GOVERNMENT OF INDIA MINISTRY OF RAILWAYS - Indian … for... · ISMC 250x 82 2.5 m 2 10. ISMC ......

Document No:

Technical Pamphlet No. G-107 Version No: Nil Date Issued: May-2015

Document Title: PROCEDURE FOR RECAMBERING OF BOGIE RAIL WAGON TYPE BRN/BRNA/BRNAHS

Page 1 of 17

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS

lR;esot;rss

PROCEDURE FOR RECAMBERING OF BOGIE RAIL WAGON TYPE

BRN/BRNA/BRNAHS

ISSUED BY:

MINISTRY OF RAILWAYS, GOVERNMENT OF INDIA

RESEARCH DESIGNS & STANDARDS ORGANIZATION

LUCKNOW-226 011

MAY, 2015

Document No:



Page 2 of 17

ITEMS LIST

S.No. Description Length Quantity

1. Hex. Hd. bolt M10x100 100 mm 4

2. Check Nut M10 - 4

3. Wing Nut M10 - 4

4. Plain Washer - 8

5. Piano Wire 14 m 2

6. M.S. Strip 50x6Th. 200 16

7. Stopper for central girder - 4

8. Optical Pyrometer/Heat sensitive

crayons to measure temperature up to

750C

- -

9. ISMC 250x82 2.5 m 2

10. ISMC 250x82 830 mm 2

11. ISMC 250x82 819 mm 4

12. ISMC 150x76 618 mm 2

13. ISMC 100x50 2845x2 mm

14. Rib (Shown as Item No.1 in Fig.1) - 24

15. Side Bearer Supporting Plate (Shown

as Item No.2 in Fig.1)

542x160x20 mm 4

16. Centre Pivot Supporting Plate (Shown

as Item No.3 in Fig.1)

509x390x20 mm 2

17. M-20 Nut-Bolt with Standard Washer

for Item No.2 in Fig.1

90 mm 8

18. M-22 Nut-Bolt with Standard Washer

for Item No.3 in Fig.1

100 mm 8

19. Suitable Turn Buckle More than 1200mm 2

Document No:



Page 3 of 17

1. DRAFT PROCEDURE FOR RECAMBERING OF BOGIE RAIL WAGON

TYPE BRN/BRNA/BRNAHS INTRODUCTION

1.1 Railways have been reporting about loss of camber at the centre in Bogie Rail

Wagon type BRN/BRNA/BRNAHS after a period of service. Due to this

sagging wagon ends get lift up. Railways experience difficulties in maintaining

the buffer height.

1.2 In view of the difficulties faced by the railways to maintain the wagons, a

procedure for carrying out re-cambering of wagons has been drawn up and is

given below. The re-cambering of wagons should preferably be done at the

time when wagons require POH.

2. PROCEDURE FOR MEASUREMENT OF CAMBER OF INCOMING

WAGONS

2.1 Cut the centre pivot top huck bolts/Rivets and side bearer nut bolts and run out

the wagon bogies. Support the wagon body on trestles of equal height as

shown in fig.1 and clamp them with nut and bolts at side bearers and centre

pivot location, so that the body weight is borne equally by the trestles as shown

in fig.2. Secure the trestles with rails. Also place suitable stoppers below

headstock of such a height, so that after recambering process headstock does

not bend below the limit of required CBC height, as shown in fig.2.

2.2 Weld vertically 8 Nos. of steel plates, each having a slot and of size

200x50x6mm on the bottom of the sole bar at center line of the body bolsters

and wagon head stocks as shown in fig.3. The slot of 11x50mm provided in

each plate is to pass the piano wire through it. The plates so welded should be

erect and parallel to each other.

2.3 Place a piano wire along the length of the wagon passing through the

rectangular slots in the plates welded to the sole bars and head stock. Secure

the ends of the piano wire to 100mm long hexagonal head screws provided

with wing and check nuts and washers.

2.4 Tighten the piano wire adequately to ensure that the piano wire is straight and

there is no kink or sagging effect at any location along the wire length. This

can be done by loosening adjusting the check nut.

2.5 Adjust the height of the screw by moving up or down in the rectangular slot of

the plates welded at wagon head stock so that the distance between the top of

the piano wire and bottom of the sole bar at body bolster locations is equal.

Once it is ensured, tighten the wing nuts without disturbing the distance

Document No:



Page 4 of 17

between the top of the piano wire and bottom of the sole bar at the center of the

body bolster locations.

2.6 Let the height between the top of the piano wire and the bottom of the sole bar

at body bolster location be 'a'. Rotating the wing nuts without disturbing the

clearance 'a' mentioned above tighten the piano wire finally. Measure the

clearance between top of the piano wire and the bottom of the sole bar at the

center of the under frame on either side. Let this clearance be 'b'. Therefore, the

camber of the under frame at the center shall be 'b-a'. Likewise the vertical

distance between the top of the piano wire and the bottom of the head stock at

the wagon ends on either side is measured. Let this clearance be 'c',d, etc.

Therefore, the camber (lifting) of the under frame at its ends shall be 'c-a',d-a',

etc.

2.7 If the reverse camber is measured at the under frame center by the procedure

given above. Re-cambering of the under frame at its center shall be carried out

as per the procedure detailed below.

3. PROCEDURE OF THE RECAMBERING (LIFTING) OF WAGON BY

APPLICATION OF HEAT AND FORCE AT WAGON UNDERFRAME

MEMBERS

3.1 Follow instructions given at Para 2.1 above to run out the bogies and placing of

the wagon body on trestles of equal heights as shown in fig.2. Place load of 8

ton on wagon floor near headstock.

3.2 Place 4 No. stoppers under the central girder (2 Nos. on either side of the

wagon) at locations shown in fig.2. Place stoppers i.e. 4 Nos. below the central

girders up to they are tight with central girder bottom flange. Provision of

securing at the wagon body bolsters would ensure that the level of the under

frame at these locations remain undisturbed during the process of lifting the

wagon under frame and also it will not droop while heating the girders.

3.3 The heat source can be oxyacetylene mixtures. The torch nozzle should be a

medium to large "rosebud" type. But it would be preferential to select a multi

nozzle torch to save the time as well as uniform heating of sections as shown in

fig.9. The temperatures shall be monitored by optical pyrometer/heat-sensitive

crayons in the real time as the heating progresses.

3.4 Heat cambering should be limited to low carbon steels. IS:2062 Fe410CuWA

steel should not be heated above 600C, during the cambering process. The

consequences of overheating are not readily apparent to the naked eye but

nonetheless they are present in the form of microstructure changes in the steel.

Document No:



Page 5 of 17

Most heat cambering is accomplished by heating wedge-shaped segments at

intervals along the length of the member. If the member is over-heated beyond

the transformation temperature, there will occur "islands" of altered

microstructure; in other words, the steel will be non-homogenous. This is to be

avoided at all costs.

3.5 Remove floor plate of width of about 1.5 feet in entire width just upon the

location of heating zone. This will facilitate the removal of heat of cutting

flame as well as the resistance of underframe for recambering. Then cut the slit

at the cross-section of Side Rail at the location where floor plate has been

removed as shown in fig.2. Fix two, any suitable Turn Buckles at the location

of Head Stock and Rails with the help of suitable brackets.

Schematic Diagram of Differential Heating

3.6 Start the flame spreader at point A as shown in figure above. Heat spot A to a

light red colour 600C. Proceed slowly in a serpentine path in the direction of

the arrow. Direct the torch toward that direction, moving slowly, bringing each

area to a light red colour. The area of differential heating B A C should be

Document No:



Page 6 of 17

roughly the shape of an isosceles triangle with the angle at A varying from 20

to 40, the larger number producing more movement. It is not necessary to

return to point A to reheat. When the web heating is finished, start the flange

heating at point D and proceed toward the center. (The flange heating may be

started, using an additional torch, as the web heating is nearing completion.)

Always advance the torch along the path bringing the steel to a light red colour

as it proceeds. The flange to be heated is on the concave side of the camber

curve; consequently, point A should be about 50mm, in from the convex side

of the camber curve. Heating zone shall be the girder and solebar locations as

shown in fig.2&5. These all locations shall be in straight line of underframe

cross-section. And floor plate shall be removed above these locations only. All

the prescribed locations shall be heated simultaneously to ascertain uniform

heating of underframe cross section. During heating, turn the screws to tighten

both turn buckles to facilitate the lowering of head stock. Continue this process

of heating and lowering of Head Stock with the help of Turn Buckles upto 10-

15mm lower than the standard limit of 1105mm, so as to compensate the

spring-back tendency of underframe when all loads are removed. Take the

measurements of respective locations to ascertain that adequate camber is

achieved, after that heating process should be stopped. For best results, let the

heated member cool by itself. Now, properly weld both slits of side rails, then

weld and grind flush the floor plate at its location. Note that the heat wedges

do not necessarily have to be equally spaced, but they should be symmetrical

about the centre line of the span (see Fig. 5&6). Care should be taken in

spacing the supports so that the member will not sag too much as the heating

progresses (see Fig. 2). For best results, allow the beam to cool naturally. If the

initial heating does not provide enough camber, additional wedges may be

heated until the desired results are obtained. In order to cut down the time

expended on heat cambering, several wedges can be heated simultaneously, as

required.

3.7 Once the heating starts, it should not be interrupted until the serpentine path

described below is completed. As the heating proceeds, the member may start

to bend in the direction opposite to that intended. However, after the heating is

finished and the beam starts to cool, the beam will commence to straighten and

then continue to bend in the desired direction.

3.8 As these members would get cooled, under frame camber should be gained.

Tight the Turn Buckles as needed.

3.9 As a precautionary and strengthening measure, weld channel pieces vertically

at web from top to bottom at the centreline of wagon, at both the girders and

also weld a channel below the floor plate throughout the width at 300 mm

Document No:



Page 7 of 17

offset, both sides from wagon centre line as shown in fig.10. This will help to

prevent the buckling of centre girder and floor plate during service.

3.10 Measure the camber at the centre of the under frame and CBC height at Head

stock during the process of lifting till a positive camber of at least 13 mm and

CBC height of 1105 mm is achieved. Then release the turn buckles and remove

the stoppers and load.

4. CRITERIA FOR ASSESSMENT OF PROCEDURE

After the recambering procedure is done, following points should be

observed:-

4.1 Deflection of wagon under frame shall not be more than 132 mm under

vertical load condition and once the load is removed the under frame should

come back to its original position.

4.2 Structural members, member joints, central girders on visual examination

should not show cracks or permanent distortion during tests.

4.3 Since joining knees between bolster and central girder & centre sill and

bolsters are vulnerable to cracks during this process. They should be properly

checked for their efficacy. Gusset plates should also be checked.

4.4 Re welding of knees or joining members may be needed.

Document No:



Page 8 of 17

ISM

C 2

50

x 8

2

20

TH

. P

LA

TE

20

TH

.PLA

TE

3

1

22

3

20

TH

. P

LA

TE

6

6 66

66

ITE

M N

O.

DE

SC

RIP

TIO

N

CE

NT

RE

PIV

OT

SU

PP

RO

TIN

G P

LA

TE

SID

E B

EA

RE

R

SU

PP

RO

TIN

G P

LA

TE

RIB

321

737

737

513

737

737

513

14

74

20

321

R35

542

100

100

160

462

23

.54

38

509

235

390

25

00

819

830

819

fig.1

: S

chem

atic d

iagra

m o

f tr

estle to s

upport

underf

ram

e

Document No:



Page 9 of 17

C.L

. O

F B

OLS

TE

R

8 TONNE

9144

650650

1474

648

fig.2: recambering procedure diagram

(showing underframe support arrangement and location of

lifting jacks at the central girder portion of the wagon)

xy

8 TONNE

Document No:



Page 10 of 17

fig.3: camber measuring arrangement

'X'

= =

50

16

11

50

15

200

6

100

41

41

Document No:



Page 11 of 17

TU

RN

BU

CK

LE

FA

ST

EN

ED

BE

TW

EE

N

HE

AD

ST

OC

K A

ND

RA

IL

R.L

.

fig

.4:

turn

bu

ckle

tie

d b

etw

een

he

adsto

ck a

nd

ra

ils

Document No:



Page 12 of 17

fig

.5:

he

atin

g z

on

es o

n c

entr

al girder

Document No:



Page 13 of 17

fig.6

: heating z

ones o

n s

ole

bar

Document No:



Page 14 of 17

fig

.7:

ca

mb

er

me

asurin

g lo

ca

tio

ns

Document No:



Page 15 of 17

fig.8:Schematic Arrangement of weights

Document No:



Page 16 of 17

fig.9:Multi Nozzles heating torch

Document No:



Page 17 of 17

fig.10: Welding of channels at central girder and below floor plate

ISMC-150 CHANNEL TO

BE WELDED AT WEB

AT THE CENTRELINE

OF WAGON, AT BOTH

THE GIRDERS

ISMC-100 CHANNEL TO BE

WELDED BELOW FLOOR

PLATE THROUGHOUT THE

WIDTH AT 300 mm OFFSET,

BOTH SIDES FROM WAGON

CENTRE LINE

GOVERNMENT OF INDIA MINISTRY OF RAILWAYS - Indian … for... · ISMC 250x 82 2.5 m 2 10. ISMC ......

Documents

Transcript of GOVERNMENT OF INDIA MINISTRY OF RAILWAYS - Indian … for... · ISMC 250x 82 2.5 m 2 10. ISMC ......