING.

WALE - OAK FR - - I

10" X 3" DECKHG - -- -,---F.ft*liti~ " 6" II BEAMS-OAK 111=9 5= 6 C

SHELF - (W( or FIR ~ ~ r-W=6· 5 = IS· IN 3 S ES 7 _ ~"v"'~n L.OCI( STRAKE .. = 1" SET I" INTO BEAMS

DEPTH

13' - 0"

T -I FRAME: ~ .. ;--.... . SfWlNG

A' 3~ CR. TOCH. DOOBLE ~- SAWN Q;\\I( SIDED 6·~

j t1 -II· AT KEEL 7i -AT BILGE AND -St· AT [£CI(

~ LINE I _ _ _______ _

FISH ; HOLD

HOLD

\J.J to-'

~- OAI( 5"12" W=14"

SHOE 3" OAK HALF BREADTH

., FIG.4- MIDSHIP SECTION FOR 100· WOODEN COMBINATION FISHING VESSEL

w -0\

(')

o z ~ ;::::l ~ z (') ~

o Z "'l :;; ::t Z o <: to: til til !:"=": r

8 Z ~ ::e c: (') -l 5 z :::: :> ~ r-l

" ;; r til

BlLWMK

I·r DIA. PIPE

RERODS.* - DIA. 5.R. on 2" CRS.

REMESH. 4 LAYERS of CHIO<BI WIRE.

SHELL WOOD FENDER f-

REIt-!F~CEM~ MESH~ 1st LAYER - HARDWARE CLOTH. l1£N '3 LAYERS of CHICKEN. WIRE INSIDE 8 OUTSIDE

~EMENT_..BQQS.;:­

LONGIT:-'}- 01A. S.R. TO T\M (IF BILGE

1- DIA. S.R. ABOVE. DEPTH WELDED TO FRAMES SPACED 3" CRS. MCXJLOED

TRANS:- I.e. INTERNED. FRAMES 1." 4 OIA. S.R.FROM KEEL

13'-0"

TO BULWARK. TIED TO LONGIT. RODS. SPACED 6"CRS.

MATERIAL SPECIFICATION

RAIL f. B. WI1"H OAK RAIL CM J

OF Is.-CC*ST. OF

II ...... _. COAII8II TO

3-

t 8--------- 6 b g TUNNEL ,.---- --------~-

BEAM KNEE .

I ~- I QECK LONGn: I L!:!!.ECAST R_ FRAME

II" DIA. PIlE 2· CIA. PIPE SMCEO REROOS a REMESH SMeED 24- I TO StJT.

I, AS FOR SI£LL. I I I

MAIN FRAMES SPACED t8" F ISH H 0 L 0 , 2f -DiA. PIPE TO UPPER I r

\

TURN Of' BILGE a 2" DIA. ' I PIPE CARRIED UP Tol jLUMlNlII1 01 STfEL fl3H NOLO STANOfIONS... \.-.)

FORM BULWARK •• I I I\)

~ WELDED SCARPH. 1 StIAEI TUNfIIEL

. If DIA. PI PE SPACED 18"

FLOORS SPACED Itt' REROes. r DlA. 5.R. 4f CRS.

, . TOP PI P~ If DIA. I REMESH. I LAYER of

____ ,~ RERODS * DIA. SR. 2"CRS WARDIIME CLOTH a - _ ,EMESH 6 LAYERS fII . 6 LAYERS of Ct«:ICEN WIRE.

~ "uICKEN WIRE\ I r 1 ! PIPES - NOM. DIA. SCH. 40 S.R. RODS - HIGH TENSILE STEEL HARDWARE CLDT.H - r GAL WI SPACE SCREEN

CHCKEN WIRE -',fGAUGE 20 GALvd

~-~ 'INTERCOSTAL LC*GITS

2~- DlA. PI PE

HALF BREADT

FIG. 5 - MIDSHIP SECTION FOR 100' FERRO-CEMENT COMBINATION FISHING VESSEL

~ ~

~

~ o ~ ~

IN --.J

318 CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

UNIT WEIGHT DISTRIBUTION FIG 6

30~----------~~~~~----------------+---~~~~------~

HULL WEIGHT

TONS

20~----------------~---------=~~----+-~~-------~~ . ____ . . ,c-"

.-- ..... ~1.. ~ - --.- - - - .............. lJ~~ ------- --- .... :..rt!~lJ~~ .

........ "! ------------------- . ................. , IO~----------------~------------------+---------~~--~~ ........

2 3

UNIT NUMBER

..... ....... .........

4

D. J. Fraser, C. Eng. 319

180

160

140 HULL COST

SxlOl

120

fOO

80

,~

COST COMPARI SON SER I ES

PRODUCTION 100 FT LOA HULL

\""'" \

.... ' ...

...... , ............

\ .... ...... ------.

FIG 7

~\ ---------1---------

~ t-••• ~

"", ~ -----.~--'"" ------== -"'- - .... "'-

i'- ..................

~-~ ~ ~. . -

5 10 15 ' 20' 25 NUMBER OF VESSELS

ALUMINUM

WOOD

STEEL

FRP

FERRO­

CEMENT

320 CONFERENCE ON FISHING VESSEL CONSTRUCTION MATERIALS

WEIGHT COMPARISON FIG 8

KEY STEEL ••• WOOD + + +. ALUMINUM )( lC )C.

F.R.P. 4)00 FERRO-CEMENT ..... "

140

120r-------~--------_+--------_r~--_,~;_------~

'00r--------;--------_+------~_r~------;_------~

80r---------r_--------r-~~~--~--------r_------~

HULL

WEIGHT

TONS

BENFOR

60~--------~----~_rHL--------r+ __ ~----~------~

40r---------r.~r_----r-----

",.K ... "

" ", .-

/

, ,. /

/ /

/ ,.

20r----T~~--~~~",-",-,-",+-"-... -------+---------+--------~

2 3 4

LOA x B x 0 xlO

. 4 5

D. J. Fraser. C. Eng.

300

2~0

200

COST

SxIO!

I~O

100

321

COST COMPARISON FIG 9

KEY &TEEL G®@ WOOD ... ~ + ALUMINUM )( X )(

f.R.P. 000 FERRO -CE MENT .... *~

; I'

I; I '(I' I

,IV I :

, , II /,/ B_~,~~IFORD STEEL

VI ) . , 'j! //1. /; ~~

/',' 'J ~

, V' /,1 / ,,/ ./ . ./

c ~./

..? ... 0

2

LOAxBxOxIO~

FERRO CEMENT BIBLIOGRAPHY

Compiled By:

Compiled For:

G. W. Bigg

J. Delaney

T. Wood

Carleton University

Vessels & Engineering Division

Industrial Development Branch

Department of Fisheries & Forestry

January 15, 1971

,

Notes on the Ferro-Cement Bibliography

This bibliography is in addition to the quantified

bibliography provided to the Department of Fisheries and Forestry

by the British Columbia Research Council.

Included are some of the papers on concrete ships which

are of historical interest. No attempt has been made to include

many appropriate supplemental references on concrete, thin shell

theory, epoxies, vessel design, etc., which would be useful to

the design of ferro-cement vessels but which do not mention

ferro-cement explicitly.

PART A

This list has been quantified as follows:

Column Symbols Quantity

1 X Hard Information ) ) Narrative

0 Soft Information )

2 X Tables

3 X Diagrams and Figures

4 X Scale Drawings

Sa X Strength and Stress Analysis ) )

5b X Construction Methods ) ) Performance

Sc X Detail Design ) )

5d X Materials )

6 X Photographs

7 X Costs

- 2 -

Column Symbols Quantity

8 F Fishing Boats ) ) Relevance to

0 Other Boats ) Fishing Vessels )

X Supplemental Information)

PART B

This bibliography lists sources which were unavailable on

short notice. For a variety of reasons it is felt that these refer-

ences would be worth pursuing to complete an assessment of the state

of the art in ferro-cement. It is believed in particular that the

Russian literature is rich in technical information on ferro-cement.

PART C

This list contains references to ferro-cement which were

unavailable and which are deemed to be of.limited value.

.. PART A

AUTHOR TITLE PUBLICATION

1 2 '3 4 5 678 a b c d

"Paint and Waterproofing American Concrete Institute, Applied to Concrete Ships" June 1943 0 X

ACI Committee 506 "Shotcreting" ACI Pub SP-14, 1966, pp. 219-243 Proposed ACI Standard Recom- X X X X

mended Practice for Shotcreting

Blue Circle Group "Ferro-cement boat hulls" Technical Note 68-5 Cement Marketing Co. Ltd. Portland X X F House Stag Place, London SW7

iiA Remarkable Concrete Boat" Building, 29 July, 1966. 0 0

Article about the tug "Cefer" Canadian Fisherman; June 1968, 0 0 page 54.

"Concrete Boat Construction" Commercial Fishing (July 1967). 0 X F page 13

"Shale Aggregate Mix" Concrete pp. 5-8 Jan. 1954 X X X X X X (Lightweight aggregate)

"The Hull of a 34 ft. Motor Concrete and Constructional Cruiser". Engineering Vol. 56, No. 12 0 X 0

pp. 432-433

Khaydukov "Roofs- Ferro-cement folded Beton i Zhelozobeton (Concrete Units" and Ferro-concrete), No '. 1, 1964 X X X X ? X X - - - -

(In Russian)

) "Featherstone Ahoy" Concrete Construction, July 1963 0 X 0 I -~ '----

AUTHOR TITLE PUBLICATION 1 2 3 4 5 673 abc d

r--

"Ferro-cement," Concrete Construction, Vol. II, 9 September 1966, pp. 355 0 X X

Rolt, H. Engineer; July 18, 1941, pp. 35 0 X 0

"Reinforced Concrete Hull Engineering, 10 November 1961 0 X 0 for 34 Foot Boat"

"Concrete Barges And Ships Engineering News Record pp. 36, 0 X Built by Great Britain" August 28, 1941

Design and Construction of Engineering News-Record 1918 Reinforced Concrete Ships. July 25, pp. 167 X X X X X X X X X X Complete design and Construction Dec. 12, pp. 1058 of Concrete Ships up to 3500 tons Nov. 28, pp. 986

July 4, pp. 17

Problems occurr.ing in Concrete Engineering News-Record 1918 Ships Dec. 2, pp. 1089

Articles Include --Moisture Dec. 5, pp. 1019 X X X X X X X X X Seepage Problems -- (Gas & Water) July 25, pp. 167 DurabilitY--Weight and Strength July 4, pp. 958 Problems

Development of Aggregates for Engineering News-Record 1918 Use in Concrete Shipbuilding July 18, pp. 136 X X X Development of Light weight July 11, pp. 67 Aggregate also - use of sieve

I

analysis __ L - ---- - -- -- - - - ----- -- --- ----- ---------- ---- ------- --- - ~-~ ~ -~ -

AUTHOR TITLES PUBLICATION

I "Testing on Reinforced Concrete Engineering News - Record 1918

, with Particular Interest in July 4, pp. 48 I Problems with Concrete Ships" Nov. 14, pp. 903

Shear as a critical Design Dec. 5, pp. 1019 Criteria - hogging and sagging Dec. 2, pp. 1089 wave Pressures on Ships - Tight~

ness of Hulls with particular interest in oil and water seepage

"Down to Sea in Cement" Life Magazine, Sept. 11 1970

HFerro-Cement Boats" Marine West, January & Feb. 1968

Metal Lathe Centering Techno- Metal Lathe Manufacturing Assoc. logical Bulletin No. 6 Engineering Building, Cleveland Show 4 types of Metal Lathe. Ohio, September, 1953

"Cement Yacht is Lot of Boat National Fisherman, June 1967 for Money"

"Plasterers Work Full Shift on Plastering Industries March Unique Concrete Boat" 1967

Reinforced Concrete Review December 1956, page 251

Sporting Boats with Concrete Schiffbautechnik, III, Vol. 13 Hulls (In German) pp. 163-164, 1963

- - -- -- ---- -

1 2 3 4

X

0

0

0 X

X X

0

X

0

- ,-- -

5 abc d

678

I X

X 0

I

X X F

X X

X X X 0

X F

X v 0 " X

X 0

-- -- '--- -

AUTHOR TITLE PUBLICATION

Concrete Hulled Craft Shipbuilding and Shipping Record Vol. 100 No. 23 pp. 733-4, 1962

"Concrete Cruiser for France" Shipbuilding and Shipping Record Vol. 102, No. 11 pp. 356, 1963

"Ferro-Cement Tug Hull is 40 Western Fisheries, Jan. 1968 Percent Cheaper

"Notes in Regard to the Physical Windboats, Ltd.; Wroxham, Norwich Properties of Seacrete" Norfolk, Nor 03Z, England

"Seacrete Hull-Only Prices" Windboats, Wroxham, Norwich Prices for Fabricated Hulls. Norfolk

Success of Concrete Boats World Fishing No. 1, pp. 6-7 1965

"Concrete hulls for Fishing World Fishing Vol. II, Jan. 1962 Boats" pp. 83

Abeles, Paul William Article about Prestressed wire Journal of the American Concrete in Concrete Beams analysed with Institute Vol. 16, No. 3 interest in Cracking Jan. 1945, Detroit pp. 181-213

I Alexander and Poore "A Technical Review of Ferro- Commercial Fishing August 1967 Consulting Engineers cement Construction" pp. 11 in Aukland

--- - -- - ---- - -

I

1 2 3 4

0 X

0

0

X

0 X

0

X X X

X X X X

5 abc d

X

X

X X

678

X F 0

X 0

X F

X F X

X

X F

X F

X

F

AUTHOR PUBLICATION 1 2 345 678

abc d TITLE

Ame1'yanovich, K.K. "Features of Estimation of Sudostroyeniye (Shipbuilding) Antipov, V.A. Strength of Ship Designs of No. 12, 1964. (in Russian) X X 0 Lapin, Yeo I, and Prestressed Concrete and Stinsov, G.M. Reinforced Concrete"

Ame1'yanovich, K.K. Reinforced Concrete - Sudostroyeniye, No. 12, 1964 and Shipbuilding Material. X X X F

Verbitskiy, V.D.

Bonn, W.E. Supt. "Regulatory Aspects of Proc. Con.on Fishing Vessel Hulls & Equipment Traditional and New Construct- Construction Materials, X X X X XX F

Division, ion Materials" Montreal, Oct. 1968, pp.74-90 X Marine Regulations Br. D.O.T.

Bruhn, E. F. Analysis and Design of Flight Cincinnati: Tri-State Offset X X X X X Vehicle Structures Company.

I

Byrne, J. G. and "An Investigation of 'Ferro- Concrete and Constructional Wright, W. Cement' Using Expar'.kd Metal" Engineering, Vol. LXI, 12 X X X X X 0

December 1961 pp. 429-432

Brochure Cefer Designs Ltd. 899 River Road, Richmond, B.C. 0 X X Phone 278:-8240

I

Collen, L.D.G. and "Some Notes on the Character- Civil Engineering and Public Kirwan, R. W. , istics of Ferro-Cement" Work Revie~v, (February 1959) X X X X X X Trinity College, pp. 195-96 Dublin

Collins, John, F. "Tensile Strength of Mesh- Term Project -- M.I.T. May Reinforced Mortar" 1968, 1. 46 X X X X X X

--~- - --

AUTHOR 1 2 3 4 678 PUBLICATION TITLE b d u ... ~

Colvin, Thomas, E. Detail design sketches and National Fisherman, Feb. 1968 X X F N.A. Miles, Virginia Letter pp. 6-8

Dunham, Clarence W. Pages 63 and 134 The Theory and Practice of Mention wire mesh reinforcement Reinforced Concrete, 1st and X X

4th eds., New York: McGraw-Hill Book Co.

English, W. J. General comments on the use of Conference on Fishing Vessel Pres. EV Assoc. Ferro-cement in the construct- Construction Material. 0 F

ion of fishing vessels. Part Montreal, Canada. Oct. 1968 of a discussion with a panel

Ferguson, P.M. Nothing directly related to Reinforced Concrete Fundamentals Ferro-cement New York: John Wiley and Sons, X X

March 1966

Fraser, D. J. Civil "Estimated Hull Hark and Proc. Con. on Fishing Vessel Eng. Naval Architect Material Content for 100 ft. Const. Materials X X X X X X F Commercial Marine Combination Fishing Vessel in Montreal, Oct. 1968 pp 305-321 Services Ltd .. Different Materials." Hontrea1

Gardner, John, "Ferro-Cement is Hottest Thing National Fisherman (June 1967) 0 X F in Boatbui1ding"

Cardner, John, Wide Interest Shown in Ferro- National Fisherman (Sept. 1967) 0 X X F Cement Boats. pp. 8A

Gardner_, John, "To Sea in a Stone" The Skipper,(December 1967) 0 0

Gardner, John, "The Future of Ferro-Cement" National Fisherman (1968) 0 X F

, -

..

AUTHOR TITLE PUBLICATION 1 2 3 4 5 678

/ abc d

52 Gardner, John Ferro-cement moves from back- National Fisherman (Oct. 1968) 0 X X X F I yard to shop

53 Gardner, John Need for Ferro-cement back- National Fisherman (March 1969) 0 X 0 I ground stressed.

54 Gardner, John From trunnels to Ferro-cement National Fisherman (March 1969) 0 X I

55 Gardner, John Interest in Ferro-cement National Fisherman (Aug. 1968) burgeons. Careful tests of 0' X X X X F materials needed

56 Gardner, John "Ferro-Cement Features Spark National Fisherman (July 1969) I Differing Views"

0 X 0 I X

57 Goldfein, S. Fibrous reinforcement for Modern Plastics (April 1965) X X X X X X X X I portland cement I

I

58 Harper, Walter R. Concrete Ships Constructed by ACI Proceedings Vol. 18 pp. 83, X X X X X 0 U.S. Shipping Board 114, 1922

;9 Hartley, Richard "Designing For Ferro-Cement" Sea Spray Oct. 1967 pp. 48-51 X X X X X 0 I I

Hartley's Boat Plans I

Ltd. Box 30, 094

I Takapuna, North, N.Z.

iO Hedges, Leonard Designs of Ferro~Cement Yachts Marine and Industrial Design I ARINA and Fishing Boats" 60 Caringbah Rd. 0 X X X X X 0

Data Sheets Caringbah N.W.S. Australia ~-----~ .- -- - -- - -- - '--- -

AUTHOR TITLE PUBLICATION

61 Hedges, Leonard, and "Ferro-Cement Fishing Vessels" Con. on Fishing Vessel Const. Perry, E., Naval Materials, Montreal 1968 Architects and Civil pp. 427-9 Eng. Caringbah, N.S.W. Australia

62 Jackson, Gainor "Future with a Promise for Part I Concrete Construction Concrete Boat Building" Sept. 1969 pp. 344-346

Part II Concrete Construction Oct. 1969 pp. 331-383

63 Jackson, Gainor Concrete Boat Building Today Reprinted from Sea Sp~ay

64 James, T.L. "A New Boatbuilding Material" Sh~p and Boat Building International (April 1967)

65 A. Kamasundara Rao "A Study of Behaviour of Ferro- Cement and Concrete (India -C. S. Kallappa cement in Direct Compression" New Delhi) Vol. 10 No. 3 Gowder Oct. Dec. 1969 A SARU Cement

Service Magazine pp. 231-237

66 Kelly, A.M. and "Ferro-Cement as a Boat Building Vancouver, British Columbia: Mouat, Material" British Columbia Research

Included in final report to DOF Council Sept. 1968

67 Lachance, L. Ferro-shotcrete: a promising Ocean Industry Nov. 1970 pp. Dept. of Civil Eng. Material 60-62 Laval University Quebec City, P.Q.

68 La Belle, N. Short history oti Nervi and his Engineering News-Record accomplishments V166 April 27, 1961 pp. 58-64

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AUTHOR TITLE PUBLICATION

69 McLaughlin, R.E. "Powered Concrete Ships of WII" Engineering News-Record Oct. 19, 1944 page 4721

70 Morgan, Roland "Lambot's Boats" Concrete page 128 March 1968

71 Muhlert, H. Ferro-Cement trawler, design Department of Naval Architecture Jergovich, N. and report, Unpublished report. and Marine ENgineeering. The Coleman, J.F. University of Michigan 1968

72 Neal, John, A. Seminar Notes: Fibre Reinforced Dec. 1967 pp. 1-9 Prof. of Eng. Concrete UNY at Buffalo

73 Nervi, P.L. "Structures" Publisher- F.W. Dodge Co. N.Y. pp. 50-62;69, 86. 1956

74 Nervi, P.L. Small craft construction in Shipbuilding and Shipbuilding ferro-cement. Record Vol. 88 No. 12, 1956

75 Nervi, P.L. Ferro-Cement in building The Builder Vol. 192 No. 5939 construction 1957

76 Nervi, P.L. Aesthetics and Technology in Cambridge, Hass.: Harvard Building University Press (1965)

pp. 200

77 Norris, C.F. Why not ferro~cement? Marine Technology Jan. pp. 43 - 47 1969

78 See also SNAME, Pacific NW Section Undated. Same title

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79 Ens. D. A. Perry, "Ferro-Cement - Its Potential for Naval Ship Engineering Center X X X X X X X F USNR and J.E. Pinto Naval Craft (A State of its art Hyattsville Maryland. Report

study) July, 1969 I

80 Reyner, A.N. and Reinforced Concrete Yacht Shipbuilding, No.6, 1966 0 X X X 0 Fro1ov, N.A. "Dream·· ("Mechta") (In Russian)

81 Riley, G. "Chinese Build Concrete Boats" Concrete Products December 1966 0 X F I I

;

82 Romua1di, J.P. "The Behavior of Reinforced Proceedings, ACI, Vol. 60 0 and Concrete Beams With Closely June, 1963 X X X X X X X

· Batson, G.B. Spaced Reinforcements" X

83 Romua1di, J.F. "Tensile Strength of Concrete Proc. ACI Journal Vol. 61, No. X X X X X X X I and , Affected by Uniformly Distributed 6, 1964 Mandel, J.A. and Closely Spaced Short Lengths

of Wire Reinforcement"

84 Samson, John Ferro-cement boats construction Conference on fishing vessel construction materials. X X X X X F Montreal, Canada. Oct. 1968

I

85 Samson, John "Concrete Boats" Letter to Editor Boating 0 X 0 Feb. 1968

1 86 Ferro-cement Boat Construction Samson Marine Design Enter- F

SUPPLEMENTS 1910 10 to date prises, Box 98, Ladner, B.C. X X X Dc IX X X IX X 0 5 for $5. Most material Dc alternately incorporated into Editions of Samson's Book

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AUTHOR TITLE PUBLICATION 1 2 345 678

abc d

87 Shepard, E.R. Concrete Gasoline Tanks for ACI April 1944 XX X X X X X X X Military Use

88 Smith, Jack What do you know about ferro- Yachting April 1969 X X X F

cement? Guniting emphasized pp. 84-

89 Smith, J.D. and The Development of Ferro-Cement Technical Supplement May 31 Greenius, A.W. For Fishing Vessel Construction 1970 Report to Ind. Dev. Br. X X X X X X X F

DOF by B.C.R.C.

90 Sutherland, Morley "Ferro-Cement Boats" Sea Spray Annual (1966) X X X F

91 Talbot, M.R. "Cement Hull Cuts Building Fishing Gazette January Costs" 1968 pp 12 ·0 X F

92 Taylor, W. H •. Concrete Technology and Practice American Elsevier X X 0 Publishing Co. Inc., Chap. 35 X

93 Traung, J .0. and' "New Thinking on the Use of Proc. Con on ~ishing Vessel Gulbrandsen, o. Materials in the Construction CJnstruction Materials 0 X F Fishery Resources' of Fishing Vessels" Montreal, Oct. 1968 pp. 5-22 X Department of Fisheries FAO Rome

94 Wishwanath, Teka1 "Test of a Ferro-Cement Precast Journal of the Structural Folded Plate" Division, Proceedings of the I

I

American Society of Civil X X X X XI Engineers Dec. 1965

AUTHOR TITLE PUBLICATION

95 Waddell, R. L. and "Ferro-Cement has Arrived" "Gam on Yachting~ Aug-Sept Beckett, T. W. 1968 pp. 3-6 Saga Tech Associated

96 Waddell, R. L. "Fabricating in Ferro-Cement" Gam on Yachting Oct.-Nov. Good critique of Male Mold 1968 pp. 6-9

97 Waddell, R. L. "Fabricating in Ferro- Gam on Yachting Jan. Suspended Hull" 1969 pp. 7-8

98 Wellens, Geoff "Ferro-Cement -- Revolutionary Western Fisheries; April Development for the Amateur 1968 pp. 30 Fishboat Builder"

99 Wig, R. J. Method of Construction of ACI Proceedings Vol. 15 Concrete Ships. Most Complete pp. 241-288 1918 article on 1918 Concrete Ships.

100 Frolov, LA. & Yachts made of Reinforced Shipbuilding (In Russian) Reyner -Concrete No. 10, 1961

101 Kelly, A.M. and Ferro-cement as a fishing Report .to rnd. · Dev. Br. English, W. N. vessel construction material of D.O.F. March 1970 B.C.R.C. Includes ref. 63 as an

appendix.

l02 Anonymous Aussies Outline Boat National Fisherman Oct. 1967 Building in Fer.ro-Cement

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PART B

Anonymous, "Build Yourself a Ferro-cement Boat-A manual" Fairfibre Prod. Ltd. Victoria, B.C.

" "

" "

" ."

Anonymous,

Anonymous,

Anonymous,

Beletskiy, V.F.

Benford, Harry,

Benford Harry,

Benford, Harry &

Kossa, Miklos,

Benford, Jay R.

" ______ " Appears to be an important Russian magazine", Betoni Zhelozobeton (Concrete and Ferro-cement) No. 12, 1961, No.9, 1961.

Collection, "Reinforced Concrete and Reinforced Concrete Design" Gosstroyizdat 1962.

Collection, "Reinforced Concrete Spatial Designs", Gosstroyizdat, 1961.

"Le Costruzioni Navali in Ferro-Cemento," Industria Italiana Del Cemento, No. 7-8, 1950

"Tentative Requirements for the Construction of Yachts and Small Craft in Ferro-Cement" Lloyd's Register of Shipping, Yacht Technical Office, January 2, 1967.

"Fibrous Reinforcements for Portland Cement Concrete," Ohio River Division, U.S. Corps of Eng., Tech., Report, May 1965, pages 2-40.

"Reinforced Concrete Instead of Wood," Stroitel (Builder), No.2, 1960.

"General Cargo Ship Economics and Design," Ann Arbor: College of Engineering, The University of Michigan, August 1965.

"Fundamentals of Ship Design Economics," Ann Arbor: Department of Naval Architecture and Marine Engineering, The University of Michigan, August 1965.

"An Analysis of U.S. Fishing Boats--Dimensions, Weights and Costs," Paper presented before the Second World Fishing Boat Congr~ss, Rome, Italy, 1959.

"Practical Ferro-cement Boatbuilding--Construction Manual", Box 456-J Friday Harbour, Wash. 98250, $10.00, 180 pages.

Biryukovich, K.L. "Small Ships Made of Glass Concrete and Reinforced Concrete," Sudostroyeniye, 1965. Biryukovich, Yu.L.

and Biryukovich, D.B.

Bonduryankiy, Z.P. "Seagoing ferroconcrete ships," (Hull Design) Shipbuilding Publishing House, NAVSHIPS Translation No. 1175~ (Abtract only) 1966, 199 pages.

Collen, L.D.G. and

Kirwan, R.W.

"The Mechanical Properties of Ferro-Cement," Civil Engineering and Public Works Review, December 1958.

Collen, Lyal D.G., "Some Experiments in Design and Construction with Ferro-Cement," The Institution of Civil Engineers of Ireland, Trinity College, Dublin, Jan. 1960, Vol 86 pp. 39-58.

Corten, H.T.

Fusch, K.

Kudryavtsev, A.A.

Mikhaylov, N .. V.

Moavenzadeh, F., Kuguel, R., and Keat, L.B.

Pospelov, V.I.

Pospelov, V"I.

Protopopov, V.B.

"Micliromechanisms and Fracture Behaviour of Composites," Modern Composite Materials, Addison-Wesley, 1967.

"Impact Strength of Fiber-reinforced Neat Cement Paste," ,Unpublished term project report, Dept. of Civil Engineering, Mass. Inst. of Technology.

"On the question of the Impact Strength of Reinforced Concrete and Thin Ferro-concrete Plates, II In the collec.: "Reinforced Concrete and Reinforced Concrete Designs," published by editors of Journal: "Bulletin of Technical Information," Glavleningradstroya, 1959.

"Basic Principles of New Technology of Concrete and Ferro-concrete," Gosstroyizdat, 1961.

"Fracture of Concrete," Research Report R68-5, Department of Civil Engineering, School of Engineering, Mass. rn,st. of Technology, March 15, 1968.

"Allowance for Flexibility in Strength Calculations of Marine Ferro-concrete Elements," Abstract Journal (NAVSHIPS translation No. ,1176. Abstract only.)

"Investigating the Strength of by Flexures -and Compression," Abstract only).

Marine Ferro-concrete plates at Independent Load Abstract Journal (NAVSHIPS Translation No. 1177.

Experimental Study of Impact Strength of Reinforced Concrete Platings. Trans. of Gorky Institut~ of Engineering Water Transport, No. 45, 1962

Rassbach, W.

Samoy10v, B.N.

Savinov, O. A. , Lavrinovich, Yeo V. and Tsukerman, N. Ya.

Shah, S.P.

Spratt, G.W.

Yunin, V.P.

"An Introduction to Ferx.:o-Cement in Shipb~i1ding," Presented to the Pacific North­west Section of the Society of - Naval Architects and Marine Engineers, March 1, 1969.

Calculation of Elements of Reinforced Concrete Designs and of Ferro-Concrete Designs with Disturbed Reinforcement. Pub1. of Kuybyshev Engineering - Construction Institute, 1964.

"Contribution to the Question of The Reinforcement of Thin-walled Ferro-Concrete Designs," In the co11ec.: "Steric (Spatial) Designs in the USSR," Stroyizdat, 1964

"Ferrocement as a New Engineering Material," Presented-Precast Concrete and New Advances in Concrete Materials Course, Canadian Capital Chapter, ACI, Ottawa, Dec. 1970.

"Research and Development in Ferro-cement Usuage," Seminar: Ferrocon Industr. Vancouver, B.C., Canada. March 1963.

"Investigating the Effect of Various Patterns of Reinforrnment on the Strength Characteristics of Shipbuilding Reinforced Concrete," Trans. of Gorky Inst. of Eng. Water Transport, No. 45, 1962.

.,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

.., •

PART C

"Une Relique Retrouv~e" La Barque de Lambot," Batir, 47, 1955, page 9.

"New Fibersteel for Docks and Boats," Bay and Delta Yachtsman, January - February 1966

'·'Shipbuilding in Concrete," The Blue Circle, Vol. 17, No.2, 1963, pages 8-9

Concrete Cruiser," Boating, August 1967.

"Ferro-cement Boats," The Boating Industry, September 1967.

"Ferro-Cement: Tomorrow's Homemade Boat Boom?" Boating Journal, February - Uarch 1968.

"Concrete" page 18 July 1921 and page 2 May 1942.

"A Ferro-Cement Boat," Concrete and Constructional Engineering, March 1962.

"New Splash for Concrete," Concrete Construction, November 1960, page 326.

"Ferro-cement Boats," New Zealand Concrete Construction, February 12, 1963.

"Ferro-cement boats," Concrete Construction, Vol. 10, No.9, New Zealand, September 12, 1966.

"American Concrete Yacht, 'Featherstone' Proves Herself Seaworthy," Concrete Construction, Vol. 7, No. 11, New Zealand, November 12, 1963, page 206.

"Concrete Freighter Shows Amazing Durability," Concrete Products, September 1961.

"Rubb a Dubb Dubb -- 3 Men in a Concrete Tub," Concrete Products, June 1963.

"Concrete Ahoy," Corrosion Technology, October 1961.

"Value of Boats Built in B.C.," D.B.S. Ottawa Reports.

"History of Windboats, Ltd.," East Anglia Life, May 1965.

"Consolidation -- In Concrete?" The Economist, January 6, 1962.

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymot- ,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

Anonymous,

"Concrete and Structural Form," Engineering, October 1955, page 601.

"Announcement to Marine Builders," Fibersteel Co., December 5,1967.

"Cement for Sail," Gam on Yachting, .Ontario Edition, January 1968.

"Cement Boats," Macleans Magazine, 1966.

Marine Review; September 1918, page 373.

Maritime Review, September 1918, page 419.

Mechanical Engineer, Volume 49, November 1927, page 1195.

"Concrete Racing Yawl," Mechanix Illustrated, July 1963.

"~otor Ship, July 1942, page 108.

Modern Boating (New Zealand), July 1966, August 1966.

Nautical Gazette, November 1942, pages 33 and 39, (Non-typical ship), April 1943, page 20.

"Concrete Ship to Bridge a Gap," The Ne\v Scientist, July 24, 1958.

"Hearts of Concrete for Russia," The New Scientist, February 20, 1958.

"Valeo .•. 55' Design Series for Ferro-cement Construction," Sea and Pacific Hotor Boat, August 1967.

"Awahnee 11akes History" Sea Spray, August 1965.

"Marire -- A Matangi Design Built in FerrO-Cement," Sea Spray, April 1965.

Shipbuilder, July 1929, page 20.

"Making a Concrete Punt," The Sphere, Vol. 233, NO. 3034, May 24, 1958, page 295.

"Seacrete, " Windboats, Ltd., Wroxham, Norwich, Norfolk, Nor. 032, England, ~farch 1962.

Anonymous,

Abner,

Chapin, William,

Cox, Eric,

Curry, R.,

Dique, Nigel,

" " ,

Freeman, J. E.

Gardner, Joh1;l,

C> •

"The Seacrete Hull," Windboats Ltd., Wroxham. Norwich, Norfolk, Nor 032, England.

"Reinforced Concrete Ship," The Architect and Building News, Vol 219, No. 24, June 14, 1961, page 779.

"Out to Sea-- In Cement," San Francisco Chronicle, March 18, 1968.

"It's an Easier Way," Yachting Monthly, December 1966, pages 294-95.

"Prestressed Concrete Barges," American Bureau of Shipping, August 1966.

"Just Add Water and Mix," Seacraft, May 1966.

"A Report on Fer-ro-cement Boat Building and other Construction," E.V. Associates inc. Miami, Florida, Oct. 1968.

"Development of Concrete Ships and Barges," Proceedings, ACI Vol. 14, 1918.

"Fly Ash for Ferro-cement Could Help Utilities," National Fisherman, Dec. 1967.

Griffith, Nancy H. "The Building of AWAHNEE". Boating Part II March, 1969.

Hacking, Norman,

Hacking, Norman

Huxtable, A.L.

Irons, Martin E ..

Kallappa Gowdar, C. S.·

"After Subsidy, What?" The Province, Vancouver, January 16, 1968.

"Tug Made of Cement and Wire Launched by Lulu Island Yard," The Province, Vancouver.

Pier Luigi Nervi, George Bragilleu Inc., New York, 1960 128 pages.

"Ferro-cement Advice from an Expert," National Fisherman June 1967, pages 7-B, 23B, 24B.

. Technology of Ferro-cement:, Thesis, Mysore University, 1968

Kamesundara Rao, A. "A method of design for ferrocement elements", Thesis, Mysore University, 1968

Lysaght, 1.

Manning, A

"Shiver-me-Timbers - Now Concrete Hulls for Yachts." Atlantic Advocate 1967.

"The First New Zealand Hade Concrete Boat" Concrete Construction, Vol 7, No.2, page 23, New Zealand, 12 February 1963.

Maynard, John A.

Mishutin, V.A.

Nervi, P.L.

Noble, H. Morgan,

Rath, Dick,

Robinson, H.,

Ross, Stanley,

"Sea-going Concrete," Seacraft, vol. 32, Nc. 2, pp. 28-30, (Au~tralian), March 1964.

"Investigation of shipbuilding concretes." Shipbuilding Publishing House, Leningrad. (NAVSHIPS Translation No. 1174. Abstract only.)

"II Ferro-Cemento e la Prefabbricazione Struttural," In: Colonetti, G., Sciense Delle Construzioni, Vol. III Page 13, Torino Scientifica Einaudi, 1957.

"Concrete Pontoons for Marinas, "Noble Harbour Engineering, Newport Beach, Calif.

"Ferro-Cement Details," Boating, February 1968.

"Researchers Find New Ways to Wed Sheet Metal, Concrete," Financial Post, Feb. 16, 1963.

"Concrete Floats" Smooth Sailing Ahead," Concrete Products, Vol. 66, p. 29-32, October 1963.

Salvardori, G. & M. Structures by Pier Luigi Nervi, New York: McGraw-Hill Book Co. p. 118 1956

Scavino, G. L.

Skinner, G.,

Small, G.

Tonge,- P.

Tyrell, . D.

Vasta., J.

Verney, M.

Verney, M.

. Wellens, G.

Weilens, G.

J

"Use of Reinforced Concrete in Building Naval Ships," The Italian Cement Industry, 35, No.2, pp. 191-200, 1965.

"World Cruise Concrete Yacht," Modern Boating, January 1968.

"A concrete suggestion" Yacht~ng World, pp. 136-139, March 1968.

"Launch It, Leave It Boating Approach," Christian Science Monitor, March 8, 1968.

"Dr. Bob Griffith," (Circumnavigation of Globe in, Ferro-cement Boat,) The Sun, Vancouver.

"The Concrete Ship Program of World War II," Paper presented before the Chesapeake Section of the Society of Naval Architects and Marine Engineers, May 8, 1952.

"Concrete Keels," Yachting Monthly, pp. 314-317, June 1963.

"Plastering Industries," An Account of 44-ft. ferrocement fishing trawler building by Gordon W. Ellis, Victoria, British Columbia, March 1967.

"Pioneer Will Soon be Rolling Stone," The Province, Page 18, May 10, 1968 .

"Sailor of Fortune's · Tales are Stranger than Fiction," The Province, Vancouver, November 15,1967.

Wellens, G.

Wellens, G.

Wellens, G.

.,

"Builder in a Hurry," The Province, Vancouver, October 13, 1967.

"Paradise in a Trimaran," The Province, Vancouver.

"The Awahnee': When all the World was a Watery Stage," The Province, Vancouver,

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Compiled By:

Compiled For:

r

FERRO-CEMENT BIBLIOGRAPHY

British Columbia Research Council Vancouver, British Columbia.

Vessels & Engineering Division

Industrial Development Branch

Department of Fisheries & Forestry

April 21, 1971.

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. <ll til til <J .c

<ll OM eo t:: P-f.. BOOKS AND REPORTS. - 1 - :> .... 6 til til

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Author and Affiliation Title (volume. date. paging) III III OM <J <ll .c No. z E-I Q U) p.. p..

l. Saga Technical Associates Bibliographic introduction to Toronto, Saga 1969? x x x x x x (designers, publishers) ferrocement.

2. Bezakladov, V. F. et al. Ship hulls made of reinforced Leningrad, 1968 x x x x x x Shipbuilding Publishing House, concrete. Translation pub. by CFSTI Leningrad. AD680 042, 1968

3. Canby, Charles D. Ferro-ceme.nt, with particular Ann Arbor, 1969 x x x x U. of Michigan, Dept. of Naval reference to marine applications. Departmental No. 014 Architecture & Marine EngineerinK·

· 4; Lin, T.Y. & Associates, Ferro-cement panels v. 1 Report No. CR 69.008 x x x x x Consulting Engineers (For U.S. CFSTI AD850630, 1968 Naval Civil Engineering Lab., Calif)

5. Geymayer, H.G. Strain meter & stress meters for Tech. Report No. 6-811 , U.S. Army x x x x x U.S. Corps of Engineers. embedment in models of mass Engineer Water-Ways Exper. Station

concrete structures. Vicksburg, Mass. 6. Use of epoxy or polyester resin Tech. Report No. C-69-4, U. S •. Army x x x x X

r in tensile zone of composite Engineer Water-Ways Exper. Station concrete beams. Vicksburg, Mass.

7"':"' Gibbs & Cox, Inc. Marine design manual for New York, McGraw Hill 1960 x x x x x Fiberglass reinforced plastics.

8. Harper, Ross et al Boatbuilding in ferro-cement The Authors, Vancouver, B. C. , x x Consultants. 1967(?)

9. Hartley, R.T. :Soatbuilding with Hartley Aukland, N. Z. , the author, 1967. x x x x x Builder 3rd ed.

10. Jackson, G.W. & W.M. Sutherland. Concrete boatbuilding. London, Allen & Unwin, 1969 x x x x x x

11. Mowat, Dallas N. Flexural testing of ferr-cement H.Sc. Thesis, 1970. x x x x x Univ. of Calgary,. Dept. of Civil planks Engineering. .

12. 11uhlert, Hans F. Analysis of ferro-cement in Ann Arbor, 1970 x x x x Univ. of Michigan, D~pt. of Naval bending. Departmental No. 043 Architectur & i1arine Engineering.

l3. Samson, John and Wel~ens,.Geoff How to build a ferro-cement boat. Vancouver, Samson Marine Design x x x x Samson Marine Design Enterprises Enterprises, . l968. . Ltd.

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B. ARTICLES & PAMPHLETS. • ..-f e ~ Jj Ul ~ ~ eo C\l Q) Ul Q) 0 o u;

Journal and Citation ~ r-! bO'r-! ~ Jj~ ~ .0 C\l C\l ~ o u:

(volume, date, paging) C\l C\l • ..-f C) Q) ~ c

No. Author and Affiliation Title Z H 0 (/) ~ ~(.;

14. Anon Chinese build concrete boats Concrete Products v. 69(12) x x x Dec 66 p. 36"'37.

15. " Concrete barges multiply in Gulf. Concrete Products v. 70 x x Jan. 1967 p. 56-58.

16. " Concrete-hulled pilot launch for Shipbuilding & Shipping Rec. 1966 x x x Bahrain. v. 49:437.

17. Anon Construction of an IBM ferro- U.S. Joint Publications Res. x x cement hyperbolic hull - Communist Service. China. JPRS 4167, 1960

18. " Ferrocement Concrete construction 1966, - x v. 11:355

19. " Ferro-cement: does it have a The Work Boat. Feb. 1969. x x x x future in the work boat field?

20. " Progress in ferro-cement. Yachting Monthly. Sept. 1967 p. 120-124. x x x x

2l. " Seacrete stern trawlers. Fishing News International x x x v. 7, 1967, p. 69-70

22. I Thin-shelled reinforced concrete Engineering 1963 x x ------...- in the U.K. 8 Feb. 232-3.

J. I YM and Ferro Report from Yachting Monthly 1969? x x x x 24.- Allen, R.T.L. & Terrett, F.L. Durability of concrete in coastal Conference on coastal engineering. x x

Cement and Concrete Assoc. protection work 1968. Chap 75 : 1200-1207. 25. Barnes, Sam. Concrete boats. l1achine Design. April 1968, p 44-45 x x 26. Bellport, B.P. Combating sulphate attack on In: Symposium on Performanc~ of x pc x pc

U.S. Reclamation Bur~au. concrete on Bureau of Reclamation Concrete. Toronto~ University projects. Press 1968, p 77-92.

27. Burgess, John •. Seacrete Method developed by Fishing News International x IX x pc British yard.· v. 8, May 1968: 44-45.

28. Cassie, W. F:isher. Lambot s boats. Concrete (London) v.l 1967; 380-82. x ~ 29. Cement & Concrete Assoc. of Ferrocement boats. Concrete Information No. C-39, x IX pc

Australia. 9 pp 1968? 30. Fondriest, F.F. & Control of cracking in concrete. Battelle Technical Review x :x pc

Birkimer,Donald L. Sept/Oct 1968: 3-9. 31. Fyson, John F. Ferro-cement construction for Fishing News Internat. v.8,

Supr. of Boatbui1ding fishing vessels Pts 1-3. April 1968; 51-55, May 39-43, pc ~

FAO Regional OR Bangkok. June 30~32 (or FAO reprint). 32. 9au1, R.W. & E.D. Smith Effective & practical repair of In: Epoxies with concrete. Am •. x x ~

cracked concrete. Concrete Inst. Pub. SP-2l, 1968 p. 29-36.

33. Gardner, John. Ferro-cement makes strong huLL; Nat~onal. 1r~snerman. March 196/, x IX Tech. Editor. micro-balloons help lick resin sag. p. 8a

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34. Gibson, Peter. Fishboats in'Ferro-cement. Western Fisheries 1968. January Correspondent. 25, 26, 28. x x

35. Gt. Brit. Building Research Station Zinc-coated reinforcement for Digest 11109. Watford 1969. x x x concrete.

36. Hagenbach, T.M. Ferro-cement boats. Conf. on fishing vessel constrn • . 'jX x ~.

Seacrete Ltd. Mat'ls. Hontreal, 1968. p 365-371. 37. Hurd, N.K. Ferro-cement boats. Am. Concrete lnst. J. x x

I Am. Concrete Inst. 1969: March p 202-4. 38. lorns, Martin. Fibersteel Corp. Cement boatbuilding problems aired. National Fisherman. Hay 1967. x 39. Ferro-cement advice from an National Fisherman. June 1967, x x

expert. June 1967, p 7B, 23B, 24B. 40. Kaiser Cement. Ferro-cement seagoing architectural Oakland, Cal. Kaiser x x .

concrete. undated. 7 pp. 4l. Kelly, A.M. & Mouat, T.W. Ferro-cement as a fishing vessel Paper presented at Conf. on Fishing x x x x ~

B.C. Research, Vancouver. construction material. . Construction Materials. Montreal, I

1968. 42. Kristinsson, G.E. The growing acceptance of Ferro- Sea Harvest Ocean Sci. x x

Commercial Marine Services, Ltd. , cement as a first-class boat- Dec 69/Feb 70. 32-34. I

Montreai. , building material. 43. 1 2p Construction of a ferro-shotcrete L'Ingenieur, March 1970. v. 56. x x ~ ?c. Lachance, L. & , Fugere.

motor-sailer hull. (translation available) lLaval University. 2Consulting Eng.

44. Hather, B. Field & laboratory studies of the In: Symposium on the performance x x ~ sulphate resistance 'of concrete. of concrete. Toronto', Univ. Press

1968. p 66-76. 45. Hathews, S.T. Main hull girder loads on Great Soc. Naval Architects & Harine x x x ~

Ship Division N.R.C. Lakes bulk carrier. EnKineers. Spring Meeting, 1967. Proceedings Paper No. II.

46. Horgan, Rowland G; Underwater concrete. Underwater Science & Technol. J2, x x l{

U. of Bristol. 1970, June, 74-80. 47. Concrete as a shipbuilding material International Harine & Shipping x x

Conf. (London) 1969. Section 11, Materials. p ·9-14.

48. Nervi, Pier Luigi. Conc.rete and structured form. Engineering, 1955. 601-603. x II.

Nervi & Bertoli (Rome) 49. Ferro-cement: its characteristics L lngegnere 1951 (trans.) x ~ pc

& potentialities. 50. Ferro-cements: chapter 4 of McGraw Hill, 1956 x x pc pc

his Structures.

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51. Nervi, Pier Luigi, Precast concrete offers new American Concrete Institute J. x x Ix Nervi & Bertoli (Rome). possibilities for design of shell v. 25: 537-548, 1953.

structures. 52. Thin reinforced concrete members Civil Engineering 1951, x x

from Thorn exhibition hall. v. 46:25-31. 53. Oberti, Guido. Prof. The penstock of Castelbello Energia Elettrica 1953. v. XXX x x IX x

(Trans I. ) No. 5. 17 p. 54. Some conclusions about Undated paper (Transl.) x x Ix

deformability & resistance in tension ferro-cement.

55. Rath, Dick. Concrete boats - are they for real? Boating Oct 1967. 37-42. x Ix x 56. Romualdi, J.P. Two-phase concrete and steel U.S. Patent 3,429,094 x x x x

Battelle Development. material. Feb 25, 1969. 57. Ross, Stanley. Concrete floats: smooth sailing Concrete products. v. 66, 1963 x Ix

ahead. Oct: 29-32. 58. Schutz, B.J. Epoxy resin adhesives for bonding In: Epoxies with concrete Am. x x Ix

concrete to concrete. Concrete Inst. Pub. SP-21. Detroit, 1968 p. 19-28.

59. Stevenson, H.1. , Use of concrete ships for mill log Unpublished notes. 1964 . . ~ pond breakwater at Powell River.

60. Swenson, E.G. Admixtures in concrete National Research Council x Div. Building Res., N. R.C. NRC Tech. Paper No. 18l. Ottawa.

6l. Tuthill, Lewis H. Concrete operations in the concrete Am. Concrete Inst. J. x x IX ~ x U.S. Reclamation Bureau. ships program. 1945 v. 16: 137-180.

0

I and Discussion & closure. Supp. Nov. 1945 Ix

Coff, L. lSO-l - lSO-5.

Collen, L.D.G. Some Notes on the Civil Engineering and Public Trinity College., Dublin Characteristics of Ferro- Works Review (U. K. ) v.54:l95-

. Cement 196, Feb. 1959 x x x x

Collen, L.D.G. Some Experiments in Design Bulletin of the Institution of - and Construction with Ferro- Civil Engineers of Ireland. - x x x x x

Cement v.86: 39-58, Jan. 1960.

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