revision of specification / str item name: non-asbestos ‘k

REVISION OF SPECIFICATION / STR

Item Name: Non-Asbestos ‘K’ Type Composition Brake Blocks for Freight Stock of Indian

Railways with 1000 mm & 840 mm Wheel Dia.

Specification No.: WD-14-ABR-2019 (Supersedes WD-14-ABR-2007)

1. RDSO is reviewing the specification/STR to cater to the 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 the abovementioned item may be submitted in the following format along with 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. Whether firm is registered with RDSO for the subject item. If yes, details like date of registration, current status etc. If no, firm’s experience in manufacturing of subject item or similar item

8. Whether any technical document/Report/Study 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 it 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 following address within one month from the date of publication on rdso.indianrailways.gov.in Director/Wagon Research Designs and Standards Organization Manak Nagar, Lucknow – 226011 Email: [email protected]

mailto:[email protected]

WD-14-ABR-2019 (Superseds WD-14-ABR-2007)

Page 1 of 15

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS

SPECIFICATION

FOR

NON-ASBESTOS ‘K’ TYPE – COMPOSITION BRAKE BLOCKS

FOR

FREIGHT STOCK OF INDIAN RAILWAYS WITH 1000 MM AND 840 MM WHEEL DIA

WD-14-ABR-2019

ISSUED BY

RESEARCH DESIGNS AND STANDARDS ORGANISATION

MINISTRY OF RAILWAYS

LUCKNOW April’ 2019 PRICE:


Page 2 of 15

1. SCOPE

This specification covers the technical requirements of non-asbestos ‘K’ type composition brake blocks for application on freight stock of Indian Railways having 1000 mm dia. wheels and 840 mm dia. wheels. These brake blocks have a high co-efficient of friction and called ‘K’ type brake blocks.

2.0 GENERAL

2.1 FUNCTIONAL REQUIREMENTS

2.1.1 The controlling dimensions of brake blocks shall conform to the requirements given in the RDSO Drg. No. WD-00006 S-01 Latest Alt. for freight stock having 1000 mm dia. wheel (Annexure VI) and to Drg. No. WD 15023 S-01 latest alt. for freight stock having 840 mm dia. wheel. (Annexure VII B).

2.1.2. The ‘K’ type composition brake blocks shall be non-interchangeable with low friction composition brake block (‘L’ type) already in use in freight stock. The parameters for freight stock using ‘K’ type brake blocks are given in Annexure-I

2.1.3 The constructional features of the brake block must enable them to wear down to a thickness of 10mm, including the back plate, without the later or the securing components with the brake head coming into contact with the running surface of the wheel.

2.1.4 Weight of Brake Block shall be shown in the drawing.

2.1.5 The composition of the material and the manufacturing process for series production of ‘K’ type composition brake blocks must always conform with that of the composition brake blocks for which approval has been given by RDSO and no change shall be made in the composition and drawing against which approval has been granted.

2.1.6 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.

2.1.7 The composition of the material constituting the brake block must be chosen so as to give the best balance between: - - the braking characteristics, - the wear and service life of blocks, - wear on the running surface of the wheels, - the effect on adhesion between the rail and wheel.

2.1.8 The characteristics laid down in this specification must be maintained for the complete usable thickness of the braking material.

2.1.9 The supplier will advise the detailed procedure for disposal of used/condemned composition brake blocks and will also associate with railways to set up facilities for disposal of used/condemned composition brake blocks.

3.0 PARTICULAR REQUIREMENT

3.1 TECHNICAL REQUIREMNT

3.1.1 The use of asbestos is prohibited.

3.1.2 The use of Lead and Zinc in the metal state or in the form of compounds is not allowed. The same applies to all other components, if in the form of powder, particles or gas produced during the use of the brake blocks, which may constitute a danger to health.


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3.1.3 ‘K’ type brake blocks have an average co-efficient of friction of approximately 0.25.

3.1.4 The values of density, hardness, compression modulus, cross breaking strength, acetone extract, ash

content (loss on ignition) and back plate pull off strength must be given for acceptance purposes.

3.1.5 The brake block and its back plate must be designed to withstand the forces likely to occur during service. 3.1.6 In Dynamometer test, 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 specific wear value of each brake block found by weighing should not exceed 5 cc/kwhr.

3.1.7 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.

3.1.8 The tolerance bands of the instantaneous and average coefficient of friction shall be as per Annexure-II of this specification. The definition of the friction co-efficient is given in Annexure- IV.

3.1.9 During bedding-in, the coefficient of friction must not vary by more than +15% from the value obtained when bedding-in is complete.

3.1.10 Under the influence of dampness 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.

3.1.11 After prolonged braking followed by braking to a stop, particularly high temperature occurs (maximum 375

0 C on the opposing friction surfaces). The average coefficient 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 the cold and dry state.

3.2 ELIGIBLITY CRITERIA 3.2.1 The tenderer seeking to supply brake blocks to Indian Railways must have a technical collaboration with a

foreign manufacturer who has experience in manufacturing rail road brake blocks. The foreign collaborator must have complete 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 para 3.1.6 – 3.1.11 and other details in accordance with clause no 3.1.4. The test on dynamometer will be carried out by the collaborator as per test scheme given in Annexure- III.

3.2.2 The condition of foreign collaboration is strictly applicable for those companies, which are not in the

business of manufacturing friction composition materials for industrial use. However, the companies, which are in the business of friction composition material for industrial use 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 firms should submit dynamometer test results after testing of samples on their own dynamometer.

3.3 APPROVAL REQUIREMENT


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3.3.1 For New supplier

3.3.1.1 The tenderer will have to produce adequate evidence from their collaborator in support of good performance of the collaborator and adequate experience in manufacture and supply of composition brake blocks for Rail Road application.

3 3.1.2 The tenderer shall also submit following documents - (i) Copy of approval certificates issued to their collaborator by any of railroads for composition brake blocks. (ii) Copy of memorandum of understanding (MOU) jointly signed by the tenderer and collaborator. (ii) List of past supplies made by their collaborator to different railroads along with specifications followed for

manufacture and supply of brake blocks. (iii) List of plant and equipment available along with capacity, no. of such equipments, manufacturer name etc.

available with collaborator. (v) Detailed drawing of the brake block in line with clause 2.1.1 for approval of RDSO.

3.3.1.3 The tenderer will have to submit from the collaborator, the results of dynamometer test of samples carried out by the collaborator according to test scheme indicated in Annexure V. The details of friction properties as 3.1.6 – 3.1.11 and other details in accordance with clause no 3.1.4.

3.3.1.4 The information in para 3.1.1 to 3.1.11 should be presented together with a request for type acceptance

test by RDSO. 3.3.1.5 The supplier will submit six number of brake blocks for type acceptance test on RDSO’s brake

dynamometer and samples will be tested as per Test Scheme given in Annexure-III The testing charges will be paid by the supplier.

3.3.1.6 During the tests, the blocks must not reveal any sign of combustion, formation of flaking, sweating of the

binding material, permanent grating or other defects. 3.3.1.7 The blocks tested on the dynamometer must meet the requirements given in para 3.1.6 – 3.1.11 of this

specification. 3.3.1.8 On successful completion of the dynamometer testing at RDSO, 1000 indigenously manufactured brake

blocks shall undergo field trials for a period of six months. The supplier has to submit the drawing as per para 2.1 and QAP as per clause 3.3.2.2 for approval before undertaking indigenous manufacture of these brake blocks.

3.3.1.9 Manufactured brake blocks will be supplied for field trial only after inspection by Wagon Design

Directorate of RDSO. 3.3.1.10 Based on the technical evaluation after field trial of 1000 Nos. of brake blocks further action will be taken

for series production of composition brake blocks. 3.3.2 For supplier already cleared for indigenous supply 3.3.2.1 The supplier shall submit detailed drawing of the brake block in line with clause 2.1.1 for approval of


Page 5 of 15

RDSO. 3.3.2.2 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 and quality records maintained. The QAP must also contain the acceptable readings of the following parameters along with the method of testing.

a) Compression modulus. b) Cross-braking strength. c) Acetone extract. d) Ash content. (Loss on ignition) e) Hardness. f) Density. g) Back plate pull off strength. h) Any other tests.

3.3.2.3 The supplier will submit six number of indigenously manufactured brake blocks for type acceptance test on RDSO's brake dynamometer and samples will be tested as per Test Scheme given in Annexure V. The testing charges will be paid by the supplier.

3.3.2.4 On successful completion of the dynamometer testing at RDSO, 1000 indigenously manufactured brake blocks shall undergo the field trials for a period of six months.

3.3.2.5 Manufactured brake block will be supplied for field trial only after inspection by Wagon Design Directorate of RDSO.

3.3.2.6 Based on the technical evaluation after field trials of indigenous lot of 1000 No., further action will be taken for series indigenous production of composition brake blocks.

3.4 Approval for composition brake blocks for 840 mm wheel dia

3.4.1 The firm cleared for regular supply of `K’ type composition brake block for freight (with 1000 mm wheel dia.) or coaching or Loco may also manufacture the `K’ type brake block for wagons (with 840 mm dia. wheel). The first lot shall be manufactured in presence of RDSO officials. Sample of brake blocks will be drawn by the RDSO representative for dynamometer testing at RDSO.

3.4.2 The first lot shall be manufactured in presence of RDSO representative. Sample of brake block will be drawn by the RDSO representative for dynamometer testing at firm’s premises. The test will be carried out as per test scheme given in Annexure-III duly witnessed by RDSO representative.

3.4.3 On successful completion of dynamometer testing, brake blocks shall undergo field trial in two rakes of BLC wagons for six months’ duration. For this field trial, 1000 nos. of brake blocks will be supplied by the firm.

3.4.4 Manufactured brake block will be supplied for field trial only after inspection by Wagon Design Directorate of RDSO.

3.4.5 Based on technical evaluation after field trial, further action will be taken for series production of composition brake block for 840 mm wheel dia freight stock.


Page 6 of 15

3.5 RDSO DRAWINGS (i) WD-00006 S-01 Latest alt. (ii) WD 15023 S-01 latest alt.

3.6 VENDOR CHANGE IN APPROVED STATUS

All the provisions contained in RDSO’s ISO procedures laid down in document No. QO-D-8.1-11 (version 1.0, dated 12/09/2018 (Titled “Vendor – Changes in approved status”) and subsequent version/ amendments thereof, shall be binding and applicable on the successful vendor/ vendors in the contracts floated by Railways to maintain quality of products supplied to Railways.

3.7 PACKAGING

The brake blocks shall be securely packed in cardboard boxes so that there is no damage to brake blocks during transit. Packing should be in accordance with the recommendations of the collaborator. This shall be got approved from RDSO along with drawing.

3.8 MARKING

3.8.1 The marking on back plate and clamp of each brake block shall be as per Drawing No. WD-00006-S-01 with latest Alt. placed at Annexure VI and Drawing No. WD 15023 S-01 Latest alt.

Annexure VII.

3.8.2 These markings shall be punched in such a manner so that the block can be identified even after being fully worn in service. 3.8.3 The condemning limit shall be marked in orange colour on the side of brake block, manufactured to drawing

no. WD-00006-S-01 latest Alt. and with Yellow colour for brake block manufactured to drawing WD 15023 S-01 Latest alt.

4 TESTING FACILITIES

4.1 Suppliers shall have complete facilities / gauges for checking of brake blocks according to dimensional tolerances shown on the drawing.

4.2 Suppliers shall have adequate facilities for determining the characteristics as laid down in para 5.1.

4.3 The supplier shall have in house full scale dynamometer facilities to test the brake block as per test scheme laid down in Annexure-III. The frequency of testing samples on Dynamometer should be as laid down in the QAP approved by RDSO. The supplier shall submit test results to RDSO.

5 INSPECTION 5.1 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 its parent mix batch number & heat No.

iii) The inspector shall inspect the quality records maintained by the supplier for the entire lot.


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iv) Each lot offered for inspection shall consist of 2000 brake blocks or part thereof. The lot No. shall

represent the mix batch numbers & heat No. out of which these brake blocks have been manufactured. v) 1% of lot of 2000 nos. brake blocks offered by the supplier will be selected at random and checked for

dimensional accuracy. Dimensions are to be 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) Two brake blocks selected at random from the same lot and each brake block shall be tested for the

following: a) Compression modulus. b) Cross braking strength c) Acetone extract. d) Ash contents / loss on ignition. e) Hardness. f) Density. g) Back Plate Pull-off Strength The block shall be accepted based on acceptable values given in the RDSO approved QAP of the

supplier. The method of testing shall be as given in UIC –541-4 OR or as per the method of testing followed by manufacturer indicated in their approved QAP.

vii) Two brake block selected at random from the same lot to be tested for back plate pull off strength and

accepted based on acceptance values specified in approved QAP of the firm. viii) Two brake block selected at random will be subjected to any other test to be included in the QAP of the

firm, as decided by the manufacturer and RDSO. 5.2 The brake blocks shall conform to the requirements mentioned in the QAP of the firm and approved by

RDSO. If any of the samples selected as per clause 5.1 fail to meet the requirements of any of the requirements, double the quantity of samples stipulated in the para shall be selected for tests. If during retesting any of the brake blocks fail to meet the requirements of any of the tests the entire lot of brake bocks offered for inspection shall be rejected and brake blocks shall be rendered unserviceable.

5.3 The rejected lot shall be destroyed. 5.4 The supplier shall undertake full scale dynamometer test (as per Annexure V) on the brake blocks under

supply to Indian Railways at intervals as per QAP approved by RDSO. For this purpose, requisite samples shall be picked up by RDSO and the supplier shall arrange testing of the blocks. Alternatively, the supplier may send the block for testing at RDSO at his own cost. To maintain quality, RDSO at their discretion may pick up samples at any time for testing at RDSO dynamometer.

6 GUARANTEE / WARRANTY The warranty on account of manufacturing defect shall be 24 months from the month of supply or duty life

cycle i.e. time taken in reaching the wear limit of the brake block, whichever is earlier.


Page 8 of 15

ANNEXURE-I

PARAMETERS FOR FREIGHT STOCK

S. No. Particulars DATA

1. Maximum axle load (Tonne)

25

2. No. of wheels per wagon

08

3. Wheel dia (mm) For 1000 mm wheel dia.

New

Condemning For 840 mm wheel dia.

New

Condemning

1000 mm 906 mm

840 mm 780 mm

4. No. of brake block per wheel

01

5. Max. speed (kmph)

100

6. Type of brake system

Air Brake


Page 9 of 15

ANNEXURE-II


Page 10 of 15

ANNEXURE-III

TEST SCHEME FOR TYPE ACCEPTANCE TEST FOR `K’ TYPE COMPOSITION BRAKE BLOCKS FOR

FREIGHT STOCK (with 1000 / 840 mm wheel dia.)

1. Wheel Diameter –1000 / 840 mm 2. Number of brake blocks/wheel – one 3. Axle load – 25 tonne 4. No.of samples to be tested -- Two(minimum)

Brake application

No.

Speed km/h.

Force per brake block

(Kgf)

Initial temp. of wheel

tread (deg C).

Remarks.

1 2 4 5 6

0.1 to 0.x 60 1000 Braking to stop until 80% surface seated. Weigh

1.1 30 2200

2.1 60 ,,

3.1 100 ,,

4.1 120 ,,

5.1 30 1100

6.1 60 ,,

7.1 100 ,,

8.1 120 ,,

9.1 30 3300 50 - 60 Braking to stop dry after cooling pause.

10.1 60 ,,

11.1 100 ,,

12.1 120 ,,

1.2 30 2200

2.2 60 ,,

3.2 100 ,,

4.2 120 ,,

5.2 30 1100

6.2 60 ,,

7.2 100 ,,

8.2 120 ,,

9.2 30 3300

10.2 60 ,,

11.2 100 ,,

12.2 120 ,,

1.3 30 2200

2.3 60 ,,

3.3 100 ,,

4.3 120 ,,

5.3 30 1100


Page 11 of 15

6.3 60 ,, 50 - 60

Braking to stop dry after cooling pause. 7.3 100 ,,

8.3 120 ,,

9.3 30 3300

10.3 60 ,,

11.3 100 ,,

12.3 120 ,,

13 14 15 16

60 100 30 120

3300 ,, ,, ,,

100-120 100-120 120-140 120-140

Braking to stop, dry with high initial temperature

17 18

60 60

1100 3300

50 – 60

Braking to stop, dry after cooling pause weigh

N19 N20 N21 N22 N23

30 100 120 60 30

1100 3300 3300 2200 1100

20 - 30 Braking to stop, wet after cooling pause

24 25 26 27 28

30 100 120 60 30

1100 3300 3300 2200 1100

50 – 60 Braking to stop, dry after cooling pause weigh

D29 H30

60 60

- 3300

20 –30 Holding braking for 20 minutes, 35kw per wheel braking to stop after holding braking Weigh

31 32 33 34 35

30 100 120 60 30

1100 3300 3300 2200 1100

50 – 60 Braking to stop, dry after cooling pause

D36 H37

60 60

- 3300

50 – 60 Holding braking for 10 minutes, 50kw per wheel (2) braking to stop after holding braking Weigh

Note: D = Long brake application (holding braking). H = Braking to stop after holding braking at its initial temp. without cooling pause. N = Braking in wet condition with a water volume of 14 l / h for v < 120km/h.

Braking in wet condition with a water volume of 22 l / h for v > 120km/h. (1) During the test, interruption of maximum 3 days is permitted only before test 1.1, 1.2, 1.3, and D 29. (2) Braking to stop when the wheel temperature during the test reaches 375º C. (3) The following parameters shall be recorded / measured during the above test.

a. Wheel tread diameter before and after the test. b. 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.

c. Max. temperature reached on brake block and wheel tread for each test. d. General observations regarding smoke, smell, sparks and noise.

(4) Location of brake block, rotation of wheel with respect to brake block fitted on dynamometer and location of thermocouple are shown in Annexure –V.


Page 12 of 15

ANNEXURE-IV

DEFINITION OF CONCEPTS:

As far as tolerances on the co-efficient of friction are concerned, a distinction must be made between:

-the instantaneous co - efficient of friction μ a, which can be defined, and each moment of braking, by the ratio

of the braking effort Ft to the total force F b

Ft

μ a = ------------ Fb - the average co-efficient of friction μm, which can be defined throughout the duration of the brake application from the moment when 95% of the brake block force has been established until coming to a halt. The average coefficient of friction μm is obtained by integration of the instantaneous coefficient of friction μa, over the stopping distances S 2.

1 S 2

μm = --------- ƒ μa, ds where

S 2 0

S2 [m] = stopping distance from the moment when 95% of the brake block force Fb has been applied untill coming to a halt m [Kg] = proportion of axle load to be braked by the wheel R [m] = Wheel radius

I bench [kg.m2] = moment of inertia of test bench

I nom [kg.m2] = moment of inertia corresponding to the portion of the axle load to be braked by

the wheel according to the test programme. Fb (N) = total block force. Ft (N) = braking effort. MW (Nm) = friction moment of the test bench at certain wheel load and speed; determined by the method specified in Appendix 1 of ORE B126/RP8

I nom = m*R2

If Irig is not the same as I nom. The weights must be adjusted by applying a correction of the initial braking speed

V nom to V k as follows:

Inom

V k = K * V nom with K =

Ibench


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ANNEXURE - V


Page 14 of 15

ANNEXURE - VI


Page 15 of 15

ANNEXURE-VII

revision of specification / str item name: non-asbestos ‘k

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