Part A: Basic Information R5.pdf · Ajay Kumar Srivastava SSE/Carriage Checked By S. K. Sharma/ Jt....

Contact Details for comments on Spec/STR`s

Revision in Spec. No. - C-9907 (Rev.4) Amendment 1

Title- Specification for Non Asbestos based low friction

Composite Brake Blocks for application on coaching stock

of Indian Railways.

1. RDSO has revised the above specification/STR in line with latest technological

developments in the field, modify clauses not relevant in the present context

and making them more enabling with focus on functional requirements.

2. It is requested that your comments / suggestions with regard to improvements

/ modifications in specification / STR of this item may be submitted in the

following format alongwith the justification for the changes required.

Part A: Basic Information

SN Particulars Information

1 Name

2 Designation

3 Professional Qualification

4 Organization / Firm’s Name

5 Address for Correspondence

6 Contact No.

7 Email ID

8 In case of Firm / Individual: Manufacturing experience of item (or similar Item) on which comments are offered

9 Where relevant: Whether any technical document to support suggested changes is available / enclosed for better appreciation

Part B: Comments / suggestions on the specification

SN Clause No. of RDSO STR / Spec

Clause, as exists in RDSO STR / Spec

Clause , as it should read after incorporation of comments / suggestions in the RDSO Spec / STR

Justification for changes

Comments may be sent to:

Executive Director /Carriage

Research Designs and Standards Organization

Manak Nagar, Lucknow – 226011

Email: [email protected], [email protected]

mailto:[email protected]

Ref: CG-WI-

4.2.1-1 Ver 2.0

Page 1 of 26 Date of issue

June, 2020 Spec. No. C-9907 (Rev.5)

Signature

Name & Designation

Dhirendra Kulsrestha JE/D/Carriage Prepared By

Ajay Kumar Srivastava SSE/Carriage Checked By

S. K. Sharma/ Jt. Director Carriage/E&S and Brake

Approved By

INDIAN RAILWAYS

SPECIFICATION FOR NON ASBESTOS BASED LOW FRICTION COMPOSITE

BRAKE BLOCKS FOR APPLICATION ON COACHING STOCK OF

INDIAN RAILWAYS

S. No. Month/Year of

Issue

Revision/

Amendment Page No. Reason for Amendment

1. October, 1999 First Issue - -

2. September, 2002 Revsion-1 10 to 12 Friction band and test scheme

modified

3. December-2003 Revsion-2 All Acceptance procedure

modified

4. January-2009 Revsion-3 All

Upgraded as per UIC-541-4,

May2007

5. May, 2009 Revision-4 5,6,8,9,15 to 19,21

& 23

Make test procedure more

clear for inspection

6. September, 2016 Amendment-1 3

To include the ISO Doc.

No. September, 2016

Amendment-1 3 00-0-

7.1-1 1, New sub clause

No.1.2 added under

clause no. 1 of Scope.

7. June, 2020 Revision-5 3, 6, 7, 11

Acceptance procedure

modified to enhance

indigenous vendor base.

Issued By

Research Designs and Standards Organization

Manak Nagar, Lucknow-226 011

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




Approved By

INDEX

S. No. Description Page No.

1.0 Scope 3

2.0 Requirements 3

3.0 Acceptance procedure 6

4.0 Inspection 8

5.0 Testing facilities 10

6.0 Packing 10

7.0 Warranty 10

Appendix-I Features of Main Line Coaches 11

Appendix -II Mean Coefficient of Friction 12

Appendix -III Test Scheme for Type Acceptance Test on Brake Blocks 13

Appendix -IV Shear Strength Test 15

Appendix -V Bending Strength Test 16

Appendix -VI Test Methods of:

A. Measurement of Density

B. Hardness Test

C. Acetone Extraction Method

D. Modulus of Elasticity (Compression)

E. Ash Content

F. Cross Breaking Strength

G. Location, form and dimensions of test specimens

19

19

21

22

23

24

25

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




Approved By

SPECIFICATION FOR NON-ASBESTOS 'L' TYPE COMPOSITE BRAKE BLOCK FOR

COACHING STOCK OF INDIAN RAILWAYS

1. SCOPE:

1.1 This specification covers the technical requirements of Low Friction 'L' type non asbestos based

composite brake blocks to replace cast iron brake blocks on BG main line coaches without

altering the brake head.

1.2 All the provisions contained in RDSO's ISO procedures (titled "Vendor - Changes in approved

status") latest, shall be binding and applicable on the successful vendor/vendors in the contracts

floated by Railways to maintain quality of products supplied to Railways

2. REQUIREMENTS:

2.1 General

2.1.1 The brief features of mainline coaches are given in Appendix-I

2.1.2 The wheel profile is as per RDSO drawing number SK-91146 with latest alteration. For

bedding in, the cross section profile of the brake block must correspond to the profile of wheel

given in RDSO drawing No.SK-91146 with latest alterations.

2.1.3 The composition of the material and the manufacturing process for series production of `L' type

composite brake blocks must always conform with that of the prototype brake blocks for which

approval has been given.

2.1.4 The use of asbestos and other fibers harmful to health is prohibited .The use of lead and zinc in

the metal state or in the form of compounds is not advised. Use of other substances of any

composition, which could cause a risk to health and the environment in the form of dust, fibres,

particles or gas released during use of the composite brake block, is not recommended.

PPM level of these compounds if present in traces should be below the OSHA guidelines.

2.1.5 The composition of the material constituting the brake blocks must be selected so as to

guarantee the best compromise between: -

Friction properties.

Wear and service life of composite blocks.

Wear on running surface of the wheels and aggressiveness against the wheel tread. The effect on adhesion values between the rail and wheel.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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2.1.6 The characteristics laid down in this specification must be maintained for the complete usable

thickness of the braking material.

2.2 FRICTION REQUIREMENTS

2.2.1 As far as possible the co-efficient of friction must be independent of the initial braking speed,

the state of bedding-in of the brake block, the specific pressure as well as the temperature and

atmospheric conditions.

2.2.2 The tolerance bands of the mean coefficient of friction shall be as per Annexure-II. 80% of the

mean co-efficient of friction values must lie within the band. Not more than 5% values should

be above the band.

2.2.3 During bedding-in, the coefficients of friction must not vary by more than ±15% from the

values obtained under the same conditions when the bedding is complete .

2.2.4 Under the influence of water, i.e. under wet conditions the average coefficient of friction must

not vary by more than ± 15% in relation to the value obtained during braking when dry with

other conditions remaining the same.

2.2.5 After prolonged braking followed by braking to a stop, particularly high temperatures occur.

Even in the case of these temperatures (Max. 400C on the opposing friction surface) the

average co-efficient of friction must not vary with the other conditions remaining the same by

more than ±15%, in relation to the value obtained during braking in cold and dry state.

2.2.6 During tests on the friction test bench on the brake blocks, there must be no flame formation,

excessive smoke, bonding agent sweating, sustained crushing, severe odour formation, large

area crumbling or detachment or other defects which reduces the mechanical strength

2.3 GEOMETRICAL CHARACTERISTICS

2.3.1 The controlling dimension of the brake block shall conform to the requirements given in RDSO

drawing number SK-99048 with latest alteration.

2.3.2 The constructional features of the brake block must enable them to wear down to a thickness of

10mm, including the back plate, without parts of the reinforcement or back plate coming into

contact with the running surface of the wheel tread.

2.3.3 The composite brake blocks must have permanently legible wear limit marks in yellow colour in

the area of the brake block side facing away from the flange, where marks have a distance of

10mm from the rear of the backing plate.

2.4 MECHANICAL, PHYSICAL AND CHEMICAL FEATURES

2.4.1 Proof obligations of manufacturer:

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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The manufacturer of CBB must present a product specification giving sufficient detail of the

mechanical, physical and chemical features in their QAP. The values of density, hardness,

compression modulus, cross breaking strength, acetone extract & ash content must be given

for acceptance purposes. The test procedure of these properties shall be as per Appendix-VI of

the specification.

2.4.2 The various elements making up the brake blocks must be spread uniformly in the body of the

block. There must be no pitting, flakes or other defects. The material must not attack the

opposing friction surface or give rise to the formation of metallic inclusions.

2.4.3 No method is laid down for fixing the composition material to the back plate. The back plate

must be designed to withstand the forces likely to occur during service.

2.4.4 The blocks must not reduce the adhesion between the wheel and rail to an unacceptable degree

compared with that normally obtained from vehicles fitted with cast iron brake blocks.

2.5 Mechanical requirements

2.5.1 Shear Strength:

The backs of the brake block and method of connection between the backing plate and friction

material must be designed so that any stresses occurring can be safely resisted. The connection

shall be tested using the test device shown in Appendix-IV with a test load of minimum

15KN. After the end of the test, there should be no damage to the friction material/backing

plate connection.

2.5.2 Bending Strength:

The bending strength is tested in the method shown in Appendix-V.

After the end of test there must be no visible surface or through cracks and no detachment

from the backing plate.

2.6 Thermal Requirement:

2.6.1 The friction material must not cause heat damage to the wheel treads in service. Also it must

not damage the friction surface or have a tendency to form metallic inclusions.

2.6.2 Composite brake blocks must resist the maximum heat stresses occurring within the limits

without burning, melting, forming and sewer deposits on the wheel treads or wearing to an

unusually great extent during service.

2.6.3 The brake blocks in service should give least/controlled smoke emission and should not give

away unpleasant/burning odour.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




Approved By

2.6.4 The frictional material should be able to withstand a temperature of 400 0C, without

worsening of its performance properties, measured on the rubbing surface of the brake block.

2.7 MARKING

2.7.1 The composite brake blocks must bear the following marking on the backing plate:

a) Manufacturer's name / short name.

b) Month & Year of manufacture

c) Type designation of brake block i.e. "L C"- to indicate 'L' type material for coaching stock.

Above marking shall be embossed or punched and must be applied so that each composite

brake block can be identified even after complete wear.

d) Condemning limit

e) The manufacturer’s name/short name, Batch and Lot Number shall be marked

on the side of brake block in black on the condemning limit mark, so that it should be visible

throughout the service life of brake blocks.

3. ACCEPTANCE PROCEDURE

3.1 For new Supplier/Manufacturer

3.1.1 A Supplier / manufacturer seeking to supply brake blocks to Indian Railways must have a

technical collaboration with an foreign manufacturer who has experience in manufacturing rail

road brake blocks. The foreign collaborator must have existing manufacturing and test facilities

including full-scale dynamometer for manufacturing and testing of brake blocks. The foreign

company collaborator will have to give detailed information including type acceptance test data

run as per Clause No. 2.2 and other details in accordance with Clause No. 2.4.1. The tests on the

dynamometer will be carried out by the collaborator as per Test Scheme given in Apprndix-III.

The companies, which are in the business of friction composition material and have established

all the requisite manufacturing and testing facilities including full scale rail dynamometer for

indigenous manufacture of the Railway brake block and are following a quality assurance plan

to the satisfaction of RDSO, should submit dynamometer test results after testing of samples on

their own dynamometer as per Test Scheme given in Appendix-III and other details in

accordance with Clause No. 2.4.1.

3.1.2 The condition of foreign collaboration is strictly applicable for those companies, which are not

in the business of manufacturing friction composition materials. However, the companies,

which are in the business of friction composition material and have established all the requisite

manufacturing and testing facilities including full scale rail dynamometer for indigenous

manufacture of the Railway brake block and are following a quality assurance plan to the

satisfaction of RDSO may be exempted by RDSO from the requirement of foreign

collaboration. Such firm's should submit dynamometer test results after testing of samples on

their own dynamometer. A Supplier / manufacturer (who is not in business of friction material)

seeking to supply brake blocks to Indian Railways must have a technical collaboration with a

reputed manufacturer who has experience in manufacturing rail road brake blocks. The

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




Approved By

collaborator must have existing manufacturing and test facilities including full-scale

dynamometer for manufacturing and testing of brake blocks. The collaborator will have to give

detailed information including type acceptance test data run as per Clause No. 2.2 and other

details in accordance with Clause No. 2.4.1. The tests on the dynamometer will be carried out

by the collaborator as per Test Scheme given in Appendix-III.

3.1.3 The collaborator presenting a new composition brake block would have to ascertain it’s

performance and particularly it's possible deleterious effects on wheels by means of trials

carried out in service. The tests must be continuous for at least six months.

3.1.4 The supplier shall submit a copy of approval certificate issued to their collaborator by any rail

road for composition brake blocks.

3.1.5 The supplier shall submit a copy of memorandum of understanding (MOU) jointly signed by the

supplier and collaborator.

3.1.6 The supplier shall submit the list of past supplies made by their collaborator to different rail

road along with specifications followed for manufacture and supply of brake blocks.

3.1.7 The supplier shall submit the list of plant and equipment available along with capacity, numbers

of such equipments, manufacturer name etc. available with collaborator.

3.1.8 The report on the tests mentioned in clause 3.1.1, 3.1.2 and 3.1.3 as applicable should be

presented together with a request for type acceptance.

3.1.9 The supplier shall submit detailed drawing of the brake block for approval of RDSO. The

dimensions mentioned in the RDSO drawing No.SK-99048 with latest alteration must be

complied for the fitment aspects and design aspect (except fitment aspect) can be suggested by

the manufacturer.

3.1.10 The supplier will submit six numbers of brake blocks for test on RDSO's own brake

dynamometer and four samples will be tested as per Test Scheme given in Appendix-III. The

test charges will be paid by the supplier.

3.1.11 The wear should be uniformly distributed over the entire depth of the block. It should be as low

as possible and be largely independent of the type of brake load application. The wear value

found by weighing should not exceed 3 cc/ kwh / block.

3.1.12 The average wear rate recorded during dynamometer testing at RDSO on prototype brake blocks

for which approval has been given will form the basis for further quality checks. The wear rate

in subsequent dynamometer testing should not be more than 20% higher than the wear rate of

prototype brake block for which approval has been given. The manufacturers will specify the

wear rate in their QAP. This will be only part of quality checks not the acceptance test.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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3.1.13 The brake blocks tested on the dynamometer must meet the requirements concerning friction

and temperature given in clause 2.2 of this specification.

3.1.14 On successful completion of the dynamometer testing at RDSO the brake blocks shall undergo

extended field trials. The field trial shall be carried out in two phases. The first phase shall

consist of field trials of 1000 imported brake blocks for six months or 1,00,000 Kilometers

whichever is earlier. On successful completion of these field trials 1000 indigenously

manufactured brake blocks shall undergo the field trials for six months or 1,00,000 Kilometers

whichever is earlier. The field trials shall be monitored by DG/RDSO or his authorised

representative. Imported trials may be dispensed with at discretion of RDSO subject to firm

having all facilities for indigenous production and testing including dynamometer. Wherever

such dispensation is granted either for imported or indigenous suppliers the field trial scheme

will be suitably modified to have more assurance of the brake block and will be nine months or

1,50,000 Kilometers whichever is earlier

Field Trial:

On successful completion of the dynamometer testing at RDSO the brake blocks shall undergo field

trials.

i. For supplier as per clause 3.1.1- The field trial shall be carried out on 1000 nos. brake

blocks for six months or 1,00,000 km whichever is earlier.

ii. For supplier as per clause 3.1.2- The field trial shall be carried out in two phases. The first

phase shall consist of field trials, of 1000 collaborator brake blocks for six months or

1,00,000 km whichever is earlier. On successful completion of these field trials 1000 brake

blocks manufactured by the supplier shall undergo the field trials for six months or 1,00,000

km whichever is earlier. The field trials shall be monitored by RDSO. Collaborator trials

may be dispensed with at discretion of RDSO subject to supplier having all facilities for

production and testing including dynamometer. Wherever such dispensation is granted for

the field, trial scheme (for supplier’s brake block) will be suitably modified to have more

assurance of the brake block and will be nine months or 1,50,000 km whichever is earlier.

3.1.15 Based on the technical evaluation further action will be taken for manufacture of composition

brake blocks.

3.2 For supplier/manufacturers already cleared for imported/indigenous supply

3.2.1 The supplier shall get his Quality Assurance Plan approved by RDSO before undertaking

manufacture of the brake block. The Quality Assurance plan must contain the details of process

of manufacture, process controls, quality records maintained, specific wear rate and values of

following parameters.

a) Density : Variation should be within + 0.10 units

b) Ash content (in %) : Variation should be within + 3

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

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c) Acetone extract : Should be less than 3%

d) Hardness : To be within + 10 Units.

Also, out of all nine individual hardness reading, at least 7

values should be within the specified range of + 10 Units and

remaining two readings may be within the range of + 15 units.

e) Minimum Cross-breaking strength value.

f) Maximum Compression modulus value.

The base values of above properties shall be taken as per actual test results obtained on

prototype brake blocks for which type approval was given.

The location for taking test specimen from brake block is given in Appendix-VI.

3.2.2 The supplier shall undertake full-scale dynamometer test on the brake blocks under supply to

Indian Railways, as per test scheme given at Appendix-III. For this purpose requisite samples

shall be picked up by RDSO/Inspecting Authority and the supplier shall arrange testing of the

blocks. To audit the quality control RDSO at their discretion may pick up samples for

dynamometer testing at RDSO/Lucknow.

The frequency of testing samples on dynamometer should be after manufacture of every

20,000 numbers of brake blocks.

3.2.3 In case dynamometer is under break down due to any of the reasons, the dynamometer testing

shall be conducted at the collaborator plant or at RDSO. The manufacturer shall bear the testing

charges in case blocks are tested at RDSO.

4 INSPECTION

4.1 The inspection of the brake block shall be carried out by Director General/RDSO or his

authorised representative at the premises of the supplier.

4.2 The inspection will be carried out as per the following procedure.

i) Supplier to submit pre-inspection report for the lots offered for inspection as per the

approved QAP of the firm.

ii) Supplier to ensure traceability of each block to it's parent mix batch number.

iii) The Inspecting Authority shall inspect the quality records maintained by the supplier for the

entire lot.

iv) Each lot offered for inspection shall consist of 2000 brake blocks or part thereof and shall

represent the mix batch numbers out of which these brake blocks have been manufactured.

The brake block of the lot shall be kept batch wise in such fashion that random sampling

from all batches of the offered lot is made possible. The brake blocks manufactured from

same mix shall constitute one batch.

v) Minimum 20 numbers of every offered lot of 2000 numbers brake blocks are part thereof

will be selected at random and checked for dimensional accuracy. Dimensions are to be

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




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checked as per approved drawing of manufacturer. However it is to be ensured that blocks

from different mix batches will be taken up for inspection.

vi) One brake block selected at random will be subjected to shear strength test as per Appendix-

IV.

vii) At least five brake blocks shall be tested for bending strength test for each condition given in

Appendix-V.

viii) One brake block selected at random from the above lot shall be tested as per Appendix-VI

for the following which should confirm to the values approved in the QAP of the supplier. In

case, two brake blocks are selected for the test, then test specimen for density, ash content,

hardness, acetone extract and compression modulus shall be taken from the one brake block

and only the test specimen for cross breaking strength shall be taken from other brake block.

a) Density

b) Ash contents

c) Hardness

d) Acetone extract

e) Cross breaking strength

f) Compression modulus

g) Any other test specified by RDSO

The block shall be accepted based on acceptable readings given in the approved QAP of the

supplier. The test methods are given in Appendix-VI.

ix) One brake block selected at random from the lot shall be subjected to any other test as

decided by the manufacturer and RDSO.

4.3 The brake blocks shall conform to the requirements mentioned in clause 4.2. Should any of the

samples selected as clause 4.2 fail to meet the requirements of any of the requirements, double

the quantity of samples stipulated in clause-4.2 shall be selected for tests. Should any of the

brake blocks fail to meet the requirements of any of the tests on retesting, the entire quantity of

brake blocks offered for inspection shall be rejected and brake blocks shall be rendered

unserviceable.

5 TESTING FACILITIES

i) Supplier shall have adequate facilities for checking of brake blocks according to dimensional

tolerances shown on drawing.

ii) The supplier shall have adequate facilities for determining the characteristics laid down in

clause 4.2.

iii) The supplier shall have in house full scale dynamometer facilities to test the brake block as per

test scheme laid down in Appendix-III. The brake block tests on full-scale dynamometer shall

meet the requirements given in clause 3.1.11 to 3.1.13.

6 PACKING

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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The brake blocks shall be securely packed in cardboard crates with enough cushions so that there is

no damage to brake blocks during transit.

7 WARRANTY

The composite brake block will have warranty against any manufacturing defect noticed during the

service before the condemning limit is reached or 18 months from the date of supply whichever is

earlier. Manufacturer shall replace the defective brake blocks within a month’s time from the receipt

of information from user railways without any cost.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




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Appendix-I

FEATURES OF MAINLINE COACHES

1. Max. axle load (t) 16.25

2. No. of axles per coach 4

3. Wheel dia. (mm)

New 915 +3/-0

Condemning 813 825

4. No. of wheels/coach 8

5. Brake blocks/wheel 2

6. Brake force on block (Kg) 2500

Max 2500

Min 2000

7. Maximum speed (Kmph) 140 130

8. Type of brakes system Underframe mounted twin pipe graduated release air brake

system.

9. Type of brake head. ICF Drg. No. T-3-1-617

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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Appendix -II

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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Appendix -III

TEST SCHEME FOR TYPE ACCEPTANCE TEST ON `L’ TYPE COMPOSITION

BRAKE BLOCKS FOR PASSENGER COACHES

1. Diameter of wheel – 915mm (ICF BG Main Line Wheel)

2. No. of brake blocks per wheel – 2

3. Axle load – 16.25t.

Brake

application

No.

Speed

km/h

Blower

speed

rpm

Force per

brake block

(kg)

Initial temp. of

wheel tread

(deg. C)

Remarks

1 2 3 4 5 6

a-n 60 750 2000 20-60 Braking to stop until running in

conditions of 80% is obtained. weigh.

1-6 50 750 2000 20-60 Braking to stop under dry conditions

after cooling the wheel if necessary

7-12 80 750 2000 60-80 -do-

13-18 120 750 2000 80-90 -do-

19-24 50 750 2000 20-60 Braking to stop under wet conditions


25-30 80 750 2000 60-80 -do-

31-36 120 750 2000 60-80 -do-

37-42 50 750 2500 20-60 Braking to stop under dry conditions


43-48 80 750 2500 60-80 -do-

49-54 120 750 2500 80-90 -do-

55-60 50 750 2500 20-60 Braking to stop under wet conditions


61-66 80 750 2500 60-80 -do-

67-72 120 750 2500 60-80 -do-

Weigh at the end of last stop

73 60 750 20-40

Drag braking at speed of 60 kmph with

30 KW for 20 minutes immediately by

braking to stop with brake block force

of 2500 kg under warm condition.

Measure temperature of wheel & brake

block after drag braking and

immediately after drag braking to a stop.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

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Appendix -III (contd.)

NOTE: -

1. The wear values found by weighing shall not exceed 3 cc/kwh. Wear measurement will be carried

out at the beginning of the test and at the end of last stop before drag braking test is carried out.

2 The following parameters shall be measured/recorded during the above test,

Wheel tread diameter before and after test.

Instantaneous coefficient of friction.

Mean coefficient of friction.

Surface condition of brake block after the test specially in respect of grooving metallic

inclusions, burning, uniform wear, over-heating etc. and the wheel tyre in respect of

polishing, pitting, flaking, cracking and other defects after the test is over.

Maximum Temperature reached on brake block and wheel tread during the test.

General observations regarding smoke, smell, sparks and noises.

3 Before beginning the test on a tyre turned wheel, the running tread of the wheel shall be polished by

direct brake applications with composition brake blocks.

4 Friction characteristics shall be evaluated as under:

The value of instantaneous coefficient of friction should be plotted and presented for

generating data.

The mean coefficient of friction should lie within the following values:

Brake Block Force Speed,

in kmph

Coefficient

of Friction

Coefficient

of Friction

2000 50 0.095 0.26

80 0.095 0.22

120 0.095 0.21

2500 50 0.095 0.21

80 0.095 0.18

120 0.095 0.17

5 For other parameters analysis of data shall be done as per methods given in UIC leaflet 541-4 OR

and ORE Report B-64 / RP 10

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

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Appendix-IV

Shear Strength Test

Test conditions:

Test load, F = Minimum 15 KN

Test Specimen: Brake block having a groove of minimum 3mm width in centre upto back plate as shown

above.

Apparatus/ Equipment:

Universal testing machine, capable of loading of minimum 15KN within the four seconds and

maintaining the load for minimum two minutes.

Testing device as shown above.

Procedure:

The test is to be carried out on UTM with testing device as shown above.

A new block is to be used for the test.

Test load 'F' is to be applied evenly in the direction of the circumferential load when braking and

increased to the maximum load of minimum 15KN within 4 seconds and maintained constantly for

minimum two minutes.

After end of the test, brake block should meet the requirements specified under clause-2.5.1.

Brake block shall be tested at both ends.

This test is based on UIC code 541-4 OR, May 2007

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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Appendix –V

BENDING STRENGTH: - Test procedure is based on UIC code 541-4 OR, May 2007

Test Conditions:

For Test-1: -

Test Force, Fb = Minimum 28 KN

Support width, Ls1 = 220 mm

Deflection, Δ h1= Minimum 2 mm

For Test-2: -

Test Force, Fb/2 = Minimum 14 KN

Support width, Ls2 = 85mm

Deflection, Δ h2= Minimum 1 mm

Test Specimen: Brake block

Apparatus/Equipment:

Universal testing machine (UTM) should be capable to apply test force at speed of 30mm/min. and should

be able to maintain the test force constantly for minimum two minutes. Machine should also have the

facility to display/record the load & deflection with accuracy of minimum two decimal places.

Fixtures shown in fig. 2 & fig.4.

Support bracket shown in fig. 3 & fig. 5.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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Test – 1:

Note: 1. The height ‘H’ to be kept as that the back plate of brake block become horizontal.

2. The dimension, 62 +0/-2, support length LS1, 220 +5/-0 and support radius R5±0.1 must be

maintained.

3. All dimensions are in mm.

Test procedure:

Mark the support locations on brake block.

Place the support bracket shown in Fig.-3 on UTM.

Place the brake block on support bracket as shown in Fig.1.

Place the fixture (Fig.-2) on brake block for load application.

To ensure the positive contact between the fixture and brake block, apply a load of minimum 100N

and set the deflection at zero.

Increase the load of minimum 28KN or for deflection of minimum 2mm at the speed of

30mm/min., hold constant for minimum two minutes and then release the load.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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Brake block should meet the requirements specified under clause-2.5.2.

Five tests must be performed.

Test-2: -

Note: 1. The height ‘H’ to be kept as that the back plate of brake block become horizontal.

2. The support length LS2, 85 +5/-0 and support radius R5±0.1 must be maintained.

3. All dimensions are in mm.

Test procedure:

Mark the support locations on brake block.

Place the fixture shown in Fig.-4 for load application on UTM.

Place the support bracket (Fig.-5) on fixture for load application.

Place the brake block on support bracket as shown in Fig.1.

To ensure the positive contact between the fixture and brake block, apply a load of minimum 100N

and set the deflection at zero.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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Increase the load of minimum 14KN or for deflection of minimum 1mm at the speed of

30mm/min., hold constant for minimum two minutes and then release the load.

Brake block should meet the requirements specified under clause-2.5.2.

Five tests must be performed.

Appendix –VI

TEST METHODS: - The test methods given in this appendix are based on UIC code 541-4 OR, 1990 and

ORE Report B-64 / RP 10.

Preparation of Specimens

The specimens are obtained from the brake blocks as described in this appendix.

The diagram shows their location, form and dimensions.

A MEASUREMENT OF DENSITY

Preparation of Specimens:

Cut sample of 40 x 40 x 10mm from the block as shown in sub clause-G of Appendix-VI.

The specimen intended for the hardness test may be used for measuring the density, before the hardness test

is carried out. The specimen should be dried suitably to carry out the hardness test on the same specimen.

Two methods are available for use:

1 The specimen is weighed to an accuracy of 1mg and measured to an accuracy of 50 µm.

The density is obtained by the following formula:

Mass of specimen (g) --------------------------------- = Density (g/cm3)

Volume of specimen (cm3)

2 The specimen is suspended by a thin thread from the hook to a weighing scale and its weight

in air is measured to an accuracy of 1mg. The specimen is then freely suspended in water at

a temperature between 18ºC and 24ºC and then weighed again. Before weighing, any air

bubbles adhering to the specimen must be removed, which can be facilitated by adding a

trace of detergent to the water. The density is then obtained by the following formula:

Weight in air

------------------------------------ = Specific gravity

Weight in air- weight in water

Density = Specific Gravity x Density of water i.e. 1g/cm3

3 Test specimen shall be taken from the location of brake block shown in sub clause-G of

Appendix-VI.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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B HARDNESS TEST

Preparation of Specimens

Cut sample of 40 x 40 x 10mm from the block as shown in sub clause-G of Appendix-VI and

machining the back until the whole holding plate has been removed and a smooth surface parallel to

the top side (braking side) obtained.

The specimen intended for the hardness test may be used for measuring the density, before the

hardness test is carried out. The specimen should be dried suitably to carry out the hardness test on

the same specimen.

After recording the hardness measurements on the upper surface (To preparation refer to paragraph

2) this surface is ground down 5mm parallel to the lower surface. A new series of hardness

measurements is then obtained.

2 Test method

The test is carried out in accordance with method A of standard ASTM D 785

For soft materials (<100HRX) a non-standard 19 mm ball is used in order to prevent wide

scatter. The minimum (initial) load is 10kgf (98.0665N), the maximum (total) load is 60 kgf

(588.399N).

The test scale is called "X"

For hardness values greater than 100HRX standard scale "R" is recommended.

2.1 Method A (scales "X" and "R")

After putting the specimen into position, the minimum load of 10 kg is applied and the small

pointer is set to zero within 10 seconds.

The large pointer is set to (B) 30 on the red scale. Within 10 seconds, after the application of

the minimum load and immediately after setting the dial, the minimum load of 10kgf

(98.0665 N) is increased to maximum load of 60kgf (588.399N). The maximum load is then

reduced to the minimum load after 15 seconds.

The Rockwell hardness HRX is read off on the red scale 15 seconds after the reduction of

the maximum load.

The HRX hardness value is obtained as follows:

HRX value=130-penetration depth (scale divisions)

Note: If the depth of penetration exceeds 130 scale divisions (0.26mm), negative values are

obtained

3 Number of measurements and calculation of hardness

Nine measurements are to be obtained on the two surfaces. Five measurements are to be

obtained from upper surface and four measurements are to be obtained 5mm below the

original upper surface. The minimum distance between two penetrations or between one

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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penetration and the edge of the specimen shall be 10mm. The arithmetical mean of these

values is the surface hardness.

C ACETONE EXTRACTION TEST

The following materials and equipment are required:

a) Pure acetone

b) Apparatus for crushing the specimen into powder

c) A sieve with a nominal mesh of 425 µm in accordance with ISO standard 565 (1)

d) A sieve with a nominal mesh of 250 µm in accordance with ISO standard 565 (1)

e) An analytical scale with an accuracy of 0.001g.

f) A Soxhlet extraction apparatus, or other apparatus, which has been shown to produce similar

results.

g) A drying oven with air circulation adjustable to 50±2 ºC.

Specimen Preparation:

A specimen representative of the friction material is reduced to powder form by filing, milling,

turning or boring, without excessively heating the material. The powder is then sieved, using the

sieves described under c) and d) above, preserving for extraction only the matter having passed

through sieve c) and retained by sieve d). Suitable precaution must also be taken to prevent the

powdered specimen from absorbing moisture.

Test Procedure:

Two portions of the sieved material must be tested. One specimen of approx 3g is weighed to an

accuracy of 0.001g on calibrated filter paper with large pore size or in a thin extraction crucible. The

use of whatman filter paper is considered acceptable for this purpose. After covering the crucible, or

the filter paper containing the specimen, so that none of the powder can escape, the specimen is

placed into the siphon of the extraction apparatus. The condenser, siphon and flask, into which 50 to

200 ml of pure acetone has been filled, are then assembled. Heating is regulated so that siphoning

occurs 20 to 30 times per hour and extraction is continued for at least 6 hours. At the end of this

period the flask is withdrawn and the content is transferred to the smaller flask or a bowl having

previously been weighed to an accuracy of 0.001 g. The empty flask is rinsed with approximately

20 ml acetone, which is then added to the extract.

The acetone is then evaporated by a suitable method, taking care that the temperature does not

exceed 50 ºC. The receptacle holding the residue is then placed into the oven, where it remains for

30 minutes at a temperature of 50±2 ºC. The receptacle is then removed from the oven, cooled in a

drier to room temperature and weighed heating, cooling and weighing is repeated until a consistent

mass is obtained, i.e. until the difference between two successive weightings does not exceed

0.003g.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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The specimen content of matter soluble in acetone is obtained in the form of a mass percentage by

applying the following formula:

m1

---- x 100

m0

where:

m0- Mass of the test specimen in g,

m1- Mass of dry extract in g.

The arithmetical mean of the values obtained from the two portions of the test specimens is

considered to be the specimen content of matter soluble in acetone.

The test report should present the following details:

a) Reference to this method.

b) Complete description of the specimen.

c) Method used to reduce the block material into powder form.

d) Content of matter soluble in acetone of each portion of the test specimen.

e) Arithmetical mean of the results obtained from the two portions.

f) Date of test.

Test specimen shall be taken from the location of brake block shown in sub clause-G of Appendix-

VI.

D MODULUS OF ELASTICITY (COMPRESSION)

The diameter and the height of the 6 specimens are measured to an accuracy of 10 µm.

The specimens are submitted to a test on a Rockwell hardness tester, on which the ball has been

replaced by a cylindrical mandrel of 13.3mm diameter.

The minimum (initial) load is 10kgf (98.0665N) and the maximum (total) load is 35 kgf

(343.233N).

Before the test is started, the deflection of the test apparatus between minimum and maximum loads

is measured without the test specimen.

The following test sequence is applied to each specimen as shown in sub clause-G of Appendix-VI.

The specimen is placed centrally underneath the mandrel, the minimum load is applied and the dial

is again set to zero (black scale). The maximum load is then applied for 45 seconds, followed by an

application of the minimum load for a further 10 seconds. The dial is again set to zero and the

maximum load is applied again. The reading is taken, when after approximately 10 seconds the

movement of the pointer suddenly slows down.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

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The deflection of the apparatus is then subtracted from this reading and the net deflection expressed

in scale graduations is multiplied by two in order to obtain the depression h of the specimen in

µm.

The modulus of elasticity E (mean value of the results obtained with the 6 specimens) is then

calculated by the formula:

3.122 x 105 x h

E = ------------------ N/mm2

D2 x h

H = height of specimen (mm)

D = diameter of specimen (mm)

h = depression of specimen (m )

Test specimen shall be taken from the location of brake block shown in sub clause-G of Appendix-

VI.

E ASH CONTENT

Preparation of test specimen:

A specimen of fine particles of the brake block is prepared by drilling out with 10mm dia. Drill bit

without overheating. The drilling is done perpendicular to the working surface and the depth of the

drilled holes shall not be more than 50% of the total block thickness. Specimen is to be prepared

from the area shown in the Appendix-VI.

Apparatus:

1. Analytical Balance with an accuracy of 1mg.

2. Muffle furnace with pyrometric control to ±50 0C with temperature to 10000C

3. Crucible

4. Tongs

5. Desiccator

No. of tests: One

Procedure:

Weigh previously ignited and cooled empty crucible (without lid) and the record the weight W1.

Load the drilled particles of 1gm in the pre-weighed crucible and weigh to an accuracy of ± 0.1gm

(W2). The crucible containing the sample is placed in the muffle furnace at 825 ± 15 0C and left for

2 hours. After ignition, the crucible shall be removed, cooled in a desiccators and weigh (W3). The

ash content shall be calculated as follows,

W3 – W1

Ash Content in % = ------------ x 100

W2 – W1

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

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W1 = Weight of the crucible in gms

W2 = Weight of the crucible and sample in gms

W3 = Weight of the crucible and sample (after ignition) in gms

Test specimen for this test may be taken from the location of brake block shown in sub clause-G of

Appendix-VI.

F CROSS BREAKING STRENGTH

Test specimen: Size of the test specimen is 120mm x 15mm x 10mm. Test specimen is to be

prepared from the area shown in the clause-G of Appendix-VI.

Apparatus:

1. Universal Testing machine (UTM)

2. Suitable Jig & fixture having supporting span of 100mm

No. of tests: One

Procedure:

The test shall be carried out at room temperature. The top portion of the jig shall be placed in the

adjustable crosshead of the Universal testing machine and lock in with the key. Place the bottom

portion of the jig in the centre position of the UTM table and adjust the jig so that the top portion of

the jig is aligned to the middle of the bottom portion of the jig. Place the specimen on the jig. Select

load range of the UTM for testing the sample. Apply the load until the sample breaks. Read the load

in kgf. Calculate the cross breaking strength of the specimen using the following equation,

W x L

Cross breaking Strength = 1.5 x --------

b x d2

Where, W= Load in Kgf

L = Distance between jaws of cross break jig

b = width of the specimen (cm)

d = Thickness of the specimen (cm)

Test specimen shall be taken from the location of brake block shown in sub clause-G of

Appendix-VI.

Ref: CGW 0001

(Rev. – 4)


May, 2009 Spec. No. C-9907 (Rev.4)

Signature

Name & Designation




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G LOCATION, FORM AND DIMENSIONS OF TEST SPECIMENS:

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