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Int. J. Engg. Res. & Sci. & Tech. 2014 Abdulfatai O Ambali et al., 2014

DESIGN AND MANUFACTURE OF A HYDRAULICWORKSHOP CRANE

Work related musculoskeletal disorders are supposed to be casually linked to physical loadlifting resulting from occupational activities. Disorders or injuries affecting muscles, tendons,joints, ligaments and bones are mainly by mechanical overload of the respective biologicalstructures. Examples of occupational activities coinciding with high mechanical requirementsare handling of objects as in transportation jobs or the application of pushing or pulling forces totools and machines (Luttmann et al., 2003). Handling of heavy objects is a daily activity in mostmachine shops, welding and fabrication workshops and with the consistent maintenance needto mount heavy objects in machines, overhaul motor vehicle engines once in a while, handlingof such heavy objects or engine has become a major problem in operational/automobileworkshops, occasioning musculoskeletal injuries at most times where humans directly handlethe carriage and installation of the vehicle engines and axles. That machining, welding andfabrication and auto mechanics work are laborious is a common saying born from the fact thatmost carriage and handling jobs in most workshops are purely manually executed. There arehowever few shops who have shop cranes. These shop cranes are imported at exorbitant costand as such not within the reach of most operational/automobile workshops.In recognition ofthis need, this project intends to develop a made in Nigeria, affordable shop crane.

Keywords: Work, Crane, Workshop, Injury, Affordable

INTRODUCTIONThe technological growth of Nigeria though slowhave been fostered by the increase in weldingand fabrication shop which arose from increaseduse of iron and steel, engineered in the 1970sthrough the establishment of Ajaokuta steel plant1 Hydraulic Equipment Development Institute (HEDI), National Agency for Science and Engineering Infrastructure (NASENI),

Federal Ministry of Science and Technology, Kano, Nigeria.2 National Board for Technology Incubation (NBTI), Federal Ministry of Science and Technology, Abuja, Nigeria.

Int. J. Engg. Res. & Sci. & Tech. 2014

ISSN 2319-5991 www.ijerst.comVol. 3, No. 3, August 2014

© 2014 IJERST. All Rights Reserved

Research Paper

and other small steel plants in the country. Thegrowth has been steady though slow. Thisrelatively slow growth is followed with thegeometrical increase in the importation ofvehicles, making land transport the primetransport system in the country compared to water

Ibrahim O Abdulmalik1, Michael C Amonye2, Mahdi Makoyo2, Ahmed A Kano2,Abdulfatai O Ambali1* and Akonyi N Sule1

*Corresponding Author: Abdulfatai O Ambali [email protected]

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transportation and other modes of transportation.Continuous operation of these vehicles impliesconsistent repair and maintenance. It is noticedthat there has been remarkable increase in thenumber of automobile workshop and spare partsdealersin order to meet the maintenancerequirement of many vehicle plying the Nigeriaroads. However the much drudgery experiencedactivities in both welding and fabrication worksand automobiles repair job in the countrycontinuously repels youths from taking up suchcareers. They therefore preferred to look foralternative means of livelihoods; hence the driftis toventure into commercial motorcycle riding.Much of these drudgery and job difficulties areeither caused by improper handling of materialsor handling materials that are too heavy, therebyexposing operators to health hazard as well asrisking the damage of tools and fittings duringassemble exercise.

As far back as the middle ages, cranestructures were used to lift objects that were tooheavy or cumbersome for hands on lifting. Thedevelopment of cranes since then has gone handin hand with the development of modern industry(Thompson Geoffrey, 2007). The welding andfabrication industry as well as the automobilerepair workshop have grown tremendously inNigeria, but without the matching indigenousdevelopment of equitable lifting contrivances likethe movable shop crane, foldable shop crane andworkshop overhead crane.

The high level of usage of vehicles for bothprivate and commercial activities coupled with theinflow of second hand vehicles from abroadpopularly called “Tokunbo Vehicle” brought aboutthe need for very efficient and effectivemaintenance. Often times, the garages orworkshops where the maintenance activities are

carried out are of low capital base. A close look atthe equipment being used reveals the level ofpoverty of the technicians (Fapetu and Akinola,2008).

The development of engineering over the yearshas been the study of findings ever more efficientand convenient means of pushing and pulling,rotating, thrusting and controlling load, rangingfrom a few kilograms to thousands oftones.Cranes are widely used to achieve this. Inhydraulic crane, the force generation,transmission and amplification are achieved usingfluid under pressure. The liquid system exhibitsthe characteristics of asolid and provides a verypositive and rigid medium of power transmissionand amplification. In a simple amplification, asmaller position transfers fluid under highpressure to a cylinder having a larger positionarea, thus amplifying the force. There is easytransmissibility of large amount of energy withpractically unlimited force amplification (Sumailaand Ibhadode, 2011).

A typical shop crane consist of a pump (smallpiston and handle which up and down motionactuate the small position’s up and down motionadmitting oil from a reservoir on one stroke andexpelling the oil at higher pressure into the largerposition on the other stroke); a hydraulic cylinder,two one-way non-return valves, one release valveand piping. The hydraulic crane can therefore bedesigned and produced for any desired tonnagecapacity. It is invaluable equipment in allworkshops, laboratories and industries especiallyfor lifting and transportation of heavy objects.

A look at the workshop in Nigeria reveals thatall such machines are imported into the country(Sumaila and Ibhadode, 2011). It is thereforeintended to design and manufacture a shop crane

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which is low cost and hydraulically operated usinglocally sourced materials. This will not only helpto recover monies lost in the form of foreignexchange but will enhance the level of our localtechnology in the exploration of hydraulic fluidpower transmission.

STATEMENT OF THEPROBLEMNigeria’s aspiration to be among the world’s firsttwenty industrialized nation by the year 2020 maynot be met unless adequate and endogenousworkshop equipment are deployed to supplementimported ones in all its maintenance andproduction shops. Available data from the NigeriaPorts Authority shows that about 900,000 vehicleswere imported into the country between 1992 and2003. This figure has increased geometrically inthe last ten years. According to the Nigeria AutoIndustry QuarterlyUpdate 2012, the country hasan annual demand of 300,000 new vehicles(Business Monitor International, 2013). Repairand maintenance of these vehicles are regularand must take place for their continued operation.This informs the reason for the ever increasingnumber of such automobile repair shops in thecountry. Most shops however are grosslyunequipped for proper handling and job executionin the shops.

Sound professional best practice aimed atworkshops injury and accident prevention andreduction ensures the utilization of appropriatetools for any job. Motor vehicle repair andmaintenance often require the lifting of the entirevehicle or sub-assembly part of it or the lifting upand down of its heavy components. Also in otherindustries and welding shops, there are items andrepairs which need the employment of shopcranes. The lack of shop crane utilization in our

industries and automobile repair shops not onlyleads to injury and accident but also to poor repairand maintenance occurrence.

The few crane and lift facilities currentlyemployed in Nigeria production and maintenanceshops are all imported at exorbitant costs. Thereis the need for the development of home initiatedand home built shop cranes that are affordablewith simplified technology which, could beproliferated to SMEs in order to ensure adequateusage of proper lifting tool in those sector. Thisproject intends to address this issue from theangle of evolving the built of an affordable shopcrane using mostly available materials.

OBJECTIVEThe broad objective of the work is to ease materialhandling in Small and Medium Scale Industrialworkshops by the development and manufactureof various capacity hydraulic shop cranes inNigeria. This will be value addition, as it woulddrastically reduce the drudgery andmusculoskeletal injuries currently experienced inthe operations of such industries. The specificobjectives are:

• To design various hydraulic shop craneswithin the range of 200 kg to 1 tonne.

• To manufacture their prototypes.

• To test-run the prototypes equipment andevaluate its performance and cost incomparison with imported ones.

• To disseminate the technology to SMEs formass production.

METHODOLOGYThe research methodology is as follows:

• Review of existing work on HydraulicWorkshop Cranes and Cranes in general.

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• Design of the equipment for various capacities.

• Selection of materials for the construction ofthe crane mainly from the local market.

• Fabrication of the prototype.

• Parametric studies of the prototype equipmentin other to ascertain its performance andstandardize it.

• Performance evaluation as economically incomparison with imported ones.

BACKGROUND HISTORY OFCRANE EVOLUTIONCrane use and evolution started with the needsin the erection of anvil and structural works.Travelling cranes of the hand operated type werein use in the 1880s. About this time complicateddesigns of powered motion were offered byEnglish and American builders involving a drivingshaft along the runway and multiple clutches fortransferring the power of the driving shaft to thehoist, trolley or bridge motions. Successive cranedevelopment ran thus: 1880 saw the handpowered crane, 1900 the electrical driven cranewith a motor for each motion; by 1920 definitestandards had been established for cranes ingeneral and for various types of services; 1940brought the enclosed gear cases, roller bearingsand standardized designs; and 1960 producedthe changes in crane control which resulted insmoother operation, safer handling of load,remote operation and new safety features forprotection of equipment and personnel (Greiner,1967).

From the cranes used in building and structuralengineering works, cranes have been developedfor all cadre of material handling jobs inmanufacturing and service industries. As a result,many different varieties of crane exist.

Broughton (1958) grouped all cranes into fourmain categories, which remain applicable today,as enunciated by Thompson Geoffrey (2007):

Overhead Travelling Crane: This consist offixed rails lying on one or two elevated girderswith the trolley or crane bridge (with hoistingapparatus) that can transverse the length of therails.

The Jib Crane: This consists of an inclinedmember that can rotate about a central point andsuspend the load from the outer end of theinclined member.

Gantry Crane: This is a girder or girdersconnected to vertical members which are eitherfixed or move along tracks at the base of thevertical member, the hoisting equipment can beusually traverse the bridge girder or girders.

Cantilever or Tower: This is a vertical mast witha horizontal cantilever that rotates horizontallyaround the vertical member. The trolley andhoisting equipment move along the horizontalcantilever. The hydraulic shop crane is a smallcantilever crane operated manually and can bemoved in all directions through the action of thesteel or rubber tires installed at the base.

Current efforts in developed countries likeGermanyand the USAare geared towards thedevelopment of automated cranes; but Nigeriais yet to develop small cranes for small andmedium scale material handling in industries.According to a document of control engineeringpractice, in the context of further automation ofmanufacturing processes, automatedtransportation of heavy weight using cranebecomes more and more important. Applyingthe skills or Robots to crane automation, a widemarket of new applications could be developed(Sawodny et al., 2002). A wide market of

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Actuating Pump MathematicsWhen a hydraulic cylinder is operated by a handpump, the cylinder plunger moves a certaindistance per pump actuation. This distancedepends on the cylinders effective area and onthe pump’s oil flow per stroke. When two-speedhand pumps are used, the low pressure oil flowVLP applies for cylinder movements without loadand the high pressure oil flow VHP applies forcylinder movements with loads.

The formula:

S(mm) = [V(cm³).10.]/A(cm²) ...(3)

where

S = Cylinder’s shift in mm

V = Pump’s oil flow per stroke in cm³

A = Cylinder area in cm²

applications exists awaiting the development ofmatching shop cranes in Nigeria.

DESIGNBoth the hydraulic plunger actuation and the craneoperation are built on the simple lever principle.Characteristic parameters in hydraulic cylinderand actuating pump as well as the crane boomoperations are given hereunder.

Force of Hydraulic CylinderThe force of a hydraulic cylinder results from thepressure in the cylinder, p, on the piston of thecylinder.

The formula:

F(kg) = p(bar) x A(cm²) ...(1)

where

F = Force acting on the cylinder in kg

p = Operating pressure in bar

A = The cylinder effective area in cm² whichis calculated from the piston diameter:

A(cm² ) = x d2/4 ...(2)

Figure 1: Hydraulic Cylinder

Figure 2: Actuating Pump

The Shop Crane

Figure 3: Schematic Drawing of the ShopCrane

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The Crane Boom as a LeverLever is a simple machine consisting of a rigidbar that rotates about a fixed point, called afulcrum. Levers affect the effort, or force, neededto do a certain amount of work, and are used tolift heavy objects. To move an object with a lever,force is applied to one end of the lever, and theobject to be moved (referred to as the resistanceor load) is usually located at the other end of thelever, with the fulcrum somewhere between thetwo. By varying the distances between the forceand the fulcrum and between the load and thefulcrum, the amount of effort needed to move theload can be decreased, making the job easier.Physicists classify the lever as one of the foursimple machines used to do work. There are threeclasses of levers: (a): Class 1 (b): Class 2 and(c): Class 3; depending on the arrangement of

the force, the load, and the fulcrum along the leverbar. Each class of lever affects force in a differentway, and each class has different applications

The class 1 lever has the fulcrum between theforce and the load. The class 2 lever has thefulcrum at one end, the force at the other end,and the load in the middle. A class 3 lever has thefulcrum at one end, the load at the other end, andthe force in the middle. From Figure 3 it is seenthat the crane boom is a class 3 lever. The loaddiagram is given in Figure 5. The crane intendedcapacity at highest load point is 5,000 kg. Thespecification of the hydraulic cylinder is put at10,000 kg admitting a 50% factor of safety; butthe computation for minimum load is executedwith the 50,000 kg load capacity at maximum loadpoint.

Hence taking moments,

Minimum Load x 152 cm = 5,000 kg x 40 cm

cmcmkgLoadMinimum

15240000,5

= 1,315 kg

Acceptable load at minimum load point =1,000 kg.

From Equation (1), the operating pressure isevaluated and used to procure the requisite

Figure 5: Moment

Minimum LoadPoint

MaximumLoad Point

Hydraulic cylindereffort = 10, 000 kg

Figure 4: Levers

Load Effort

Effort

Load

EffortLoad

CLASS 3 LEVER

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hydraulic hoses for the system. Where thecylinder diameter is 46 cm;

Area = D2/4 ...(4)

Hence,

Pressure = Load/Area

P = 10,000/( x 462/4)

= 6 Bar

Similarly using Equation (1) and the numberof strokes to achieve maximum extension of thecylinder, the quantity of hydraulic fluid for theactuating pump operation can be evaluated.

CONCLUSIONThe equipment was fabricated and tested, andwas observed to execute the lifting of highest ratedload of 5,000 kg for one hour. Figure 6 is the

picture of the Fabricated Shop Crane as it wasdisplayed during the 2013 Abuja InternationalTrade Fair tagged “ABUCCIMA 2013”.Arrangement is ongoing to cede the technologyto SMEs who will erect production factories forthe continuous of production of the product.

REFERENCES1. Business Monitor International (2013), p. 41.

2. Fapetu O P and Akinola A O (2008),“Optimizing Auto – Repair Practice: AkureMetropolis as Case Study”, AU J.T., Vol. 11,No. 4, pp. 232-233.

3. Greiner H G (1967), Whiting CraneHandbook, p. 6, Whiting Corporation, HarveyIllinois.

4. Luttmann A, Jager M and Griefahn B (2003),“Preventing Musculoskeletal Disorders in theWorkplace”, p. 3, ISBN 92 4 159053X,Publication of World Health Organization.

5. Sawodny O, Aschemann H and Lahres S(2002), “An Automated Gantry Crane as aLarge Workplace Robot”, ControlEngineering Practice, Vol. 10, p. 1323.

6. Sumaila M and Ibhadode A O A (2011),“Design and Manufacture of a 30 tonHydraulic Pres”, I. J. T, Vol. 14, No. 3,pp. 196-197.

7. Thompson Geoffrey (2007), “Best Practiceof Crane Support Structures Design—AnExpert Survey”, p. 2, A Master’s of Scienceof Engineering Degree of University ofStellenbosch, Germany.

Figure 6: A Prototype Hydraulic Shop CraneDeveloped at HEDI Kano, Nigeria

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