Seminar Paper Corrected

8/3/2019 Seminar Paper Corrected

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INTEGRAL COACH FACTORY - MODERN TRENDS IN SUB-URBAN

ROLLING STOCKL.M.Sahore, Chief Electrical

Engineer/ICF

Indian Railways a mammoth railway system that runs across the length

and breadth of the Indian sub-continent over 65000 kms of track, carrying

12 million passengers every day. In the commercial capital of India i.e the

Mumbai megapolis alone, every day, over 6.5 million users patronise the

most intensively used sub-urban railway system in the world, the Mumbai

suburban. The population of Mumbai has gone up from 40 lakhs in 1947 to

120 lakhs in 2000 and it is expected to cross 200 lakhs by 2015. This

extraordinary growth in population has been posing a tremendous

challenge to the Indian Railways and all efforts are made to ensure that

the services on the Mumbai sub-urban commensurate this growth rate.

The Mumbai suburban railway system is the lifeline of the megapolis,

helping these 6.5 million people commute between home and work spots

everyday for the last more than eighty years. Despite being taxed to its

limits , the Mumbai suburban boasts of extremely high efficiency levelswith punctuality record showing figures in excess of 95 %.

During peak hours, despite running trains at frequencies of a train every 2

to 3 minutes, each 12 car train is packed with more than 6000 passengers,

a per coach capacity exceeding 500 passengers which translates to a

passenger loading density of a near impossible to imagine figure of 16

passengers per sq.m of area. Needless to say, transportation of local

passengers over the suburban sections of Mumbai has become the

biggest challenge of the time for Indian Railways.

The Mumbai suburban started in 1925, with a 1500 V DC system ofelectrification. With progressive growth in the population of Mumbai, the

frequency of trains and the passenger loading has been increasing year

by year. The 1500 V DC system of electrification has been getting

stretched with the need for additional substations to meet the

augmented load. Today a stage has come when the 1500 V DC system

has reached saturation. There is a need to switch over to a higher system

voltage so that the requirement of substations comes down. The 25 kV AC

system available in the rest of the electrified routes on Indian Railways, is

now being adopted in a phased manner in Mumbai. The targets for

conversion is now set on Western Railway 31.03.2009 for complete

conversion to 25kv ac single phase system in MUTP phase I whereas theconversion targets for Central Railway being 31.03.2010.

The trains running on the 1500 V DC system are with DC series traction

motors with series parallel system of control and friction brakes (electro-

pneumatic). Since, the conversion has to be done without disturbing the

existing services, the switchover to 25 kV AC calls for a rolling stock suited

for dual voltage operation. The necessity for Change in Propulsion from a

1500 V DC system to 25 KV AC system has been combined with a change

in the drive from DC drive to three phase AC drive so that the technical


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problems associated with the DC drive limitations could be overcome

and the following benefits of three phase technology also could be

derived :-

a) Use of VVVF based three phase drive using GTO/IGBT based converterinverters for 4 QC control.

b) Use of three phase squirrel cage type induction motors, free fromcommutation problems and need for frequent attention to brush gear

associated with DC motors.

c) Higher power is to weight ratio of AC traction motors 25 to 30 % higherpower for the AC motors

d) Availability of regenerative braking feature more than 35 % powersaving vis-a-vis DC drive in addition to reduction in wheel and brake shoe

wear. The saving in the power bill of the Railways is to the tune of Rs. 0.5

crores per rake per year. In addition, this feature has also enabledRailways to accrue carbon credit .

e) Use of microprocessor based control system and TMS for smootheracceleration, effective monitoring of all performance and safety related

parameters for enhanced performance, safety and reliability

The development of the rolling stock for the Mumbai suburban has also

undergone a sea change in other areas too and a new look AC DC rake

equipped with world class aesthetics introduced in Mumbai area are

becoming a sort of role model to be adopted in future AC EMU stock, so

that commuters are provided with latest state of art technological

coaches. The latest features are briefly discussed below:

a) Drivers safetyThe drivers cab is in line with UIC 651 requirements with respect to

dimensions, layout of the cab, visibility from the drivers cab, drivers desk

and location of main operating equipment and control system and

drivers seat. With the provision of nose cone sliding doors on both the

entrances and routing of the cables through roof and side walls, the

dimensional requirement of head room, access, visibility and level floorhave been achieved. Wider lookout glasses are provided for better track

and signal visibility. In lieu of toughened look out glass, a polycarbonate

lookout glass which is stone proof and shatter proof has been used. With

the provision of fluorescent lamp with enclosed diffuser, a uniform level of

illumination of 200 lux has been achieved compared to 30 lux in the

existing coaches and 60 lux as prescribed in UIC. In addition to the

fluorescent tubes, spot lights also have been provided for the use of the

drivers during driving. With the provision of 2 nos. of 400mm sweep


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swivelling type carriage fans in the drivers coach, the ventilation

requirement has been met to ensure 55 m3 of air per min per fan.

The drivers desk and main operating equipments and control system such

as the master and braking control(MBC), brake instrumentation,

speedometer(SPM) and the man machine interface(MMI) have been

organised in such a manner that the driver need not divert his attention

while operating these equipments from observation of the tracks and

signals. The controls for head light, flasher, automatic vigilance device,lights & fans for the coaches and the indication equipments are also

suitably located to have ease of access to operate these equipments

from the drivers seat. Each of these switches, instrumentations have been

provided with bakelite indications for proper identification during

operation. Sufficient leg space have been provided for leg and knee

movement between the seat and the desk. The drivers seat has been so

designed to facilitate the vertical adjustment as well as longitudinal

adjustments duly taking into account anthropometric dimensions with

reference to the conditions of visibility of signals. The Man Machine

Interface provides graphic information regarding the working of various

equipment and amenities on the entire train formation and trouble

shooting guidance. An Automatic Warning System is provided to ensure

brake application in the event of restrictive signal.

Further to enhance the drivers comfort, cab air-conditioning is also being

planned. The front face of the EMU has been redesigned with a nose

cone design to impart a world class look which in addition has helped in

crediting more space.

b) Low Noise Pneumatic Compressors for air supply & SS pipelines:Low noise reciprocating type of compressor with 3 phase 415 V

drive, built-in inter and after coolers have been provided in these

trains. These compressors have inlet air from under frame whereas

the compressors in existing design have inlet air from passenger

area through a separate filter. These compressors deliver 920 lpm at

rated speed. Due to use of stainless steel pipelines and fittings in

new train for air supply system as well as use of regeneration

braking, the duty cycle of compressor have been in the order of

OLD DESIGN OF CAB IN DC EMU CAB DESIGN IN NEW GENERATIONEMU


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27% with all compressors in service. A typical comparison indicates

distinct advantage of air supply system.

Details Existing rakes New rake

Compressor

rating

9.7 kW 110 V dc 6.7 kW 3 415 V

Noise level 80 db 66 db

Duty cycle 60% 27%

Air intake / filter External In built.

c) Brake blending, Wheel slip / slide protection & Anti skid controlsThis new generation AC DC EMUs

have been provided with advanced

braking control mechanism to

achieve maximum regenerative

braking over full range of speed. This

system of regeneration braking is fully

blended with electro pneumatic (EP)brakes, so that any set of braking

effort demand in EP region is met by

maximum regenerative energy for Motor coaches and EP brakes for

trailer coaches to supplement difference between the demand

and the regenerative braking effort achieved. The system also

takes care of the condition of (i) Non-effectiveness of regenerative

braking by changing over to EP fully and (ii) EP failure condition by

changing over to automatic brakes within a preset time

automatically through BECU (brake electronic control unit).The

wheel slip and slide protection system in all modes of acceleration

and deceleration (braking) and anti skid control for regenerative

mode are integrated into traction control unit to achieve these

controls.

For EMU and main line applications, ICF has already switched over from

cast iron brake blocks to composite brake blocks which has reduced the

frequency of brake block replacement by a factor of four. This has also

considerably reduced resource requirement for maintenance as well as

maintenance costs.

d) Polycarbonate SeatsThe present desktop is provided with MS frame with powder coating and

the seat made up of compreg laminated sheet conforming to RDSO

specn. C 9407 type 1. These sheets generally require replacement due to

wear and tear.

Polycarbonate has been used for the passenger seat material in lieu of

compreg which will result in reduced wear and tear and maintenance.


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outer frame rods, etc. There used to be number of complaints of thefts

and miscreants activities as no grills to prevent such activities are provided

in the windows of the coach. These windows were also very small in size

and not possible to look through them for observing the names of the

stations from the window.

Windows also had a problem of poor ventilation during rainy days

when the window glass is closed. The

size of the windows were 610 x 762 mm.

Windows of AC DC EMU:

a. Window frames Alu. IS: 733 86, 64300 WP

b. Fixed louver shutter Polycarbonate clear finish

2.5mm thick

c. Movable Glassshutter Assy. IS: 2553 (Part 1) 1990. 6mm thick.

i. Second class clear toughened safety float glassii.

First class tinted medium brown toughened safetyfloat glass.

d. Grill S.S. AISI 304. Powder coated (clear)e. Inner fame Alu. To IS: 737: 86, 31000 HZ Powder coated.f. The size is 915 x 990 mmg. 3mm Stainless Steel wire for grills to Specn. IS: 6528

f) State-of-the-art coach lighting systemIn existing DC EMU trains, the coach illumination is achieved by 26 no. of 1

x 18 W fluorescent tube in a mesh type fitting. The illumination thusachieved was around 30 lux. A scientifically designed lighting system

using Fluorescent lights with energy efficient electronic lamp ballast has

been provided in the passenger area. In the new trains, 1 x 36 w fitting

with polycarbonate diffuser is arranged in the central duct to have

uniform illumination of 300 lux. These fittings have been developed to

confirm to IP 66 to have jet washable feature. These fittings will be

requiring less maintenance due to higher IP level protection against dust

etc.

g) GPS based Passenger Information SystemA GPS based passenger information system with high quality LED

displays, high performance speakers and LED destination boards


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has been provided in the passenger area. The selected LEDs ensure

excellent day time visibility as well as angular vision.

The passenger information system - a complete new feature of the

new train which has the following salient facilities:

Destination indicator (head code) in drivers compartment withhigh resolution LED.

Public Address system with speakers in each coach, Microphone indrivers cab.

Auto announcement of stations and other information Visual graphic display of station names and platform in the coach

(LED type with wider view angle).

Driver guard communication Data communication through CANBUS & RS 485 communication.

Auto volume control through ambient noise monitoring

h) Ventilation systemA very serious problem on Mumbai

suburban has been that of a verysuffocating ambience in the interiors

in the event of Super Dense Crush

Passenger Loading - in a trailer

coach almost 600 passengers travel

during peak hours. A major

improvement done on the new

generation EMUs manufactured by ICF for the Mumbai suburban (MRVC)

is the provision of a forced ventilation system to get over this problem.

The Ventilation system comprises three main components or

subsystems:

1. Air handling units (AHUs) discharge outside fresh air to thesaloon area. There are two AHUs per rail coach.

2. The fresh air ducts distribute the outside fresh air evenlyover the length of the rail coach. The fresh air leaves the

duct through diffuser grills.

3. Ceiling fans tore-circulate the air in the passenger area.A ventilation system cannot guarantee the highest possible level of

comfort to rail passengers. For optimum comfort, it is not sufficient to

ensure only a defined supply of fresh air, but in addition, temperature as

well as humidity and air velocity have to be controlled. This can only be

achieved by means of an air conditioning system. The ventilation system,

however, is well suited to control the concentration of carbon di-oxide in

the breathable air, thus eliminating potential health hazards. In addition,

the dilution of body odours will significantly add to the passenger comfort.


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Calculation of Fresh Air Flow Rate:

Under HDCL (High density crush load) conditions, a coach may carry up

to 600 passengers.

Doors & windows are closed and no natural ventilation takes place. If no

fresh air is provided, the concentration of carbon di-oxide concentration

would reach unacceptable limits within a few minutes as a simplified

calculation shows:

The CO2 generation rate of a person is approximately 0,0003 m3/min

(ANSI/ASHRAE standard 62-2001, informative appendix C). CO2

concentrations exceeding 5000 ppm are considered dangerous for

health (ANSI/ASHRAE standard 62-2001, table B-1).

Within one minute, 470 passengers will generate (0,0003 m3/min x

470 x 1 min) 0.141 m3 of CO2. With the given coach dimensions and

taking into account the volumetric effect of the passenger load, the

air volume in the fully-loaded coach will be approximately 50 m3.

At a CO2 generation rate of 0,141 m3/min and assuming a CO2Concentration of 500 ppm in the ambient fresh air, the maximum

permissible CO2 concentration of 5000 ppm would be exceeded

within less than 2 minutes!

A forced ventilation system is, therefore, required if no sufficient natural

ventilation can be provided. ANSI/ASHRAE standard 62-2001

recommends that the steady-state CO2 concentration in a space should

not be greater than about 700 ppm above outdoor level. If this can be

achieved, not only the CO2 concentration will be acceptable (500 ppm +

700 ppm = 1200 ppm). At the same time, odours from human bioeffluents

will be diluted to an extent that 80% of unadapted visitors to a space will

feel comfortable. The required ventilation rate (flow of fresh air) can be

determined as follows:

V = N/(CR CA)

V = Ventilation rate

N = CO2 generation rate per person

CR = CO2 concentration inside the rail car

CA = CO2 concentration in the outdoor ambient air

with

(CR - CR) = 700 ppm and

N = 0,0003 m3/min

This ventilation rate amounts to approximately 7 l/s/passenger.

With a load of 600 passengers, the ventilation system will have to provide

a flow of fresh air at a rate of (7 l/s/passenger x 600 passengers) = 4200 l/s

= 15000 m3/h.


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Fresh Air Duct Arrangement:

As specified in documents there is 1 duct running at the centre of the

coach.

AHU Arrangement:

Each rail coach is fitted with two roof mounted air handling units (AHUs).

The AHUs are located in roof troughs & end wall of the coaches.

Note: By using two AHUs per coach, the velocity in the fresh air duct

System is brought under control, as with only 1 AHU, the duct

Velocity would not be manageable.


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The AHU arrangement satisfies the permitted moving dimensions. D-seals

will be provided around the fresh air blower openings. These D- seals

will be compressed and a leak-tight connection to the duct will be

established as soon as the AHU is fastened to the coach.

Description of Main components:

In the following, the main components of the proposed ventilation system

will be described.

Air Handling Unit:

Each rail coach is provided with two air handling units (AHUs). The AHUs

will be completely interchangeable.

The AHU comprises 2 motor/blower units. The motors are RDSO-approved,

3 phase induction motors. The insulation system is capable to withstand

the voltage stress from the trains static inverter. The motor leads are

wired to quick-release connectors conforming to RDSO and Indian

Defense Standard Joint Services specification.

Electric

D-seal

Blower

500

21

32

1120

1240

86


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Based on the extensive experience M/s. SIDWAL has gained in the design,

manufacturing and maintenance of roof mounted railway air conditions,

the weather protection grills on the outside of the case assembly have

been selected, dimensioned and located to ensure that no rain water

can enter the fresh air duct.

The fresh air enters the blowers through air screens. They consist of

corrugated expanded aluminium sheets. The purpose is to preventforeign particles of substantial size (e.g. insects, leaves, etc.) from entering

the fresh air duct. The air screens are removable.

The AHU case assembly will be manufactured from grade 202 with 1%

nickel stainless steel. This alloy is being used in Ducting and Paneling in AC

DC EMU coaches being built at ICF. Other alloys are available on request.

Electrical Control System:

The electrical control system comprises:

Contactors to operate the blower motors MCBs and motor protection relays

No switchgear is installed inside the AHU. All switch gear are

accommodated in an existing coach control panel.

Fresh air Duct & Diffusers:

The duct is completely made of stainless steel. For the ease of

manufacturing, transport and assembly the duct is structured into

sections.

Diffuser grills are arranged along the duct length. The grills are ruggedlydesigned, made of aluminium and power-coated for enhanced corrosion

protection.

Design Verification:

A full-scale mock-up of the complete ventilation system was set up and

tested before the final design was released for production. With help of

this mock-up, it is possible to test and verify all system components before

start of production, e.g.

the distribution of fresh air flow over the length and width of thecoach

the fresh air flow rate in different modes of operation and underdifferent operating conditions (e.g. windows open/closed).

the air velocity at diffuser grills and at defined heights from the floor the power consumption, influence of voltage variations & phase

unbalances

the sound pressure level at different modes of operation eventhough the actual coach may show somewhat different test results.


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Ceiling Fan arrangement:

The ceiling fans are very important for the passenger comfort. Since the

ventilation system is unable to control temperature and humidity, a high

air velocity is most welcome in a hot and humid climate.

It is important to understand that the fresh air supply system

does not much contribute to the air velocity in the passenger

area. The velocity felt by the passengers is mainly

determined

by the ceiling fan arrangement.

Measures to prevent ingress of water

The water ingress in the AHU and duct posed the biggest challenge. Most

critical location was the drawal of rain water through the intake filter of

AHU which draws air @ 15000 m3 / hr. The following measures have

helped in arresting water leakage:

1. Double gaskets have been provided all along the periphery ofthe AHU instead of only around duct cut out.

2. Sealing the metal interface as additional precaution3. Rubber skit around AHU air inlet.

Challenges of technology adoption and new practices in manufacturing

the AC DC EMU: World class cabling practices

The new look AC DC EMU had posed challenges in the form of new

equipments, new connectors, huge workload in form of volumes of wiring

and cabling activity. ICF had been traditionally manufacturing DC EMU,

AC EMUs & DEMUs with DC drives. The traction control methods followed

in these type of SPVs were traditional methods requiring comparatively

less wiring and inter vehicular couplers etc. A brief comparison of work

load in terms of man hours is given below:

Coach

type

AC

EMU

AC/DC

EMU

(BHEL)

AC/DC

EMU

(Siemens)

B Coach 5823 7595 10096

C Coach 1476 2350 3629

D Coach 1566 3980 5668

HC

Coach

1557 4149


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The new generation EMU deploys Train Management System (TMS) which

is achieved by integrating and multiplexing signals for control and

monitoring of the system. This new system calls for multi vehicular bus

(MVB) for achieving the control and monitoring. Thus it is extremely

important to handle and lay the special cables for this purpose.

There are 34 types of cables used in the new trains including those of

special purpose cables. In this type of train deploying multiplexing anddata transmission, the electromagnetic interface among the cables,

circuits are very important considerations as the effect of EMI can be

disastrous affecting the control of the train. In order to overcome the

problem of EMI & EMC, the circuits were categorized into A, B & C and

the minimum clearance was prescribed between them. The cables are

laid in aluminium conduits located at prescribed distance and earthing

are provided at every 1m interval to take care of shielding.

The cables have been laid in the conduits and trays with proper care of

edge protection at inlet and outlet of conduits, Abrasion resistant conduitand wrappers are used over wires while the wires are laid on end wall and

in open area. These practices protect the cables against abrasion at

sharp edges and protection against other materials. These practices are

one of the best cabling practices in railway coaches which will provide

trouble free service with respect to cables.

This train deploys various type of cables and circuits calling for new type

of I.V. couplers for connection between coaches and new type of

connectors within the coaches. A set up of a motor coach (Mock up )

has been created to achieve wiring & connection in free area (as motor

coach area is cramped with equipments). Here in mock up, a group ofworkmen lay the cable of entire coach, terminate with various types of

connectors (Harting type), marking ferrules etc. This process simplified the

wiring in high tension compartment and also cut down the belt time

drastically.

Belt time reduction

Belt time

ACEMU 25 days

AC DC (BHEL) 45 days

AC DC EMU(Siemens)

30 days

Testing & Commissioning:

Testing and commissioning has been the essential component of train

manufacturing. These new generation trains having train management

system, requires different protocol compared to the existing EMUs.

Generally the commissioning tests are divided into two parts, i.e.,

precommissioning at ICF (coach builder) and commissioning at Mumbai.


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The precommissioning checks involve continuity check, high voltage test

and current sharing test before control energisation.

The steps later followed are

i. Loading of softwareii. 110 V dc (control ckt) proving test also known as static

control test

iii. 3 phase testsiv. brake testsv. HV (1500 dc, 25 kV AC) static testvi. HV dynamic test at Basic unit level followed by Rake

level.

In addition Rake protocol is also done during rake test which includes PIS,

changeover etc. These trains are tested during precommissioning in form

of Basic units comprising of 3 coaches, i.e., each 3 coach (BU) has one

Motor coach in the middle and two trailer coach on either end. The End

basic units (EBU) have driving coach as one of the trailer coach whereas

the middle basic units (MBU) have one NDTC (a trailer coach havingcompressor) as one of the component. Thus for completing one rake

formation, four BUs (2 EBUs + 2 MBUs) have to be pre-commissioned and

the rake is formed thereafter.

The precommissioning period have been also brought down from 7 days

to 3 days for BUs and 10 days to 5 days for rakes. Thus substantial

reduction in precommissioning time has helped in reducing the net time

taken in turning out the rake from coach builders (ICF) premises.

Energy conservation:

The present Mumbai Suburban system is run on DCEMU rakes on Central

and Western Railways. These trains are provided with Rheostatic control

and Electro pneumatic braking through Friction Brake Blocks. The specific

energy consumption for these DCEMUs is in the order of 40 KWH / 1000

GTKM. The 3 phase AC DC EMUs with regenerative braking has a specific

energy consumption of 29.5 KWH/GTKM.

The data on the W.Rly indicate that the regeneration is on an average

greater than 35%. The projected figures of energy consumption / saving

in the EMU rakes in Mumbai area will bea. Present consumption (204 rakes) : 55 Cr. Units (KWH)

b. After MUTP 1 if present D.C. EMU

Technology were continued (253 rakes) 75 Cr. Units (KWH)

c. After MUTP-1 with New technology EMU

rakes having regenerative braking

are introduced (253 rakes) : 55 Cr. Units (KWH)

d. Energy Saving inspite of increase in

rake holding from 204 to 253 : 20 Cr. Units (KWH)


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2.0 Benefits of Carbon Credits: Credit accruals;This is the first project in transport sector to be qualified for carbon

credit.

Reduction in Carbon consumption:

Coal : 4.6 x 108 Kg

LPG : 14.26 x 108 Ltr.

Crude Oil : 21.46 x 108 Ltr.

Natural Gas : 21.6 x 108 m3

Reduction in Pollution:

CO2 : 2.092 x 108 Kg

SO2 : 18 x 108 gm

SPM : 5 x

108 gm

Soot Carbon :

0.2 x 108 gm

NO : 20 x108 gm

Cost of the rakes:

The cost of the rakes is also

important aspect of the manufacturing process. Due the advanced

features of the propulsion system and use of FRP paneling, stainless steel

for roof panels, hand hold, partition and luggage rack, seat frames and

polycarbonate for seats, the cost of these rakes are higher compared to

existing DC EMU rakes. The largest metro in India has witnessed new type

of EMUs during the last few years with 3 phase propulsion system. Acomparison of cost per 12 car equivalent is given below:

Cost / 12 Car Feature

New AC/DC

EMU, MUTP

Phase I

INR. 25 Cr. 3 propulsion, + Air ventilation

(2007) (Corton steel coach

body)

DMRC Phase I INR 84Cr 3 propulsion + air conditioning

+ auto door closure+ stainless

steel coach body (2004)

A brief of Public Reaction as first AC DC EMU rake with Siemens electrics

rolled out to Mumbai area.

This train has passed through a critical review by traveling public and

media in Mumbai. The leading national dailies and local dailies have

quoted the public responses.

Well lit, well ventilated commuter friendly. Silver bullet. A popular name given by the public.


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Future generation is here It is quite spacious ,airy and bright

With the introduction of more and more AC DC EMU rakes with Siemens

electrics, the image of suburban trains is changing, ending the ordeal of

esteemed commuters. Till today 19 rakes have been inducted in the

Mumbai area, providing additional service. By the end of the current

financial year, a total of 50 rakes would be inducted which will ease out

the congestion and crowding.

Documents

Seminar Paper Corrected