INDIAN RAILWAYSSummer Training Report

Electric Loco Shed, Kanpur

Spring Failure In Train

Submitted To:Mr. R.V Singh Yadav

Submitted By : Anuvrat Shukla Sachin Awasthi Bhirendra Singh Rishabh Sharma Shyam Dayal Sanjay Singh

Types of Springs in Loco

WAG 7:-1. Inner Spring2. Outer SpringWAP 4:-3. Primary Spring4. Secondary Spring

(A) Material failure(Dimensional)- Parallelism. Squareness. Biting Effect. (B) Metallurgical.  (C) Improper Critical Parameters during assembly: - It is observed that the failures occurs due to bad maintenance practices in respect of improper critical parameters.

Causes Of Spring Failures

Spring squareness is the angular difference between the outermost limit of a spring diameter when compared to a straightedge at a right angle to a horizontal flat plate on which the spring is standing.

This affects how the axial force produced by the spring can be transferred to adjacent parts in a mechanism. 

Spring Squareness

Spring parallelism relates to the ends of the spring and how parallel they are to one another.

A compression spring cannot be closed and ground so consistently that its ends will always be square (in parallel planes at right angles to its axis).

Spring Parallelism

Spring should be checked properly for its Parallelism Squareness & 75% tapered area and a gap of minimum 1.0 mm between effective coil and tapered end coil.

If there is no gap between effective coil and tapered end coil then the biting effect will take place and the spring will be break at that point.

Biting Effect

The following parameters should be ensuring before putting the spring in the system to avoid breakage.  (i) Free height, working height.(ii) Stiffness and Deflection(iii) Squareness.(iv) Parallelism.(v) End tapper. Where,• Stiffness= Working load in kg/ Total

deflection=Kg/mm• Deflection=Free Height-Working height

in mm.

The following precautions may be taken during assembly of the springs in the

bogie.

• Primary spring sheet of bogie frame to be checked for any uneven surface and crackness.

• Primary spring sheet of axle box to checked for any uneven surface and crackness.

• The squareness & surface finish of axle box crown also to be ensured for nil gaps for proper fitment.

• Provision of polyurethane spring pad (Happy pad) to be made at top & bottom side of the springs as recommended by RDSO.

SPRING TESTING MACHINE ELECTRIC LOCO SHED KANPUR

Standard Parameters of WAP-4 & WAG-7 Suspension spring

S.No. Parameters WAP-4 Primary Sups. Springs RDSO Drg No.SKDL-3472.

WAP-4 Secondary Sups. Springs RDSO Drg No.SKDL-3473.

WAG-7,Outer Spring RDSO Drg.No.SK-VL-039

WAG-7,Inner Spring RDSO Drg.No.SK-VL-037

1. Free Height

385+6_6mm 478+7-7 mm 552+9-9 mm 512+9-9mm

2. Working Height

320 399 447 402

3. Solid Height

267.3

345.8 364 327.5

4. Working load in kg.

3695 4110 4284 1700

5. Outer Dia. 178

210+1.5-1.5 mm 240 154

6. Inner dia. 112

134+1.5-1.5mm 160 104

7. Wire dia. 33

38+.10-.10mm 40 25

8. Variation in wire dia.

+ -0.1mm + -0.1mm + -0.1mm + -0.1mm

9. Variation in coil dia.

+ -1.5mm + -1.5mm + -1.5mm + -1.5mm

10. No. of turns 8.5

9.5 13.5 9.5

11. Wound RH

RH RH LH

12. Out of squareness

3.8 mm max. 4.8 mm max. 5.5 mm max. 5.1 mm max.

13. Parallelism 2.7mm max.

3.2 mm max. 3.8mm max 2.4mm max

14. Stiffness kg/mm

16.77 to 20.29kg/mm

49.59 to 54.82 kg/mm

21 To28 kg/mm

57 to 73 kg/mm

15. loaded height

316 to 323 mm 394 to 403 mm 441to 451mm 396 to 406mm

WAG-7 (Inner Spring) Dated:- 25-06-15

Sr No.

MAKES YEARS FREE HEIGHT DIG. HEIGHT

LOADING FREE HEIGHT

LOADING DIG.

1 GBD 01-14 515 514.4 401 400.6

2 GBD 08-13 518 518.5 397 397.0

3 GBD 01-14 513 513.6 392 392.3

4 GBD 01-14 513 517.8 396 395.0

5 GBD 01-14 513 512.2 408 407.8

6 GBD 01-14 513 512.2 392 391.4

7 GBD 01-14 517 516.7 396 396.6

8 GBD 01-14 512 510.8 396 395.7

9 GBD 01-14 515 514.3 393 392.4

10 GBD 01-14 512 511.4 397 396.3

11 FSK 05-07 513 512.4 416 417.0

12 AFJ 06-08 517 516.0 408 408.6

13 GBD 12-05 511 510.7 396 395.8

14 GBD 12-05 516 514.8 396 395.8

WAG-7(Outer Spring) Dated:- 24-06-15

Sr No. MAKES YEARS FREE HEIGHT

DIG.HEIGHT LOADING FREE HEIGHT

LOADING DIG.

1 AFJ 10-12 556 557.7 441 441.22 AFJ 10-12 556 556.0 438 436.93 AFJ 10-12 557 557.1 441 440.34 AFJ 10-12 557 556.9 460 461.15 AFJ 10-12 563 562.6 455 450.9

6 FSK 08-07 560 560.4 446 445.07 FSK 02-06 555 555.0 458 457.98 AFJ 10-12 558 557.4 443 442.49 AFJ 10-12 555 555.5 441 439.710 FSK 03-07 555 555.1 449 448.911 GBD 09-12 552 551.9 438 437.812 FSK 02-07 556 555.4 444 449.113 FSK 01-07 561 560.4 454 455.114 GBD 09-05 554 554.3 446 447.8

Sr No. MAKE & YEAR FREE HEIGHT LOADED HEIGHTAnalog Gauge Digital Gauge Analog Gauge Digital gauge

1 AFJ: 12-11 521

521.6 404

405.8

2 CSN: 06-97 519 520.2 400 401.43 CSN: 12-97 519 519 404 404.94 FSK: 12-10 523 523.9 409 408.75 CSN: 10-98 515 514.9 394 395.26 GBD: 07-09 521 521.7 402 402.87 CSN: 04-99 516 517.1 391 392.28 CSN: 11-98 523 522.2 409 408.89 CSN: 05-01 519 517.9 402 401.810 FSK: 07-07 520 520.8 408 409.211 CSN: 11-00 519 518.8 404 404.612 CSN: 06-97 519 520.2 404 405.913 CSN: 12-97 516 517.3 409 410.214 CSN: 02-95 521 522.3 408 408.815 FSK: 06-08 519

519.6 404 405.3

Testing Of Inner Spring (WAG-7) Dated:-16-01-15

Sr No. MAKES YEARS FREE HEIGHT DIG. HEIGHT LOADING FREE HEIGHT

LOADING DIG.

1 FSK 07-12 390 390.3 324 324.72 GBD 05-14 394 395.3 334 335.43 GBD 05-14 393 394.3 324 323.84 GBD 05-14 396 397.2 328 328.65 GBD 05-14 396 397.2 327 328.26 GBD 05-14 395 395.5 329 328.97 GBD 09-13 388 388.6 331 331.38 GBD 09-13 388 388.8 322 322.59 GBD 09-12 392 393.4 323 322.510 FSK 12-11 386 386.7 317 316.611 GBD 05-14 394 394.8 329 329.512 FSK 08-11 388 387.1 320 320.413 GBD 09-13 391 391.9 334 333.614 GBD 05-14 395 396.4 334 333.715 GBD 09-13 389 388.2 317 316.916 GBD 09-13 390 389.5 328 328.0

WAP-4 (Primary Spring) Dated:-30-06-15

Four years details of failure / breakage of Primary & Secondary Suspension Springs, etc are as under.

S.No. Name of Equipment

2009-10 2010-11 2011-12 2012-13

1. Primary Spring of WAP-4

21 02

POH=03

NIL

2. Secondary Spring of WAP-4 04

Nil 01

NIL

3. Primary Suspension Spring of WAG-7(Outer/Inner)

11

07 05 NIL

4. Breakage of Bolster of WAP-4

03 06

02=POH =01 AOH=01

01

5. Breakage of Connection straps. 12 12 POH=04

NIL

References• I prepared this report from the various study materials

provided by the staff officials. • Study materials and entire technical parameters of the

subject item provided by Mr. R.V. Singh Sir.• Entire aspects and critical parameters of the spring are

got available by Mr. R.V. Singh. Sir, Once again I would like to thank all the staff officials for their support and helping us in our project throughout our training period.

• We are very Thankful to Mr. SANJAY SINGH Sr.DEE/RS for giving us an Opportunity to complete our Summer Training at Electric Loco Shed Kanpur.