Report on Ajni electric Loco shed Nagpur

Report on Ajni electric Loco shed Nagpur

1. Industrial Training
At

Electric Loco Shed, Ajni, Nagpur
Of


Completed By
:
1. Prasad S. Thote
2. Suhas A. Ghangare
3. Gunjan U. Korde
4. Rushikesh A. Porate

2. Industrial Training Report
On
Training at Electric Loco Shed, Ajni, Nagpur.


Submitted By


1) Prasad S. Thote (2016BEL014)
2) Suhas A. Ghangare (2016BEL601)
3) Gunjan U. Korde (2016BEL001)
4) Rushikesh A. Porate (2017BEL507)













Department of Electrical Engineering

Shri Guru Gobind Singhji Institute of Engineering and Technology,
Vishnupuri, Nanded

(2019-2020)

3. CERTIFICATE







This is to certify that the following students of VI
th
semester

Bachelor of
Technology students in ELECTRICAL ENGINEERING from “Shri Guru Gobind
Singhji Institute Of Engineering And Technology, Vishnupuri, Nanded” has
completed the Practical Summer Training From 03.12.2018 to 15.12.2018 in Electric
Loco Shed Ajni, Nagpur. During training, their brilliance towards discipline and
training is commendable.

Name of students:

1) Gunjan Udaramji Korde
2) Rushikesh Arun Porate
3) Suhas Anil Ghangare
4) Prasad Sadanand Thote


Serial No.:- 366

Letter No.:- Electric Loco Shed/Ajni/B.T.C/09

Date: 15.12.2018







Electric Loco shed
Ajni, Nagpur
(Central Railway)

4. ACKNOWLEDGMENT



It is indeed a great pleasure for us to present the industrial training report on
Electric Loco Shed, Ajni, and Nagpur as a part of the curriculum of the Bachelor of
Technology (Electrical Engineering) degree
We take the golden opportunity to thank all the mentors of LOCO SHED
who with their support and venerated guidance made this training a real success. We
express our sincere thanks to officers of LOCO SHED who in spite of their busy
schedule have lend their precious time for helping us to understand various system used
in LOCO SHED.
We will be failing in our duty if we will not mentioning the technical
demonstrations as given by the reverent staff of LOCO SHED. Getting training at such
an organization is an exquisite learning experience that made the mark at the
profoundest part of our mind.
Last but not the least we place a deep sense of gratitude to our family
members and our friends who have been a constant source of inspiration during training
period.

5. CONTENTS


Abstract………………………………………………………………………………………………….1
1 INRODUCTION……..……………………………………………………………………………2

1.1 About Indian Railways…………………………………………………………………………...2
1.2 Organization Overview………………………………………………………………….……….2
1.3 Undertakings of Ministry of Railways ………………………………………….……................3
1.4 Manufacturing…………………………………………………………………………………...4
1.5 Electric Loco Shed, Ajni…………………………………………………………………….……5
1.6 Specifications of the Loco’s in Loco Shed………………………………………………….…...6
2 CLASSIFICATION OF LOCOMOTIVES ……………………………………………….……...9
3 TRACTION MOTOR SECTION ………………………………………………………….…….10
3.1Traction Motors ………………………………………………………………………….…....11
4 POWER SECTION…………………………………………………………………………….….12
4.1 Transformer ……………………………………………………………………………………...... 12
4.2 Vacuum Circuit Breaker……………………………………………………………………….…. 13
4.3 Potential Transformer…………………………………………………………………………...14
4.4 Harmonic Filter…………………………………………………………………………………. 15
4.5 Battery………………………………………………………………………………………...... 16

5 PANTOGRAPH ………………………………………………………………………………….….. 17
6 AIR BRAKE SYSTEM………………………………………………………………………….......19
CONCLUSION……… ………………………………………………………………………………..22

6. Ajni Electric Loco Shed, Nagpur

7. 1

ABSTRACT

This loco shed belongs to central Railway territory! It belongs to the Nagpur division.
This shed was established in 1990. The first Electric locomotive 23502 (WAG-5) was
commissioned on 22.10.1990 and 100th Locomotive 23863 “Shakti” was commissioned on
07.04.1994. 1st three phase locomotive was commissioned on 02.11.2003. Now 200th
locomotive “ASHOKA” belonging to new generation high horse power technology
commissioned. Ajni is the first shed in Central Railway and 7th in Indian Railway to hold 200+
locomotives.
The focus of the detailed study of this electric loco shed is to understand the working
of the organization as well as to understand the functioning of the engine and various parts used
to achieve the traction. Safety and system reliability concerns dominate in this domain. With
such motivation various issues are tackled related to the improper functioning of the loco or
the complete failure of the loco.

8. 2

CHAPTER 1: INTRODUCTION
1.1 About Indian Railways
Indian Railways, a historical legacy, are a vital force in our economy. The first railway
proposals for India were made in Madras in 1832. The country's first train, Red Hill Railway run
from Red Hills to the Chintadripet Bridge in Madras in 1837. The first passenger train on Indian
sub-continent ran from Bombay to Thane on 16th April 1853. Fourteen railway carriages
carried about 400 guests from Bombay to Thane covering a distance of 21 miles (34
Kilometers) on 1,676 mm (5 ft 6 in) broad gauge track.
It is interesting to note that though the railways were introduced to facilitate the commercial
interest of the British, it played an important role in unifying the country. Railways are ideally
suited for long distance travel and movement of bulk commodities. Regarded better than road
transport in terms of energy efficiency, land use, environment impact and safety it is always in
forefront during national emergency.
Indian railways, the largest rail network in Asia and the world’s second largest under one
management are also credited with having a multi gauge and multi traction system. The Indian
Railways have been a great integrating force for more than 150 years. It has helped the
economic life of the country and helped in accelerating the development of industry and
agriculture. Indian Railways is known to be the largest railway network in Asia.
The Indian Railways network binds the social, cultural and economic fabric of the country
and covers the whole of country ranging from north to south and east to west removing the
distance barrier for its people. The railway network of India has brought together the whole of
country hence creating a feeling of unity among Indians.

1.2 Organization Overview
Indian Railways is headed by a seven-member Railway Board whose chairman reports
to the Ministry of Railways. Railway Board also acts as the Ministry of Railways. The officers
manning the office of Railway Board are mostly from organised Group A Railway Services
and Railway Board Secretariat Service. IR is divided into 18 zones, headed by general
managers who report to the Railway Board The zones are further subdivided into 68
operating divisions, headed by divisional railway managers (DRM) The divisional officers of

9. 3

the engineering, mechanical, electrical, signal and telecommunication, stores, accounts,
personnel, operating, commercial, security and safety branches report to their respective DRMs
and are tasked with the operation and maintenance of assets. Station masters control individual
stations and train movements through their stations' territory.

Table 1: Railway Zones and their Headquarters

1.3 The Ministry of Railways has following nine undertakings:
 Rail India Technical & Economic Services Limited (RITES)
 Indian Railway Construction (IRCON) International Limited
 Indian Railway Finance Corporation Limited (IRFC)
 Container Corporation of India Limited (CONCOR)
 Konkan Railway Corporation Limited (KRCL)
 Indian Railway Catering & Tourism Corporation Ltd (IRCTC)
 Railtel Corporation of India Ltd. (Rail Tel) 8. Mumbai Rail Vikas Nigam Ltd.
(MRVNL)
 Rail Vikas Nigam Ltd. (RVNL)
Indian Railways have their research and development wing in the form of Research,
Designs and Standard Organization (RDSO). RDSO functions as the technical advisor and
consultant to the Ministry, Zonal Railways and Production Units.

10. 4

1.4 Manufacturing
Indian Railways is a vertically-integrated organization that produces majority of its
locomotives & rolling stock at in-house production units, with a few recent exceptions.
Locomotives:
 Chittaranjan Locomotive Works in Chittaranjan, West Bengal manufactures electric
locomotives.
 Diesel Locomotive Works in Varanasi, Uttar Pradesh manufactures diesel & electric
locomotives.
 Diesel Locomotive Factory in Marhowra, Bihar, a Joint Venture of Indian
Railways & General Electric manufactures high capacity diesel locomotives, used
especially for freight transportation.
 Electric Locomotive Factory in Madhepura, Bihar, a Joint Venture of Indian
Railways and Alstom SA manufactures electric locomotives.
 Diesel-Loco Modernization Works in Patiala, Punjab upgrades and overhauls locomotives.
They also manufacture electric locomotives
Rolling Stock:
 Integral Coach Factory in Chennai, Tamil Nadu
 Rail Coach Factory in Kapurthala, Punjab
 Modern Coach Factory in Raebareli, Uttar Pradesh
 Coach Manufacturing Unit in Haldia, West Bengal
Wheel & Axle:
 Rail Wheel Factory in Bangalore, Karnataka
 Rail Wheel Plant, Bela in Chhapra, Bihar
The repair and maintenance of this vast fleet of rolling stock is carried out at 44 loco sheds,
212 carriage & wagon repair units and 45 periodic overhaul workshops across various zones
of IR

11. 5


1.5 Electric Loco Shed, Ajni
The Electric Loco Shed was set up in 1990, Shed is spread over a land area of 18 Acres
in which covered shed is 3 Acres. Since past 24 years shed has maintained various types of
locomotives such as WAM-4 for Mail Express trains, 5000 HP WAG-7 locomotive for hauling
goods train and now prestigious WAP-7 and WAG-9 three phase ‘State of Art technology’
locomotives to haul important trains like Rajdhani, Duranto and other Mail/express and goods
trains respectively. Goods locomotives are mainly utilized for wide spread freight operations
primarily in Central Railway and in other railways as well.
1st shed in Indian Railway to hold highest 140 three phase locomotives. Out of these,
126 locomotives are with GTO based technology and 14 are with latest and most advanced
IGBT technology. 1st IGBT locomotive was commissioned on 18.04.2011. With the increase
in locomotive holding up to 200.
The main purpose of the shed is to maintain the Electric and diesel trip Locomotive of
the Models WAG-7, WAG-9, WAG-9I, and WAP-7. Present Loco holding is around 200+.

12. 6


1.6 Specification of the Loco’s in Loco Shed:
WAP 7:
First loco transferred from GZB. Locomotive WAP-7 30543 of this shed named "OJAS"
 Manufacturers: Chittaranjan Locomotive Works (CLW)
 Traction Motors: 3-phase squirrel-cage induction motors 850 kW (1,140 hp), 2180 V,
1283/2484 rpm, 270/310A; Weight-2,100 kg (4,600 lb.), forced-air ventilation.
 Pantographs: Two Stone India (Calcutta) type AM-12, 235 kg (518 lb) including 4
insulators
 Gear Ratio: 72:20, 70:22(for HS Version)
 Torque: 6,330–7,140 N-m ~88% efficiency.
 Quantity: 64

Fig no. 1 WAP 7

13. 7

WAG 7:
On 3 March 1992, the first WAG-7 locomotive was inaugurated and christened the
name SHANTIDAN in honor of Mother Teresa. The loco is controlled by a tap changer.

 Traction Motor: Dc series Motor, 630 kW (840 hp), 750 V, 900 A, 895 rpm
 Transformer: CCL India, type CGTT-5400, Primary rating (5670 kVA, 252 A)
Secondary rating (5400 kVA, 1000 V, 5400 A), Tertiary rating 270 V, 32 taps,
12,200 kg (26,900 lb), Forced Oil cooling, Class A Insulation
 Rectifiers: Two silicon rectifiers, 64 per bridge, Continuous rating 2700 A / 1050 V per
cubicle, Max starting current 3300 A.
 Pantographs: Two Stone India (Calcutta) type AM-12, 235 kg (518 lb) including 4
insulators
 Quantity: 48


Fig no. 2 WAG 7

14. 8


WAG 9:
It was the most powerful freight locomotive of its fleet until the formal induction of
the WAG-12. It is similar to the WAP-7 class locomotive but features a different gear ratio,
which makes it suitable for heavy freight operations.
This class named WAG-9H, with the "H" meaning "Heavy".
Chittaranjan Locomotive Works (CLW) turned out its first 9,000 hp WAG-9 freight locomotive
on 31 March 2019

 Traction Motors: ABB's 6FRA 6068 (850 kW, 2180V, 1283/2484 rpm, 270/310A.
 Transformer: ABB's LOT 6500, Class A Insulation, OFAF cooling, Primary (25 kV,
6531 kVA), Secondary rating(4x1269 V, 4x1450 kVA, 4x1142 A)
 Pantographs: Two Secheron ES10 1Q3-2500, 186 kg (410 lb) (without insulators).

 Quantity: WAG 9- 40
WAG 9H- 127

15. 9

CHAPTER 2: CLASSIFICATION OF LOCOMOTIVES
The classification of Electric locomotives is based on the type of service used for. The alphabet
stands for:
The first letter (gauge)
W >>> Broad (wide) Gauge 5 ft 6 in (1,676 mm)
Y >>> Meter Gauge 3 ft or 1000mm
Z >>> Narrow Gauge (2 ft 6 in)
The second letter (motive power)
A >>> AC locos
C >>> DC locos
D>>> Diesel locos
CA >>> AC/DC locos
The third letter (job type)
M >>> Mixed Traffic (Goods or passenger Services)
G >>> Goods Service
P >>> Passenger Service
U>>> Multiple units (EMU, DMU)
And the number after it represents the model number of that locomotive.
EXAMPLE: If we want to name a locomotive which is used in broad gauge with AC supply
and for goods and model 7. How would it be written?
ANSWER: WAG 7

16. 10

CHAPTER 3 - TRACTION MOTOR SECTION

Motor is machine which converts the electrical energy into mechanical
energy. DC motor works on the principle of attraction and repulsion.

TYPES OF DC MOTORS:

1. Separately excited motor
2. Series excited motor.
3. Shunt excited motor.
Out AC locos are provided with DC series excited motors. In this type of motor
armature and inductors are connected in series to a single DC source. So it is called as
series excited motor. They are most useful for traction purpose.

ADVANTAGE OF DC SERIES EXCITED MOTOR:
1. Starting torque of is very high (torque in the force that tends to produce a turning
effect on the shaft).
2. Reversal of the rotation of the motor is very easy.
3. Variable speed is possible than by any other type of DC motors.
Reversing the direction of the rotation of a motor:
For reversing the direction of rotation of motor the direction of the flow of the current
should be changed either in the field or in the armature coil. But, if the direction of flow of
current is charged in the both field as well as armature, the rotation of the motor will not
change. On AC locos for changing the direction of rotation of the traction motor the direction
of flow of current is changed in the fields (inductors) with the help of reversers. This in turn
will reverse the direction of the locomotive.
Note: The reversal of the rotation should be done after stopping the motor (i.e.
locomotive). Otherwise serious damages will be caused.

17. 11

3.1 TRACTION MOTORS:
In WAG-5 loco, TM-1, 2, 3 are provided in bogie-1 and TM-4, 5, 6 are provided in bogie-
2. These motors are axle-hung, nose suspended type. There are two types of traction motors
supplied by CLW i.e., TAO 659 & Hitachi.
Grease lubricated roller bearings are used for the armature & for suspension in Hitachi
motors. In TAO 659 motors, Roller bearings for the armature & white metal plain sleeve
bearings for suspension are used.
Special provision has been made in design of the motors to ensure that locomotive can
be operated satisfactorily on flooded track, to a maximum flood level of 20 cm above rail level.

MAKE CLW CLW
Type HS 15250 A TAO 659
Continuous output 630 KW 585 KW
Voltage 750 V 750 V
Starting current 1350 A 1100 A
Current (continuous) 900 A 840 A
Speed 895 rev/min 1060 rev/min
Maximum service speed 2150 rev/min 2500 rev/min
Insulation CLASS C CLASS H
Number of poles Main 6,
Interpoles 6
Main 6,
Interpole 6
Table 2: Traction Motor details
There are total 6 traction motors used in the WAG 9/ WAP 7 loco. TM 1-2-3 are
mounted in bogie 1 and fed from traction converter 1 whereas TM 4-5-6 are mounted
in bogie 2 and fed from the traction converter 2. In case of WAP 5 there are 4 traction
motors in which traction converter 1 fed to TM 1-2 whereas traction converter 2 fed to
TM 3-4.
In WAP 7 and WAG 9 the traction motor is forced air cooled and intended for
transverse installation in a 3 motor bogie. Traction motor is suspended on axel, by axel
cap at one end and on link at another end.

18. 12

CHAPTER 4 - POWER SECTION

This section deals with the power instruments used in the locomotive such as VCB, oils
in the transformers test etc.
4.1 TRANSFORMER:
Transformer is a static device used for stepping up or stepping down the AC supply
voltage (In traction is intended for stepping down from OHE catenary supply of 25 KV
to 1750 V and 380 V). This is located in the HT compartment of the locomotive. It is an
oil immersed type with forced circulation cooling. The power from OHE collected through
pantograph and circuit breaker is supplied to the regulating winding of the Auto
transformer. Arrangement of the various windings on the limbs of transformer is as
shown in the diagram. The transformer has 3 limbs. The first limb carries the windings
of auto transformer regulating winding. This winding is provided with 32 taps. The
wining is suitable for giving a rated output of 3640 KVA. The tapings taken out are
connected to tap changer. The tap changer is driven by SMGR driven by air motor. The
air motor can be operated even with minimum air pressure of 3 kg/cm 2. Another auxiliary
windings (TFWA) is intended for supplying single phase 50 HZ, 380 ± 22.5% volts
supply to ARNO converter. The coil is suitable for 180 KVA load. The primary winding
(A0 – A34) and secondary winding (a3 – a4 and a5 – a6) are carried on limb 2 and limb
3.
The primary winding consists of two groups in series on limbs 2 and 3. The
secondary winding consists of four groups and occupies symmetrical group positions on
limbs 2 and 3 in relation to primary groups. All the coils are disc (or pan cake) type since
tap changer oil is subjected to heavy duty (i.e. arcing during movement of contact roller
on contact segments) it requires frequent changing and maintenance as compared to
transformer oil. So the transformer oil is sealed off from tap changer oil such as to facilitate
drawing out of tap changer oil alone for maintenance purpose cooler is (MVRH) mounted
on the transformer cover oil circuit pipe line connections need not be removed for
maintenance. Recent developments in some transformers are SF6 gas cooling is used. The
transformer magnetic circuit consists of laminated magnetic cores interleaved to form the
three limbs. H.V. circuit is connected to DJ through condenser type bushing. The upper
bushing is mounted on the roof of the locomotive. The lower bushing is fitted on the cover

19. 13

of transformer and middle part of bushing (in between) is screwed to the bottom bushing.
The secondary winding (L.T.) is connected to the external circuit taken out of transformer
through 4 bushings and are also mounted on the cover of transformer. Oil conservator is
situated above the transformer. The pipe leading to it is serving as a safety valve having
an oil over flow chamber above it. The oil over flow chamber has a discharge pipe to lead
the blown out oil down underneath the locomotive body. This complete system thus acts
as a pressure relief device. The oil pump and the cooler are connected to the conservator
by a venting pipe. Air does not come in contact with the oil directly. The moisture in the
air entering breather is completely absorbed by silica gel acting as an air dryer.

4.2 VACCUM CIRCUIT BREAKER:
Vacuum circuit breakers are replacing the air blast circuit breakers used on
electric Locos/EMU'S due to following advantages.
1. Less Maintenance
2. Greater Safety
3. Greater Reliability
4. Simplified Control
5. Noiseless Operation

CONSTRUCTION:
The main switching unit consists of two vacuum interrupters connected in series and are
mounted in the Horizontal support insulator. Each interrupter houses a pair of contacts. The
interrupters operating rods are connected to a pneumatic dual piston. Operating mechanism
is mounted in the main cradle between the interrupters, which closes the contacts by the
application of air supply. The contacts are held normally open by heavy-duty springs. When
actuating rod through the crank pins, operates auxiliary DJ interlock unit. It is fixed to the
spring plate. The relay valve body is bolted to one side of the air cylinder. The control air pipe
and main air pipe, which are made up of special nylon, are routed between the relay valve
and the base of the circuit breaker inside the insulator. The regulated and filtered air pressure
of 5 Kgs/cm
2
is supplied from air reservoir QPDJ setting is kept at cut in 4.65 Kgs/cm
2
and
cut out 4.0 Kgs/cm
2
.

20. 14

OPERATION:
When the magnet valve is energized, control air is admitted to the bottom chamber of
the air relay valve and pushes the puppet valve upwards to allow operating air through main
pipeline in to the cylinder via 2mm diameter choke. The operating air in the cylinder piston
moves outwards against the pressure of springs, thus closing the contacts in those
interrupters. Air cylinder has small and large ports. When the magnetic valve is energized
air enters in to the cylinders first the small port and then at through energized touch with
each other by the large port, thus the contacts are fully closed. When the magnet valve is
de-energized the cylinder exhausts to atmosphere thus causing the piston to accelerate
rapidly inwards by the face of springs.


4.3 POTENTIAL TRANSFORMER:
The primary voltage transformer is situated on the converter roof hatch and attached to
the pantograph via the roofline. The primary voltage transformer reduces the catenary
voltage, approximately 25 kV, to 200 volts AC. A resistor is placed across. The primary
voltage transformer to provide a reference load. The output signal is used in three ways;
1) Main converter electronics = 4 volt AC
2) Catenary voltmeters on the driver’s console = 10 volt DC
3) Minimum voltage relay.
When panto is raised this potential transformer fed to U meter and U meter shows
the OHE supply in drivers cab. As such we can have an idea of availability of OHE supply
before closing DJ and also idea of rising of panto. However our responsibility of seeing
panto is not finished, we have to check the condition of panto physically

21. 15


Fig no. 3 Power circuit of locomotive


4.4 HARMONIC FILTER:
Line harmonic filter is connected with primary winding of main transformer which
consists of resistances and capacitor. This harmonic filter reduces/suppressed the high
frequency harmonics to avoid disturbances in signaling.
If the harmonic filter gets bypassed by the system, the speed of the loco / train will be
Automatically restricted up to max 40 KMPH by CE.

22. 16

4.5 BATTERY:
In ABB loco NiCD Battery is used. There are total 78 cells in the batteries which are
placed in 2 boxes at either side of the locomotive. Each box contains 39 cells and each battery
has 3 cells. Capacity of battery is 199 A-H and output is 110 V. To charge the battery, one
battery charger is provided with circuit breaker no. 110 situated in SB2. Main switch for
battery is 112 which is placed in a box provided near battery box no. 2. For control circuit
supply 1 MCB no. 112.1 is provided in SB2. To show the battery voltage UBA is provided
in either cab.
Note:-
1. If battery voltage is 92 V for more than 30 seconds, P-2 Fault will appear on the screen.
2. If charging current is reduced by 10 A, P-2 fault will appear on screen.
3. If battery voltage is reduced below 82 V, P-1 message with shutdown of loco will appear.
4. If cab is activated and panto is lowered than 10 minutes CE will switch off automatically.
5. Loco CE get power supply directly from battery and can supply upto maximum 5 hours.
6. For machine room light power supply is given directly through MCB 327.4.
Technical Specification:
Cell model = SBL-199
Cell type = Nickel/Cadmium
Number of cells per battery = 3
Number of batteries per battery box = 13
Number of battery boxes = 2
Total nominal capacity = 199 Ah
Nominal voltage of each cell = 1.4 V
Total battery voltage = 1.4 x 3 x 26 =110 V

23. 17

CHAPTER 5 – PANTOGRAPH

Pantograph is an apparatus which mounted on the roof of electric train to collect power through
with an overhead tension wire. It lift or down on the basis of the wire tension. Typically a single wire is
used with the return current running through the track. It is a common type of current collector. Typically,
a single wire is used, with the return current running through the track.

The electric transmission system for modern electric rail systems consists of an upper, weight-
carrying wire (known as a catenary) from which is suspended a contact wire. The pantograph is spring-
loaded and pushes a contact shoe up against the underside of the contact wire to draw the electricity needed
to run the train. The steel rails of the tracks act as the electrical return. As the train moves, the contact shoe
slides along the wire and can set up acoustical standing waves in the wires which break the contact and
degrade current collection. This means that on some systems adjacent pantographs are not permitted.

Pantographs with overhead wires are now the dominant form of current collection for modern
electric trains because, although more fragile than a third-rail system, they allow the use of higher voltages.
Pantographs are typically operated by compressed air from the vehicle’s braking system, either to raise the
unit and hold it against the conductor or, when springs are used to effect the extension, to lower it. As a
precaution against loss of pressure in the second case, the arm is held in the down position by a catch. For
high-voltage systems, the same air supply is used to “blow out” the electric arc when roof-mounted circuit
breakers are used.

24. 18

Pantographs may have either a single or a double arm. Double-arm pantographs are usually
heavier, requiring more power to raise and lower, but may also be more fault-tolerant.

25. 19

CHAPTER 6 - AIR BRAKE SYSTEM

In the air brake system, a lot of developments have taken place such as bogie mounted Air
brake system, Twin pipe air brake system, Automatic load sensing device etc,. As a result, the maintenance
and requirements have changed considerably.
SINGLE PIPE GRADUATED RELEASE AIR BRAKE SYSTEM
Some of the Air Brake goods stock on IR is fitted with single pipe graduated release air brake
system. In single pipe, brake pipes of all wagons are connected. Also all the cut off angle cocks are kept
open except the front cut off angle cocks of BP of leading loco and rear end cut off angle cock of BP of
last vehicle. Isolating cocks on all wagons are also kept in open condition. Auxiliary reservoir is charged
through distributor valve at 5.0 kg/cm
2
.

A. Charging stage
During this stage, brake pipe is charged to 5kg/cm
2
pressure which in turn charges control reservoir and
auxiliary reservoir to 5 kg/cm
2
pressure via distributor valve. At this stage, brake cylinder gets vented to
atmosphere through passage in Distributor valve.



B. Application Stage
For application of brakes, the pressure in brake pipe has to be dropped. This is done by venting
air from driver‟s brake valve. Reduction in brake pipe pressure positions the distributor valve in such a

26. 20

way that the control reservoir gets disconnected from brake pipe and auxiliary reservoir gets connected to
brake cylinder. This results in increase in air pressure in brake cylinder resulting in application of brakes.
The magnitude of braking force is proportional to reduction in brake pipe pressure.
Note: Brake Application takes places when Brake pipe pressure is dropped by Intentional or Accidental.





C. Release stage
For releasing brakes, the brake pipe is again charged to 5 kg/cm
2
pressure by compressor
through driver‟s brake valve. This action positions distributor valve in such a way that auxiliary reservoir
gets isolated from brake cylinder and brake cylinder is vented to atmosphere through distributor valve and
thus brakes are released.

27. 21



FIG. LAYOUT OF SINGLE PIPE AIR BRAKE SYSTEM

28. 22


CONCLUSION

The study work was conducted to learn the working and maintenance practice at
Electric Loco Shed, Ajni, Nagpur .The Locomotive is a railway vehicle starts that proviced the
motice power for the train. The Report start with the brief introduction to the railways followed
by the details of railway workshop, Ajni, Nagpur, where we underwent in-plant Training.
It gives the detailed description of a Electric locomotive engine. The major secions like
power sections, traction motors, and pantograph section have been described. We have learned
the advantages of electric locomotives such that they can save fossile fules which are limited
in amount and the pollution induced due to them also reduced by using neat and clean electricity
as the power source for locomotives.