THIS PRESENTATION TAKES OVERVIEW OF BRAKING SYSTEM USED IN RAILWAY. IN THIS I EXPLAINED ALL BASIC CONCEPTS USED IN RAILWAY BRAKES AND HOW IT WORKS.

1. TE SEMINARPRESENTATION
ON
“RAILWAY BRAKING SYSTEM”
By
Mr.ShrinivasKale
UndertheGuidanceof
Prof.N.R.PATIL
Department of Mechanical Engineering, PES’s MODERN COLLEGE OF ENGINEERING, PUNE

2. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATION SUMMARY :
• Introduction
• Literature Review
• Problem Formulation
• Objectives
• Methodology
• Hypothesis
• Work Plan
• References

3. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATION
INTRODUCTION :
A railway brake is a type of brake used on
the cars of railway trains to enable deceleration,
control acceleration (downhill) or to keep them
immobile when parked.
 While the basic principle is familiar from road
vehicle usage, operational features are more
complex because of the need to control multiple
linked carriages and to be effective on vehicles left
without a prime mover.
Clasp brakes are one type of brakes historically used
on trains.

4. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATIO
N
Sr.
No.
Title of
Paper
Author and Year
of Publication
Summary
1 Braking Systems
in Railway
Vehicles
Rakesh Chandmal
Sharm, Manish
Dhingra,
Rajeev Kumar Pathak
Brake is an essential feature in order to retard
and stop the railway vehicle within minimum
possible time. This paper presents a discussion
about the different braking systems used in
railway vehicles.
2 Energetic
optimization of
regenerative
braking for high
speed railway
systems
Amedeo Frilli, Enrico
Meli, Daniele
Nocciolini, Luca Pugi,
Andrea Rindi
The current development trend in the railway
field has led to an ever increasing interest for
the energetic optimization of railway systems,
with a strong attention to the mutual
interactions between the loads represented
by railway vehicles and the electrical
infrastructure, including all the sub-systems
related to distribution and smart energy
management such as energy storage systems.
3 Observer Based
Traction/Brakin
g Control
Design for
High Speed
Trains
Considering
Adhesion
Nonlinearity
Wenchuan Cai,
Wenhao Liao,
Danyong Li, and
Yongduan Song
Train traction/braking control, one of the key
enabling technologies for automatic train
operation, literally takes its action through
adhesion force. However, adhesion coefficient
of high speed train (HST) is uncertain in
general because it varies with wheel-rail
surface condition and running speed; thus, it
is extremely difficult to be measured, which
makes traction/braking control design and
implementation of HSTs greatly challenging.
LITERATURE REVIEW :

5. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATIO
N
Sr.
No.
Title of
Paper
Author and
Year of
Publication
Summary
4 Towards
enhanced
mechanical
braking
systems for
trains
MANDEEP SINGH
WALIA
Modern trains are equipped with different braking
systems, between which the braking effort can be
distributed. Among these, tread braking is still the
most common system for friction braking. Tread brake
systems are cheap and robust. However, extensive
usage of tread brakes demands knowledge of
operational limits to ensure safety and to decrease life
cycle costs (LCC) of the running gear.

6. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATIO
N
PROBLEM FORMULATION

7. OBJECTIVES
METHODOLOG
Y
HYPOTHESI
S
WORKPLAN
END!
21
OBJECTIVES :
The overall purpose of
copyright law is to prevent
unfair competition by
protecting the use of a
symbol, word, logo, slogan,
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that uniquely distinguishes
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firm, Patents, Trademarks,
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To Study about
1. Railway Braking
Mechanism.
2. Different types of
braking systems.
3. safety parameters for
railway wagons while
braking.
4. the topic in accordance
to the recent & further
scope

8. OBJECTIVES
METHODOLOG
Y
HYPOTHESI
S
WORKPLAN
END! METHODOLOGY :
Aim: New system required for
Railway Braking
Background information:
Old system are not efficient
Idea Overview:
Railway braking wit respect to
railway wagons and engine
Claims :
Developing new railway Braking
System

9. HISTORY :
 The first trains had brakes operative on the locomotive tender and on
vehicles in the train, where "porters" or, in the United
States brakemen, travelling for the purpose on those vehicles operated
the brakes.
Some railways fitted a special deep-noted brake whistle to locomotives
to indicate to the porters the necessity to apply the brakes. All the
brakes at this stage of development were applied by operation of a
screw and linkage to brake blocks applied to wheel treads, and these
brakes could be used when vehicles were parked.
In the earliest times, the porters travelled in crude shelters outside the
vehicles, but "assistant guards" who travelled inside passenger vehicles,
and who had access to a brake wheel at their posts, supplanted them.
The braking effort achievable was limited and it was also unreliable, as
the application of brakes by guards depended upon their hearing and
responding quickly to a whistle for brakes.

10. TYPES OF RAILWAY BRAKES :
Air Brake :
1. The air is drawn into a compressor and stored
in a main reservoir at 7-10 bar (100-140
lbs/sq.in). Compressed air from the main
reservoir is distributed along the train through
the main reservoir pipe.
2. On each vehicle, the pipe is connected through
a triple valve to an auxiliary reservoir which
stores air for use on that vehicle's brake
system.
3. The flow of air between the auxiliary reservoir
and the brake cylinders is controlled through
the triple valve or distributor. The control of
the distributor is achieved by varying the
pressure in a second pipe called the brake
pipe, which is connected to a brake valve in
the drivers cab.
4. Increasing the pressure in the brake pipe
causes the brakes to release, while decreasing
the pressure causes the brakes to apply.

11. Braking performance of the Westinghouse
Air-brakes :
Braking
system
Train weight with engine Train speed Stopping distance Time to stop
(s)
Deceleration
Rails
long tons tonnes mph km/h yd m g m/s2
Westinghous
e automatic
203 ton
4 cwt
206.5 52 84 304 278 19 0.099 0.97 dry
Clark
hydraulic
198 ton
3 cwt
201.3 52 84 404 369 22.75 0.075 0.74 dry
Smith
vacuum[9]
262 ton
7 cwt
266.6 49.5 79.7 483 442 29 0.057 0.56 dry
Clark and
Webb chain
241 ton
10 cwt
245.4 47.5 76.4 479 438 29 0.056 0.55 dry
Barker's
hydraulic
210 ton
2 cwt
213.5 50.75 81.67 516 472 32 0.056 0.55 dry
Westinghous
e vacuum
204 ton
3 cwt
207.4 52 84 576 527 34.5 0.052 0.51 wet
Fay
mechanical
186 ton
3 cwt
189.1 44.5 71.6 388 355 27.5 0.057 0.56 wet
Steel &
McInnes air
197 ton
7 cwt
200.5 49.5 79.7 534 488 34.5 0.051 0.50 wet

12.  Straight Air Brake System :
1. The straight air brake system does not have a
control valve or Auxiliary air reservoir in each
coach as in automatic air brake system. Activation
of brake valve forces C compressed air from
straight air pipe to brake cylinders, activating the
basic braking mechanism.
2. As the straight air pipes do not contain compressed
air during normal running conditions, the brakes
would fail if coaches became uncoupled. In order
to avoid this, the straight air brake system may be
used in conjunction with the automatic air brake
system.
3. It can also be avoided by using another pipe, called
a main air reservoir pipe, from the first to the last
coach. The air pressure in main air reservoir pipe
acts like the compressed air in the brake pipes of
the automatic air brake system.
4. If compressed air in this main air reservoir pipe
falls, or if it leaks from air pipes or from air hoses
between coaches, etc., pressure drop is detected
and brakes are applied automatically.

13.  Twin Pipe Graduated Release Air Brake
System :
1. The Brake pipe is charged to 5 kg/cm2 by the driver's brake
valve. The auxiliary reservoir is charged by the feed pipe at
6 kg/cm2 through check valve and choke.
2. The brake cylinder is connected to the atmosphere through
a hole in the D.V. when brakes are under fully released
condition.
3. To apply brakes, the driver moves automatic brake valve
handle either in steps for a graduated application or in one
stroke to the extreme position for emergency application.
By this movement the brake pipe pressure is reduced and
the pressure differenced is sensed by the D.V. against the
reference pressure locked in the control reservoir.
4. Air from the auxiliary reservoir enters the brake cylinder
and the brakes are applied. At the time of release the air
in the brake cylinder is vented progressively depending
upon the increase in the brake pipe pressure.
5. When the brake pipe pressure reaches 4.8 kg/cm2 the
brake cylinder is completely exhausted and brakes are fully
released.

14.  Single Pipe Graduated Release Air Brake System :
1. The operation is same as that of the twin pipe system except that the
auxiliary reservoir is charged through the D.V. instead of feed pipe,
since there is no feed pipe in single pipe system.
2. As compared to single pipe graduated release air brake system, twin
pipe graduated release air brake system is more suitable for passenger
coaches.

15. MECHANICAL BRAKING SYSTEM :
1. The basic braking devices used by mechanical braking systems are: wheel tread brakes (Fig. 10), axle-
mounted disc brakes (Fig. 11), and wheel-mounted disc brakes (Fig. 12). These brake mechanisms use a
brake shoe that applies friction force to the disc.
2. The applied pressure is adjusted to control the braking force. In wheel-tread brake, the brake shoe applies
friction force to the wheel tread, creating a sliding effect. High-speed trains cannot use this type of brake,
because doing so may damage the wheel tread. Therefore, they use axle- or wheel-mounted disc brakes.
Axle-mounted disc brakes require sufficient space to accommodate therefore used in trailer bogies.
3. Wheel mounted disc brakes are used on motor bogies because it requires accommodating the traction motor
only and having insufficient space for an axle-mounted brake. In both systems, compressed air or oil is
applied to a brake cylinder that pushes the brake lining against the disc. Brake discs are dead weight that is
useful only during braking, therefore operators can install lighter discs.
4. Carbon/carbon- composite multi-discs and aluminum composite discs offer lighter weights and are widely
used. The carbon/carbon-composite multi-disc has alternate sections of carbon-fiber rotors and stators.
During braking, they rub against each other to create a frictional force that slows down the wheel or axle.
5. The disc is lighter in weight than conventional materials and has good heat-resistant properties. (Fig. 13)
Aluminum composite brake discs may be made much lighter than today’s forged steel and cast-iron brake
discs. Moreover their structure is common for both axle- or wheel-mounted discs, achieving a much lighter
disc without design.

16. Principle of wheel tread brakes
Principle of axle-mounted disc brakes
Principle of wheel-mounted disc brakes

17. ELECTROMAGNETIC BRAKING SYSTEM :
1. Conventional train braking systems depend heavily on adhesion between
the wheel tread and the rail. In the case high-speed trains, adhesion
decreases as speeds increase, making it necessary for the train to reduce
braking force to avoid wheel sliding.
2. This result is longer braking distances. To overcome this problem, a
electromagnetic brake system that does not depend on adhesion was
developed. It produce a braking force by using magnetic repulsion obtained
from eddy currents generated on the top surface of the rails.
3. Earlier it was not used because of assumption that the eddy currents would
heat small sections of the rail to such a degree that the rail would bend
sideways.
4. This is solved by development of a electromagnetic brake that uses eddy
currents and frictional force. Fig. 14 shows the principle of electromagnetic
brake. The electromagnetic brake on bogie is connected to batteries that
create alternating north and south poles forming magnetic fields between
the poles.
5. The magnetic fields generate eddy currents in the top surface of the rails,
creating a force acting in an opposite direction to the movement of the
train, in other words, a braking force.

18. Principle of electromagnetic brake
An on field view of electromagnetic brake

19. CONCLUSION :
 Vacuum brakes have extremely limited applications because of
longer to function and unsuitable for high speed trains.
 Air brakes are efficient as compared to vacuum brakes; however
they require considerable stopping distance therefore cannot be
used for emergency braking.
 Mechanical brakes should be kept in reserve in parallel with
another breaking technique and should be used to completely
stop the engine at low speed.
 The required braking forces can be obtained in a wide range,
with regeneration braking used in a highspeed range and rheostat
braking in low speed range.
 Electrodynamic brake systems occasionally malfunction because
they have complex circuits. Therefore they cannot be used as
emergency brakes.
 Electromagnetic braking in high-speed train is
 efficient method of breaking.

20. APPENDIX :

21. Future Scope

22. REFERENCES
 G. Bureika & S. Mikaliunas, “Research on the compatibility of
the calculation methods of rolling‐stock brakes”, Transport,
vol. 23, issue 4, 2008, pp. 351-355.
 L. Liudvinavicius & L. P. Lingaitis, “Electrodynamic braking in
high‐speed rail transport”, Transport, vol. 22, issue 3, 2007,
pp. 178-186.
 Vernersson, “Temperatures at railway tread braking. Part
Calibration and numerical examples”, Proceedings of the
Institution of Mechanical Engineers, Part F: Journal of Rail and
Rapid Transit, vol. 221, issue 4, 2007, pp. 429-441.
 S. Teimourimanesh, T. Vernersson, R. Lunden, “Modelling of
temperatures during railway tread braking: Influence of
contact conditions and rail cooling effect”, Proceedings of the
Institution of Mechanical Engineers, Part F: Journal of Rail and
Rapid Transit, vol. 228, issue 1, 2014, pp. 93-109.

23. OBJECTIVES
METHODOLOGY
HYPOTHESI
S
WORKPLAN
END!
THANK YOU