(Fig1.1Indian railway logo)
"Lifeline of the Nation"
Type :Public sector undertaking
Reporting mark :IR
Founded :April 16, 1853
Headquarters :New Delhi, India
Area served :India
Chairman :Mr. Suresh Prabhu
Services :Passenger railways
:Catering and Tourism Services
:Parking lot operations
:Other related services
Track gauge :1,676 mm (5 ft 6 in)
:1,000 mm (3 ft 3 3⁄8 in)
:762 mm (2 ft 6 in)
:610 mm (2 ft)
Electrification :23,541 kilometers (14,628 mi)
Length :68048 kilometers (42283mi)
Revenue : ₹1.707 trillion (US $25 billion 2015-16)
Net income : ₹105.02 billion(US $1.6 billion 2015-16)
Owner(s) :Government of India (100%)
Employees :3 million (2015)
Parent :Ministry of Railways through Railway Board (India)
Zones :17 Railway Zones
Website : www.indianrailways.gov.in
1.1About North WesternRailway:-
(Fig1.2Logo of NorthWesternRailway)
“Serving Customer with Smile”
Headquarters :Jaipur, Rajasthan
General Manager :Anil Singhal
Track gauge :1,676 mm (5 ft. 6 in)
:1,000 mm (3 ft. 3 3⁄8 in)
Length : 54449.29 kilometers
(Fig. 1.3 NWR region railway map)
Mechanical Department of NWR is headed by Chief Mechanical Engineer Shri Nikhilesh
Jain. Mechanical Department looks after the maintenance of rolling stock i.e. coaches,
wagons and diesel locos. Under this department there are carriage and wagon workshops
(Looking after heavy maintenance of coaches & wagons), diesel sheds (Looking after
maintenance of diesel locomotives) and divisions where there two wings viz. C&W wing
and Loco wing. C&W wing looks after minor schedule of coaches and wagons & Loco
wing looks operation of diesel loco and crew management.
There are three workshops in NWR viz. Ajmer C&W workshop, Bikaner workshop and
Jodhpur workshop. Also there are three Diesel Sheds viz., Abu Road diesel shed ( BG ),
Bhagat Ki Kothi diesel shed ( BG ) and Phulera Diesel Shed ( MG ).
The Mechanical Department of NWR is having cadre strength of (approx.)
Officers = 57
Staff = 19221
1.2 About Ajmer RailwayWorkshop:-
Aimer has been in the limelight from the time of the great king Prithvi Raj Chouhan. It
continued to maintain its importance during the Moghul dynasty. Subsequently, British
resident was head quartered here for controlling the princely states of Rajputana and
Rajputana State Railway was opened on 18th Aug 1876. The Railway was renamed as
Rajputana-Malwa Railway when a new line from Ajmer to Khandwa was added to it.
Bombay Baroda & Central India Railway came into existence in 1890 and Rajputana-
Malwa MG system was leased to it Central Workshop was setup at Ajmer in 1877.
The foundation of the prestigious Central Workshop was laid in 1876 and established in
1877 to undertake repairs and manufacture of steam locomotives, carriages and wagons of
Rajputana-Malwa MG system Carriage and Wagon activity was shifted in 1884 to south of
Carriage and Wagon workshop was built in 1884 for repairs and manufacture of Carriage
and Wagon for the Rajputana-Malwa Railway. This Workshop has proud privilege of
being the first workshop in the country to set up facilities in 1902 for the production of
steel castings. The manufacturing of new coaching and wagon stock continued in this
workshop till the setting up of Integral Coach Factory and till development of certain
private and public sector factories for the manufacture of wagons. This Workshop was
modernized during 1986-92 at a cost of Rs. 31.81 crores. Gauge conversion in the
Workshop took place in 1995-96.
Ajmer Workshop Group consists of following Administrative units.
1. Carriage Workshop (IMS certification)
2. Ajmer Diesel Loco & Wagon Workshop (ISO 9001,ISO 14001)
3. Electrical Workshop
4. Electrical Production Shop
5. Central Chemical & Metallurgical Lab.
6. EDP Center
7. Supervisors Training Center
8. Ajmer District of Stores, Ticket printing
9. Workshop Accounts Office
10. Workshop Personnel Office
At Ajmer, Signal shop was set up in 1885 for manufacturing of signals, signal points and
crossing. Present it is headed by ASTE.
1.3 About Carriage Workshop:-
Till recently, Indian Railways have been transporting passenger traffic mainly through
coaches of ICF (INTEGRAL COACH FACTORY, KAPURTHALA) design. These
coaches are being manufactured at ICF and RCF. A limited number of these coaches are
being manufactured at BEML/Bangalore also. These type of coaches are having limitations
in terms of
1. Speed potential.
2. Heavy corrosion.
3. Poor riding comfort.
4. Wearing of parts in the under gear.
To overcome these limitations, Indian Railways entered into supply and technology
transfer contracts with M/s. ALSTOM LHB/Germany to initially supply 24 coaches
consisting of 19. AC chair cars, 2 AC Executive Class Chair cars and 3 Generator cum
Brake vans. The bogies for these coaches are manufactured by M/s. FIAT/SIG
Switzerland. These coaches arrived in India and got commissioned in the year 2001 and
put in service on route. These type of coaches are far superior with respect to passenger
comfort, safety, speed, corrosion, maintenance and aesthetics in appearance. These
coaches are also longer as compared to ICF design resulting into more carrying capacity.
The expected benefits from these types of coaches are as under:-
1. Higher carrying capacity.
2. The weight of LHB coach is lesser as compared to ICF design coaches.
3. Low corrosion.
4. Low Maintenance.
5. Resist water seepage.
6. Better passenger comfort.
7. Better passenger safety.
Carriage workshop is also works on the overhauling of the carriages in the particular time
period that is POH time. Ajmer carriage workshop also works on heritage trains like Palace
on Wheels, Royal Rajasthan On Wheels, SPA train etc.
MAINTENANCE OF THE TRAINS
The maintenance of the trains is an important criterion for every coaching facility and
workshop. This is very important to make the system run smoothly and to look after the
passenger safety. So knowledge about the proper maintenance is essential.
Seen from the point of view of the train itself there are three kinds of maintenance
available in Eastern railways.
2.1 Primary Maintenance
According to the rules of railways, every division of railways possesses the responsibility
of running some specific trains. For those trains under the consecutive divisions primary
maintenance is done before that train leaves that section of railways. In other words the
primary maintenance is done at the mother or the terminal station.
Here every aspect of pressure related systems and aspects of public safety are checked. The
continuity, the bonding between coaches etc is also taken care of this takes at about 5 – 6
and half hour duration until it is given the fit to run certificate. Each primary maintenance
comprises a form which is known as the v-5 form this form has information spaces about
those aspects that are secured during this maintenance. If a train is given fit instead of any
fault not so fatal, that is certificate.
2.2 Round trip/Turn around Maintenance
This maintenance takes place after the train reaches its final destination from the staring
one. This is a short duration maintenance preparing the train to send it back to the terminal
station. Just the necessary maintenance is carried out. This takes about one hour forty
minutes to about two hours to complete.
2.3 Secondary Maintenance
Secondary maintenance is a specific type of the primary maintenance. When the train runs
for about 3500 kilometers or about 3 days, either way, then at the destination station the
train undergoes the secondary maintenance. Here the measures taken are just similar to the
primary one. The duration is about six to seven hours.
Maintenance Schedules orThe Overhauling:-
There are normally seven kinds of maintenance schedules depending on the condition of
coaches and wagons. They are respectively
1. A- Schedule - after 30 days of manufacturing or of periodic overhauling, repetitive
2. B-Schedule - after 90 days of manufacturing or of periodic overhauling, repetitive
3. C-Schedule - after 180 days of manufacturing or of periodic overhauling, repetitive
4. Intermediate Overhauling - after 9 months of manufacturing or of periodic
5. Periodic Overhauling - after the returning date given by the workshop after periodic
6. Non-Periodic Overhauling - This is done after 12 months or 18 months after the
Manufacturing date or the periodic overhauling date depending on the condition of the
7. Inter lifting schedule - This is a special kind of maintenance done within the
maintenance facility with lifted coach and parts.
Periodic overhauling is the best available process of maintenance of coaches in India. This
generally operated after 12 or 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. Here are some varieties
1. 12 month basis
2. 18 months basis
POH Date And Return Date
POH date is that date on which its POH has been done previously in a workshop. This is
written on the coach. And the return date is the date on which it is to be dropped off from
the track and to be taken for another periodic overhauling. Generally they have a 12 month
or 18 month gap between them in accordance with the definition of the POH. Both of the
dates should be given by the corresponding workshop where its POH has been done.
Significance Of CoachNumber
Every coach has its own unique number attached to it which obviously carries some
significant information to us. Generally in India that is of five numbered. The first two
digits represents the year of manufacturing of the coach. And the rest three digits represent
the list of types of coaches. It represents of which type the coach is.
EXAMPLE. 0602, we can write it up as 06 and 023
06 represents the year of manufacturing which is year 2006
And 023 represent the type which is an FAC type coach.
Ajmer carriage workshop deals with the all type of maintenance plan according to
requirement on coaches.
AIR BRAKE SYSTEM
In Air Brake system compressed air is used for operating the brake system. The locomotive
compressor charges the feed pipe and the brake pipes throughout the length of the train.
The feed pipe is connected to the auxiliary reservoirs and the brake pipe is connected to the
brake cylinders through the distributor valve. Brake application takes place by dropping
the pressure in the brake pipe. The schematic arrangement of the brake system is shown as
(Fig 3.1 Schematic Layout Of Twin Pipe Graduated Release Air Brake System)
3.1 ICF CoachesBraking System:-
3.1.1 Charging the brake system
Brake pipe throughout the length of train is charged with compressed air at 5 Kg/cm2.
Feed pipe throughout the length of train is charged with compressed air at 6 Kg/cm2.
Control reservoir is charged to 5 Kg/cm2.
Auxiliary reservoir is charged to 6 Kg/cm2.
3.1.2 Brake application stage
For brake application the brake pipe pressure is dropped by venting air from the driver’s
Subsequently the following actions take place
The control reservoir is disconnected from the brake pipe. The distributor valve connects
the auxiliary reservoir to the brake cylinder and the brake cylinder piston is pushed
outwards for application of brakes.
The auxiliary reservoir is however continuously charged from feed pipe at 6 Kg/cm2.
3.1.3 Brake release stage:
Brakes are released by recharging brake pipe to 5 Kg/cm2 pressure through the driver’s
The distributor valve isolates the brake cylinder from the auxiliary reservoirs.
The brake cylinder pressure is vented to atmosphere through DV and the Brake cylinder
piston moves inwards.
3.1.4 Air Brake Sub Assemblies
The various Air Brake sub-assemblies and components are:
iii) Brake pipe and feed pipe
iv) Brake pipe coupling
v) Cut-off angle cock
vi) Brake cylinder
vii) Dirt collector
viii) Auxiliary reservoir
x) Distributor valve
xi) isolating cock
(Fig 3.2 Air Brake Hoses & Cut Off Angle Cock)
i. Hose Pipes:-To maintain continuity through out the length of train, the brake pipe
(BP) and feed pipe (FP) are fitted with flexible hoses. For easy identification
coupling heads are painted with green colour for B.P and white colour for F.P.
ii. Cut off angle cock:-To disconnect two coaches braking system and to continue in
remaining coaches cut off angle cock is used.
iii. PEASD & PEAV:- These are safety valves that is used in the emergency braking
like chain pulling and coach partitions.These valves having 8mm hote to release the
(Fig 3.3 Auxiliary Reservoir & Brake Cylinder)
3.2 LHB coachesBraking syatem:-
i) Brake Container (Brake Equipment Panel)
ii) Distributor valve
iii) Pressure Tanks (125 liters, 75 liters, 6 liters)
v) B.P./F.P. Couplings and Hoses
vi) Emergency Brake Pull Box
vii) Emergency Brake valve
viii) Bogie Brake Equipment, consisting of- brake disc, hoses etc.
ix) Brake Caliper Units (consisting of Brake Cylinder, Brake Calipers, Brake Pads)
x) Wheel Slide Control System, consisting of-
xi) Microprocessor Control Unit
(Fig. 3.4 LHB Coach Brake)
i. Brake Discs:-
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
(Fig. 3.5 Axle Mounted Brake Discs)
ii. 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. The brake pad
holder is provided with a dovetail guide into whom the pad is slipped. The pad is held in
place by a captive gate, which is pivoted at the pad holder. To lock the gate a locking
spring of spring steel has been provided which is pre-tensioned such that in one position it
secures the gate in the pad holder and in the other (released) position it holds the gate open.
For each brake disc a right and a left hand brake shoe are required.
(Fig.3.6 Brake Shoe)
iii. Brake Cylinders:-
U-series brake cylinders with automatic slack adjustment are used to operate the friction
brakes in rail vehicles. U-series brake cylinders are essentially distinguished by their
integral, force controlled slack adjustment mechanism which is designed as a single
acting clearance adjuster. The working of this mechanism is not influenced in any way by
the elastic brake rigging deflection, which varies according to the brake force. In the
course of braking, the slack adjuster quickly and automatically corrects the increasing
brake pad or brake block clearance due to wear.
iv. Braking Control Panel:-
In LHB coaches at the place of distributer valve control panel is available to apply the
(Fig 3.7 Control Panel of Braking System)
3.2.2 Working principle:-
Applying the service brake charges the brake cylinder and presses the brake pads against
the brake disc. Brake force is built up when the pads are applied. Venting the brake
cylinder releases the service brake. The return spring in the brake cylinder moves the
caliper levers to the release position.
The handbrake lever is moved mechanically. The piston is pushed forward, and the brake
pads are applied to the disc. When the parking brake is released, the caliper levers are
drawn to the release position by the return spring in the brake cylinder.
3.2.3 Brake Application:-
1. The driver lowers the BP pressure by engaging the A-9 valve in the engine.
2. This loss in pressure is transmitted from one bogey to the next.
3. Since CR pressure remains same, the main diaphragm (above the CR) moves up in
response to the pressure drop in DV.
4. As a result the ‘three pressure valve’ opens the AR-BC port .
5. Thus the AR pressure of 6 kg/cm^2 flows into the BC through pressure limiters which
reduces BC pressure to 3.8.
3.2.4 Brake Release:-
1. BP pressure is again increased to 5 kg/cm2.
2. Consequently, main diaphragm move down and the ‘three pressure valve’ closes the AR
3. BC port and opens the BC-atm port.
4. BC pressure is released and the brake caliper is disengaged
(Fig. 3.8 Bloke Diagram of Control panel)
WHEEL AND AXLE ASSEMBLY
This is the part of a rake which is just adjacent to the tracks. It basically consists of three
1. Wheel Profile
3. Bearing and Housing
Wheel profile of a rake is a specifically made cylindrical portion having an outer edge
shape to fit in the railway track. The material is stainless steel and tapper angle of 20 to
(Fig. 4.1Wheel and axle assembly)
Axle is the main long cylindrical bar on which wheels are fixed with the help of bearings.
This is also made of stainless steel as below. 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.
(Fig. 4.2 Axle)
4.3 Components Of WheelAnd Axle Assembly:-
A wheel set is an assembly mainly of two components:
A. Wheel discs(solid) on both sides of the axle
B. An axle to hold these wheel discs in position
1. Two brake disks (4), diameter 640mm and width 110 mm.
2. In built slack adjusting brake cylinder fitted
3. Two wheel disc of tread
4. dia 915 (New), 845 (worn).
(Fig. 4.3 Components of Axle)
4.4 Axle Box Assembly
In passenger coaches of Indian Railway system, only single bearing type axle box
arrangement is used. The inner ring of the bearing is provided with either a cylindrical bore
(Direct Mounted type) or with a taper bore and withdrawal sleeve (Sleeve Mounted type).
All new passenger coaches built by Indian Railways, use only direct mounted type
spherical roller bearings. Therefore,
practices related to the sleeve mounted bearings.
4.4.1 Axle Bearing
A taper roller cartridge type bearing is used and it makes up a preassembled unit. The axle
bearings on the bogie are fitted with sensors for detecting speed (whose signal is
elaborated by the ant slipping system) and a current return device.
The ends of the control arms are fitted with centering devices for the primary suspension
spring assembly. The bearing lubricating plug is fitted in the lower part.
4.4.2 Procedure For Opening Of Roller Bearing
1. Bring Journal (Axle box removed) at the bearing opening work place.
2. Open end locking nuts using proper key wrench and remove end locking plate and locking
3. Remove roller bearings using Inventom Bearing Extractor (Hydraulic machine uses oil at a
pressure of 4 Kg./cm2)
4. Take roller bearings for cleaning.
5. Remove distance ring with ring cover and felt ring from journal and take them at their
respective cleaning places.
6. Ensure end lock nut and plates should not be used again.
7. Also take retaining ring to the cleaning place.
8. After the bearing is sent to the bearing washing plant.
4.4.3 Cleaning Of Roller Bearing
Cleaning of roller bearing is done by “PROCECO” Machine and is carried out in three
steps basically. Three tanks are provided there in the machine. Pressure of these tanks is
kept 5.3 Kg./cm2. Processes included are mentioned in table below :
Table 4.1: Washing And Cleaning Chart For Roller Bearings:-
S.NO. PROCESS USED PROCESS USED IN
1. Cleaning of Grease and Oil
stucked on roller bearings
Washing by hot water (In
2. Cleaning of Grease and Oils using
Alkali Chemical Reaction
Performed in Wash tank 165º C
3. Washing of Chemicals stucked
during Chemical Reaction
Performed in Rinse tank 105º C
From PROCECO machine, bearings are sent to the other cleaning process is done with
kerosene or petrol. After this bearings are sent to the inspection section.
4.4.4 Inspection of Roller Bearing
The inspection of roller bearings is done in following steps :
1. After washing roller bearing in PROCECO washing plant, wash roller bearing
2. either in kerosene or in petrol and put in on for inspection process.
3. Inspect all parts of bearings like inner race, outer race rollers, and cage.
4. Measure bearing radial clearance taking help of filler gauges. The standards limit of this
clearance is as given in the table.
5. After this inspection send it for Zyglo testing carefully
Table 4.2: Clearance Table of Roller bearing:-
BEARING TYPE RADIAL CLEARANCE FOR
NEW BEARING (In mm.)
UPPER LIMIT OF
FOR USED BEARINGS (In
1. NEI / FEG / NORMA 0.145 – 0.190 0.1 – 0.135 0.27 0.25
2. SKF / NACHI 0.145 – 0.190 0.1 – 0.135 0.195 0.25
4.4.5 ZYGLO Testing Of Roller Bearing
1. Dip the bearing in the fluorescent emulsified dye for 10 minutes.
2. Excessive dye to be drained.
3. Excessive dye to be washed off with water.
4. Put the bearing in the oven for dryness.
5. Apply developer powder (BaSO4) on the dried bearing for the contrast.
6. Examine the bearings (Inner race only) under Ultra Violet light for any crack
7. and mark the rejected bearings by a red mark.
4.4.6 Assembly Of Roller Bearing
In assembly section roller bearing is assembled on the journal by using various processes.
Induction heating is done for expanding inner race of the bearing of so that it can be
mounted on the journal of the wheel without any problem. Induction heating includes
following features :
1. Temperature is maintained at 120º C.
2. Minimum time for heating between induction coils is 5 to 7 minutes.
4.4.7 Quantity Of Grease Required For Lubrication Of Bearing
1. Broad Gauge - 1.75 Kg.
2. Meter Gauge - 1.65 Kg.
4.4.8 Bearing Defects
1. Excessive Clearance
2. Inner Race Crack
3. Roller Damage
4. Roller Pitted
5. Outer Race Pitted
6. Outer Race Crack
(Fig. 4.4 Assembly of Bearing on Axle)
BOGIE AND SUSPENSION SYSTEM
5.1 ICFBG Bogie
Bogie is basically the separated part containing the wheel and other similar components
which are essential to run a coach. When they are attached with the body they are called
the bogie. Here we are going to discuss about the trolley parts of the ICF coaches.
1. Trolley Frame: - trolley frame is the main construction of the trolley on which the other
components rest. This is a metallic construction just like a cage having different gaps in
between to fit the components.
2. Center Pivot: - this is the centrally situated hole which will indicate the correct position of
the trolley when fitted with the body. There is a counter part of the hole attached at the
body itself to indicate the perfect position of the trolley. When assembled they should
3. Side Bearing: - Side bearing is the bearing space engulfed by lubes and a bearing made of
bronze which plays a good role in distributing the weight throughout the trolley.
4. Brake Cylinder: - If we see the trolley in the direction of the motion we will see two
brake cylinders one after one which have the air supply through one outlet. These brake
cylinders operate in a critical air pressure and contains a piston which we call the slug
adjuster. At that particular pressure the piston inside those cylinders moves and the brakes
hold firm onto the wheels.
5. Brake Blocks: - In ICF coaches we generally use the K & L types of brake blocks. These
are used as components of shoe brakes attaches at wheels. These special type of blocks are
used because of their increased coefficient of friction and also the heat absorbing
6. Equilateral Sterod: - This is attached to the trolley symmetrically along the trolley frame
horizontally to minimize the lateral force when in motion.
7. Anchor Rod: - These are rods attached vertically to minimize the longitudinal load. Both
of them are made of stainless steel.
8. Suspension Systems: - These are anti-vibrational attachments which are attached to the
main frame and the wheel bearing.
(Fig.5.1 ICF/BG Bogie)
5.2 LHB Bogie
The FIAT Bogie is two-axle type, with a primary and a secondary suspension. The bogie
assembly is shown in Fig. 11. The Salient features of FIAT Bogie are:
1. Solid welded Bogie Frame: - made up of two longitudinal components connected by two
cross beams. The bogie frame rests on the primary suspension spring units and supports the
vehicle body by means of Bolster beam. The Bolster beam is connected to the bogie frame
by secondary suspension.
2. Primary suspension: - consist of two steel coil springs (internal/external) laid out on the
Control Arm upper part.
3. Secondary suspension: - consists of two spring packs which sustain the bolster beam over
the bogie frame. Each spring pack is made up by an internal and external spring. An Anti
roll bar fitted on the bogie frame realizes a constant, reduced inclination coefficient during
running. The bogie frame is linked to the bolster beam through two vertical dampers, a
lateral damper, four safety cables and the traction rods. The bogie frame is linked to the
coach body through two yaw dampers.
4. Traction Centre: - The traction Centre transmits traction and braking forces between
bogie frame and body by a traction lever on the bolster beam pin and two rods.
5. Disk Brakes: - The FIAT bogie is fitted with pneumatic disk brakes. The pneumatically
operated brake cylinders are fitted with automatic device for taking up the clearances.
6. Taper Roller Cartridge Bearing: - Fiat Bogie is fitted with 130 mm Cartridge type roller
(Fig. 5.2 LHB Bogie)
5.3 Suspension System
5.3.1 Primary suspension
Primary suspension is implemented by two units of two steel coil springs internal and
external laid out on the control arm upper part by a centering disk and adjustment shims,
The secondary suspension enables lateral and vertical displacements and bogie rotation
with respect to body when running through curves.
It is implemented by two spring packs which sustain the bolster beam over the bogie
frame. Each spring pack is made up by an internal and an external spring mounted and
positioned through the centering discs. An anti-roll bar fitted on the bogie frame, realizes a
constant, reduced inclination coefficient during running.
The bogie frame is linked to the bolster beam through two vertical dampers, a lateral
damper , four safety cables and the traction rods
(Fig.5.4 Secondary Suspension)
5.4 Spring Section:- Two types of coil springs are used for suspension :
1. Bolster Plate Spring
2. Axle Box Spring
5.4.1 Inspection And Testing Of Coil Spring
1. Dismantle springs are obtained.
2. “Sand Blasting” is done for cleaning and stress relieving.
3. Visual inspection of spring :
If found any crack, seam, dent, pitting or breaked coil than reject immediately the spring if
not then pass.
4. Checking on magnetic crack detection machine by ultra violet light and reject the defective
5. Load Testing :
Check free height of spring.
Apply the load on the spring by load testing machine
According to given table check the height at any particular load. That should be according
to the table.
Table 5.1: Spring Loads and Parameters:-
LOAD (In mm.)
Axle Box Spring
33.5 360 2000 279 – 295
Axle Box Spring
33.5 375 2800 264 – 282
42 385 3300 301 – 317
42 400 4800 291 - 308
BODY FRAME/SHELL & PAINT ON COACH
The bogie frame is a solid welded frame made by steel sheets and forged or cast parts. The
frame is made up of two longitudinal components connected by two cross-beams which
also support the brake units. The various supports which connect the different bogie
components are welded to the frame. The bogie frame rests on the primary suspension
spring units and supports the vehicle body by means of a bolster beam. The bolster beam is
connected to the bogie frame by the secondary suspension.
Leading dimensions of ICF, BEML and IRS are:-
Table 6.1: Different Coach Sizes:-
(Fig. 6.1 Coach Size Diagram)
The integral shell is made of a framework of series of hoops, consisting of floor
crossbeams, body side pillars and roof carlines located transversely at regular intervals, to
suit door and window openings. These hoops are connected together by sole bars, waist
rails, light rails, cant rails and carlines longitudinally.
This frame work is sheathed all over by 2 mm thick corten steel (IRS-M-41) on the side
walls and 1.6 mm thick corten steel on the roof. At the bottom 2-mm thick corten steel
corrugated trough floor is provided between the sole-bars and running over the length
between the head stocks of underframe. The whole forms a tubular shell of integral
construction in which the sides and roof panels also share the load.
The corrugated trough floor with its corrugations running longitudinally from one head
stock to the other takes up the buffing loads. Below lavatory the tubular constructions are
provided in place of trough floor to avoid corrosion due to seepage of water. In coaches
with stainless steel trough floor, no tubular structure is used.
6.1Body Frame Parts
1. Cross Bar: - Cross bar is the connection between the two ends of the trolley which also
maintains the uniform distribution of the hauling force to all wheels to ensure equal
(Fig. 6.2 Coach Frame)
2. Bolster Assembly: - Bolster assembly is the host of the secondary suspension system. In
other words it is like two interconnected housing for springs.
It also connects trolley and the body of the rake. The main function of bolster assembly is
to transform the hauling force and the raking force form body to wheel and from wheel to
3. Draw and Buffing Gear Assembly: - Draw and buffing gears are attached to the end of
one coach and this two gear mechanisms are made to suit two adjacent coaches into an
uniform continuous movement. They also transform the hauling force from main engine to
the following rake, draw gear is specialized for these purposes, and where as the buffing
gears are essential for maintaining a vibration less motion of a coach with respect to its
former one. We have two different arrangements of draw and buffing gear assembly in ICF
and LHB coaches.
4. Screw coupling: - the side buffer serves the aforesaid purpose in case of the draw and
buffing gears respectively in case of ICF coaches. Screw coupling not only gives the boost
but also let two coaches to connect in the formation of a continuous rake. The two jaws of
the screw on both sides are guarded with spring and rubber to minimize the vibration the
hauling force produces. They are called the draft gears.
5. Side buffers: - they are uniquely shaped buffers. They have a flat plate made of stainless
steel and duly lubricated in contact to each other facing each other in motion. They are also
guarded with the iron plated and spring and rubber to minimize the vibration as much as
6. Body- Bogie connection: - Specially in case of the LHB Coaches, there are a special kind
of bolts called swing bolts, which are four numbered in each trolley. These connect the
body to the bogie to the body. Each bolt is fastened with a pin which can swing in the
direction of the motion
6.2 Paint on Coaches
After the coach body is fully repaired and the flooring work completed, it should be swept
and cleaned of all dust, shavings, etc., before the coach is placed in the Paint shop for
painting and polishing.
If the condition of the paint so warrants or at every 5th POH of a coach, the paint should be
completely removed to the bare metal and the coach repainted as per paint schedule `A'. If
the general condition of the paint is good, follow paint schedule `C'. These paint schedules
cover the exterior painting of coaches with synthetic enamel paint system. There are two
types of paint schedules are available.
6.2.2 Type of Schedule:-
184.108.40.206 A Schedule (Nine Days)
1. 1st Day : Remove old paint
2. 2nd Day : One coat of Red Oxide Zinc chromate primer.
3. 3rd Day : One coat of brush filler followed by spot putty to fill up holes/dents where
4. 4th Day : Filler second coat (including spot putty where necessary)
5. 5th Day : Rub down with silicon carbide water proof paper Gr. 120 & 220
6. 6thDay : One coat of under coat
7. 7th Day : Flat with silicon Carbide water proof Paper Gr. 320. One coat of enamel
8. 8th Day : Flat with silicon Carbide water proof Paper Gr. 400 and apply a second coat of
synthetic enamel finishing.
9. 9th Day : Lettering with Golden yellow and miscellaneous work (cleaning window
220.127.116.11 POH Painting Procedure "C" Schedule
1. 1st Day : Cleaning with soap solution or any other cleaning solution and wash thoroughly
with water touch up damaged portion with primer recommended under A sch edule .
2. 2nd Day : Spot putty if necessary and one coat of under coat.
3. 3rd Day : Flat with silicon carbide water proof paper Gr. 120 & 220, and apply one coat of
4. 4th Day : Flat with silicon carbide water proof Gr. 400 and apply a second coat of
synthetic enamel finishing.
5. 5th Day : Lettering with golden yellow and miscellaneous work.
6.2.3 Coach Painting Procedure:-
Epoxy-Polyester- Polyurethane system:-
This is also called PU paint and this is highly efficient system. In PU paint a computer
controlled painting machine and dry machine is use. This machine is able to paint a coach
in only 8 minutes. The schematic diagram of PU painting machine is as follows.
(Fig. 6.3PU Paint Machine Schematic Diagram)
1. Surface Preparation.
2. Primer Application.
3. Putty Application on joints.
4. First & Second Coat Putty application.
5. Putty Rub-down.
6. Fine Putty Application.
7. Fine Putty Rub-down.
8. PU Primer Application.
9. Spot Filling.
10. PU Under Coat Application.
11. First PU Top Coat Application.
13. Second PU top Coat application.
14. De masking.
AIR CONDITIONING OF COACHES
Types of AC coaches on Railways can be classified broadly as under :
(Fig. 7.1 Classification of AC coaches)
7.2 PowerSupply System: As far as power supply system is concerned, the coaches
are of the following two types :
(i) End-On-Generation (EOG) : In this system two types of Power cars are used
b. Coaches with out stepdown transformer suitable only for old low capacity power cars.
(ii) Self Generating (SG) : Based on AC equipment, there are two types of Self
a. 110 V DC with under slung type AC equipment working from 110 V DC.
with the help of 25 KVA inverters mounted on underslung as well as onboard.
7.3 MajorEquipments Used In AC Unit are :
1. Compressor (open type for under slung, sealed type for Roof Mounted Package Unit
2. Condenser including liquid receiver and dehydrator.
3. Expansion Valve
4. Evaporator with heater element.
5. Motors for compressor, condenser, evaporator .
6. Other protective devices and control panels.
7. Thermostat, Filters etc.
7.4 RoofMounted Air Conditioning
7.4.1 Package Units For Railway Coaches :-
(Fig. 7.2 RMPU unit Diagram)
The roof-mounted AC equipment for AC coaches of Indian Railways would provide more
comfortable journey and also help attach more coaches in the superfast trains like Rajdhani
Expresses. These roof-mounted AC units of new design are more efficient and lightweight
and are manufactured indigenously. Two high capacity packaged air-conditioning units of
minimum of 7.0 TR of cooling in 45°C ambient i.e. 14.0 TR for one coach, will replace the
present underframe open type AC system of capacity 5.2 TR each (Total 10.4 TR) for each
coach. Two packaged units are used in one coach each mounted above the toilets on both
ends supplying conditioned air into a tapered duct to serve the coach end to end. The units
(two in each coach) are fitted with 4 compressors but operate under normal with 3
compressors and the 4th one acts as standby and works only during peak days of the
Compressors are started in sequence with time delay to reduce the peak
demand of electricity during start ups. These units are thus more energy efficient and are
more reliable than the existing open units and would be better in operation. The high
capacity AC units of roof mounted type is a fore runner to futuristic super fast trains. This
units can work on E.O.G. systems in addition to S.G. systems.
1. Evaporator Unit:-
The evaporator unit consists of a thermostatic expansion valve, a heat exchanger, a
resistance heating unit and centrifugal blower driven by a motor The thermostatic
expansion valve controls quantity of high pressure liquid refrigerant and allow to expand to
a lower pressure corresponding to the load demand The expanded refrigerant passes
through the distributor into the heat exchanger consisting of finned copper tubes. The
return air from the air conditioned compartment (75 %) is mixed with fresh air (25%)
The refrigerant vapour drawn from the evaporator is compressed by means of a multi
cylinder reciprocating compressor and compressed to a pressure ranging from 10 to 15
Kg/Cm2 according to the load demand. In RMPU Scroll type compressor is use.
The condenser serves the function of extracting the heat absorbed by the refrigerant
vapour in the evaporator and the heat absorbed during the compression process. The
condenser consists of a heat exchanger, which is forced-air-cooled by means of two or
three axial flow impeller fans. The refrigerant vapour is liquified when ambient cool air is
passed through the heat exchanger.
4. Gauge panel;-
Gauge panel consists of pressure gauges (HP, LP, and OP) and pressure cutouts to
protect the compressor against, (i) High pressure, (ii) Low pressure
a. High pressure cutout:-
It is a safety device against build up of excessive delivery pressures and protects the
compressor and piping system from damage. It is a pressure operated switch which
switches off the compressor drive motor when the pressure exceeds a preset value ( 17.6
Kg/Cm2). The plant can not be restarted unless the cutout is reset manually.
b. Low pressure cutout:-
It is also a pressure operated switch similar to the H.P. cutout switch, but it shuts down the
compressor if the suction pressure drops down below 0.7 Kg/Cm2. It protects the system
against unduly low evaporator temperatures and formation of frost on the evaporator.
5. Air duct :-
The air conditioning system includes three air ducts as follows:
a. Fresh (Inlet) air duct.
b. Main air duct.
7.5 Underslung Type Air Conditioning
Before 1996 the air conditioning system was underslung type where each and every unit of
AC is fitted individually. After this this type of system is not used because it is very heavy
setup. In underslung system there are following units are used.
1. Compressor :-Twin cylinder V type compressor
3. Evaporating valve ( Capillary type)
4. Pipe line of 25 meter
(Fig. 7.3 Twin cylinder V type compressor)
The schematic diagram of Underslung type air conditioning system is as follows:-
In this section all kinds of machining is done to obtain the correct size and shape of the job.
Besides, machining of steel job, Aluminum-plates are also machined here. Machining is
other performed manually or on automatic machines.
Machines are two types
There are three types of automatic machine.
8.1.1 Numerical Control-The machining parameter are feed from the control panel by
pushing buttons .The job is machined according to the parameter There are N.C. boring
machine in this shop.
8.1.2 Computer Numerical Control-In this machine all the data corresponding to the
initial work piece to the final product is feed into the computer. All the process required in
the order of action is fed with the help of programmer .In this machine one, has to just fix
the job is to the chuck. All the other process is done automatically. This is the machine use
for large scale production. In this shop there is one CNC chucker turret Lathe machine.
8.1.3 Direct Numerical Control-This machine is controlled by installing a control room
away from the work place .These machine are D.N.C. machine. These are fully automated
.The machine shop is divided into different divisions to the task accomplished.
8.2 Special Purpose Machine:-
8.2.1 Wheel Turning Machine:- This is fully automatic CNC machine that is used to cut
the rail wheel in the profile.
(Fig. 8.1 Wheel turning Machine)
8.2.2 Axle Turning Machine:- To shape a cylindrical rod into an axle is performed by
axle turning machine this is also fully automatic computer controlled machine. This is also
used for the making an axle to transition fit.
(Fig. 8.2 Axle turning Machine)
8.2.3 Wheel and Axle Assembly Machine:-
Axle and wheel are assembled in the transition fit and to assemble the wheel on the axle a
CNC machine is use. This machine applies the 80 tone load to assemble the wheel on the
(Fig. 8.3 Wheel and Axle Assembly Machine)
CONTROLLED DISCHARGE TOILET SYSTEM (CDTS)
LHB or ICF coaches are fitted with controlled discharge toilet units to avoid soiling of
track in station and inhabited areas. The toilet system is designed to operate with a
pressurized water bowl wash that covers 100% of the toilet bowl area. The waste is
removed from the toilet bowl and transferred to a retention tank with a minimal amount of
water. 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 bowl.
9.1 Salient Features
2. Requirement of less Air and Water.
3. P.L.C Controlled.
4. Easy to clean.
9.2 Operating Principle of CDTS
1. This system works on electrical & pneumatic pressure arrangement. The retention tank
stores effluent has two openings. These two openings activates by double acting pneumatic
cylinders fed by Feed pipe of air brake system with the help of electromagnetic solenoid
2. The system starts working on a single push of flush switch. As the flush switch is pressed,
water flows into the toilet bowl & the upper slide valve opens which is connected between
the toilet bowl & retention tank. All the toilet waste is transferred into the retention tank.
At the end of each flush cycle the supply of water is stopped & the upper slide valve is
closed. Thus, the toilet is sealed from the retention tank, preventing odour entering from
the toilet room.
3. The waste accumulated in the retention tank remains in the retention tank until two
parameters are satisfied.
4. A predetermined no. of flush counts.
5. The train is reached a predetermined speed.
6. As soon as these above two parameters are met, the lower slide valve of retention tank
opens & the toilet waste accumulated in the tank is discharged out of the tank to the rail
side, away from the station & city.
The lower slide valve of the retention tank remains open for only small period of time to
empty the retention tank. The lower slide valve then remains closed until the above
discharge parameter conditions is again satisfied.
(Fig. 9.1 CDTS System)
9.3 General Operations of CDTS
1) Stand-by condition
2) Flush Cycle
3) Retention Tank Discharge Cycle
9.3.1 Stand-by condition
Water Pressurizer – Off
Water check Valve – Closed
Upper Flapper Valve – Closed
Lower Slide Valve – Closed
9.3.2 Flush Cycle
Step – 1
Water Pressurizer – On (for a predetermined time)
Water check Valve – On (for a predetermined time)
Upper Slide Valve – Open (for a predetermined time)
Step - 2
Water Pressurizer – Off
Water check Valve – Off
Upper Slide Valve – Closed
9.3.3 Retention Tank Discharge Cycle
If train speed is - below 30 kmph then the retention tank
lower slide valve – closed.
If the train speed is above 30 kmph and Flush Count isbelow Predetermined value,
then the Retention Tank Lower Slide Valve remain closed
If the train is above 30km/h and Flush Count is equal or above Predetermined
value, the Retention Tank Lower Slide Valve Opens (for a predetermined time).
BIO-DIGESTER TOILET (GREEN TOILET) SYSTEM
10.1 Introduction :-
In 2014, Indian Railways and DRDO developed a bio-toilet to replace direct-discharge
toilets, which are currently the primary type of toilet used in railway coaches. The direct
discharge of human waste from trains onto the tracks corrodes rails, costing Indian
Railways tens of millions of rupees a year in rail-replacement work. Flushing a bio-toilet
discharges human waste into an under floor holding tank where anaerobic bacteria remove
harmful pathogens and break the waste down into neutral water and methane., which can
then be harmlessly discharged onto the tracks. Indian Railways plans to completely phase
out direct-discharge toilets by 2020-2021. All new coaches will be installed with bio-toilets
from 2016, with older rolling stock to be gradually retrofitted.
1. Effluent goes into a maceration chamber directly under the bowl.
2. Macerated by violent blending of air, water and chemicals for 70 seconds. Then dumps
into retention tank.
3. Holds effluent below speed of 35 KMPH.
1. Anti-bacterial liquid used per flush - 2ml.
2. Water used per flush -1 Liter specified.
3. Air pressure - 6 Kg/Sq. cm.
4. Waste retention tank capacity - 100 liters.
(Fig. 10.1 Chart of Green Toilet)
There are 7 chamber in green toilet and here waste is passes through there chamber one by
one and here waste is decomposed by the bacteria and therefore by adding the chlorine to
the end chamber waste is removed from the tank at the the stations using some
The schematic diagram of Bio toilet tank shown in figure.
(Fig 10.2 schematic diagram of Bio toilet)
Using the bio toilet there are some data shown in table that shows that how much is
important bio toilet to clean the track of railway
Table 10.1 Stastical Data for Bio Toilet System:-
# Parameter (as perAPHA
for next six months
1 pH 6 to 9 6 to 8
2 Total Solids Max 750mg/100ml 500mg/100ml
3 Total Dissolved solids Max 350mg/100ml 250mg/100ml
4 COD levels Max 2000 ppm Max 700 ppm
My practical training at CARRIAGE&WAGON WORKSHOP helps me to fill the gap
between the practical and theoretical aspects of engineering life.
The main objective of this practical training firstly is to get acquainted with the industrial
life and secondly to prove our worth to management so that it may be beneficial in our
During this practical training we come to know the importance of human relation in
industrial life. The engineering is not any individual’s job but it’s all about the teamwork.
The better is your team the better will be your efficiency.
It was a good opportunity to be in such a giant organization. The allotted 60 days period
was insufficient, yet we tried our best to air our knowledge & to get equipped with tools
which may stand by us in forthcoming industrial life.