- The Model Railway Society of Pune, consisting of 25 members with diverse professions but a shared love of Indian railways, visited the Chittaranjan Locomotive Works (CLW) in West Bengal. - CLW began modestly in 1948 and built its first steam locomotive in 1950. It has since expanded to build over 4,600 electric locomotives as well as diesel and steam locomotives. - The 16 members of the society toured CLW's assembly shops, locomotive testing facilities, and steel foundry. They learned about CLW's locomotive production processes and history from the technical staff.

1. CHITTARANJAN LOCOMOTIVE WORKS
ModelRailway Society is a cohesivebody madeup of some25 men coming togetherfromvarious
partsof Pune. Having diverse professions,they sharean intenseloveforIndian railways.TheSociety
is now25 years old and haspaid visits to several importantrailway locations in thepast.
Chittaranjan LocomotiveWorkshad been theirsavored dream fora long time. A Sixteen- member-
team communicated withtheChief PRO atCLW, who managed a semiofficialvisit for themembers.
The teamreached Chittaranjan on themorning of 22nd
July 2013 and stayed overnightto continue
the visit on the following day.Thisarticle stemsfromthe actualinformation given by the technical
staff on site and also fromsomeformalpublications,furnished by thePROof the CLW.Every effortis
madeto maintain accuracy in thetechnical information.Wehopethis shortaccountshould help a
railway enthusiastto obtain an overview of whatChittaranjan LocomotiveWorkstoday standsfor.
History of CLW : Before Independence, nearly42 private railway companiesowned the railwaysof
Indiaand they hadtheirownwaysof procuringthe locomotive powerandall were importedfora
longtime.Afterthe greatWorldwars,these companiesfoundit difficulttoprocure locomotives
fromoverseasanda unified needwasfelttohave these locomotivesbuiltindigenously.Howeverit
was onlyafterindependence thatthe unifiedefforttobuildalocomotive plantwasrealized.
ChittaranjanLocomotive Workshada verymodestbeginning,whenthe tinySanthal village inwest
Bengal wasidentifiedasaplace to establishalocomotive factory. The closestrailwaystation tothis
area wasMihijamon the Asansol Patnasection.ThisindigenousLocomotiveplantwas named
“Chittaranjan”topay tribute tothe greatDeshbandhuChittaranjan Das.(There isalegendthatthe
landformerlybelongedtothe Chittaranjanfamily afterwhomthe plantwasnamed).Eventhe
Mihijamrailwaystationwaslaterchristened “Chittaranjan”.
Tata had established TELCO in 1945, which built the some Meter gauge steam locomotives for
Indian railways, but they soon found difficult to cope with the growing demands of the fast
expanding railway industry in India. CLW as it is now called (CHIREKA in Hindi), was thus established
in February 1948 by the Government of India and the first freight Steam locomotive, WG was rolled
out in November 1950. The production soon expanded to build WP’s, WT’s and WL’s. It also built
YG’s for Meter Gauge traffic in India. CLW built a total number of 2351 Steam locomotives for Indian
Railways.
Although the CLW are now renowned for building Electric Locomotives alone, the factory built a
large number of Diesel Locomotives for Indian Railways from 1968 to 1994. They mainly built Diesel
Hydraulic Locomotives including WDS4, WDS8, YDM2 and a number of locos for the narrow gauge
railways. Today the CLW stands proud not only in manufacturing the conventional electric
locomotives with DC traction Motors, but it also builds microprocessor controlled modern mainline
Electric Locomotives using three Phase AC induction Motors. With a modest beginning by building 5

2. electric Locos in 1961, CLW has increased its tally to 250 locos in the year 2012, taking the total to
4646 ElectricLocomotivestodate.
Our Tour : Model Railway Society, Pune has about 25 members. Sixteen of them had volunteered to join
the trip to Chittaranjan. 14 of them took the Duronto on 20th
July to reach Howrah on 21st
evening. Me
and Pande flew to Kolkata and joined the group on Howrah station on the 22nd
morning to board the
Poorva Express at 08 00 hrs. Poorva was swift enough to take us to Chittaranjan at 11 sharp.
Chittaranjan Station is a beautiful tiny station and is surprisingly clean. Believe or not, but the CLW
officials had arranged a minibus to collect us and take us to the Guest House. After a quick wash we
went and met the Chief PRO Mr. Mantar Singh. He is a very warm and receptive character and was truly
pleased to see a team of 16 people travelling all the way from Pune only to visit CLW. He gave us a plan
of the tour andlaterdirectedusto the mainassemblyshop.
This was a rapid tour which showed us the building of Electric Traction Motors (Both DC and 3 phase AC)
and their alignment over the bearings of the axles. The most exciting part was the alignment of the Spur
gears between the motors and the axles. We saw machining and grinding of the axle rods and the
wheels to ultimate precision. The winding of the stators was a treat to see. Body shells of the
locomotives are either casted as whole or fabricated, depending on the model protptype. The
magnitude of the workand the dimensionof the hardware issimplymindboggling.
Later we visitedthe machiningshop,where we saw the axle turning,wheel machiningandassemblyof
the wheel sets. Modernlocomotivesuse fabricatedbogies.Completemachiningandfabricationof the
bogiesisperformed comprehensively inthisshop.
On the morning of the second day they took us to visit a small loco museum, named Deshbandhu Loco
Park. A number of famous CLW products were on display, notably the last WG (wrongly named Antim
Sitara, since the real Antim Sitara was a YG). We also saw some live steam models, which are currently
out of function. A 1/4th
gauge garden railway exists on the premises, but works only on special
occasions.
Later on that day we visited the “Testing and Quality” lab. The most impressive item was the “Foundry
Master”, a German equipment, which analyses a metal and gives us the constituents (or impurities)
literally in a flash. We also saw various other equipment, which tested and estimated the tensile and
compressive strengths of the metals again in a very short time. Somehow the enthusiasm of the staff
rather exceededoursand thissessionturnedouttostretchour patience abit.
The best part of our trip was yet to arrive. We had asked to see a qualified Electrical Engineer to answer
some of our questions. Mr. Mantar Singh arranged a meeting of ours with Mr. Sahu, who was a true
genius. Just as our session began getting interesting, a person of Managerial level walked in and rudely
interrupted our session. He said he wanted to start an important meeting. Anyhow the session with Mr.
Sahu wasthoroughlyabsorbing.

3. Steel Foundry
The Steel Foundryisan impressive plant,locatedaboutakm.away fromthe workshop.Establishedin
1963, incollaborationwith M/s.F.H. Lloydof UK in1963, the foundrynow isvirtuallyself sufficientand
casts Bogie Frames,axle rods,axle box housesandsuspensiontubes.Italsocasts a numberof itemsfor
Traction Motors suchas Rotor Clampsand BearingBrackets.Theyare now cast inlightweightsteel and
are transportedtothe Machine Shop formachining,turning,finishingandfinal assembly.
In the heartof the forgingfurnace,the temperature of the moltenmetalis raisedto1620 degree Celsius
by an electrical current of 60 kiloamperesat12 kV to produce a powerful arc. We saw the burning
furnace whichmade a frighteningandcracklingsound.Howeverwe were notable tosee the actual
casting,since thisisperformedonlyatcertaintimesof the day. The temperature laterdropsto 1580
degreeswhilethe metal ispoured intothe moulds. All inall thiswasa thumpingexperience.
As we approached the end of our visit, Mr. Mantar Singh invited us all in his office and presented each
one of us a CLW calendar and a Brochure. We had a wonderful experience all-round. As we bid good bye
to the CLW, we all had a proud feeling about CLW. After a thoroughly informative experience, we drove
back to Asansol Railway Stationtoboardthe 12321 Up to catch our wayback.
While we returnedbyHowrahMumbai Express,everyoneof uscarrieda proudsentimentwithinus.
What a great experience it wasfortwofull days.Nosurprise reallythatthe Electrical energy,when
harnessedandcontrolledbyelectronics,candowondersinthisworld.
Some of my jottingsabout the CLW,which I would love to share with my Railfan Colleagues.
Electric PowerSupply : CLW draws itspowersupplyfromDamodarValleyCorporation(DMC) situatedat
Maithan,a small town15 kmsawayfrom Chittaranjan. DMC hostsa Hydroelectricplantof 40 MW and a
Gas Turbine Unitof 90 MW connectedtothe main grid. Chittaranjanalsohasan in-house generating
capacityof 11.6 MW as a backupfacility.
The Conventional ElectricLocomotives: Conventionallythe electrical circuitiscompletedthroughthe
bodyof the locoand earthedviathe rails. 25 kV single phase ACsupplyisdrawnbythe pantographs
and isfedto the transformers.Thisisfurtherrectifiedto750 V DC and suppliedtothe tractionmotors
througha tap changer (essentiallythroughaseriesof resistances).DCTractionmotorswere believedto
have a higherinitial torque andwere universallyusedinmostsituationsincludingall the diesel electric
locomotives.

4. The Technologyof ModernLocomotives (as I understood) :The Pantographreceivesthe fixed
frequency (50Hz) alternating currentof 25 kV from the overheadequipment(OHE).Thisisfiltered
throughProtectionCircuitstoremove impuritiesinfrequency.ItissubsequentlyfedtoaTransformer
for steppingdown.There are foursecondarycoils.The outputfromsecondarycoilsisdistributedas
follows.
Coil 1. Fedto Gate Turnoff Circuit(GTO),whichconvertsthe outputtoDC and laterchoppedto
three phase AC,supplying variablefrequencyandvariable voltagetothe TractionMotors. This
technologyisnowgettingupgradedtoIGBT(InsulatedGate BipolarTransistor)
Coil 2. Main CompressorMotors.These are simple ACinductionMotors
Coil 3. BlowerMotors(AC).There are at leastthree setsof these.
Coil 4. Suppliesaccessoryequipmentof the Locomotive.
ConventionalACMotorsare simple inductionmotors,where the statorreceiveselectrical current
thoughradiallyarranged fieldcoils.The electromagneticinductionthusproduced,movesthe Rotorin
the directionopposite of the poles.The speedof rotordependsdirectlyonthe frequencyof currentand
the numberof poles.(e.g.n= Frequency*120 / no.of Poles).Thustheirspeed synchroniseswiththe
frequencyandare therefore calledSynchronousMotors. These motorshave afixedspeedandfixed
torque,whichmakesthemunsuitable astractionmotors,where the demandsof torque andspeedare
variable.
Three Phase AsynchronousMotors : The three phase technologyowesitsrootstoBobardier
TransportationSwitzerland.The Statorinthese motorsissuppliedwithphasesatthree differentpoints
distributedat120 degreesangle witheachother.The inductionthusproducedhasa motive powerat
three pointsina cycle.The resultantspeedandtorque of the rotor dependsonthe frequencyandthe
voltage of the inducedfield.A microprocessormodulatesthe frequency,phase andthe voltage to
generate the requiredtorque andspeed. AsIunderstoodthe voltage variesbetween1and2180 V AC
and the frequencyvariesbetween40and 65 Hz. CLW commencedbuildingof 850 kW and 1150 kW 3-
phase tractionmotorsin 1998 and startedrollingoutmodernelectricLocomotivesin1999.
Traction Motors: This basic motive force is the soul of CLW. It now builds Type 15250A DC series
motor which works on 750 V DC and produces 630 kW of power. These are used for conventional 5000
BHP 25 kV locomotivessuchasWAP 4 and WAG 7. Thistechnologyhas now given way to the modern 3
phase AC asynchronoustractionmotors.CLW thusisnow engagedinbuilding two important types of 3
phase motors, the 850 kW 6FRA 6068 and the 1150 kW 6FXA 7059 for use in WAP 7, WAP 5 and WAG 9.

5. Current CLW products can be tabulated in the following form
Type
Power
Output
No.
of
Axles
Axle
Load
Traction Motors Purpose
Speed
potential
Technology Bogies Highlights
WAP-
4
5000
BHP
6
18.8
Tonnes
ConventionalDC
Fast
passenger
140
kmph
Tap Changer
Flex-coil
Cast Steel
Hauls Mainline
Superfast Trains
including Rajdhani
Expresses
WAG-
7
5000
BHP
6
19.5
Tonnes
ConventionalDC
Heavy
Freight
100
kmph
Tap Changer
Fabricated
High
Adhesion
Hauls Air Braked Heavy
Freight Stock
WAP-
5
5400
BHP
4
20.8
Tonnes
Three Phase AC
Asynchronous
Superfast
passenger
160
kmph
Microprocessor
(GTO)
Controlled
variable
Frequency
variable
Voltage
Two Axles
per Bogie
Disk
Brakes
Originally ABB
transferredTechnology.
Useful Regenerative
Potential
WAP-
7
6000
BHP
6
20.5
Tonnes
Three Phase AC
Asynchronous
Long Fast
Passenger
Trains
160
kmph
Microprocessor
(GTO)
Controlled
variable
Frequency
variable
Voltage
The only Loco with
Head-on Generation
capability eliminating
the need for End-on
Generator car
WAG-
9
6000
BHP
6
20.5
Tonnes
Three Phase AC
Asynchronous
HeavyDuty
Air Braked
Freight
traffic
100
kmph
Microprocessor
(GTO)
Controlled
variable
Frequency
variable
Voltage
Loco has Air
Conditioned Driver's
Cab
WAG-
9H
5000
BHP
6
20.5
Tonnes?
Three Phase AC
Asynchronous
HeavyDuty
Air Braked
Freight
traffic
100
kmph
Microprocessor
(GTO)
Controlled
variable
Frequency
variable
Voltage
High
Adhesion
Increased Axle load to
improve the wheel
Adhesion. Suitable for
long and heavy Freight
Rakes
WAG-
9i
5000
BHP
6
20.5
Tonnes?
Three Phase AC
Asynchronous
HeavyDuty
Air Braked
Freight
traffic
100
kmph
GTO replaced
by IGBT based
Propulsion
System
Improved performance
and reliability, better
control and
regeneration, reduced
losses. Modular Design

6. Some Photos taken during our visit
1. AntimSitara”showcasedin the formof a WG
2. Photographof the oldSanthiavillage,wherethe plantwasestablished
3. The majesticbuildingof the Asansol JunctionRailwayStation
4. Entrance to the “DeshbandhuLocoPark”
5. The Furnace of the Steel Plant
6. Sunsettingoverthe ChittaranjanTownship
7. The expanse of the Steel Foundry
8. The freshlyrolledout WAG9H and WAP4
9. The Gang that visitedCLWinJuly2013

7. Steam Locomotivesbuiltby CLW so far
WG (1908), WP (259), WT (30)
WL (94),YG (60)
Total SteamLocos= 2351
Diesel Locomotivesbuiltby CLW so far
WDS-4,WDS-8,YDM-2
NDM-5, ZDM-3, ZDM-4A, ZDM-5
Electric Locomotivesbuiltby CLW so far
WCG-2, WCM-5
WAG-1, WAM-4, WAG-7
WAP-1,WAP-3,WAP-4,
WAP-5,WAP-7
WAG-9, WAG-9H, WAG-9i

8. Downside of the CLW
It ispainful towrite these lines afterhavingsuchan exciting tour.Howeverwhile we visitedthe place,
we foundthe followingaspectsratherdisturbing.
1. The machine shopsappearedratherbaronand lookedasif nothingmuchisgoingon there.
There istoo much of space whichisbaronand unutilised.
2. We all feltalot of more workcouldhave beendone inthe plant,particularlywhenwe sawalot
of machinerylyingidle.The numberof workers whoreallyworked appearedveryscarce.
3. It was a pityto see a numberof itemsprocuredbyoutsourcing,especiallythe fabricated body
shellsof locomotives.The fabricationunitinside the plantlookedquite capable of doingthe job.
4. It was ratherhard to findpersons,whowere trulyqualifiedtoanswerthe technical queries
raisedbyour members.
Thisaside,we hada memorable experience all round.CLWisnotonlya heavyindustrial plant;it’salsoa
proudsymbol of a distinguishedand enviableventureof the IndependentIndia.
Acknowledgements: We are extremely indebted to thePRO of CLW, Mr. Mantar Singh,who was
committed to makethis visit a reality. We all owea lot to ourSecretary Mr. Amod Gune,who took
immenseeffortsto make thishappen. Iam also indebted to ourmember Mr.JayantKelkar,who
virtually educated mein the science of Electrical Engineering during theentire courseof our visit.
Shirish D. Yande
5 August2013