" Lifeline Of The Nation "
RAILWAY SHASHIKANT CHOUDHARY
WHEEL PROFILE & DEFECTS
TYPE OF COACH
AXLE , BRAKE DISC & BRAKE SHOES
AIR BRAKE SYSTEM
BODY SHELL & WINDOW UNIT
-: INDIAN RAILWAY :www.indianrailways.gov.in
First passenger train introduced in India on 16 April 1853 between Mumbai to
Thane (34 km).
Over 10,000 trains daily, transporting over 8,900 million passengers and over
1050 million tones of freight per year.
Indian Railways is the world's ninth largest organisation, by number of
employees, with over 1.4 million employees.
The number of zones in Indian Railways increased from six to eight in 1951,
nine in 1952 and sixteen in 2003. Presently there are 17 zones & 84 divisions.
As of 31 March 2013, 23,541 km (36%) of the total 65,000 km route length was
East Central Railway
East Coast Railway
North Central Railway
North Western Railway
North Eastern Railway
Northeast Frontier Railway
South Central Railway
South Eastern Railway
South East Central Railway
South Western Railway
West Central Railway
-: Coach Repair Workshop, Harnaut :Foundation stone was laid by A.P.J. Abdul Kalam on
June 30, 2003
Harnaut, Distt- Nalanda (Bihar) ,under ECR
113 Acres (workshop 76 , staff quarters 37)
Year of sanction
Rs. 224 Cores.
Revised sanctioned Cost
Rs. 337 Cores.
Rs 252.03 Cores. (up to 31.03.13 )
POH of 50 coaches per month
-: THE MAINTENANCE SCHEDULES AND THE OVERHAULING PERIODS :1. Trip schedule- After every trip by primary
2. Schedule A - Monthly (1 month )
3. Schedule B - Quarterly (3 months )
4. IOH – 9 months
5. POH – 18 months
> POH <
Periodic overhauling is the best available process of maintenance of coaches in India. This
generally operated after 18 months after the manufacturing or the previous periodic
overhauling done in any workshop. This undergoes a huge process of lifting the coach,
isolating the all parts, and changing or replacing the necessary or damaged parts. In other
words this is the process of renewing the coaches.
-It stands for periodic overhauling.
-POH is allowed in nominated workshops only.
-Painting of whole coach is necessary.
-Profiling of wheel is necessary
-: DEFECTS :Thin Flange :- When the flange thickness reduces from 28.5 mm to 16 mm or less, then the
flange is called thin flange.
Sharp Flange :- When the radius given at the tip of flange is worn out from 14.5mm
to 5 mm or less is called Sharp Flange.
Thin Tyre :- If the remaining thickness of tyre is less than 25 mm, it is called thin tyre.
Hollow Tyre :- If the groove on the wheel tread is up to 5 mm or more, it is called Hollow tyre
Tyre defect gauge
Noise level 100 decibels
Linke Holfmann Busch
Noise level 60 decibels
DIMENSIONS OF COACH SHELL
Length With Buffer
Length Without Buffer
-: AXLE :-
It is the main long cylindrical bar on which bogie are fixed with the help of bearings. This
is made of steel as above. Each axle contains 2 wheels, the brake cylinders are also
attached to it and in case of LHB coaches, the braking discs are fixed on to the axle.
The axle mounted brake disc consists of a gray cast iron friction
ring and a cast steel hub, connected by means of radially
arranged elastic resilient sleeves which are secured in the hub by
means of hexagon screws. The friction ring is manufactured as a
solid component or in a split version. In the latter case, the two
halves are held together by two tight –fit screws.
-: AIR BRAKE SYSTEM
: The brake system in which compressed air is used in the brake
cylinder for the application of brakes is called air brake system.
MAIN COMPONENTS :Control Reservoir 9 liter, 5 kg/cm2
Brake pipe – Dia. 32 mm
Auxiliary Reservoir 200 liter, 6 kg/cm2
Feed Pipe – Dia. 25 mm
-: Working Principle :The different processes involved in working :a) Charging
Under normal conditions the Brake pipe is charged with 5kg/cm2 from the
loco. The control reservoir and the Auxiliary reservoir are charged with 5
kg/cm2 and 6 kg/cm2 respectively from BP through Distributor valve.
When the brake pipe is charged at 5 kg/cm2 the brake cylinder is connected
to exhaust through distributor valve in order to keep the brake in released
Whenever the brake pipe pressure is reduced below the CR pressure, the
DV connects the auxiliary reservoir with the brake cylinder and the air from
AR is sent into the brake cylinder to apply the brake.
Whenever the brake pipe pressure is equal to CR pressure the DV
disconnects the BC from AR and in turn connects the BC with Exhaust for the
release of brakes fully.
-: BRAKE SHOE :The brake shoe is provided with a brake
pad holder carrying replaceable pads.
The brake shoe consists of the brake pad
holder, the vertical pins and the brake pad.
Due to BC pressure, the piston moves
forward and strikes against the brake caliper.
The lever arm of the brake caliper presses
onto the disc brake through the brake shoe.
The disc brakes are mounted on the wheel
axle and so rotate along with the wheels.
Due to application of brake shoes, the discs
begin to lose their angular speed.
As a result the axle also begins to slow down
since the two are connected.
Ultimately, the wheels stop rotating as they
are mounted on the same axle.
-: BOGIE FRAME :1.Bogie frame longitudinal component
The frame is made up of two
connected by two cross-beams (2)
which also support the brake units.
The various supports which connect
the different bogie components are
welded to the frame.
-: BODY SHELL :The body shell is of integral light weight
construction consisting of separate
assembly group for under frame, side
wall, roof and end wall. The individual
assemblies are joint to each other by
welding. Three types of steel are used for
manufacture of body shell.
X2 Cr8 Ferritic Steel
( C< .03%, Cr 1012%, Si 1%, Mn
X5 CrNi 18 10
Austenitic Steel (SS
( C< .07%, Cr 18%,
Ni 10 % Si 1%, Mn
IRS M-41 / Corten
( C < .01%, Cr .35 .6%, Ni .2 - .4%
Cu .3 - .6% Si .3 .7%, Mn .25%)
-: WINDOW UNITS :-
The sealed window units consist of 8.4 mm outer glass
and 4 mm inner glass with 6 mm Argon gas filled.
Argon is an inexpensive, non-toxic,
odorless gas .
characteristics of the window.
Minimizes heat exchange through
Argon will not corrode the window
This type of windows can even
block ultraviolet rays.
-: Controlled Discharge Toilet System (CDTS) :Objective: -The main objective of introducing this type of
lavatories in coaches of Indian Railways to have clean environment
around Railway Track within city limits, station premises and
maintenance sidings. This system works on electro- pneumatic
principle where in, the waste generated from the coach lavatories
during run is collected in a retention tank and is disposed off far
away from the city limits on meeting certain predefined conditions.
-: Working cycle : On each flushing (Collection):- Simply pressing flush
button, starts the flow of water into the toilet bowl and opens
the flapper valve connecting the toilet bowl to the waste
retention tank. At the end of each flush cycle the wash water
stops and the toilet is sealed off from the retention tank by the
flapper valve, which acts as an effective stench trap,
preventing odor from entering in the toilet room.
The retention tank discharge valve remains open only for a
small period of time (one minute or less) long enough to
The waste is stored in the retention
tank until the following two parameter
1) The train should be in acceleration &
running above 30kmph and the number
of flushing should be More than five.
2) Train should be in retardation and
reducing speed of 30kmph irrespective
number of flushes.
Water consumption is only 2.5 liters per
flush cycle for the Indian style toilet Bowl
and 1.5 liters for the European style toilet
Programmable Logic Controller
It is the heart of the system. It
senses the speed of the coach and
no of flushes and gets all the
operations done by actuating
3 types of TANKS :- are provided in LHB coach
685 liters: -2 stainless steel water tanks of 685 liters capacity
each. These tanks are installed in under frame are fixed with
frames and are secured by safety belts. These tanks constitute
the fresh water reserves in the passenger coaches. Water level
indicator has been provided in these tanks.
30 liters:- 3-stainless steel water tanks of 30 liters
capacity installed one in each lavatory in the roof and are
continuously fresh-water-fed by means of pumps. These
tanks are installed alone and are fixed with 2 supports
which are equipped with belts.
450 liters: -One stainless steel water tanks of 450 liters capacity.
These tanks are installed in under frame, fixed with frames and is
secured by safety belts. This tank installed in the under frame
constitute the fresh water reserves for the generator car.