Indian Railways operates the fourth largest railway network globally. It carries over 30 million passengers and 2.8 million tons of freight daily, earning $20.8 billion in 2011-2012. The ICF bogie is a conventional bogie used on Indian Railway passenger coaches. It has a fabricated steel frame and uses helical springs and roller bearings for suspension. The bogie transfers the weight of the coach to its wheels through side bearers and a pivoting bolster.

1. INDUSTRIAL TRAINING REPORT
ON
INDIAN RAILWAYS
(MECHANICAL)
DATE: 11th
JUNE TO 9TH
JULY 2012(4 WEEKS)
AT SECR (BILASPUR)
SUBMITTED BY:AGNIVESH P.SHARMA
BRANCH :MECHANICAL
COLLEGE :SSEC,JUNWANI,BHILAI

3. I EXPRESS MY HEARTIEST GRATITUDE TO
THE MR.LALIT DHURANDHAR
SIR,SR.DME,SECR,BILASPUR

4. Indian Railways (reporting mark IR) is an iconic
Indian organisation, owned and operated by the
Government of India through the Ministry of
Railways. Indian Railways has 114,500 kilometres
(71,147 mi). of total track over a route of 65,000
kilometres (40,389 mi) and 7,500 stations. It has
the world's fourth largest railway network after
those of the United States, Russia and China. The
railways carry over 30 million passengers and
2.8 million tons of freight daily. In 2011-2012
Railway earnt 104,278.79 crore (US$20.8 billion)
which consists of 69,675.97 crore (US$13.9
billion) from freight and 28,645.52 crore (US$5.71
billion) from passengers tickets.

5. Indian Railways is the world's fourth largest
commercial or utility employer, by number of
employees, with over 1.4 million employees.|~|
BCN DEPOT

6. bogies
THE BOGIE FRAME AND COMPONENTS ARE OF ALL-
WELDED LIGHT CONSTRUCTION WIITH A WHEEL BASE OF
2.896M.THE WHEEL SETS ARE PROVIDED WITH SELF-
ALIGHNING SPHERICAL ROLLER BEARINGS MOUNTED IN
CAST STEEL AXLE BOX HOUSINGS.THE WEIGHT OF THE
COACH IS TRANSFERRED THROUGH SIDE BEARERRS ON
THE BOGIE BOLSTER.THE END OF THE BOGIE BOLSTER
REST ON THE BOLSTER HELICAL SPRINGS PLACED OVER
THE LOWEST SPRING BEAM SUSPENDED FROM THE
BOGIE FRAME BY THE INCLINED SWING LINKS AT AN
ANGLE 7’.

7. *BOGIE BOLSTER SUSPENSION :THE BOLSTERS
REST ON THE BOLSTER COIL SPRINGS TWO AT EACH
ENDS,LOCATED ON THE LOWER SPRING BEAM WHHICH IS
SUSPENDED FROM THE BOGIE SIDE FRAME BY MEANS OF
BOLSTER SPRING SUSPENSION HANGERS ON EITHER
SIDE.
*SPRINGS:IN ICF BOGIES,HELICAL SPRINGS ARE USED
IN BOTH PRIMARY AND SECONDARY SUSPENSION.THE
SPRINGS ARE MANUFACTURED FROM PEELED AND
CENTRELESS GROUND BAR OF CHROME,VANADIUM
CHROME,MOLYBEDENUM STEEL CONFORMING TO STR
NO.|~|
* PRESSURE SETTING OF TORQUE
WRENCH FOR TIGHT AXLE CAP
WHEEL STUD SIZE REQUIRED
PRESSURE
BOX-N 25 MM. 40 KGM
BOX 20 MM 20 KGM
ICF 16 MM 09 KGM
BEML 10 MM 02GM

8. *VARIOUS TYPES OF WAGONS
BOXNHS
BOBRN
BOBY
BCN
BRHNEHS
BOXNHL
BOXNM
WHEEL SPECIFICATIONS
WHEEL
TYPE
NEW CONDE
MNING
MIN.SHOP
ISSUE SIZE

9. 1. NEW AND CONDEMNING SIZE OF WHEELS
(ALL THE DATA IS IN MM.)
2. WORN WHEEL PROFILE
*NEW—28 MM THICKNESS
*INTERMEDIATE PROFILE-25 MM
THICKNESS
*INTERMEDIATE PROFILE-22 MM
IRS SOLID 1000 990 996
TYRED 1000 1015 1021
BOXN-
BCN
SOLID 1000 925 931
TYRED - - -
BOX-CRT SOLID 1000 860 866
TYRED 1000 902 908
ICF SOLID 915 813 819
TYRED 915 851 857
BEML SOLID 914.5 813 819
TYRED 914.5 838 844

10. THICKNESS
*INTERMEDIATE PROFILE-20 MM
THICKNESS
3. LIMITS OF WHEEL DIA.FOR MANUAL
ADJUSTMENT OF BRAKE GEAR ON BCN WAGON
a b c d e
Ф=57 mm
Tyre defects
THIN FLANGE-16 MM.(28.5MM)
WHEEL DIA.ON
TROLLEY
BETWEEN-
1000
&
982
981
&
963
962
&
944
943
&
925
924
&
906
HOLES TO BE
USED FOR BRAKE
ADJUSTMENT
a b c d e

11. SHARP FLANGE-5 MM.(14MM)
DEEP FLANGE-35 MM.(28.5MM)
THIN TYRE-LESS THAN NORMAL
FLAT SURFACE ON TYRE
HOLLOW TYRE-5 MM.HOLE ON
SURFACE
ROUTE RADIUS LOW-13 MM(16 MM)
SPECIAL REPAIRS
1. THE SPECIAL REPAIRS BY WORKSHOPS ARE THOSE
REPAIRS WHICH CAN NOT BE DONE IN THE SICK
LINE WITH THEIR EXISTING FACILITIES OR ARE

12. SPECIFICALLY PROHIBITED TO BE CARRIED OUT ON
THE DIVISIONS.
2. SPECIAL REPAIR COACHES SHOULD BE SENT TO
THE BOGIE WORKSHOPS ONLY AFTER OBTAINING
THE PERMISSION OF THE CHIEF MECHANICAL
ENGINEER AND ACCORDING TO THE CALLING IN
PROGRAM OF THE WORKSHOP.
3. THE SUPERVISOR INCHARGE OF THE DEPOT
SHOULD PREPARE A COMPLETE LIST OF DAMAGE
AND DEFICIENCIES AND FORWARD IT TO DIVISIONAL
MECHANICAL ENGINEER FOR GETTING PERMISSION
OF THE CHIEF MECHANICAL ENGINEER TO BOOK
THE COACH OF THE SHOP FOR NON-POH REPAIRS.A
COPY OF THE LIST OF DAMAGES AND DEFICIENCIES
SHOULD SIMULTANEOUSLY BE SENT TO THE
WORKSHOP CONNECTED FOR PLANNING IT IN THEIR
CALLING IN PROGRAMME.
AIR BRAKE SYSTEM
An air brake is a conveyance braking system actuated by
compressed air. Modern trains rely upon a fail-safe air
brake system that is based upon a design patented by
George Westinghouse on March 5, 1872. The

13. Westinghouse Air Brake Company (WABCO) was
subsequently organized to manufacture and sell
Westinghouse's invention. In various forms, it has been
nearly universally adopted.
The Westinghouse system uses air pressure to charge air
reservoirs (tanks) on each car. Full air pressure signals
each car to release the brakes. A reduction or loss of air
pressure signals each car to apply its brakes, using the
compressed air in its reservoirs
In the air brake's simplest form, called the straight air
system, compressed air pushes on a piston in a cylinder.
The piston is connected through mechanical linkage to
brake shoes that can rub on the train wheels, using the
resulting friction to slow the train. The mechanical linkage
can become quite elaborate, as it evenly distributes force
from one pressurized air cylinder to 8 or 12 wheels.
The pressurized air comes from an air compressor in the
locomotive and is sent from car to car by a train line made
up of pipes beneath each car and hoses between cars.
The principal problem with the straight air braking system
is that any separation between hoses and pipes causes
loss of air pressure and hence the loss of the force
applying the brakes. This deficiency could easily cause a
runaway train. Straight air brakes are still used on
locomotives, although as a dual circuit system, usually
with each bogie (truck) having its own circuit.
In order to design a system without the shortcomings of
the straight air system, Westinghouse invented a system
wherein each piece of railroad rolling stock was equipped
with an air reservoir and a triple valve, also known as a
control valve.

14. Rotair Valve Westinghouse Air brake Company[1]
The triple valve is described as being so named as it
performs three functions: Charging air into an air tank
ready to be used, applying the brakes, and releasing them.
In so doing, it supports certain other actions (i.e. it 'holds'
or maintains the application and it permits the exhaust of
brake cylinder pressure and the recharging of the
reservoir during the release). In his patent application,
Westinghouse refers to his 'triple-valve device' because of
the three component valvular parts comprising it: the
diaphragm-operated poppet valve feeding reservoir air to
the brake cylinder, the reservoir charging valve, and the
brake cylinder release valve. When he soon improved the
device by removing the poppet valve action, these three
components became the piston valve, the slide valve, and
the graduating valve.
If the pressure in the train line is lower than that of
the reservoir, the brake cylinder exhaust portal is

15. closed and air from the car's reservoir is fed into the
brake cylinder to apply the brakes. This action
continues until equilibrium between the brake pipe
pressure and reservoir pressure is achieved. At that
point, the airflow from the reservoir to the brake
cylinder is lapped off and the cylinder is maintained
at a constant pressure.
If the pressure in the train line is higher than that of
the reservoir, the triple valve connects the train line
to the reservoir feed, causing the air pressure in the
reservoir to increase. The triple valve also causes the
brake cylinder to be exhausted to the atmosphere,
releasing the brakes.
As the pressure in the train line and that of the
reservoir equalize, the triple valve closes, causing the
air pressure in the reservoir and brake cylinder to be
maintained at the current level.
Unlike the straight air system, the Westinghouse system
uses a reduction in air pressure in the train line to apply
the brakes. When the engineer (driver) applies the brake
by operating the locomotive brake valve, the train line
vents to atmosphere at a controlled rate, reducing the
train line pressure and in turn triggering the triple valve on
each car to feed air into its brake cylinder. When the
engineer releases the brake, the locomotive brake valve
portal to atmosphere is closed, allowing the train line to
be recharged by the compressor of the locomotive. The
subsequent increase of train line pressure causes the
triple valves on each car to discharge the contents of the
brake cylinder to the atmosphere, releasing the brakes
and recharging the reservoirs.

16. Under the Westinghouse system, therefore, brakes are
applied by reducing train line pressure and released by
increasing train line pressure. The Westinghouse system
is thus fail safe—any failure in the train line, including a
separation ("break-in-two") of the train, will cause a loss
of train line pressure, causing the brakes to be applied
and bringing the train to a stop, thus preventing a runaway
train.
Modern air brake systems are in effect two braking
systems combined:
The service brake system, which applies and
releases the brakes during normal operations, and
The emergency brake system, which applies the
brakes rapidly in the event of a brake pipe failure or
an emergency application by the engineer.
When the train brakes are applied during normal
operations, the engineer makes a "service application" or
a "service rate reduction”, which means that the train line
pressure reduces at a controlled rate. It takes several
seconds for the train line pressure to reduce and
consequently takes several seconds for the brakes to
apply throughout the train. In the event the train needs to
make an emergency stop, the engineer can make an
"emergency application," which immediately and rapidly
vents all of the train line pressure to atmosphere,
resulting in a rapid application of the train's brakes. An
emergency application also results when the train line
comes apart or otherwise fails, as all air will also be
immediately vented to atmosphere.
In addition, an emergency application brings in an
additional component of each car's air brake system: the
emergency portion. The triple valve is divided into two

17. portions: the service portion, which contains the
mechanism used during brake applications made during
service reductions, and the emergency portion, which
senses the immediate, rapid release of train line pressure.
In addition, each car's air brake reservoir is divided into
two portions—the service portion and the emergency
portion—and is known as the "dual-compartment
reservoir”. Normal service applications transfer air
pressure from the service portion to the brake cylinder,
while emergency applications cause the triple valve to
direct all air in both the service portion and the
emergency portion of the dual-compartment reservoir to
the brake cylinder, resulting in a 20–30% stronger
application.
The emergency portion of each triple valve is activated by
the extremely rapid rate of reduction of train line
pressure. Due to the length of trains and the small
diameter of the train line, the rate of reduction is high
near the front of the train (in the case of an engineer-
initiated emergency application) or near the break in the
train line (in the case of the train line coming apart).
Farther away from the source of the emergency
application, the rate of reduction can be reduced to the
point where triple valves will not detect the application as
an emergency reduction. To prevent this, each triple
valve's emergency portion contains an auxiliary vent port,
which, when activated by an emergency application, also
locally vents the train line's pressure directly to
atmosphere. This serves to propagate the emergency
application rapidly along the entire length of the train.
Use of distributed power (i.e., remotely controlled
locomotive units midtrain and/or at the rear end) mitigates
somewhat the time-lag problem with long trains, because

18. a telemetered radio signal from the engineer in the front
locomotive commands the distant units to initiate brake
pressure reductions that propagate quickly through
nearby cars.|~|
SCHEMATIC DIAGRAM OF AIR BRAKE SYSTEM

19. COACHING
DEPOT
ICF BOGIE
ICF Bogie is a conventional railway bogie used on the
majority of Indian Railway main line passenger coaches.

20. The design of the bogie was developed by ICF (Integral
Coach Factory), Perumbur, India in collaboration with the
Swiss Car & Elevator Manufacturing Co., Schlieren,
Switzerland in the 1950s. The design is also called the
Schlieren design based on the location of the Swiss
company.
The bogie can be divided into various subsections for easy
understanding as follows:
Bogie frame
The frame of the ICF bogie is a fabricated structure
made up of mild steel channels and angles welded to
form the main frame of the bogie.The frame is divided
into three main sections. The first and the third
section are mirror images of each other. Various
types of brackets are welded to the frame for
supporting bogie components.
Bogie bolster
The body bolster is a box type fabricated member
made up of channels and welded to the body of the
coach. It is a free-floating member. The body bolster
transfers the dead weight of the coach body to the
bogie frame. There are two type of bolsters in an ICF
bogie: body bolster and the bogie bolster. The body
bolster is welded to the coach body whereas the
bogie bolster is a free floating member which takes
the entire load of the coach through the body
bolster.In body bolster there are 2 side bearers and a
center pivot pin are joined by excellent quality
welding. These three parts acts as a male part and

21. matches with the female part welded to bogie
bolster. These are very vital parts for smooth running
of a train.
Center pivot pin
A center pivot pin is bolted to the body bolster. The
center pivot pin runs down vertically through the
center of the bogie bolster through the center pivot.
It allows for rotation of the bogie when the coach is
moving on the curves. A silent block, which is
cylindrical metal rubber bonded structure, is placed
in the central hole of the bogie bolster through which
the center pivot pin passes. It provides the
cushioning effect.
Wheel set assembly
Wheel arrangement is of Bo-Bo type as per the UIC
classification. The wheel set assembly consists of
two pairs of wheels and axle. The wheels may be
cast wheels or forged wheels. The wheels are
manufactured at Durgapur Steel Plant of SAIL( Steel
authority of India Ltd.) or at Wheel and Axle Plant of
Indian Railways bases at Yelahanka near Banglore in
the state of Karnataka. At times, imported wheels are
also used. These wheels and axles are machined in
the various railway workshops in the wheels shops
and pressed together.
Roller bearing assembly
Roller bearings are used on the ICF bogies. These
bearings are press fitted on the axle journal by

22. heating the bearings at a temperature of 80 to 100 °C
in an induction furnace. Before fitting the roller
bearing , an axle collar is press fitted. The collar
ensures that the bearing does not move towards the
center of the axle. After pressing the collar, a rear
cover for the axle box is fitted. The rear cover has
two main grooves. In one of the grooves, a nitrile
rubber sealing ring is placed. The sealing ring
ensures that the grease in the axle box housing does
not seep out during the running of the wheels. A
woolen felt ring is placed in another groove. After the
rear cover, a retaining ring is placed. The retaining
ring is made of steel and is a press fit. The retaining
ring ensures that the rear cover assembly is secured
tightly between the axle collar and the retaining ring
and stays at one place. The roller bearing is pressed
after the retraining ring. Earlier, the collar and the
bearings were heated in an oil bath. But now the
practices has been discontinued and an induction
furnace is used to heat them before fitting on the
axle. The axle box housing, which is a steel casting,
is then placed on the axle. The bearing is housed in
the axle box housing. Axle box grease is filled in the
axle box housing. Each axle box housing is filled with
approximately 2.5 kg. of grease. The front cover for
the axle box is placed on a housing which closes the
axle box. The front cover is bolted by using torque
wrench.
Brake beam assembly

23. ICF bogie uses two types of brake beams. 13 ton and
16 ton. Both of the brake beams are fabricated
structures. The brake beam is made from steel pipes
and welded at the ends. The brake beam has a typical
isosceles triangle shape. The two ends of the brake
beam have a provision for fixing a brake head. The
brake head in turn receives the brake block. The
material of the brake block is non asbestos, and non-
metallic in nature.
Brake head
Two types of brake heads are used. ICF brake head
and the IGP brake head. A brake head is a fabricated
structure made up of steel plates welded together.
Brake blocks
Brake blocks are also of two types. ICF brake head
uses the "L" type brake block and the "K" type brake
block is used on the IGP type brake head. "L" & "K"
types are so called since the shape of the brake
blocks resembles the corresponding English alphabet
letter. The third end of the brake beam has a bracket
for connecting the "Z" & the floating lever. These
levers are connected to the main frame of the bogie
with the help of steel brackets. These brackets are
welded to the bogie frame.
Brake levers
Various type of levers are used on the ICF Bogie . The
typical levers being the "Z" lever, floating lever and
the connecting lever. Theses levers are used to

24. connect the brake beam with the piston of the brake
cylinder. The location of the brake cylinders decides
whether the bogie shall be a BMBC Bogie or a non
BMBC Bogie. Conventional bogies are those ICF
bogies in which the brake cylinder is mounted on the
body of the coach and not placed on the bogie frame
itself.
Brake cylinder
In a ICF BMBC Bogie, the brake cylinder is mounted
on the bogie frame itself. Traditionally, the ICF Bogies
were conventional type i.e. the brake cylinder was
mounted on the body of the coach. However, in the
later modification, the new bogies are being
manufactured with the BMBC designs only. Even the
old type bogies are being converted into BMBC
Bogies. The BMBC bogie has many advantages over
the conventional ICF bogie. The foremost being that,
since the brake cylinder is mounted on the bogie
frame itself and is nearer to the brake beam, the
brake application time is reduced. Moreover, a small
brake cylinder is adequate for braking purpose. This
also reduces the overall weight of the ICF bogie apart
from the advantage of quick brake application.
Primary suspension
The primary suspension in a ICF Bogie is through a
dashpot arrangement. The dashpot arrangement
consists of a cylinder (lower spring seat) and the
piston (axle box guide). Axle box springs are placed
on the lower spring seat placed on the axle box wing

25. of the axle box housing assembly. A rubber or a
Hytrel washer is placed below the lower spring seat
for cushioning effect. The axle box guide is welded to
the bogie frame. The axle box guide acts as a piston.
A homopolymer acetyle washer is placed on the
lower end of the axle box guide. The end portion of
the axle box guide is covered with a guide cap, which
has holes in it. A sealing ring is placed near the
washer and performs the function of a piston ring.
The axle box guide moves in the lower spring seat
filled with dashpot oil. This arrangement provides the
dampening effect during the running of the coach.
Dashpot arrangement
The dashpot arrangement is mainly a cylinder piston
arrangement used on the primary suspension of Indian
Railway coaches of ICF design. The lower spring seat acts
as a cylinder and the axle box guide acts as a piston.
The dashpot guide arrangement has the following main
components:
Lower Spring Seat Lower Rubber Washer Compensating
Ring. Guide Bush Helical Spring Dust Shield. Circlip. Dust
Shield Spring. Protective Tube Upper Rubber Washer. Axle
Box Guide Screw with sealing washer The axle box guide
(piston) is welded to the bottom flange of the bogie side
frame. Similarly, the lower Spring seat (cylinder) is placed
on the axle box housing wings forms a complete dashpot
guide arrangement of the ICF design coaches.
Axle box guides traditionally had a guide cap with 9 holes
of 5mm diameter each; however, in the latest design, the
guide cap is made an integral part of the guide.

26. Approximately 1.5 liters of dashpot oil is required per
guide arrangement.
Air vent screws are fitted on the dashpot for topping of oil
so that the minimum oil level is maintained at 40mm.
Traditionally, rubber washers have been used at the
seating arrangement of the primary springs of the axle box
housing in the ICF design passenger coaches on the
Indian Railways. The rubber washer is used directly on the
axle box seating area. the lower spring seat sits on the
washers. The lower spring seat is a tubular structure and
3/4 section is partitioned by using a circular ring which is
welded at the 3/4 section. On the top of spring seat, a
polymer ring called NFTC ring sits. The primary spring sits
on the NFTC ring. The lower spring seat plays the role of a
cylinder in the dashpot arrangement and is filled with oil.
In the dashpot arrangement, the top portion is called the
axle box guide. The axle box guide is welded to the bogie
frame. The axle box guide works as a piston in the Lower
spring seat filled with oil. This helps in damping the
vibrations caused during running train operation.
The axle box guide, which is welded to the bogie frame
has a polymer washer (homopolymer acetal guide) bush
fixed at the head. A polymer packing ring and a guide ring
is attached with the Acetal guide bush. These two
components act as piston rings for the axle box guide. In
order to ensure that the packing ring and the guide ring
retain their respective place, a dashpot spring is fixed
which applies continuous pressure on the piston ring.
The bottom of the axle box guide has a guide cap with
perforations so that during the downward movement of
the axle guide in the lower spring seat, the oil in the

27. dashpot rushes in the axle box guide. This provides the
dampening of vibration in a running coach.
The guide cap is fixed with the help of a steel circlip.
However in the new design of Axle box guide, the guide
cap is welded with the guide assembly and hence the
need of a guide cap has been eliminated. The complete
guide and lower spring arrangement is covered with a
dashpot cover also known as protective tube. The
protective tube has a circular ring over it called the dust
shield which prevents the ingress of the dust in the
cylinder piston arrangement of the dashpot.
Spring seating
As described above, the rubber washers sit directly on the
axle box spring sitting area. Earlier,wooden washers were
used. However, with the development of technology,
rubber washers replaced wooden washers. Presently,
RDSO, Lucknow which is a Research, Design &
Standardization organization for the Indian Railways
developed a new design for washers made from a polymer
commonly known as HYTREL. Hytrel polymer is a product
of M/s DuPont .
The reason for replacement of the rubber washers with
the hytrel washers was that the rubber washers were not
lasting for the full Periodic overhaul cycle of the Railway
Coaches which was one year. The washers also had to be
replaced in the coaching maintenance depots leading to
lifting and lowering of coaches.
Introduction of Hytrel washers was considered a
breakthrough in the ICF dashpot design. However, the
mass scale replacement of the rubber washers by Hytrel

28. washers without adequate trials lead to massive failure of
the axle Box housing.
The hardness of the washers as per the specified limits
was to be 63+- 5 Shore D hardness. Another parameters
was the load deflection characteristics of the washers.
A study was carried out on a major workshop on Indian
Railways and it was found that the washers were having a
hardness more than the specified limits. Moreover, the
load deflection characteristic of the washers were also
not found to be in line with the desired specification.
Within 6 months of provision of Hytrel washers on all the
main line coaches, the failure of Axle box housing
increased. The reason was the axle box wing cracks.
Hence on examination of the failed axle boxes, it was
noticed that the Hytrel washers were forming a deep
groove of 4 to 8mm on the seating area of the axle box
spring seating. They washers were also increasing the
diameter of the spring seating due to continuous hitting of
the raised section of the sitting area.
The coaches come to the workshop once in a year. During
examination of these coaches , it was noticed that the
Hytrel washers have not only damaged the axle box
housing but also the lower spring seat as well as the
Protective tube.
To prevent such damage, RDSO, Lucknow issued a
guideline asking the Railways to provide a delrin liner
below the Hytrel washers. However, it was indicated that
these liners are to be provided only on new coaches and in
coaches in which new wheels are fitted.
A look at the drawing of the dashpot arrangement will
suggest that this problem is universal for all the coaches,

29. whether a new coach or an old coach. Moreover, the
provision of the liners below the Hytrel washers will not
stop the damage to the lower spring seat and the
protective tube.
Problem of oil spillage
The problem of spilling of oil from the dashpot is as old as
the design itself. Numerous design changes have been
implemented in the last many years however, the problem
of oil spillage is still a challenge.
The cylinder piston arrangement of the dashpot, i.e. the
Lower Spring seat and the axle box guide is not fully
sealed due to the limitation of the design and practical
applicability. Its design provides that when a vertical
vibration occurs during the movement of the railway
coach, the axle box guide moves down. The downward
movement of the Axle box guide puts pressure on the oil
in the lower spring seat. The oil rushes up. However, since
there are holes in the guide cap, the oil passes through
these holes into the hollow body of the axle box guide.
This helps in dampening the vertical vibrations. The axle
box guide displaces the oil in the lower spring seat and
pushes it upwards. Since, only part quantity of oil is able
to move up in the hollow portion of the axle box guide, the
balance displaced oil moves up.
As per correct maintenance practice, it is to be ensured
that the hole in the guide are in alignment with
corresponding holes in the guide bush. However, this is
practically difficult to maintain in the shop floor of bogie
shop.
As the top portion of the lower spring seat is not sealed
and only covered with the help of a protective tube also

30. called the dashpot cover, the rising oil has a tendency to
shoot above the top rim of the lower spring seat and spill
out.
Oil spillage can be prevented by the following actions:
a. Change the dashpot design from the cylinder piston
arrangement to hydraulic shock absorbers.
b. Increase the hole diameter from 5mm in the guide cap
to more than the existing diameter. However, it must be
ensured that the increased diameter of the holes of the
guide cap does not lead to less dampening effect.
c. Provide a conical arrangement above the rim of the
lower spring seat up to half the height of the dashpot
cover. However, the clearances of the protective tube and
the outer dia of the proposed conical section at the top of
the lower spring seat needs to be taken care of
d. Modify the dust shield ring by incorporating a rubber
component in it in such a manner that it also acts as an oil
seal
e. Ensure that the hole in the guide are in alignment with
corresponding holes in the guide bush
Some of these proposed modifications have already been
tried out on the Indian Railways, however, the trials have
not yielded a consistent positive feedback.
Buffer Height adjustment
The wheel diameter(tread) reduces due to brake
application as the brake blocks rub against the wheel
tread. Over a period of time, the wheel diameter reduces
up to 819 mm. 819mm is the condemnation diameter for

31. the wheels. This diameter is also not sacrosanct and is
changed depending upon the supply position of the
wheels. The maximum variation in the wheels on the same
axle is permitted up to 0.5 mm , between two wheels of
the same bogie up to 5 mm and among the four wheel sets
of the same coach up to 13 mm. The diameter of a new
wheel is 915 mm. Hence maximum wheel tread wear
allowed is (915 mm - 819mm) = 96 mm. In order to adjust
for the difference in the wheel tread, a packing is placed
under the flange of the lower spring seat. This packing
ring is generally made up of NFTC(Natural Fiber
Thermosetting COMPOSITE) or UHMWPE (Ultra-high
molecular weight polyethylene) material. The thickness of
the NFTC packing ring is equal to 50% of the difference
between the dia of a new wheel and the wheel in question.
Traditionally, 13mm, 26mm, 38mm, 48 mm packing rings
are used. They correspond to wheel diameter of 899-864,
862-840, 839-820 and 819 mm. The correct buffer height is
obtained by measuring the height of the bolster top
surface from the rail level. In case the buffer height is still
not obtained even after placement of the packing ring,
then compensation rings are to be inserted below the axle
box spring ensuring that the bogie frame height is within
686 + - 5 mm.
Secondary suspension
The secondary suspension arrangement of the ICF
bogies is through bolster springs. The bogie bolster is
not bolted or welded anywhere to the bogie frame. It
is attached to the bogie frame through the anchor
link. The anchor link is a tubular structure with
cylindrical housing on both the ends. The cylindrical
housings have silent blocks placed in them. The

32. anchor link is fixed to the bogie bolster and the bogie
frame with the help of steel brackets welded to the
bogie bolster and the bogie frame. Both the ends of
the anchor link act as a hinge and allow movement of
the bogie bolster when the coach is moving on a
curved track.
Lower spring beam
The bolster springs are supported on a lower spring
beam. The lower spring beam is a fabricated
structure made of steel plates. It is trapezoidal in
shape with small steel tubes on each end. The
location of the bolster spring seating is marked by
two circular grooves in the center. A rubber washer is
placed at the grooved section. The bolster spring sits
on the rubber washer. The lower spring beam is also
a free-floating structure. It is not bolted or welded
either to the bogie frame or the bogie bolster. It is
attached to the bogie frame on the outside with the
help of a steel hanger. They are traditionally called
the BSS Hangers (Bogie Secondary Suspension
Hangers). A BSS pin is placed in the tubular section in
the end portion of the lower spring beam. A hanger
block is placed below the BSS pin. The BSS hanger in
turn supports the hanger. This arrangement is done
on all the four corners of the lower spring beam. The
top end of the hanger also has a similar arrangement.
However, instead of the BSS pin, steel brackets are
welded on the lower side of the bogie frame of which
the BSS hanger hangs with the help of hanger block.

33. This arrangement is same for all the four top corners
of the hangers. Hence, the lower spring beam also
become a floating member hinged to the bogie frame
with the help of hangers on the top and the bottom.
This allows for the longitudinal movement of the
lower spring beam.
Equalizing stay rod
The inner section of the lower spring beam is
connected to the bogie bolster with the help of an
equalizing stay rod. It is a double Y-shaped member
fabricated using steel tubes and sheets. The
equalizing stay rod is also hinged on both the ends
with the lower spring beam as well as the bogie
bolster with the help of brackets welded to the bogie
bolster. They are connected through a pin making it a
hinged arrangement.|~|
AC COACHES
TYPE OF AC COACHES ON RAILWAYS CAN BE CLASSIFIED
ON THE BASIS OF POWER SUPPLY SYSTEM AS:

34. 1. END ON GENERATION(EOG):IN THIS SYSTEM
TWO TYPES OF POWER CARS ARE USED
a) COACHES MOUNTED WITH 50 KVA,750
V/415 V,3 PHASE TRANSFORMER
b) COACHES WITHOUT STEPDOWN
TRANSFORMER SUITABLE ONLY FOR OLD
LOW CAPACITY POWER CARS.
2. SELF GENERATING(SG):BASED ON AC
EQUIPMENTS THERE ARE TWO TYPES OF SELF
GENERATING COACHES
a) 110 V WITH UNDER SLUNG TYPES AC
EQUIPMENTS WORKING FROM 110 DC
b) 110 V DC WITH ROOF MOUNTED AC
PACKAGE UNITS WORKING FROM 415 V,3-
PHASE OBTAINED WITH THE HELP OF 25
KVA INVERTERS MOUNTED ON
UNDERSLUNG AS WELL AS ONBOARD.
MAJOR EQUIPMENTS USED IN AC UNIT ARE –
1. CONDENSER INCLUDING LIQUID RECEIVERS AND
DEHYDRATOR.
2. EXPANSION VALVE
3. EVAPORATOR WITH HEATER ELEMENT
4. MOTORS FOR COMPRESSOR,CONDENSER,
EVAPORATOR
5. THERMOSTAT,FILTERS ETC.
LOAD DEFLECTION TESTING AND
GROUPING OF AXLE BOX SPRING

35. LOAD DEFLECTION TESTING AND
GROUPING OF BOLSTER SPRING
TYP
E OF
BOGI
ES
COD
E
NO.
WI
RE
DI
A.
FRE
E
HEIG
HT
TE
ST
LO
AD
ACCEPT
ABLE
HEIGHT
UNDER
TEST
LOAD
GROUP AS FOR
LOADED SPRING
HEIGHT
A
YELL
OW
B
OXFO
RD
BLUE
C
GREE
N
ALL
NON
AC ICF
TYPE
A
01
33.5
360 2000 275-295 279-
284
285-
289
290-
299
ALL AC
ICF
TYPE
A
02
33.5
375 2000 264-282 264-
269
270-
275
276-
282
HIGH
CAPACI
TY
PARCE
L VAN
A
10
39 315 2000 276-275 276-
279
280-
284
285-
289
TYP COD WI FRE TE ACCEPT GROUP AS FOR

36. E OF
BOGI
ES
E
NO.
RE
DI
A.
E
HEIG
HT
ST
LO
AD
ABLE
HEIGHT
UNDER
TEST
LOAD
LOADED SPRING
HEIGHT
A
YELL
OW
B
OXFO
RD
BLUE
C
GREE
N
ALL
NON
AC ICF
TYPE
B
01
42 385 3300 301-317 301-
305
306-
311
312-
317
ALL AC
ICF
TYPE
B
02
42 400 4800 295-308 291-
296
297-
303
304-
308
HIGH
CAPACI
TY
PARCE
L VAN
B
10
32.
5
286 6000 256-272 256-
261
262-
267
268-
272

37. MAJOR SICK
LINE
WORKS UNDERTAKEN AT

38. MSL
1.DOOR REPAIRING
2.WHEEL CHANGING
3.CBC REPAIRING
4.BRAKE SHOE REPLACING
5.WELDING/CUTTING
6.SCRAPPING
7.BRAKE SYSTEM CHANGING
TYPES OF WAGON
REPAIRED IN MSL
1.BOXNHS
2.BOBRN
3.BOBY
4.BCN
5.BRHNEHS
6.BOXNM
7.BOXNHL
TYPES OF GEARS

39. 1. BODY GEAR
2. UNDER GEAR
3. BUFFERING GEAR
4. ROLLING GEAR
PARTS OF BRAKE
1. SAB-SLACK ADJUSTING BARREL
2. BRAKE CYLINDER
3. AIR RESERVOIR
4. DISTRIBUTIVE VALVE
5. BRAKE PIPE

40. TYPES OF
BRAKE
1.AIR BRAKE SYSTEM:IT IS COMMONLY
USED NOWADAYS IN GOODS AS WELL AS
PASSENGER CARRIAGES.IT USES
COMPRESSED AIR TO STOP THE TRAIN.IT
CONSISTS OF 5 KG OF COMPRESSED AIR
PRESSURE.TWO PIIPES NAMELY F.P&B.P.
ARE USED TO CONNECT THE BRAKE
SYSTEM OF TWO BOGIES.IN PRESENT DAYS
ONLY ONE PIPE IS USED AS IT MAKES THE
SYSTEM QUICK WORKING AND QUICK
RELEASING.
2. VACCUME BRAKE SYSTEM:NOT USED
NOW A DAYS.USED VACCUME TO STOP THE
TRAIN.

41. COUPLING
CBC(CENTRAL BUFFER COUPLER) IS USED
IN TRAINS TO JOIN TWO BOGIES.IT CONSIST
OF A HOOK LIKE COUPLER WHICH
COMBINES WITH THE COUPLER OF OTHER
BOGIE AND FORMS A STRONG BOND
BETWEEN THEM.
CBC IS OF TWO TYPES:
1.TRANSITION TYPE: BOGIES HAVING
TRANSITION TYPE COUPLER HAVE A
FACILITY OF SCREW COUPLING ALONG
WITH THE CENTRAL COUPLER.HENCE
GOODS TRAIN HAVING THIS TYPE OF
COUPLING CAN BE JOINED WITH
COACHES ALSO.
2.NON-TRANSITION TYPE: THEY HAVE
ONLY CENTAL COUPLER AND CAN BE
JOINED ONLY WITH OTHER GOODS
CARRIAGES.

42. ART/ARME