PROJECT REVIEW ANALYSIS OF BUFFER IN COACHES

SUBMITED BY:- RITESH ROHAN BE/6258/11

OBJECTIVEIndispensible need for proper maintenance of buffer

and bolster assembly to improve shock absorbing capacity of coaches to provide safety and comfort to the passengers travelling . It is necessary that correct practices are followed and other maintenance schedules , so that it works efficiently and give trouble free service on time.

INTRODUCTION Indian railways was first introduced in 1853 with a stretch of 34 km from

Bombay to Thane. IR operates both long distance and suburban rail systems on a multi-gauge

network of broad, metre and narrow gauges. Indian Railways manufactures much of its heavy engineering components

at its six manufacturing plants, called Production Units, which are managed directly by the Ministry. Popular production units are CLW and DLW for electric and diesel locomotives; ICF and RCF for passenger coaches .

Each of these production units is headed by a general manager, who also reports directly to the Railway Board.

DANAPUR DIVISIONDanapur divison was formed on 1925The eastern railway was formed on 14.04.1952 and

Danapur division came under the control of eastern railway. It came under the control of east central railway w.e.f 01.10.2002.

Danapur division is being an integral part of ECR is well renowned for maintainance practices for ICF coaches.

MAINTENANCEIntermediate overhauling(IOH): 9 months or 2 lakh km Periodic overhauling(POH): 18 months or 4 lakh kmMaintenance schedules:-Schedule A (1 month ± 3 days): can be done on washing line

when needed can be sent to sick lineSchedule B (3 month ± 7 days): can be done on washing line

when needed can be sent to sick lineSchedule C (6 month ± 15 days): can only be done on sick line

ABOUT BUFFER Buffer prsent in every coach in front and back sideFour buffers are present in a coachPerforms as shock absorberBuffer height from rail is 1105mm (max) and 1090mm

(min)Length of coach from buffer to buffer is 22296mmBuffer height in loaded conditions is 1030 mm

Buffers are the horizontal shock absorbing parts with coupling the adjacent coaches of the train so need regular changing of shock absorbing rubber pads.

BUFFERS

COMPONENTSBuffer assembly consists of these important components helix nut buffer cotter buffer tightening pad destruction tube buffer projection buffer stroke spindle face plate Plunger Socket Buffer recoil pad Stiffer tube

Maximum height from rail level

Minimum height from rail level

PRODUCTION UNITS 1105 mm 1095 mm

WORKSHOP 1105 mm 1090 mm

BUFFRER HEIGHT ADJUSTMENTBuffer height adjustment should be made under tare condition.Firstly the coach is lifted using special arrangement.Packaging rings are kept under the flanges of the lowering spring.While lowering the bogie frame and bolster assembly the bogie frame

should be set evenly on the four axle boxes.The bogie assembled with packing and compensating rings as

required, should now be loaded and the height of its bolster top surface from rail level measured. Then compared with predetermined dimensions to check whether further adjustment required or not.

If further adjustment required then load on axle box springs should be released and packaging rings in halves should be inserted below the axle box springs.

BUFFER HEIGHT ADJUSTMENT

PROBLEMS ENCOUNTERED Cases of buffer casing /socket crack are very high Remedy: insufficient heat treatment is the main reason proper and timely maintenance can remove this defect Rubber pad wears out Reject pads which show tears, large material chunks, large bond failures, or

extreme wear into the steel plate edges. . Creases and folds are normal and are acceptable for reconditioned gears.

Split pins are either broken or corroded Nyloc Nut instead of Bolt-nut-split pin fitted on Coaches. Repeated occurrence of bogie side frame crack at bottom flange in axle box Remedy: By removing welding of heat affected zone at suspension strap area .

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