DELHI METRO RAIL CORPORATION LTD.

SUBMITTED BY-

MECHANICAL ENGINEERING
DELHI TECHNOLOGICAL UNIVERITY

ACKNOWLEDGEMENT
It is indeed a great pleasure for me to present this Summer Training Report on Delhi Metro
Rail Corporation as a part of the curriculum of the B.Tech course Mechanical Engineering

I take this golden opportunity to thank all my mentors at DMRC who with their support and
venerated guidance made this training a real success . I express my sincere thanks to officers
of DMRC who inspite of their busy schedule have lent their precious time for helping out me
to understand various system used in DMRC.

I will be failing in my duty if I am not mentioning the technical demonstrations as given by

the reverent staff of DMRC. There is no denying the fact that DMRC is the epitome of
modern technology and getting training at such an organization is an exquisite learning
experience that made a mark at the profoundest part of my mind.

Delhi Metro Rail Corporation

Introduction
METRO is like a dream come true for Delhi, a revolutionary change in the city transport.
Delhi needs metro system in the first place and it would change things for the better not only
for people who would be using it and but for the people living in Delhi by reducing
congestion, air pollution, noise pollution and accidents.

Formation of DMRC

A company under the name DMRC was registered on 30.05.1995 under the companies act
for construction and operation of the metro project. DMRC is the joint venture of the
Government of India and Government of National Capital Territory of Delhi. It started
functioning in November 1997. It appointed General consultant in August, 1998 to assist
them for implementation of the project. This is the consortium office international
consultancy company led by Pac Consultants International (PCI), Japan. The whole project
of approximately 200Kms is to be completed in three phases up to 2021, the first phase of the
project, comprising of approximately 62.06Kms, is currently operational.
It is having 18 stations in Line 1 (Red Line), 10 stations in Line 2 (Yellow Line) and 22
stations in Line 3 (Blue Line).

Benefits of Delhi Metro on completion

On the completion of the first phase of the Delhi Metro, it would be catering to around 2.18
million commuters per day resulting in decongestion of the roads. This would also mean that
there would be less number of buses on the roads. It has also reduced the travel time. Also the
pollution level is reduced to about 50%.

Since the first phase of the Delhi Metro is operational a large number of commuters are
having a lot of convenience in reaching their desired destination in the required time.

Advantages of Rail-based Transit System

 Can achieve carrying capacity as high as 60000-80000.

 Required 1/5th energy per passenger compared to Road-based system.

 Causes no air pollution in the city.

 Causes lesser noise level.

 Occupies no road space if underground and only about of 2 meter width of the road if
elevated.

 Carries same amount of bus traffic or 33 lanes of private motor car.

 Is more reliable, comfortable and safer than road system.

 Reduces journey time (about 50% to 75% )

Awards won

The Delhi Metro has been awarded OHSAS (Occupational Health and Safety Assessment
Sequence 18001) by RINA (Registro Italiano Navale India Pvt. Ltd.), Geneva.

To help in proper maintenance the DMRC has been divided into departments and sub
departments:

 Signaling
 Telecom
 Rolling Stock
 P. Way
 AFC

Rolling Stock Overview –

Train Formation

At present each train train set consist of four cars.Both ends of the train-set are Driving
Trailer(DT) cars and middle cars are Motor(M) cars.
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 (Here T car is the non-driving trailer car.)

Salient Features –

1. Broad Gauge

2. 25 KV Supply Voltage System

3. Three phase A.C. Induction Motor

4. Fail Safe braking with regenerative braking

5. VVVF Control

6. Reinforced conical rubber primary Suspension

7. Secondary Air Suspension

8. Uniform Floor Height

9. Jerk Controlled Braking

10. Light Weight Stainless Steel Structure

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
ITEM SPECIFICATION

Track Rail gauge 1676mm

Supply Voltage System 25kV ac single phase 50Hz
Current Collection Through Pantograph
Car Train Weight(max) DT&T : 42.0 ton, M : 42.0 ton
 Maximum Number of passengers
DT car 361 persons (seating – 43, standing – 318)
M&T car 392 persons (seating – 50, standing – 342)
Speed Control System Control of acceleration and deceleration by
Variable Voltage, Variable Frequency
(VVVF) Inverter blended with regenerative
Braking
Brake System Regenerative braking blended with
pneumatic braking by electrical command
and BP-back up brake by driver’s brake
Valve
Air Pressure MR-pressure 8.0 bar ~ 10 bar
Automatic Train Control System Automatic Train Protection (ATP)
Train Monitoring System Train Integrated Management System,TIMS
Saloon Air Conditioning System
Type Roof-mounted and Self-contained Type
Rated Cooling Capacity 41KW

Bogie Type Bolster less type bogie with air spring

Suspension
-Primary Conical bonded rubber spring
- Secondary Air spring

Maximum design Speed 90Km/h

Maximum Operational Speed 80Km/h
Round trip schedule Speed with 35Km/h
30S station & 8% coasting,
excluding terminal station turn
round time with fully loaded train

Acceleration from 0km/h to 0.78m/s ±5%

30km/h for fully loaded train on
level tangent track(Notional)

Service braking rate from 80km/h to 1.0m/s ±5%

standstill up to fully loaded train on
level tangent track

Emergency braking rate from 1.3m/s

80km/h to 0km/h up to fully loaded
train on level tangent track

Jerk rate 0.70 + 0.05m/s

INDEX
1. Aircon

2. Pneumatic and Brake System

3. Passenger Saloon Door

4. Bogie,suspension & wheels

5. Coupler

6. Saloon Interior

7. Car Body Structure

Function of air conditioning system

• to control temperature
• to control humidity
• to supply pure air

Design Conditions

Description Condition
No. of passengers :- 392
Ambient temperature:- 430 DBT& 33% RH /
390 DBT & 41%RH DBT
Inside condition:- 330 DBT&/290DBT
Present inside condition:- 240 DBT
Fresh air per passenger :- 2.3 lps
Cooling capacity:- 41 kw per unit
82 kw per car

Operating modes
TEMPERATURE TEMPERATURE
FALLING RISING

COOL2
Set Point + 1.0C

COOL2 COOL1
O
o
Set
SETPoint
POINT+ 0.5C
+1C Set Point + 0.5C

COOL1
VENT
SET POINT SET POINT

VENT

• Normal Operating Mode

In Normal Operating Mode A/C unit provides cooling and ventilation, switching
automatically by various sub modes to fulfil specified condition.

• Emergency Operating Mode

When 3 Phase. Power supply is not available , ac will work in this mode & will supply fresh
air only.

• Smoke Mode
In this mode , system shuts off the fresh air intake and provides full recirculation of return
air within the saloon.
Normal operating sub -modes

• Vent mode :-
air is supplied inside saloon without any cooling

• Cool-1 mode:-
air is supplied with cooling (only 50% of cooling capacity
is used)
• Cool-2 mode:-
air is supplied with cooling (100% cooling capacity is used.

Main component of air conditioning system -

• Refrigeration Equipment
• Air Transfer Equipment
• Electrical Equipment

A) Refrigeration equipment

1.Compressor
2. Condenser coil
3. Solenoid valve
4. Thermal exp. Valve
5. Evaporator coil

1. Compressor

The function of the compressor is to pump the refrigerant through the system and to
compress the low pressure, low temperature refrigerant into a high pressure high temperature
super heated vapour, to allow condensing to occur.

Type:- Semi-Hermetic Four Cylinder

Reciprocating Suction Gas Cooled
Speed:- 1450 rpm
Swept volume:- 82.21 m3/h
Displacement:-945ccm

2. Condenser

The function of the condenser coil is to reject the heat from refrigerant absorbed by the
evaporator coil and during the compression process

Type: Copper finned, copper tube,

brass frame heat exchanger
Quantity: 2 per unit
Air Flow:2700 l/s (each coil)

3. T-X valve

The TX valve regulates the refrigerant flow into the evaporator coil, expanding the liquid
from high pressure to low pressure, and causing a large drop in refrigerant temperature.

Refrigerant R22
Range N -40 ® +10 o C
Factory Superheat 5K
Max bulb temp. 100 o C
Max working pressure 28 bar

4. Evaporator coil

The prime function of the evaporator compartment is to deliver conditioned air to the main
supply air duct that services the vehicle

Type: Copper finned, copper tube, brass frame heat exchanger.

Quantity: 1 per unit.
Air Flow: 1350 l/s
Face Velocity: £ 2.5 m/s
Cooling Capacity: 41 kW

5. Dual pressure controller (DPC)

Its function is to switch off the refrigeration system in case of adverse system condition . It
monitors both the high and low refrigerant pressures. If the low (LP) or high (HP) pressures
reach a predetermined set point, the refrigeration system will be shut down.

Range: LP – 50 – 700 kPa

HP – 300 – 3000 kPa
Set points:-
hp fault:- 2800 / 2500 kpa
Lp fault :- 50/350 kpa
 B. Air Transfer Scheme

Fresh air
Evaporator

Supply fan
saloon
saloon

Fresh air damper

1.Supply fan
As the name applies , it supplies the conditioned air inside saloon . It draws back 70% of
return air & 30% of fresh air & moves past t

Type: Two double inlet centrifugal blower

wheels with double shafted motor
Quantity: Two (2) per unit
Supply Air: 1350 Litres/second at 470 Pa
external static pressure
Motor:- 2.2 kw @1500rpm , 415 v

2.Condenser fan

Its function is draw the atmospheric air through condenser coil , inside which hot refrigerant
is flowing , thus making the heat rejection & condensing the

Type: Multi wing axial fan, 9 blades

Quantity: two (2) per unit
Direction of flow: Draw through
RPM Range: 0 – 2045 rpm
Motor:- 2.2 KW @1500rpm , 415 v
3.Air dampers

Their function is to control the fresh air & return( recirculated) air volume as per
requirement.

Mode fresh air return air

damper damper

Vent , partially fully

Cool 1 &2 opened opened

Emergency fully fully

vent opened closed

Smoke fully fully

vent closed Opened
 PNEUMATIC & BRAKE SYSTEM
Pneumatic system is mainly used in five items in metro Brake System, Coupler, Suspension,
Horn and Pantograph. But pneumatic system work in a unit with common input and different
outputs i.e. having a common air supply equipment which supply air at high pressure in two
pipes named MAIN PIPE (M.P.) & BRAKE PIPE (B.P.) and other equipment tapped pressure
from it. Hence it has been configured as follows:-

Configuration

A - Air Supply equipment - DT, T

B - Brake Control equipment - DT, T, M
C - Mechanical Brake Actuating component - DT, T, M
G - Wheel Side Protection equipment - DT, T, M
L - Air Suspension equipment - DT, T, M
P - Pneumatic Horn equipment - DT
U - Auxiliary Air Supply equipment - DT, T,
W - Automatic Coupler Actuating equipment - DT, T, M

A) AIR SUPPLY EQUIPMENT

Its mainly consist of three parts:-

1) Piston Compressor (VV120)

2) Air Dryer Unit (LTZ015 –H)
3) Air Reservoir

Piston
compress
Ai or VV120 Air dryer unit
r
LTZ015-H

Air
Reserv
oir
1.Piston Compressor

There are two type of compressor:-

i. Main compressor:-
1. Discharge air pressure max. 10 bars.
2. Nominal discharge capacity 900 L/min.
3. Type piston type.
4. motor 3, 415V AC, 50 Hz, induction
motor

ii. Auxiliary air compressor

1. Nominal discharge capacity - 70 L/min
2. motor - 110V DC, 860W,10 minute rating

Features of piston compresseor:-

 It is W- Shaped 3-Cylinder Unit with 2-Stage

compression reciprocating type compressor (see fig.).
i. Extremely short design.
ii. Optimum cooling for all cylinders.

 It have self-supporting, Flange- Mounted, Motor –

compressor set.
i. No additional frame needed.
ii. Small installation space.

 It creates very low sound pressure level.

i. Only about 64db(A)/4.6m (76db/1.0m)

 It have closed circuit splash – type lubrication

i. Which allow low oil consumption.

 It have forced air cool type ******** heat exchanger i.e. radiator.

 Its cooler Fan speed control by temperature.

 It also has a torsion ally rigid bellow type coupling between motor and compressor
which allow no rotary vibration.

 It is mounted with car by wire rope isolators for no resonance throughout the whole
compressor speed range.
 Compressor can be drive by AC, DC and hydraulic motor i.e. very low specific
power consumption
i. It also has low breakaway torque for low starting current even at low
temperature.
2) Air Dryer Unit (LTZ015 –H)
At very high pressure when air is cooled some component of it condense in to liquid which make air
wet. So that why an air dryer unit mounted which perform following function on air:-

1) Dries the air.(Two column unit)

2) Separate oil & liquid from it.(Oil separator)
3) Filter the foreign partial from it.(MicroFilter)
4) And act as silencer for out going air to reduce noise.(Air silencer)

92.93 Insulators
(on LTZO15..H)
A Drainage port
O.. Exhaust port
P1 Air supply port
P2 Air pipe connection to
main reservoir

V... Valve seat

19a Tower
19b Tower
19.7 Desiccant
19.11 Oil separator bowl with
Ranching rings
24 Valve cone for check valve

25 Bracket
34 Duplex piston valve

3.Air Reservoir
There are 2 type of reservoir Main reservoir & Auxiliary reservoir

1) Main reservoir can have 200L of air.

2) Auxiliary reservoir can have _______L of air.

B.BRAKE CONTROL EQUIPMENT

The brake system is one of the most important parts of metro and it is controlled and designed to
interface with TIMS(Train Integrated Management System) with electrical and pneumatic
controls. The two think must be taken in consideration while designing brake system:-

1) Wheel – slide protection

2) Fail safe system

Main component of brake system are:-

1) BP (Brake Pipe)
2) BCU (Brake Control Unit)
3) BECU (Brake Electronic Control Unit)
4) ASV (Anti Skied Valve)
5) BBU (Block Brake Unit)
34.15 KNORR K-ring
34.17 KNORR K-ring
43 Valve magnet

50 Regeneration choke
55 Piston for pre control valve
56 KNORR K-ring

70 KNORR K-ring
71 Valve head for bypass valve
 1) BAKE PIPE

a. It is a tapped pipe from MRP (Main Reservoir Pressure).

b. Its max. pressure is 5 bar
c. It’s used only for braking propose.

2) BRAKE CONTROL UNIT

It is a single board which consist many type valves as

shown in fig.
It has analogue control valve which convert signal from
BECU to required pressure.
a. Combination of different valve used for different
purpose:-

i.A & B used for service brake.

ii.C, D & E used emergency brake.
iii.F & G used for auxiliary unit.
iv.J, L, M & N used for testing fittings

Different type of braking :-

i. Service brake
ii. Blend brake
iii.Emergency brake
iv. Parking brake
v. Holding brake
vi. BP- back up brake

i. SERVICE BRAKE :-

a. It is ED (Electro Dynamic) brake.

b. It is also Regenerative brakes
c. In this motor work as generator and back EMF is
produce which recharge the battery.
d. And due to generative action and opposite field a
braking force is applied on the motor.
e. This brake is controlled by C/I of M car.

ii. BLEND BRAKE

 f. It is blending of ED (Electro Dynamic) brake & EP
(Electro Pneumatic) brake.
g. It is applied when only ED brake is not sufficient.
h. Then the remaining amount of brake is applied by EP
brake
i. EP brake is control by DT car. Hence blend brake is
collectively controlled by DT & M car.

M car DT car

Train line
brake demand
TCU TCU

BECU

BECU

Blending request

F set by M & DT

F set by M EP

ED

V1 V2

iii. EMERGENCY BRAKE

j. The train set is equipped with an emergency brake

loop wire. The emergency brake loop is connected to
the emergency brake magnet valve. Which is opened
when de-energized and closed when energized (Fail-
safe system).
k. Magnet valve is de-energies by driver or interruption
it by pass the MRP i.e. MRP become 0 bar
l. Analogue control valve on BCU produce a request
signal using load limiting value.
 m. Redundancy realized for the emergency brake
pressure generation.

iv. PARKING BRAKE

n. Parking brake is used for parking the train in depot and
these are installed at Driving trailer car and Motor cars (1
set per axle).
o. It can be operated manually or by TIMS.
p. It is spring actuated brake.
q. In this first MRP pressure goes low (< 4.5 bar) by any
mean it release the pressure from spring and brake
applied.

v. HOLDING BRAKE

r. The holding brake is provided to prevent the train

from rolling backwards on a rising gradient and the
train from moving at the station.
s. This brake is controlled by C/I of M car.
t. The holding brakes are 70% of full service brakes.

vi. BP- BACK UP BRAKE

u. Additional BP (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.
v. The driver is able to apply or release the pneumatic
brake by operating the driver's brake valve.
w. By the brake valve the brake pipe (BP) pressure can
be reduced or increased depending on the time the
brake lever is maintained at "braking" or "driving".
During the normal service brake operation, the drivers
brake valve lever shall be maintained at "driving"

C.BRAKE ELECTRONIC CONTROL UNIT

1.It is microprocessor based control system which deals with many type of signal.
2.It works as an interface between TIMS & BCU.
 D. ASV (Anti Skied Valve)
Wheel slide protection is used to optimize the stopping distance and to avoid the wheel flats
under wheel sliding conditions. Wheel slide protection is active in service brake and
Emergency brake.The wheel slide protection acts per bogie on each car by the dump valves
(G2).

Wheel-slide protection is operational at all speeds down to 3 km/h.Speed sensor mounted on

the cover of each axle box, detects the speed of the associated wheel.

When a potential wheel-slide event is detected, the BECU will release/apply the brakes
through energizing/ de-energizing the magnets of the dump valves or anti skied valve.

1 Econnection
2 Double valve
magnet
3 Plate
4 Anchor spring
5 Housing
6 D – piston
7 Compressing
spring
8 Control chamber
9 Valve seat Vd
10 Bypass nozzle
11 Nozzle D
12 Bracket
13 To brake
cylinder
pressure
supply
14 To the brake
15 Nozzle C
16 Valve seat Vc
17 C-piston
18 Control chamber
 19 Outer valve seat
20 Inner valve seat

Block Brake Unit

 1 Piston packing ring 44 Compensating link
2 Piston 45 Bracket
3 Piston return spring 46 Return spring
4 Piston pin
5 Cam disc
6 Bearing pin
7 Cam roller
8 Trust ring
9 Adjuster mechanism
10 Hexagon reset head
11 Ball – shaped rod head
12 Torque pin
13 Brake block wedge
14 Brake block shoe
15 Brake block
16 Link pin
17 Hanger
18 Friction member
19 Hanger pin
20 Torsion spring
21 Housing
22 Bellows
23 Cylinder cover
24 Air supply port

L)AIR SUSPENSION EQUIPMENT

TYPES OF DOOR

 PARTITION DOOR
 CAB SIDE DOOR
 SALOON DOOR
 EMERGENCY DOOR
 Salient Features of Saloon Door

 Obstruction detection
 Door isolation
 Emergency operation
 Fault diagnosis

BLOCK DIAGRAM OF SALOON DOOR OPERATION

110 V DC
INPUT SIGNALS SUPPLY
1. CLOSE SIGNAL
2. LOCK SIGNAL
3. EMERGENCY SIGNAL ISOLATION
4. ZERO SPEED SIGNAL SWITCH

OPEN/CLOSE DOOR CONTROL UNIT TIMS

COMMAND (DCU)

SOLENOID

MOTOR ENCODER

SPINDLE SHAFT

SPINDLE NUT

DRIVE BRACKET

DOOR PANEL

DOOR
OPEN/CLOSE
Types of Coupler –

1. Automatic Front Coupler –

Coupler Length (from face to pivot) 1350 5 mm

Coupler Weight approx. 485 kg
Maximum Swing of coupler
Horizontal approx 45
Vertical approx. 6

2. Automatic Intermediate coupler –

Coupler Length (from face to pivot) 1350 5 mm

Coupler Weight approx. 365 kg
Maximum Swing of coupler
Horizontal approx 45
Vertical approx. 6

3. Semi Permanent Coupler –

Coupler Length (from face to pivot) 1240 5 mm

Coupler Weight approx. 210 kg
Maximum Swing of coupler
Horizontal approx 45
Vertical approx. 6
Different faults of aircon –

• Circuit breaker tripping i.e SFB , CBF , CMB tripping: any circuit breaker gets trips,
this fault comes.
CBF-1 or 2 tripped:- system will run as usual with increased discharge pressure
CFB- 1&2 tripped :- system will not run in cool mode
CMB tripped:- system will not run in cool mode
SFB mode:- system will not run in a any mode

• High pressure(HP) fault:- when system pressure increase beyond given safe limit for
the system, then system gets tripped. If such instances occur more than 3times in a
hours, then cooling system will shut down.

• Low pressure fault: when system pressure decreases beyond given safe limit for the
system, cooling system will shut down.

• High ambient temperature unloading.:- in case of adverse ambient condition , to

avoid overloading of cooling system , system is unloaded.

• RAT/FAT probe fault:- these faults occurs in case of failure of temperature probe.

• COTS / IOAT getting operated:- these are temperature switches , installed inside
compressor motor winding & inverter area respectively., & gets operated when
temperature exceeds the given limit.& respective system gets shutdown.