On top of the world. 15 Days in the world’s largest Locomotive factory: Chittaranjan Locomotive Works


                          Trip report presented By:-

Acknowledgement :-
My trip, my learning experience,  my understanding of the locomotives, my easy access to all 
the workshops, and my innumerable questions being answered and explained to, has all 
been possible because of the kind help and encouragement of Mr Suresh Kumar, DyCEE, 
Thank You sir, Thank you very much.
 I am ever grateful to you.

With Regards 

On top of the world. 15 Days in the world’s largest LocomOtive factory: chittaranjan Locomotive works

It all started on 1st april which was my 1st visit to CLW. 2 hours didn’t satisfy my thirst at CLW. So I made a plan that I will visit CLW once again and this time I would make sure that all my queries were responded to.
07-07-2013 :- Early morning boarded the Black Diamond Express with a friend of mine, Sony Sengupta. The Loco was a HWH P7 30322.
Reached Asansol and boarded a car to Rupnarayanpur. Rupnarayanpur(RNPR) is the station just before Chittaranjan. Rented a hotel out there.
08-07-2013 :- Took a bus from Rupnarayanpur to Chittaranjan. The bus entered from GATE NO 3. A boarding sign read  “WELCOME TO CHITTARANJAN LOCOMOTIVE WORKS. STOP PLEASE SHOW YOUR PERMIT”.

Got down at Children’s park just adjacent to Loco Park. Took an auto to the Design and Development office. Fixed up an appointment with Mr Suresh Kumar, Dy CEE, D&D, CRJ, an alumnus of IIT Kanpur. He welcomed me.

Mr Suresh Kumar
 I had already met him and got myself introduced to him during my last visit to CLW. He issued us a Gate Pass valid till 22.07.2013. We met the Senior RPF to get our gate pass. Our names along with our photographs were stamped on the Gate Pass.
Gate Pass

09-07-2013 :- Entered the factory through the D&D gate.
Two huge workshops ELF 16 and ELB 14 also known as FABRICATION SHOP the largest and longest at CLW was our entry point. As we moved we could see the entire process where iron sheets are made, polished and were being shifted from one shop to the other. Then we came across bogies of WAG 9 and WAP 5 being made and moulded into shapes. Huge Lathe machines were kept and huge cranes more than 6 in number  moved to and fro shifting steel and bogies. Then we came across the huge metal sheets where the entire Locomotive rests. We found the Cabs of G9, G7 kept at various places. More than 5-6 Locomotives of various types were in the construction process. Welding was done on a large scale basis.

As we moved through a swarm of locomotives we came across a P7 being manufactured which was unique. It was the 2nd HOG Loco P7 30365.

The Construction was in progress.  Finally our trip to this workshop came to an end. The total length of the workshop is 3.5kms. The day ended there.

10-07-2013 :-  We entered the factory through the Works Office gate. Moved downstairs to the next shop The Assembly Shop which is a few meters apart from the Fabrication shop.

The Loco’s are send here after Fabrication and Painting. The pipes, transformers, electric connexions and complete overhauling of the loco is done here before being send to the Testing Shop. More than 25 Locos comprising of  P4, P7, G7, G9 and P5 were kept there.
The equipments of auxillary part I and II and switches of 3 Phase Loco’s were being assembled. The connector pipes were being installed. Fitting of three phase and single phase transformer was being done at the assembly shop.
It took a day for us to see the whole process.

11-07-2013 :- The Traction Motor Shop. The Most Interesting and the back bone of the 3 phase powerful monsters. More than 50 stators were kept lying along with its rotor. Its none other than the asynchronous squirrel cage induction motor. The complete process of making of the huge machines is done by the mechanics/engineers in the TM shop.
The TM shop is divided into various parts. In one room the winding is done by copper wires. In another room expansion of the winding is done. In the 3rd room heat treatment is done to check if there is any fault with the stator or any other equipment in the Traction Motor. With the help of a wooden ruler the coils gets fitted inside the stator.

Finally after seeing and trying to learn about the various parts of the TM shop we moved back to Design and Development. Mr Suresh Kumar Dy CEE D&D allotted me a schedule for the various days since it was not possible to visit the whole factory in a single day.

12-07-2013 :-  ELF & ELB
Like all structural elements for trains, it begins with raw metal plates. Tons of steel and iron is used for designing the bogies. Months of fitting and tooling, and finally a bogie is made. The ELF & ELB workshop makes bogies for P5, P7 and G9. Machines from Japan and other countries are found in the workshop where fitting and shaping of bogies is done in a large scale. It took us 3 hours to understand the complete procedure taking place. We were provided helmets from the Safety Section to make sure we protect ourselves from those massive machines and huge cranes moving to and fro carrying iron sheets on top of us.

We saw the entire procedure of bogie joining with the help of electric arc machines. Ultrasonic sound detectors were being used to detect a crack in the bogie.  We saw WAP 5 and WAG 9 bogies being made but with no modifications. Only WAP 7 bogie has been modified.


15-07-2013 :- Loco Assembly Shop

A WAP 4 and a WAG 7 welcomed us.
We moved to the single phase transformer section which is still being used in conventional Locos. A supervisor explained the details of the single phase transformer. It is being supplied by BOMBARDIER and BHEL.

Then we moved further. There were several Locos in which the transformer was already fitted. We came across 3 phase transformers used in P7, P5 and G9 Locos.

The supervisor told us that there is a key component difference in a P7/P5 and G9 transformers. P7 and P5 Locomotive transformer has the facility for Hotel Load Generation which a G9 transformer doesn’t have. This was the key difference.
Then we went around the assembly shop and saw how workers were fitting the equipments in the Locomotives without any flaw. At 11am we left the shop and again we attended the shop the very next day to understand the other features.

16-07-2013 :- We entered a WAP 7 and a WAG 7 locomotive. The road number was not yet notified. The workers explained us the technique how they fix and arrange pipes moving throughout the locomotive. Then we proceeded to the Pneumatic Panel section that controls the pantograph operations. Then we saw how workers were working and fitting the SB1 and SB2 also known as filter cubicle used in three phase locos for control operations.

Mr Pankaj Sen explained to us in brief the working of capacitors inside the filter cubicle and the use of smoothing reactors used in conventional locos. He also explained the working of transformer in 3 phase locos along with its circuits.

17-07-2013 :-  The Traction Motor Shop
The T.M Shop lives for just one thing - to build the muscles for these 3 phase locomotives. The first thing that is required for the production of these motor is lots of copper. A machine handles the job. Then expansion of the coils is made and then the coils are moved from one room to the other.
 The fully wrapped coils gets fitted into the stator. It takes  team work to pull, place and align the coils into the shell.
It took three hours to see fifty percent of the work being done, which was placing the coils in the stator.  After the completion of the stator, it is send for heat treatment to find out any flaws.

18-07-2013 :- Now the stator has been dressed its time to meet its mate, the Rotor. Mr Suprobhat Ghosal explained to us in details how the motor shop functions and then we moved where the rotors were being made. We saw hundreds of DC Series Motors lying on the floor while moving to the rotor shop. We were shown with the help of a crane and a dummy how a rotor is made. It took us 1 hour to see the construction of a rotor. Then we came back to see the DC Series motors. They are supplied by HITACHI and BHEL. Production of DC Series motors will soon come to an end. P4 and G7 Locomotives will no longer be produced.


19-07-2013 :- Steel Foundry
All the steel used in CLW is produced here. It is the largest steel foundry in Asia. Raw steel is made here and are transported to various shops inside the steel foundry. Some of the shops are 1. Mould Shop, 2. Core Shop, etc. Various types of Sand is the source of different types of production. The bogies of WAP 4 also known as “Flexicoil Mark IV” bogie, and Center Buffer Coupling(CBC) couplers are produced in the steel foundry.
Several Heat Treatment plants are present inside the steel foundry to check the cracks and flaws of the bogies and the CBC couplers and reshape them so that they can be reused.
Electric Arc Welding process is used to melt the steel and transform it into its desired shape.
For testing and research purposes, there is a Chemical Laboratory.
Steel Foundry also reshapes and moulds used steel that can no longer be used and again makes it suitable for commercial use.
  Steel Foundry manufactures steel castings generally complaint with grades IS-1030 and AAR-201. To meet the requirements of different products, Steel Foundry had earlier been processing eight different grades of metal. Steel Foundry has been successful in rationalizing the same to five grades only without affecting any metallurgical, chemical or physical properties. This has resulted in improvement in productivity.

22-07-2013 :- Testing Shop
Our Last Day at CLW. The Locomotives after completion are brought here and are tested on a test track. We went inside a WAG 9H locomotive to see the IGBT module. Now, Crompton Greaves is supplying IGBT modules to all WAG 9 Locomotives. Earlier BOMBARDIER, BHEL and ABB had supplied IGBT. The Loco was 31413. It was a WAG 9H. The only difference between a WAG 9 and WAG 9H is an extra ballast installed in the machine room,  resulting in an extra weight of 12 tons.

We also spotted few more Locomotives present in the Testing Shop which would be dispatched soon.
A WAP 4 22968 with MU operation facility given.

Few WAP 7’s. Among them 30360 was ready.

Few WAG 9’s, WAG 7, a WAP 5 and few WAP 7.

Few trial runs were also being done.


Finally we left the factory at 11.30am. We reached Asansol station at 4:35pm.

Black Diamond Express arrived at Platform 5 with WAP 4 22303.

Note: Please refer GP 140 article's to know the entire history of 3 Phase Locomotives in India. 



Who Am I?

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A Rail Enthusiast. Born and brought up in Calcutta. Have interests in rolling stock and Locomotives and their control techniques.
Also love to collect information and trivia on our Indian Railway network...
Have worked with ABB, Siemens, Bombardier Transportation and Larsen & Toubro as an intern. 
I majored in Electronics and Communications Engineering as my undergraduate degree on 2nd August 2016.