Project at samastipur workshop. operation and working of air brakes in BOXNHL wagon. Contains pictures of machine from samastipur mechanical workshop.

1. Name :- Vibhanshu Kumar Jha
College :- CMR Institute of Technology
Mechanical Workshop Railway
PROJECT REPORT
2018
(AIR BRAKES)

2. A. Introduction
i) Indian railways
ii) History of Mechanical Workshop Samastipur
iii) Brief about Wagons
iv) Brief about Equipment in workshop
B. Project study
i) Introduction to braking system
ii) Parts of air brake system
iii) Function of Different parts
Of An AIR BRAKE
iv) Brake Rigging
v) Schematic of The Twin Pipe
system Air Brake
vi) Operation and working of Air Brake
System in Trains
vii) Layout of twin pipe air brake system
viii) Extra fact
ix) Things to remember
x) Bibliography

3. Indian railway is a state owned railway company of India. It comes under Ministry
of Railways. Indian railway has one of the largest and busiest rail networks in the
world, transporting over 22 million passangers and more than 2 million tonnes of
freight daily having revenue of 1.683 trillion INR. It is one of the largest
commercial or utility employer , by number of employees over 1.331 million
published as per March 2016.
Mechanical Workshop, Samastipur was established in 1881 for overhauling of
steam locomotive, POH of coaches and wagons. It originally belonged to Bengal &
North-Western Railway(BNWR) and subsequently merged with Oudh Tirhut
Railway (OTR) on 1st April,1943, and later on after formation of Zones it became
part of North Eastern Railway (NER). Subsequently on recounstruction of zones it
came under East Central Railway (ECR). At present this workshop manufavtures
BOXNHL wagons. It is also ISO9001:2015 certified.
In 2009, the workshop achieved a rare feat by manufacturing stainless steel wagon
with axle Load capacity about 22.29 tonnes. Thus this workshop is entitled to be 2nd
unit of Indian Railways where steel wagons have been manufactured. These wagons
are less in weight in comparison to old conventional wagons and also have better
load capacity.

4. BOXNHL stands for B-Bogie O- Open X- High Speed N- Air Brake HL- Heavy
Loaded.
Major parts of wagon are :-
Under frame:- Itis madeup of 29 sub parts held together in its fixture. The majorcomponents
of under frame are Center Still, Sole Bar, Headstock, Bolster, CPT(Centre Pivot Top), Cross Bar
and Spatial Cross Bar ( 2 on eavh side of the bolster) etc.
The components are joined by Manual Metal Arc Welding and Submerged Arc Welding as per
requirement.
 Side body
 End body
 Door
 Axle,Bogie,Wheels & Bearings
 Brake equipment and piping.

6. The basic Wagon operation is carried by various machine available in workshop.
i) Lathe
ii) Drill Machine
iii) Shaping Machine
iv) Plasma Cutting Machine
v) Hydraulic Press
Following are the images of Workshop Machine:-
Lathe Plasma Machining
Hydraulic Press Drilling Machine

7. BRAKESYSTEMIN “BOXNHL” WAGON

8. Braking System comprises of few mechanism working together in vehicles through
which its speed can be controlled or stopped in minimum time. Any moving train
has Kinetic Energy in order to stop them a contact material is applied to the wheel
which creates friction dissipating its Kinetic Energy in form of heat and eventually
train stops.
Nowadays, in Indian Railway train rely upon fail-safe air break for its breaking
system. It uses compressed air as the operating medium which is present in auxiliary
tank. It works on simple principle of pressure difference in piston cylinder
arrangement. The feed pipe is provided compressed air with pressure 6kg/cm2 and
Brake Pipe with compressed air at 5 kg/cm2
. Compressed air on pressure difference
pushes the bell crank lever which moves secondary brake beam which allows brake
drum to force onto wheel and reverse mechanism cause the same on primary brake
beam.
Earlier Vacuum based brakes were used in trains but with time they got replaced by
the air brake system due to more reliability, more brake power and less braking time
offered by air brake system. Air brake offers wide range of advantages over vacuum
brake both mechanically and economically.

10. FUNCTION OF DIFFERENT PARTS OF AN AIR BRAKE
Air Hose Coupling Brake/Feed Pipe
All Brake Pipe(B.P.) and Feed Pipe (F.P.) in a train is connected via Air Hose. These
are high pressure hoses and are sometimes called palm end due to their palm like
end. The design of BP and FP are always kept different so that they don’t get
connected wrongly. These Air Hoses have a MU washer present inside them for
stopping the air leakage from coupling. The hoses can be sealed at the outer ends
of the train by closing the angle cocks.

11. Cut-off Angle Cock
These are fitted at end of each coach and wagon. If the handle pipe fitted above the
cock is in normal position then the cock is in open position and vice versa. In open
position, it allows the pressurized air to pass through them. When it gets closed it
stops the compressed air and releases the pressure of air hose to atmosphere via
their vent holes.
Centrifugal Dirt Collector
Dirt Collectors are installed above BP and FP. Their function is to filter the air flowing
inside the Brake pipe and Feed pipe. They ensure proper working of the equipments
ahead.
Check Valve with Choke
The valve acts as unidirectional valve allowing the compressed air to flow from FP
to AR (Auxiliary Reservoir) but not vice versa . Function of the choke is to charge the
AR of the whole train simultaneously.
Auxiliary Reservoir
The operation of the air brake on each vehicles relies on the difference in pressure
between one side of the triple valve piston and the other. In order to ensure there
is always a source of air available to operate the brake, an “auxiliary reservoir” is
connected to one side of the piston by the triple valve. The flow of air into and out

12. of the auxiliary reservoir is controlled by the triple valve. It is charged by a pressure
of 5kg/cm2 pressure in twin pipe system. Its capacity varies from 100L to 200L.
BRAKE CYLINDER
Brake cylinder is a piston cylinder arrangement which controls the movement of
brake block. These are fitted in horizontal piston inside the Brake Cylinder is
connected to a return spring that works accordingly with application of brake.
Diameter of Brake Cylinder is 355mm for conventional brakes whereas for
BMBS(Body Mounted Brake System) is 203mm.
Isolating Cocks
These are the system used for isolating coaches, brake cylinders, branch pipes etc.
during shutdowns or any malfunction.
 Feed Pipe Isolating Cock
Fitted on the branch pipe of feed pipe, they can isolate a whole coach during
malfunction of brake pipe.
 Brake Pipe Isolating Cock
These are mounted near the dirt collector and are connected to distributor
valve. If branch pipe shows any kind of anomality then by closing the cock air
can bypassed.
 Brake Cylinder Isolating Cock
These are the two cocks installed on the pipes near the Brake Cylinder. In case
of any failure in any of the brake cylinder they isolate that cylinder and
maintain work uniformity.
 Chain Pulling Isolating Cock
These cocks are mounted on the pipe connecting brake pipe to the chain
pulling system. If there is any abnormality in the chain pulling system or

13. Passenger Emergency valve or Passenger Emergency signal system the chain
pulling system can be shut in the coach by closing its cock.
MAIN RESERVOIR
Storage tank for compressed air for braking and other pneumatic systems.
Driver’s Brake Valve
The valve allows the driver to control the brake. The Brake Valve always have
atleast these five positions:
“Release”, “Running”, “Lap”, “Application” and “Emergency”.
Sometimes a “Shut Down” position is also there to lock the valve out of use.
The “Release” position connects the main reservoir to the brake pipe raising
its air pressure are quickly as possible to get a rapid release of brake.
In the “Running” position the feed valve is selected. This allows a slow feed to
be maintained into the brake pipe to counteract any small leaks or losses in
the brake pipe, connections and hoses.
“Lap” is used to shut off the connection between the main reservoir and the
brake pipe and to close off the connection to atmosphere after brake
application has been made. It can only be used to provide a partial application.
A partial release is not possible with the common forms of air brake,
particularly those used on US freight trains.
“Application” closes off the connection from the reservoir and opens the brake
pipe to atmosphere. The brake pipe pressure is reduced as air escapes. The
driver (and any observer in the know) can often hear the air escaping.

14. DISTRIBUTOR VALVE
It is one of the most important part braking system. The valve senses the
difference in pressure in the brake pipe and thus applies the brake accordingly.
A release valve is installed on the bottom of this valve which can be used to
release the pressure manually if required. It charges the control reservoir and
auxiliary reservoir when the pressure in brake pipe is charged by AR. Below
mentioned are some of the functions performed by the Distributor valve
during change in the pressure of brake valve:
 To change the AR
 To apply the brake in steps when the pressure on the brake
pipe is reduced in steps vice versa.
 Release the air from brake cylinder to the atmosphere during
double charging and manual releasing of air.
 Control the brake time and release time in goods or
passenger train.
 Due to the presence of a special equipment for releasing the
pressure inside the distributor valve, it can release the
pressure of brake pipe throughout the length of the train.
 It protects the CR from overcharging during brake releasing.
BRAKE RIGGING

15. Schematic of The Twin Pipe System Air Brake

16. OPERATION AND WORKING OF AIR BRAKE
SYSTEM IN TRAINS
There are three stages involved in the working of air brakes viz Charging, Brake
application, Releasing or Recharging.
The Charging Stage:- The compressor in the locomotive pressurizes the air from
atmosphere and fills the main reservoir with it. This compressed air is provided to
brake pipe and feed pipe. In twin pipe system, the air with a pressure of 6kg/cm2
in
feed pipe is charged to AR after getting filtered by dirt collector through isolating
cock and check valve choke. On the other hand, AR is also charged by the Brake Pipe.
As the CR & AR of the last wagon gets charged, the pressure gauze in the locomotive
as well as brake van reaches the estimated value. This state of train is called
“Charged state”.
*for twin pipe system time taken for charging is 10 to 12 minutes.
Air flow during charging:

17. BRAKE APPLICATION :-
Normally for applying the brakes, the driver has to put the A9 handle in full service
application state due to which drops the pressure in brake pipe by 1.5kg/cm2
. This
result in drop of pressure in the distributor valve of the whole train but the pressure
in the CR remains the same. The difference in pressure disturbs the DV resulting
connection of AR with brake cylinder and air from AR flows to brake cylinder. Thus,
the brake is applied to the wheels and train stops.
Time taken for Brake Application in twin pipe system is 3 to 5 seconds.

18. 3. Releasing or Recharging
When A9 handle is released by the driver, the brake pipe gets charged by
pressurized air (p= 5kg/cm2
). Also, all the distributor valves in train gets charged by
this air at pressure of 5kg/cm2
. When the pressure gets balanced the distributor
valve performs the following functions:
i) Removes the connection of AR with Brake cylinder.
ii) The compressed air inside the brake cylinder escapes to
the atmosphere via the exhaust port of distributor valve,
and the brake is released.
In twin pipe system, the AR gets charged continuously so brake releasing time
incurred is very less.
Time taken for releasing is 15-20 seconds in Twin pipe system.

19. LAYOUT OF TWIN PIPE AIR BRAKE SYSTEM

20. Extra fact
Wagon Production rate in Workshop on monthly basis.

21. Color code

22. THINGS TO REMEMBER
 These brakes became popular because of high stopping power
compared to hydraulic brakes.
 They are fail safe.
 These are more economical than vacuum brake.
 Air brakes take less brake time.
 So, they are used in heavy vehicles like trains , trucks etc.
 Sensitivity test brake pressure of 0.6kg/cm2
is applied for 6 sec and
brake should be applied.
 Insensitivity test brake pressure of 0.3 kg/cm2
for 60 sec and brake
shouldn’t be applied.
 Brake Pressure is maintained at 5kg/cm2
and Feed Pipe pressure is
maintained at 6 kg/cm2
.

23. BIBLIOGRAPHY
Website referred:-
i) Indianrailway.gov.in
ii) Linkedin.com
Books and Pdfs Referred:-
i) Handbook on bogie mounted brake
system
ii) IRFCA