I have done training at Rolling Stock Department, Sarita Vihar Depot, DMRC. During this training period, i have learned lots of things. I have summarized all those things in this report.

1. 1
CHAPTER 1
INTRODUCTION
1.1 DELHI METRO
Fig. 1 Delhi Metro
The Delhi Metro is a metro system serving Delhi and its satellite cities
of Faridabad, Gurugram, Noida and Ghaziabad in National Capital Region in India. Delhi Metro
Rail Corporation Limited (DMRC), a state-ownedcompany with equal equity participation
from Government of India and Government of Delhi, built and operates the Delhi Metro.
Delhi Metro is the world's 12th longest metro system in length and 16th largest in ridership. A
member of CoMET,[5] the network consists of five colour-coded regular lines and the
faster Airport Express line, with a total length of 218 kilometres (135 mi) serving 164
stations (including 6 on Airport Express line). The system has a mix of underground, at-grade, and
elevated stations using both broad-gauge and standard-gauge. The power output is supplied by 25-
kilovolt, 50-hertz alternating current through overhead catenary. The trains are usually of four, six,
and eight-coach length. DMRC operates over 3,000 trips daily, with first trains starting at around
05:00 and last at 23:30.
In the financial year 2016-17, Delhi metro had an average daily ridership of 2.76 million
passengers, and served 100 crore (1.0bn) riders in total during the year.

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The Delhi Metro Rail Corporation was certified by the United Nations in 2011 as the first metro
rail and rail-based system in the world to get "carbon credits for reducing greenhouse gas
emissions" and helping in reducing pollution levels in the city by 630,000 tonnes every year.
Planning for the metro started in 1984, when the Delhi Development Authority and the Urban Arts
Commission came up with a proposal for developing a multi-modal transport system for the city.
Delhi Metro Rail Corporation (DMRC) was incorporated in May 1995, construction started in
1998, and the first section, on the Red Line, opened in 2002. The development of network was
divided into phases, Phase I containing 3 lines was completed by 2006, and Phase II in 2011. Phase
III is scheduled for completion by 2018 (originally planned for 2016).
Rapid MetroRail Gurgaon which opened in 2013, whilst linked to Delhi Metro by the Yellow Line
is a separate metro system (with a different owner/operator than the Delhi Metro), although tokens
from the Delhi Metro can be used in its network.
1.2 CURRENT ROUTES
LINE 1 (Dilshad Garden to Rithala via Kashmeri Gate)
LINE 2 (HUDA City Centre (Gurgaon) to Jahangirpuri via Rajiv Chowk & Kashmere Gate)
LINE 3 (Noida City Centre to Dwarka Sector 21 via Rajiv Chowk and Yamuna Bank)
LINE 4 (Yamuna Bank to Anand Vihar ISBT)
LINE 5 (Inderlok to Mundka)
LINE 6 (Central Secretariat to Badarpur)
LINE 7 (Airport METRO Express Line)

3. 3
Fig. 2 Metro map
1.3 ROLLING STOCK DEPARTMENT
The Metro uses rolling stock of two different gauges. Phase I lines use 1,676 mm (5.499 ft) broad
gauge rolling stock, while three Phase II lines use 1,435 mm (4.708 ft) standard gauge rolling
stock. Trains are maintained at seven depots at Khyber Pass and Sultanpur for the Yellow Line,
Mundka for the Green Line, Najafgarh and Yamuna Bank for the Blue Line, Shastri Park for the
Red Line, and Sarita Vihar for the Violet Line.
CHAPTER 2

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INTRODUCTION TO ROLLING STOCK DEPARTMENT
(SARITA VIHAR DEPOT)
Fig. 3 Rolling Stock Department
The Sarita Vihar Depot opening of the Central Secretariat – Badarpur line and includes a
workshop-cum-maintenance facility situated over 29 hectares of land with 22 stabling lines with
7 double rake lines so that all the 29 trains can be accommodated together. In addition, a test track,
four inspection bay lines, one shunting line and four workshop lines are also available in the Sarita
Vihar Depot.
The Civil work of Sarita Vihar Depot started in November 2008 and the Depot was commissioned
in less than two years. In view of the tight deadline to open the Central Secretariat – Badarpur
section before the Commonwealth Games, the DMRC started commissioning the Trains required
for this corridor at the Mundka Train Depot instead of Sarita Vihar Train Depot since the Sarita
Vihar Train Depot which is the Maintenance Depot for the Badarpur corridor is in the final stage
of commissioning.
DMRC is running trains on this line with the highest ever frequency of 2 minutes 25 seconds to
cater to the rush expected at Jawaharlal Nehru (JLN) Stadium and other Venues. Trains on this
root have 6-6 coaches and running on the standard gauge tracks. While removing the old subway

5. 5
gap, triple handle bars have been installed in these trains. With this, children will be able to hold
handle bar while standing. Apart from this, red plastic plastic covers have been provided for the
convenience of people standing near the door.
Total 32 Metro trains can be parked at the Sarita Vihar Depot. Three types of lines are used to park
the Metro trains.
These are:
1. Stabling Bay Line (SBL)
2. Inspection Bay Line (IBL)
3. Workshop Line
Stabling bay line have 22 lines for the parking of 24 trains. At line number 12 and 13 two trains
can be parked. Inspection bay line is used for the inspection of trains. In this section metro trains
are checked for proper working condition. At Inspection bay line 4 trains can be parked. Workshop
line is used for solving any kind of problem like problems in Electrical System, Electronic System,
Air-conditioning System etc. There are four workshop lines for repairing the trains. There is a 780
meters’ test track used for testing of the metro trains.
There are several departments in Sarita Vihar Depot which are continuously working for the
betterment of Delhi Metro service. These are:
1. Security Training and Depot Observation Department
2. Project Planning Information & Operation
3. Technical Department
4. Task Force
5. Mechanical Section
6. Pneumatic Section
7. Air Conditioning section
8. Electric Section
9. Electronic Laboratory
10. Human Resource Section

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Over View of
DELHI METRO
TRAIN

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Chapter 3
VEHICLE
3.1 TRAIN FORMATION
At present each train-set consists of four cars. Both ends of the train-set are driving trailer car and
middle cars are motor cars. The trailer cars are defined as "DT" car and motor cars are defined as
"M" car.
The train-set can be controlled as a complete unit or as separate units for various maintenance
activities at the depot.
1) 4 car - DT-M-M-DT
2) 6 Car – DT-M-M-T-M-DT
3) 8 Car – DT-M-M-T-M-T-M-DT
Fig. 4 Train formation
3.1.1 SALIENT FEATURES
1. Broad Gauge
2. 25 KV Supply Voltage System
3. Light Weight Stainless Steel Structure
4. Three phase A.C. Induction Motor
5. Fail safe braking system with regenerative Braking
6. VVVF Control
7. Reinforced conical rubber primary suspension
DT DTMM

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8. Secondary Air Suspension
9. Uniform Floor Height
10. Jerk Controlled Braking
11. Slip/Slide protection
12. Train Integrated Management System
13. PLC based saloon Air-conditioning system
14. Electrically Operated and electronically controlled Saloon Doors
15. Emergency Door
16. ATP/ATO
3.2 SALOON INTERIOR
The Interior Facilities consist of the following major components:
Passenger Saloon Light:
The lighting system of the passenger compartment is supplied with AC, DC power and runs the
full length of saloon ceiling with two rows of fluorescent tubes. All AC supply lights are normal
lights and all DC supply lights are emergency lights. The emergency lights are mounted on the
ceiling near each passenger door, as sections in those rows. Gangway Light:
A small circle type of fluorescent light is provided the ceiling of gangway area.
Flooring:
The flooring is composed of the sub-floor of cement composition (UNITEX) and floor covering
of synthetic rubber material.
Insulation:
The inside of roof, side, floor, front and end structure is provided with thermal and noise insulation.
The insulation is of Glass Wool.
Passenger Seating:
All passenger seats are of longitudinal type of seats for 7 persons, 4 persons and 2 persons. Total
numbers of seat are 8 sets per each DT-car and 10sets per each M-car. All seats are mounted on the
side wall.

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3.3 GANGWAY
A gangway is the flexible element that allows the movement of people between coupled vehicles.
3.4 BOGIE
The bogie comes in many shapes and sizes but it is in its most developed form as the motor bogie
of an electric or diesel locomotive. Here it has to carry the motors, brakes and suspension systems
all within a tight envelope. It is subjected to severe stresses and shocks and may have to run at
over 300 km/h in a high speed application.
Bogie Function:
1. To maintain the load of vehicle body
2. To transfer the traction force and braking force
3. To maintain good ride quality and stability
4. To pass the curved track smoothly.
Overall Description of DMRC Bogie:
The bogies, manufactured by Rotem have been developed from an existing proven range. The
bogies are of conventional H frame design, with air suspension located between the body-bogie
interface assembly and bogie frame. The bogies are designed with primary and secondary
suspension systems and centre pivot device. The primary suspension comprises conical rubber
springs between the bogie frame and the bogie interface. Centre pivot device transfers traction
forced between the bogies and the vehicle body by means of mono link system.
Bogie Frame:
The bogie frame is H fabricated frame construction with two side frames and transom. The side
frame provides the mounting for the brake equipment, driving gear mounting brackets, traction

10. 10
motor mounting brackets, the mono link mounting brackets. The centre part of the side frame
provides the mounting support for the air spring assemblies and the brackets for the brake
equipment.
Fig. 5 View of motor bogie frame (Bottom view)
Brake equipment
mounting brackets
Driving gear
mounting brackets
Traction motor
mounting brackets
Mono link
mounting brackets

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Wheel Set:
The wheel sets are designed to sustain a high axle load into line with the passenger load of one per
seat and standing as 10 persons per meter square. The axle for motor and trailer bogies are similar,
however the power bogie axles are designed to with stand the extra loads imposed by the traction
loads and have additional mounting seats for the driving gear.
Wheel Base:
The distance between axle center lines, 2.4 m, is optimized to obtain a bogie with a relatively low
wheel wear rate, whilst maintaining stability throughout its operating speed range. It also achieves
a good distribution of vehicle weight onto the role.
Fig.6 Motor bogie wheel set
Fig.7 Trailer bogie wheel set

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3.5 COUPLERS
We generally couple the bogies according to the need. For instance a DT car and M car make a
single unit. They are not uncoupled frequently; hence the coupling should be permanent.
Accordingly DT-DT coupling is automatic whereas DT-M car coupling is semi permanent.
FAC SPC IAC SPC FAC
Fig.8 Couplers
FAC Front Automatic Coupling
SPC Semi permanent Coupling
IAC Intermediate Automatic Coupling
Automatic Coupling:
The coupler enables automatic coupling of railway vehicles. Coupling of two units is achieved
without manual assistance by driving one unit up to a second unit. Automatic coupling is possible
under angular misalignment both horizontally and vertically. The coupler permits the coupled
trains to negotiate vertical and horizontal curves and allows rotational movements. Besides the
mechanical coupling, electric and pneumatic coupling is achieved. The shock absorbers ensure
cushioning effect. Connection of the air pipes is automatically accomplished as the couplers are
mechanically coupled. Uncoupling is achieved automatically by remote control from the driver’s
cab or manually from trackside.
Semi Permanent Coupling:
DT DTMM

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The semi-permanent coupler is designed to ensure a permanent connection of railway vehicles
which in traffic form a unit and therefore need not to be separated unless in an emergency or in
workshop for maintenance. The couplers halves are connected by means of easily detachable muff
couplings thus ensuring a rigid, slack free and safe connection. The coupler permits coupled trains
to negotiate vertical and horizontal curves and allows rotational movements. Connection of the air
pipes is automatically accomplished as the couplers are mechanically coupled. Separation of the
coupler halves can only be effected manually.
3.6 TRACTION MOTOR
Fig. 9 Parts of traction motors
The Traction Motor is a 220 kW, 4 pole, squirrel-cage, 3-phase self-ventilated induction motor.
The Traction Motor employs a Class 200 insulation system. The Traction Motor exterior is a
frame-less type with linking iron core clamps and a coupling plate. The motor frame is equipped
with a vehicle fitting nose and fitting seat.

14. 14
A fan is mounted to the rotor shaft to draw air into the motor to provide cooling air to the rotor
and stator. The air enters the motor through the air inlet on the top of the non-drive end of the
motor and exits through the vents in the motor frame at the drive end of the motor. A Roller bearing
is used on the drive side of the rotor and Ball bearing is used on the non-drive side of the rotor.
Location:
Two 220kW Traction Motors are mounted on the transom of each motor car bogie
Function:
The Traction Motor provides the necessary torque to move the train. This torque is applied to each
wheel set in the motor cars via an axle-mounted gearbox, which is connected to the motor via a
coupling. The Traction Motor has the capacity to reduce the speed of the train by acting as a
generator. The momentum of the train causes the motor to rotate, and by adjusting the slip
frequency in the stator, the motor generates power back into the overhead supply. This causes a
braking effect on the train, which reduces the wear rate of the pneumatic brakes.
System controls:
Each motor car has four traction motors (two per bogie), with all four Traction Motors controlled
by a Variable Voltage Variable Frequency controller (VVVF).

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Chapter 4
Train Integrated Management System
4.1 INTRODUCTION
Train Integrated Management System (TIMS) provides a centralized function to monitor the train
borne systems and devices. It also provides the operators interface via a Video Display Unit
mounted on the operator desk. This display unit shows relevant information to the operator about
the status of On board equipment as well as commanded functions.
The Train Information Management System interfaces with the following systems located
throughout the train, these systems are:
 Traction Inverter (CI)
 Auxiliary Power Supply (SIV)
 Brake Electronic Control Unit (Brake System)
 Door Control Units
 Air conditioners
 AVAS & PA
 Train Radio
 ATC System
The Train Integrated Management System also monitors Train Line status, switch and circuit
breaker positions.
4.2 FAULT DETECTION LEVELS
Fault detection is classified into five critically levels-
Level 1: Critical Fault
Faults that require the immediate action/attention of the train operator are classified as critical
fault.
Level 2: Operating Event

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An event which is triggered by the train operator.
Level 3: Maintenance Event
An event that requires the attention of maintenance staff, after the train has completed the
scheduled service operation.
Level 4: Record
A maintenance record that requires the attention of the maintenance staff during scheduled routine
maintenance
Level 5: Notice
Information or reminder to aid the train operator during normal service under defined conditions.
4.3 Tims operation mode
Operator Mode Functions:
The TIMS system has the following functions which are accessible to the driver.
 System Check Screens - On this screen, TIMS will display on the main window a list of
Train faults that have been detected.
Fig. 10 Departure check

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Additional information about other systems can be checked by driver by touching the soft keys at
the bottom of the screen display. The available soft keys and corresponding train systems are:
DOOR The status of Door system is displayed.
BRAKES The status of the Pneumatic Brake system is displayed.
POWER The status of the High Tension circuit and equipment is displayed.
AUX The status of the Auxiliary Power Supply System is displayed.
AIR CON The status of the Air Conditioning system is displayed.
HISTORY A list of previously record critical faults are displayed.
DEPARTURE The departure check screen is displayed.
MAIN The LOGOFF screen is displayed.
Maintenance Mode Functions:
The TIMS system functions available to the operator are also accessible to Maintenance staff. In
addition maintenance staff can also access the following functions.
 Data download / upload by TIMS Maintenance Terminal
 Data and status check on VDU
Fig. 11 Maintenance menu

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4.4 AUXILIARY POWER SUPPLYSYSTEM
The Auxiliary power supply System is divided into two sub-systems:
1. STATIC INVERTER
2. BATTERY
4.4.1 STATIC INVERETER
Location:
Auxiliary Converter Box (SIV Box) is located on the under frame of each DT car.
Function:
The function of SIV is to provide stable power supply to the train auxiliary loads of one unit (DT+
M).
Main Parts of SIV:
 Input charging contactor IVK 1&2 (for making contact between input converter unit)
 Output contactor SIVK (for connectivity between output of inverter and load)
 Relay unit (It contains different relays such as VCBTPR, SDRXR, SIVFLR and SIVKAR)
 Power unit (It contains IGBT’s)
 Charging resistor (RC) unit (Prevents high inrush current during initial charging)
 Transducers (For monitoring of different parameters)
 Input filter reactor (For reducing harmonics towards OHE)
 Input filter capacitor (For reducing harmonics towards OHE)
 Output filter capacitor (For reducing harmonics towards output)
 Output filter reactor (For reducing harmonics towards output)
4.4.2 BATTERY
The battery is used for following applications-
1. During Train Start up

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a) Aux Compressor
b) Control Circuit Supply
c) Emergency Saloon Lights
2. Emergency loads(when SIV not working)
a) Emergency Saloon Lights
b) Emergency Ventilation
c) Control Circuit Supply

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CHAPTER 5
BRAKES AND PNEUMATICS
This section describes the on-board, compressed air auxiliary services required by trains and how
they are provided on the locomotive and passenger vehicles.
Pneumatic Parts Providing Company:
Knorr- Bremse, Munich, Germany
5.1 Characteristics of Compressed Air
Its astonishing that pneumatics could spread so forcibly and rapidly in such a relatively short span
of time. Amongst among other reason, this is due to the fact that in some problems of automation
no other medium can be used more readily and more economically.
The characteristics that so distinguish compressed air are:-
 Amount: Air is available practically everywhere for compression, in unlimited quantities.
 Transport: Air can be easily transported in pipelines, even over larges distances. It is not
necessary to return the compressed air.
 Storable: A compressor need not be in continuous operation. Compressed air can be stored in
and removed from a reservoir.
 Temperature: Compressed air is insensitive to temperature fluctuations. This ensures reliable
operation, even under extreme conditions of temperature.
 Explosion Proof: Compressed air offers no risk of explosion or fire, hence no expensive
protection against explosion is required.
 Cleanness: Compressed air is clean since any air which escapes through leaking pipes or
elements does not cause contamination.
 Construction: The operating components are of simple construction, and are therefore
inexpensive.
 Speed: Compressed air is very fast working medium. This enables high working speed to be
attained. (Pneumatic cylinders have a working speed of 1-2 m/sec.)

21. 21
 Adjustable: With compressed air components, speed and air are infinitely variable
 Overload Safe: Pneumatic tools are operating components, can be loaded to the point of
stopping and they are therefore overloading safe.
 In order to be able to accurately define the areas of application of pneumatics, it is also
necessary to be acquainted with negative characteristics:-
 Preparation: The compressed air needs good preparation. Dirt and humidity should not be
present. (They cause wear of pneumatic components.)
 Compressible: It is not possible to achieve uniform and constant piston speed with
compressed air.
 Force Requirement: Compressed air is economical only upto a certain force requirement.
Under the normally prevailing working pressure of 700 KPa (7 bar) and dependent on the travel
and speed, the limit is between 20000 and30000 N.
 Exhaust Air: The exhaust air is loud. This problem has now, however been resolved due to
the development of sound absorption material.
 Costs: Compressed air is a relatively expensive means of conveying power. The high energy
costs are partially compressed by inexpensive components and higher performance (number
of cycles.
5.2 Safety Features
 If main air compressor is malfunctioning, information is shown to train operator through
HMI (Human Machine Interface) i.e. TIMS.
 Air dryer’s malfunctioning is also shown on TIMS.
 In case of, emergency brake applied due to opening of emergency loop, and then also
information is provided on TIMS (Train Integrated Management System).
 If any of the components of BCU is malfunctioning, then also fault is generated on TIMS.
 Also all the indication regarding parking brake and service brakes are provided on TIMS.
 Safety valves are provided so that pressure can not be built above specified unit.
 Back up brake is provided in case of total failure of electric or electronic equipments.

22. 22
 Signal protection valve is provided (two number in each car) which will stop the air supply
to other car in case of heavy leakage in other car.
Air supply is used into the following components-
1. Air Suspension
2. Air Brakes
a. Service brakes
b. Emergency brakes
c. Holding brakes
d. Parking brakes
e. Backup brakes
3. Air horns
4. Pantograph
5.3 AIR SUSPENSION
Placing the car body on air pressure springs instead of the traditional steel springs has become
common over the last 20 years for passenger vehicles. The air spring gives a better ride and the
pressure can be adjusted automatically to compensate for additions or reductions in passenger
loads. The changes in air pressure are used to give the brake and acceleration equipment the data
needed to allow a constant rate according to the load on the vehicle.
In DMRC trains, suspension provided in coaches is of primary and secondary types:-
 Primary Suspension: It is of conical rubber spring type. The springs are attached to spring
seat of the bogie frame. The wheelset transfers the forces directly through the conical
rubber springs to the bogie frame. Each of three bogies is fitted with same springs. The
assemblies are interchangeable. The conical bonded rubber springs, which are mounted
above the axle boxes, are used as primary suspension system.
 Secondary Suspension: They are provided by air bags which are controlled
pneumatically.
Secondary type is used with two principles:-

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1. To ensure good ride quality.
2. To ensure the vehicle floor height remain equal in all riding conditions.
Air bags are provided four in number on each car. They are filled with air, with the help of leveling
valve. Leveling valve will take care of the vehicle floor height in all conditions. These air bags
absorb the shocks giving very good ride comfort.
5.4 AUXILIARY FUNCTION - Pantograph
It is a mechanism which is used to tap electricity from overhead wires. It is a simple mechanism
in which lever moves up and touch the overhead wires to tap or to connect with the electricity. The
movement of this pantograph is controlled pneumatically. For this air is being taken from main
reservoir line and stored in 25l tank. From 25 l tank this air goes to pantograph controlling unit.
This pantograph control unit will use this air to regulate the pantograph mechanism. In case of no
main reservoir supply, additional mini air compressor is provided which will provide air supply
for panto mechanism by using 110 V d.c. supply (it works only for two to three minutes.)
completely dead locomotive is only possible if there is battery power and some compressed air
available to get the pantograph up to the overhead power supply. After all, nothing will work on
the loco without power. So, a small, battery powered compressor is provided to give sufficient
compressed air to raise the pantograph.
As soon as the pan is up, full power is available to operate the main compressor. For safety a 9
bar safety valve is also provided to control this mini air compressor. To control this mini air
compressor, a governor is also provided.

24. 24
Fig. 12 Pantograph
5.5 AIR BRAKES
A moving train contains energy, known as kinetic energy, which needs to be removed from the
train in order to cause it to stop. The simplest way of doing this is to convert the energy into
heat. The conversion is usually done by applying a contact material to the rotating wheels or to
discs attached to the axles. The material creates friction and converts the kinetic energy into
heat. The wheels slow down and eventually the train stops. The material used for braking is
normally in the form of a block or pad.
The vast majority of the world's trains are equipped with braking systems which use compressed
air as the force to push blocks on to wheels or pads on to discs. These systems are known as "air
brakes" or "pneumatic brakes".
5.5.1 Types of Brakes
1. Service Brakes:
This is the main braking system which provides braking to train in normal conditions. This service
brakes are provided with electric regenerative pneumatic brakes. A regenerative brake is a
mechanism that reduces vehicle speed by converting some of its kinetic energy into a storable form

25. 25
of energy instead of dissipating it as heat as with a conventional brake. The captured energy is
stored for future use or fed back into a power system for use by other vehicles. As the driver applies
the brakes through a conventional pedal, the electric motors reverse direction. The torque created
by this reversal counteracts the forward momentum and eventually stops the car.
But regenerative braking does more than simply stop the car. Electric motors and electric
generators (such as a car's alternator) are essentially two sides of the same technology. Both use
magnetic fields and coiled wires, but in different configurations. Regenerative braking systems
take advantage of this duality. Whenever the electric motor begins to reverse direction, it becomes
an electric generator. This generated electricity is fed into a chemical storage battery and used later
to power the train. But it is generally not sufficient to stop the train; therefore pneumatic auxiliaries
are used to further stop the car.
To provide service brakes components involved are:-
a. BECU- Brake Electronic Control Unit:
It is the heart of controlling services and emergency brakes. It gets input on the basis of load (from
air suspension). It has software loaded in it. It also get input from the train operator that how much
braking is required. When train operator demands for braking, he gives signal to BECU.
Accordingly BECU gives command for braking first by electric regenerative braking and if
braking effort is not sufficient then it will give command for pneumatic braking. The braking
provided is load corrected, that is, more the load more will be the pressure applied and less the
load less will be the pressure applied and jerk corrected. During braking, wheel slide protection is
also provided by a pneumatic valve known as anti skid valve. This anti skid valve is controlled by
BECU.
b. BCU-Brake Control Unit:
It takes command from BECU and act accordingly by using valves provided in it. For pneumatic
braking BECU will give electric signal to BCU. These electric signals are converted to pneumatic

26. 26
signals by BCU. According to these pneumatic signals, BCU will generate pressure for braking.
This pressure is applied to TBU.
2. Emergency Brakes:
It is used in case of emergency conditions. It can be applied by the train operator or in case if
certain conditions are not fulfilled (loop of conditions is broken). This signal will go to BECU and
BECU again give electric signal to BCU and BCU further change this signal into pneumatic signal
and applies emergency brakes. Emergency brake is also load corrected.
3. Parking Brakes:
Four number of parking brake mechanism are provided on each car, two per bogie. Parking brakes
are used for parking the train in depot and these are installed at driving trailer cars (one set per
axle).
Parking brakes can be applied manually or these may apply automatically when the main reservoir
pipe pressure is low.
4. Holding Brakes:
It is provided to prevent the train from rolling back on a rising gradient or from train from moving
at the station. It is also provided by BECU which further command to BCU by applying holding
brake. Holding brakes are seventy percent of full service brakes.
5. Back Up Brake (Bp):
Additional brake pipe controlled, back up brake system is provided in order to take over the brake
control function in case of failure of individual electronic or electrical control elements.
The driver can continue to control the pneumatic friction brake by using the driver’s brake valve.
The driver is able to apply or release the pneumatic brake by operating the driver’s brake valve
installed at the driver’s cab.

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CHAPTER 6
AIRCONDITIONING
6.1 Introduction
Purpose:
To ensure pleasant temperature and humidity inside the cab and passenger saloon.
A/C Unit Providing Company:
1. Air International Transit (AIT), Australia
2. Sidwal, India
3. AIT+ Sidwal (Joint collaboration)
Fig. 13 A/C Unit: Top View
Functions:
 To achieve and maintain acceptable indoor climate in cab and saloon
 To produce quality air for driver and passengers

28. 28
 To protect passengers and driver from the smoke outside the train
 To secure CO2 levels inside the train at the time of power failure
Location of A/C Unit on Train:
 Two A/C units are mounted on the roof of ends of each car
 One cab A/C unit is mounted on the roof behind the cab
6.2 BASIC THEORY
There are two laws that are significant to understand the basic refrigeration cycle and air
conditioning. Thermodynamics’ first law: explains that energy cannot be neither created nor
destroyed, but can be changed from one form to another. Thermodynamics’ second law: The law
state that heat always flows from a material at a high temperature to a material at a low temperature.
For heat to transfer there has to be a temperature and pressure difference. In the refrigeration
process there are two sections which produce a pressure difference: a high-pressure, high
temperature section (condenser) and a low-pressure, low temperature section (evaporator). The
refrigeration system removes heat from an area that is low-pressure, low temperature (evaporator)
into an area of high-pressure, high temperature (condenser). For example, if cold refrigerant (40°F)
flows through the evaporator and the air surrounding evaporator is 75°F, the cold 40°F will absorb
the heat from the 75°F space: By absorbing the heat from the warm space, it also cools the space.
It then transfers that heat to condenser (high side) through compressor.
A hot refrigerant from the compressor flows to a cooler location the condenser medium (air
surround condenser) for example, the refrigerant will give up the hot vapor heat it absorbs from
the indoor evaporator and becomes cool again and turns back to liquid. To move heat from the
evaporator to the condenser we need refrigerant, and other mechanical components, therefore we
need to understand how heat transfers.

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6.3 REFRIGERANT:
Refrigerant is a chemical substance that air conditioner units use; these refrigerants absorb heat
from low-pressure, low temperature evaporator and condensing at a higher pressure, high
temperature condenser. These refrigerant used be R-22 i.e. C2Cl2F4 Refrigerant can change state
from vapor (by absorbing heat) to liquid (by condensing that heat).
6.4 WORKING AND COMPONENTS
In the basic refrigeration system or any air conditioner system we will have five basic mechanical
components: a compressor, a condenser, a thermal expansion device (metering device), an
evaporator and a refrigeration copper tube that connects them. Evaporator and condenser act
as heat exchangers in the air conditioning system. There are two pressure lines and two heat
exchangers. The low-pressure line is an evaporator (it absorbs heat) and the high pressure line is
the condenser (it rejects heat). The first heat exchange that occurs in this basic refrigeration cycle
is the evaporator.
Evaporator: is a heat exchanger that is responsible for absorbing heat from whatever place
(medium) that needs to be cooled. According to thermodynamics’ second law heat always flows
from a material at a high temperature to a material at a low temperature. Since the evaporator is at
a low temperature than the air surrounding it, it will absorb the surrounding heat until the
refrigerant liquid inside the evaporator coils starts boiling as result of absorb that heat.

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Fig
5.2
Fig.
13
Fig.
Fig.14 Working of refrigerator
The liquid refrigerant is vaporized in evaporator coils at a controlled rate and temperature. The
low pressure and low temperature refrigerant in the evaporator coil absorbs heat from the sucked
across the coil by the supply air fan. The air which is a mixture of return air and fresh air passes
through the evaporator coils and is cooled and dehumidified is sent into car saloon evenly.
There will be relatively warm air flowing over the evaporator coil, lets say about 80 degrees. The
air condition system is designed so that the refrigerant will evaporate in the evaporator at a
temperature of about 40 degrees, so that it will be cold compared to the warm air flowing over it.
The system is designed so that the heat in the warm air flowing over the evaporator will be
absorbed by the cold evaporating refrigerant. This cools the air flowing over the evaporator, and
is the reason cold air blows out of your air conditioner.

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Compressor:Located between suction line (low side pressure and back pressure) and discharge
pressure (high side pressure, head pressure). The suction line is the line that pulls the low-pressure
and temperature from the evaporator and the discharge line is the line that compresses and pushes
that superheat vapor to the condenser. Its creates a pressure difference in the air conditioning
system by pulling in low-pressure, low temperature vapor from the evaporator suction line and
increasing it to high-pressure, high temperature superheat. This pressure difference what makes
the refrigerate flow in a refrigeration cycle. The compressor is also known as the heart of the
refrigeration system. The compressor is known as the vapor pump.
The refrigerating output is produced by four scroll compressors in each unit. The scroll compressor
is powered directly by 3 phase auxiliary supply. Refrigerating vapor returning from the evaporator
at low pressure enters the compressor and the compressor compresses it. The refrigerant exists in
the compressor at high pressure, high temperature superheated gas via the compressor discharge
valve and flows to the condenser coils.
The compressor is the heart of the system; it keeps the refrigerant flowing through the system at
specific rates of flow, and at specific pressures. It takes refrigerant vapor in from the low pressure
side of the circuit, and discharges it at a much higher pressure into the high side of the circuit. The
rate of flow through the system will depend on the size of the unit, and the operating pressures will
depend on the refrigerant being used and the desired evaporator temperature.
Fig. 15 Compressor

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Condenser: It's a heat exchange; it rejects both sensible (measurable) and latent (hidden) heat
absorbed by the indoor evaporator plus heat of compression from the compressor. There are three
important states that take place in the condenser heat rejection. The first state is it de-superheat or
simply rejects hot superheat vapor (it removes sensible heat). At points 3 and 4 this the state where
it rejects so many saturated vapors heat, it starts changing phase from vapor to liquid; as the
refrigerant reaches point 4 it is 100 percent saturated liquid refrigerant. From points 4 and 5 it
removes sensible heat from the saturated liquid refrigerant. This is where we can use a thermometer
and tell how much heat it has removed, as more heat is removed it’s now in the sub cooled region..
Condenser fan coil is made up of inner screw thread copper tubes aluminum fins and stainless steel
frame. The two condenser fans draw ambient air through the condenser coils. Each condenser
rejects heat to the ambient air from the high temperature refrigerant gas which has been pumped
from the compressor. When heat is rejected from refrigerant to the coil, gas cools and condenser
into a liquid refrigerant.
Fig. 16 Condenser Fans
Filters:
The air conditioning unit has two kinds of filters-
Fresh air filter: They are placed inside the fresh air intake of the unit

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Return air filter: they are placed in the ceiling panel above the return air intake to return air duct.
They are placed in this position so that no unfiltered air will enter the unit and duct system
Emergency Inverter:
In the event of 415V on-board supply failing, cooling of passenger saloon is no longer possible.
Therefore in order to maintain the supply of fresh air to the passenger compartment, an emergency
inverter is mounted inside the HVAC unit is activated.110V DC taken from the battery is converted
into 52V AC, which is further converted into 415V AC using step up transformer and this 415V
is used to run evaporator fan only
6.5 AIRCON WORKING MODES
The saloon air-conditioning works in the following modes
 Ventilation Mode: In this mode air to be circulated throughout the vehicle and at the same
time fresh air will continually be induced into the vehicle but cooling will not be initiated.
 Cool 1: During Cool 1 the air conditioning unit provides approximately 50% of the total
rated cooling capacity. This is carried out by operating compressor and energizing only
one of the liquid line solenoid valves which allows refrigerant to flow into the evaporator
 .Cool 2: During cool 2 modes the air conditioning unit provides 100% of the total rated
cooling capacity. This is carried out by operating and fully loading the semi-hermetic
compressor and energizing both of the liquid line solenoid valves which delivers refrigerant
to the evaporator coil.
 Emergency Mode: In case of Ac Power supply failure the aircons shift to the emergency
vent mode. The power is supplied by the battery and only fresh air is supplied into the
saloon.

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CHAPTER 7
Visual system
7.1 PASSENGERINFORMATION BOARD (PIB)
Fig. 17 Passenger information board
Location:
There are three PIB’s installed in each passenger saloon. All three are powered from the train
battery 110V DC supply and continues to operate when traction power is lost.
Function:
The main function of the PIB’s is to provide information to the passengers. The PIB provides the
following information:
1. Next station is …. - inside train, on the PIB’s
2. This station is … - inside train, on the PIB’s
3. Journey message …..inside train, on the PIB’s
4. Real time information (visual only) - inside train, on the PIB’s (generated by OCC)
The Passenger Information Board (PIB) has a display matrix 32 (H) x 160(W) pixels. Both Hindi
and English messages can be scrolled on the display simultaneously and in synchronism. It is
recommended that for the automatic route announcements Hindi Characters are displayed in

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yellow and the English characters in green. EMERGENCY TALK BACK UNIT (ETU) &
PASSENGER ALARM BUTTON
7.2 ETU &PAB
ETU PAB
Fig. 18 Emergency talk back unit & Passenger alarm button
In case of emergency if a passenger wants to talk to the driver he can do so with the help of ETU
i.e. EMERGENCY TALK BACK UNIT and PAB i.e. PASSENGER ALARM BUTTON.
The PAB is installed at each passenger exterior doorway. There are four PAB’s in each vehicle,
associated to doors L1 L2 R1 and R2. ETU is installed at each door position, with the
microphone/loudspeaker positioned approx 1.5m from the vehicle floor. We have four ETU’s in
each car. It is provided as an interface between the passenger and the driver. The Passenger can
talk to the driver through the ETU. As soon as the passenger presses PAB, ETU detects that PAB
has been operated, and will identify this condition to the PAMP. The PAMP then send signal to
AVAU which further informs the driver by sending information at MOP. Now driver is ready to
talk to the passenger. The position of that particular ETU is also displayed on MOP. The large red
circular button is mechanically latched and is reset by inserting and turning a square Carriage Key
in a clockwise direction. The button is red in colour, having a central part with the square key-
hole; this central part is silver in colour.
ETU is installed at each door position, with the microphone/ loudspeaker positioned approx. 1.5m
from the vehicle floor. The ETU shall identify when a PAB has been activated.
Flow diagram:

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PAB ETU PAMP AVAU MOP
Fig. 19 Flow diagram of ETU
 Loudspeaker & 100V line transformer
The loudspeaker can be driven with 4Watts of power, provided by the PAMP over the 100V line
distribution system.
Location:
It is installed with 6 sets in each saloon.

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CHAPTER 7
PASSENGER SALOON DOOR
8.1 INTRODUCTION
The passenger saloon door system comprises electrically powered, double leaf, sliding doors
designed to permit safe entry and exit for passengers from the train cars.
Location:
Five door sets are located along each side of each "DT," "M," "M," and "DT" car.
Function:
The door system is designed to permit safe entry to and exit from the train cars. The door system
is also designed to prevent entry or exit from the train when the train speed exceeds 5 km/h.
Passenger and crew safety is maintained at all times. The doors provide for physical, thermal and
acoustic separation from the external environment. All bodyside doors include emergency access
systems that are operated manually.
Fig. 20 Passenger Saloon Doors Position Numbering-Complete Train Set

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Design and performance details:
a) To allow clear passage through an area of 1400 mm wide by 1900 mm high for each saloon
door, or 600 mm wide by 1920 mm high for each cabin door.
b) To permit safe entry to and exit from the train cars.
c) To prevent entry or exit from the train when the train speed exceeds 5 km.
d) To maintain passenger and crew safety at all times.
e) To not cause injury to passengers, crew or other person under normal operating conditions.
f) Prevent ingress of dust and water.
g) To include emergency access systems that are operated manually.
h) The internal emergency release handle can be used to open doors while the train is in
motion.
i) To enable control and reporting of door actions and status to the TIMS through the DCU.
j) To allow adjustment of the door forces via a laptop computer connected to the DCU, or by
the TIMS in special LDR mode.
k) To not exceed an opening force of more than 150 N.
l) To open in a standard time of 2 to 2.5 seconds.
m) To close in a standard time of 2.5 to 3.5 seconds (at 110 V DC)
TYPES:
Four types of door system are provided for the train. These are:
TYPE LOCATION
Passenger body side door system. Each side of each "DT", "M" "M" and "DT"
car, making a total of 8 door sets per car.
Cabin body side door system. Each side of the driving cabin in the "DT" car.
Emergency door system Front of each driving cabin in the "DT" car.

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Partition door system Between each driving cabin and the saloon in
the "DT" car.
Table 7.1: Types of door system and its location
8.2 MAJOR COMPONENTS
The major components of saloon door system are as under:
1. Door Panel
2. Door Control Unit
3. Door Gear Assembly
4. Door Locking Mechanism
Fig. 21 Components of Metro door

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8.3 PassengerDoorSystemMajorComponents
 Door Panels:
Door panels are of aluminum composite construction bonded using aerospace technologies. Two
No of door panels (LH/RH) are provided in each door
.
 Door Control Unit:
The Passenger Saloon Door operates electronically, via the electronic Door Control Unit (DCU),
except when the manual emergency release mechanism is used. The DCU activates door opening
and closing on receipt of signals from the train operator's panel. Door status signals, such as "Door
Open" and "Door Closed and Locked" are returned from the DCU to the train operator’s panel. In
all instances, the DCU controls whether the door can be opened or not. The door can be manually
opened, or closed and locked, regardless of whether power is available.
 Door Gear
The Door Gear Assembly consists of:
 Mainframe Assembly: The Mainframe Assembly is located at the top of each External
Slider Door system. This is the primary fixing point for mounting the door assembly into
the car body.
 Electric Motor and Gearbox: The electric motor provides power for movement of door
panels. Motor used is a permanent magnet dc motor.

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Fig. 22 Door gear
Major Components
 Transmission Belt and Transmission Pulley: The transmission belt and pulley transmits
the motor movement to the spindle shaft. The transmission pulley is mounted on spindle
shaft.
 Spindle Shaft: On the movement of pulley spindle shaft rotates and transfer the movement
to the drive brackets via spindle nuts.
 Drive Brackets: Door brackets are mounted on door panels.
Fig. 23 Drive brackets

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 Solenoid and Door Lock: The Locking Mechanism is integrated in the Door Gear
Assembly in centre of the Door Gear Assembly. Mechanical locks are used to ensure full
locking. The centre hook assembly locks the Doors as they meet in the centre. A Lock
Switch mounted onto the Door Gear Assembly is activated by the Centre Hook Assembly
to signal the Door Control Unit that the door is locked.
 Door Isolation Switch Assembly: Door isolation switch assembly is provided in the
middle of door gear assembly. It is used to isolate the door in case of any door failure.
 Emergency Release Mechanism: Emergency release mechanism is provided to open the
any particular doors without opening all doors in case of any emergency. In every car door
no 2 and door no 6 are provided with external emergency release device. Internal
emergency release devices are provided in all cars.

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CHAPTER 9
CONCLUSION
Delhi Metro has added an extra charm to the historical city of Delhi. You can now commute with
ease from one place to other. Delhi has got a great gift in form of the Metro Railway system. It
does not take much time to go from one place to another. The ever increasing pollution problem
too has been reduced to a greater extent, with the advent of Delhi Metro. You can now avoid the
road traffic and reach your desired destination on time.
Delhi Metro has added a new direction to the transport system. Delhi Metro has hi-tech cabins
which are airy and comfortable. These have well automated gates. There are emergency gates,
which can be used in case of emergency. The security of the Delhi Metro stations is being revived,
in order to avoid any security breaches. You can even communicate to the driver of the railway
directly, if there is any emergency case.
All these things become possible due to regular maintenance of Delhi Metro. Metro depots are
playing a big role in maintaining the status of Delhi Metro. For Violet Line of Delhi Metro, Rolling
Stock Department, Sarita Vihar is the place for repairing the parts of Delhi Metro. This depot
contains several departments for any kind of technical problem in Delhi Metro Trains. The PPIO
is the planning, progress and investigation organization at the depot, which keeps the schedule of
the train maintenance as well as does a physical check every day, based on a pre-determined
schedule. If a problem is detected, it goes into the IBL or the workshop, depending on the snag. If
the train is going into revenue service without any major maintenance being planned, it only goes
through a routine cleaning.

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CHAPTER 10
REFERENCES
1. "Delhi Metro About Us Introduction". DMRC. Retrieved 16 June 2017.
2. "Delhi Metro's Cumulative Ridership for the financial year 2016-2017 crosses one billion
(100 crores)". www.delhimetrorail.com.
3. "Delhi Metro's Cumulative Ridership for the financial year 2016-2017 crosses one billion
(100 crores)". DMRC.
4. "Mangu Singh to be next Metro chief". The Times of India. 20 October 2011.
5. "CoMET and Nova Members - CoMET and Nova Metro Benchmarking
Groups". cometandnova.org.
6. "How metro rail networks are spreading across India".
7. "First and Last Train Timings" . www.delhimetrorail.com. Retrieved 16 June 2017.
8. Siemiatycki 2006, p. 279
9. Siemiatycki 2006, pp. 279–280
10."History of Delhi Metro". DMRC. Retrieved 17 September 2009.
11.Pucher, John; Nisha Korattyswaroopam,; Neenu Ittyerah (2004). "The Crisis of Public
Transport in India" .Journal of Public Transportation. 7 (4): 1–20. Retrieved 17
September 2009.
12."Structure of Delhi Metro". DMRC. Retrieved 17 September 2009.
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original on 18 April 2008.
14. "Delhi Metro showcases public sector success". The Indian Express. 13 April 2007.
Retrieved 10 September 2009.
15."China Business/International Business". MTR. Retrieved 2 June 2011.
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