On top of the world! In the world’s largest Locomotive factory once again: Chittaranjan Locomotive Works.

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, CON, CRJ.
       Thank You sir, Thank you very much.
       I am ever grateful to you.

With Regards
Sundar Mukherjee

On top of the world! in the world’s largest LocomOtive factory once again: chittaranjan Locomotive works.
First, second and now the third. Each time I live a dream. Everytime there is something new, something interesting and so many things yet to know.
It all started on the 1st of April, 2013 which was my 1st visit to CLW. Then from the 7th to the 22nd June 2013 was my 2nd stay at CLW. And once again on the 10th February 2014.
Early morning boarded the Shatabdi Express.
The Loco was a HWH P7 30205.

The coaches were none other than the new LHB type. The technology was provided by ALSTOM.

The following are the features of the newly type coaches.
  1. The FIAT-SIG bogie is a welded H frame type based on the Eurofima standard.
  2. The primary suspension is with articulated arms and coil springs, secondary suspension of integral flexicoil type with coil springs and rubber pads on top and bottom, anti-roll bar, vertical and transverse shock absorbers and anti-hunting dampers.
  3.  For braking on each axle two disc brakes with 640 mm diameter, brake cylinders and automatic slack adjuster are provided.
  4. The automatic center buffer coupler of AAR tight lock type at the coach end has a support frame which provides an anti-climbing protection.
  5.  Each coach is equipped with two compact roof-mounted air-conditioning units which have a cooling capacity of approximately 2x22.5 KW and a heating capacity of 2x6 KW and which are controlled by a microprocessor.The operating voltage of the unit is 3 phase, 415 V, 50 Hz. Each unit has 2 refrigerant circuits with hermetic refrigerant compressors, condensers with Copper pipes and Aluminum fins, evaporators and condenser fans.

I was alloted a seat in the C3 coach. It was a window seat.
The train departed at 6:05am sharp. All I can say is “ABB pulls ALSTOM”. It was a smooth ride in the new coach.

Howrah Loco Shed, the shed where I have been a regular for the last 5 years and the shed where Locomotive engineers have helped me quench my thirst about the intricacies of Locomotives and shaped me up to what little I have known about Locomotives till date, whizzed past me in a flash.
Few P4’s and P7’s was what I noticed as the shatabdi express rolled past the shed.
I felt a momentary jerk whenever the P7 accelerated or decelerated. 
A common problem in all LHB coaches because of the new coupling system, the 
AAR(Association for American railroads) type. 

The train arrived at Asansol at 8.20am sharp. 

Took a bus from Asansol to Chittaranjan. The bus entered from GATE NO 3.
 Got down at Children’s park just adjacent to Loco Park. Took an auto to the Works office.
I had already fixed up an appointment with Mr Suresh Kumar, Dy CEE, CON, CRJ. He welcomed me.


We talked and chatted with each other for more than an hour. This man is a real storehouse of information. Ask him any question on Locomotives and he answers in a flash. He explains to me as a grammar teacher explains the nuances of the language to his students. Precise, always to the point, sharp and definitely witty he always patiently answers my questions. After talking to him, it’s a feeling oh! why don’t I get to interact with him more often.
Inspite of our tete a tete being for a very short time, I take this opportunity to share with everyone whatever little I came to know from him.
·         The HOG Loco 30277 has been running successfully from 21st February 2011. CLW has developed a 2nd HOG Loco, 30365 which is also running successfully. The design concept and implementation was completely done by CLW.
·         Kalka Shatabdi Express is the train in which HOG Loco is being used.
·         CLW had planned to deliver more 3 Phase Loco’s but due to inadequate supply of electronic components by various companies they had to slow down the process of production of 3 Phase Loco’s.
·         CLW has once again started manufacturing conventional Locomotives, the WAP 4.
·         CLW has also started changing the Control Electronics software “MICAS-S2” to “MITRAC” in few WAG 9 Loco’s.
·         Currently there are no WAG 9 Loco’s being manufactured at CLW. They are manufacturing WAG 9H Locomotives where an extra ballast is installed to ensure higher TE(Tractive Effort).
·         Most of them are IGBT based. The suppliers are BOMBARDIER, ABB, BHEL.
·        GTO technology is also being used in the present fleet of  WAP 5 and WAP 7 series Locomotives.
After a short brainstorming session with Mr Suresh Kumar, I got my gate pass issued by him. It was a special day permit gate pass.
I asked him for his helmet to protect myself. A helmet is mandatory once you enter a workshop.

I entered the factory through the Work’s office Gate.

The Assembly shop was my entry point.

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.

Mr Sen one of the senior person's in the Assembly shop was my tour manager. He is one of those engineers who has worked in the project IR GP-140 where WAG 9 and WAP 5 was brought from the factory Adtranz, Switzerland. Now it is being manufactured at CLW with a TOT(Transfer of Technology).

We first move around the assembly shop. Mr Sen tells me the companies supplying various equipment's of three phase and conventional Loco’s.
The Pneumatic Panel of P7/P5/G9 Loco’s are being supplied by Faively Transportation Systems. Even the conventional Loco’s Pneumatic system is also supplied by the same company.
The units on the top are various pressure switches which sense the status of different reservoirs and pipes. The panel also has the control equipment for the loco independent brake as well as the automatic train brake.

Then we move towards the Testing Shop. There were various Loco’s in a completed state and few completed shells that were yet to be assembled were lying outside the assembly shop.

To the left the P7, and G9 shells completed were kept. A diesel Loco does the work of moving these shells from one shop to the other.
To the right a few G9(H) Loco’s completed were being tested.
There is a special bogie arrangement made where the entire shell rests. It is used to shift the complete shell from one shop to the other.

Now we move to the G9(H) Locomotives that are ready.

Mr Sen opens the door of the Locomotive using the key he has. I am already accustomed getting up in a Locomotive.

It was a freshly made G9. The road number was 31474.
I enter in CAB 1 of the G9(H) locomotive.

The braking arrangement is the Knorr type. It was used in the ABB WAG 9 that were imported from Adtranz in the year 2005 in the Gomoh G9's. Davies and Metcalfe supplied it. CLW has once again started manufacturing it. The electrical connexions can be seen. The controls are divided in three panels. Panel A is located in the centre of the field of view of the train driver. Panel B  contains the various pressure gauges which is situated to the left of the driver’s desk and Panel C to the right. At the extreme right hand side is Panel D. It contains the Assistant driver’s desk illumination switch, a vigilance push button, a hand lamp socket, and a socket hand lamp switch.

The speedometer has not yet been installed. Various electric connexions can be seen. Then we enter the machine room. Here the extra ballast is kept at the four ends of the machine room which adds to an additional weight of 12 tons to the Locomotive, thus making the locomotive reach a higher TE.

The pneumatic Panel of the G9 Locomotive.
 It is being supplied by ABB and Davies and Metcalfe.

A temperature sensor was lying on top of the Electronics panel. It is being supplied by Crompton Greaves.

Another view of the G9 cab.

We move towards the testing shop. There were 6-7 WAG 9’s kept.

We get inside 31473.

 The brake system is the conventional type here. The entire Assmbly shop can be seen from the G9 Cab. The screen in Panel C displays the diagnostics messages and display indications regarding the control of the entire Locomotive. Then we move towards the machine room.

The machine room consists of :-
1)    Scavenge Blowers (A cenrifugal filter panel  where contaminated air is removed via a scavenge flow system).
2)    Transformer
3)    Machine Room Blower
4)    Oil Cooling Units (transformer/converter)
5)    Traction Motor Blowers
6)    Single phase 415/110V auxiliary circuit
7)    Vigilance Control Module
8)    Pneumatic Panel
9)    Line Converter
10)   Auxiliary Converter
11)   Oil Pump and fan
12)   Static convertor

The static covertor of the 3 Phase loco’s are being provided by ABB. We moved through the machine room. It was a IGBT based Locomotive. Mr Pankaj explained to me the basic operation of IGBT. Earlier when a 3 Phase Locomotive would become dead, the entire bogie would not work. Now with the help of IGBT technology even if one motor becomes dead, with the help of computer electronics it can be isolated and the Locomotive can still be made to run with the help of the other motors. This is one of the added advantages of IGBT over GTO in 3 Phase.

Water Cooled IGBT module that is replacing GTO Thyristors. Basically what we see in today's G9/P7/P5 as suffix "i" is nothing but these semiconductor devices that have replaced the old GTO Technology.
Advantage: Better Switching, Fast Response, .
In Locomotive if a motor fails, the entire bogie need not be separated and the particular motor is separated using this technology.
The IGBT Modules are made by Bombardier and they are imported from Germany and assembled here in India.
The above two pictures of IGBT Module were taken with permission while i was working with Bombardier Transportation as an intern.
The IGBT panel and the earth connections were shown to me by Mr Pankaj Sen.
We get down from the locomotive and move once again towards the assembly shop. As we proceed, P7’s and G9 shells were seen.

The entire Locomotive is divided into three parts and then joined. There are the two cabs and the side walls. Together they are joined and hence the complete shell is formed. For transportation from one workshop to the other they are lifted using hydraulic cranes and are then placed over a temporary bogie which consists of two axles. A diesel Locomotive does the job of shifting the entire shell from one shop to the other. The bogie where the shell rests is a special type of Bo-Bo bogie.
As we moved towards the Assembly shop we could see the bogies.

The arrangement clearly illustrates how the bogies hold the entire locomotive. Once each and every component is installed in the Locomotive, the locomotive is lifted and the axle powered bogies are installed.

There were several G7’s too being manufactured. Cabs of some units are air-conditioned. WAG-7's also have data loggers and train parting alarms (based on sensors for detecting loss of brake pressure), as standard equipment. These Locomotives are used primarily for goods haulage. These locos have a Co-Co wheel arrangement with high-adhesion bogies.

Some technical specifications of the G7.

·         Traction Motors: Hitachi HS15250-G (a variant of the standard HS15250 with higher current rating (thicker wire gauge, better insulation); see description under WAP-4.) Motors built by CLW and BHEL.
·         Gear Ratio: 65:18
·         Transformer: CCL India, type CGTT-5400, 5400kVA, 32 taps.
·         Rectifiers: Two silicon rectifiers, cell type S18FN350 (from Hind Rectifier), 64 per bridge, 2700A / 1050V per cubicle.
·         Axle load: 20.5t
·         Bogies: Alco High-Adhesion bogies, fabricated bogie frame assembly, with unidirectional mounting of traction motors, primary and secondary suspension.
·         Hauling Capacity: 3010t
·         Pantographs: Two Stone India (Calcutta) type AN-12.
·         Current Ratings: 1350A/2min, 1200A/10min, 960A/hr, 900A continuous.

A completed WAG 9 where the AAR type couplings are being checked. The first few were imported from ABB (6 fully assembled and 16 in kit form (7 completely knocked down, the rest partially assembled), in 1996). These are numbered 31000 to 31021.

 Some technical aspects of the Loco:-
·         Manufacturers: ABB, CLW
·         Traction Motors: ABB's 6FRA 6068 (850kW, 2180V, 1283/2484 rpm, 270/310A. Weight 2100kg) Axle-hung, nose-suspended.
·         Gear Ratio: 77:15 / 64:18
·         Transformer: ABB's LOT 6500, 4x1450kVA.
·         Power Drive: Power convertor from ABB, type UW-2423-2810 with SG 3000G X H24 GTO thyristors (D 921S45 T diodes), 14 thyristors per unit (two units). Line convertor rated at 2 x 1269V @ 50Hz, with DC link voltage of 2800V. Motor/drive convertor rated at 2180V phase to phase, 971A output current per phase, motor frequency from 0 to 132Hz.
·         Hauling capacity: 4250t
·         Bogies: Co-Co, ABB bogies; bogie wheel base 1850mm + 1850mm
·         Wheel base: 15700mm
·         Axle load: 20.5t
·         Unsprung mass per axle: 3.984t
·         Length over buffers: 20562mm
·         Length over headstocks: 19280mm
·         Body width: 3152mmn
·         Cab length: 2434mm
·         Pantographs: Two Secheron ES10 1Q3-2500.
·         Pantograph locked down height: 4525mm

As we proceeded towards the assembly shop a WAP 4 road numbered 22979 was being completed.

The WAP-4 loco design was published in November 1993.Its specialty lies in being indigenously designed with higher power rated silicon rectifiers and with an indigenously-designed 5400kVA transformer. Locomotive reliability is also increased by the use of Hitachi traction motors. It has different under frame design to handle larger buffing loads. It has cast bogie, Flexicoil Mark 1 design. The weight is kept to 112t by the use of aluminium plates with a thinner under frame.

Some technical specifications:-
·         Manufacturers: CLW
·         Traction Motors: Hitachi HS15250 (630kW, 750V, 900A. 895rpm. Weight 3500kg). Axle-hung, nose-suspended, force ventilated, taper roller bearings.
·         Gear Ratio: 23:58 (One loco, #22559, is said to have a 23:59 ratio.)
·         Transformer: 5400kVA, 32 taps
·         Rectifiers: Two silicon rectifiers, (ratings?).
·         Axle load: 18.8t.
·         Bogies: Co-Co Flexicoil Mark 1 cast bogies; primary and secondary wheel springs with bolsters
·         Pantographs: Two Stone India (Calcutta) AM-12.
·         Current Ratings: 1000A/10min, 900A continuous
·         Tractive Effort: 30.8t

Then we proceeded towards the electronics section.

Various electronics components and panels filled the entire section. Each and every part of the electronic switches and circuits were being assembled in this shop.

These are various panels installed in every 3 phase Locomotives. It is being arranged and assembled at CLW. The company that provides these circuits and relays is Schneider Electric.

The Auxiliary circuits, cubicle -1 (HB1), The Auxiliary circuits, cubicle -2 (HB2), Control cubicle-1 (SB1), Control cubicle-2 (SB2), and Filter Cubicle
are assembled here. The head of this section is Mr Pankaj Sen. These cubicles contain only low voltage switching gear and electronics. The abbreviation SB means in german Steuerstrom Block (control circuit cubicle). The filter cubicle (FB) is a different cubicle which is also installed in the locomotive. In the WAP 5 and WAP 7 this cubicle also contains contactors for the hotel load equipment besides the filter capacitors. In WAG 9 there are only filter capacitors.

Mr Sen explained me in detail how he arranges and installs them.
Then I move out of that shop.  Several P7’s were being assembled.

WAP 7 is a modified version of the WAG 9. The gear ratio and control software is the only difference between the two loco’s. Some modifications have been done to the present fleet of WAP 7that are now being manufactured. Parking brake has been removed. Hotel Load connectors have been removed. And some modifications have been done in the WAP 7 bogie. An additional brake cylinder has been installed on both side of the bogie for safety reasons.
·         Manufacturers: CLW
·         Traction Motors: 6FRA 6068 3-phase squirrel-cage induction motors (850kW, 2180V, 1283/2484 rpm, 270/310A. Weight 2100kg, forced-air ventilation, axle-hung, nose-suspended. Torque 6330/7140Nm. 95% efficiency.)
·         Gear Ratio: 72:20
·         Axle load: 20.5t
·         Wheel diameter: 1092mm new, 1016mm worn
·         Wheel base: 15700mm
·         Bogies: Co-Co, ABB bogies; bogie wheel base 1850mm + 1850mm
·         Unsprung mass per axle: 3.984t
·         Length over buffers: 20562mm
·         Length over headstocks: 19280mm
·         Body width: 3152mmn
·         Cab length: 2434mm
·         Pantograph locked down height: 4525mm
·         Tractive Effort: 36.0t.
Currently there are two WAP 7 30277 and 30365 that have HOG(Head On Generation) / Hotel Load enabled.  CLW plans to manufacture more.

As I move through the assembly shop, I saw the installation of Harmonic filter for 3 phase Loco’s, and AM-12 and AM-92 Pantographs for both conventional and 3-Phase Loco’s.

As I move through the production process, a transformer for a WAG 9 Loco was being shifted from one shop to the other to get it installed in the G9 Loco.
The paint and assembling job for a WAP 4 has also been done. The pneumatic pipes were being installed for the Locomotive.

I finally say goodbye to the Assembly shop and move to the Traction Motor Shop. Here the back bone for the 3 Phase Loco’s are being made. Its none other than the squirrel cage induction motor.

There were many stators completed and many left which would later be completed at 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.

I move back to the Fabrication shop after the TM shop, which is Asia’s Longest bay.

The Loco’s are fabricated here. The shells and the body of the Locomotive is joined here.

One of the companies that manufacture the cabs of the three phase and conventional Locomotives is Jessop. Most of it is manufactured in Kolkata, and then it is transported to CLW. The complete joining of the entire Locomotive is done in the Fabrication Shop.

The bogies of WAG 9 and WAP 5 is being manufactured at the Fabrication Shop from scratch, wheras the bogie, bogie frames of the conventional Locomotives are also manufactured in the fabrication shop itself.

Finally I leave the factory at 4pm. I return the helmet to Mr Suresh Kumar and thank him once again for allowing me to visit the factory. Many Thanks once again sir.

I take an auto rickshaw to Asansol Station. Shatabdi Express arrives at paltform 5 of Asansol Station, 10 minutes late.

It was the same P7 which hauled it during its Up journey.
It took 2.5 hours to reach Howrah Station.

I reached Howrah Station at 9:10pm.

Some Snaps of Chittaranjan Locomotive Works.

The Control Panel of the driver’s desk can be seen lying on the ground and in the background a WAP 7 and a WAG 9 can be seen ready to enter the assembly shop for installation of the various electrical components.

The assembly shop that can be seen from the driver’s eye.

The Assembly Shop.

It is divided into three bays.

Bay 1- 3 Phase Locomotives
Bay 2- 3 Phase Locomotives
Bay 3- Conventional Locomotives

Beside the Assembly shop is the shop for DC Traction Motors. The entire DC Motor is being manufactured in that shop and few are being supplied by Hitachi and few other companies.

A diesel Locomotive does the work of shunting the shells from one shop to the other in the entire workshop.

WAG 7 and its bogies can be seen in the assembly shop.

The springs that are installed for the suspension system of the Locomotives.

The picture on the right shows the roof hatch equipments lying on the assembly shop floor to get installed in the Locomotives.

Another entrance to the assembly shop.

A view of the Air conditioner installed in the WAP 4 Locomotive.

The Testing Shop :-

The Loco’s are tested here and are then commissioned.

Once again many thanks to Mr Suresh kumar, Dy CEE, CON, CRJ without whose help it wouldn’t have been possible and the GP-140 engineer Mr Pankaj Sen for briefing me and showing me in details the aspects of three phase ABB’s Locomotives.    

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


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.