The Hindu Business Line : Moving on high-tech tracks

It's an initiative that has provided a big boost to the R&D and manufacturing capabilities of Indian Railways. It has also saved the country substantial foreign exchange.

The Indian Railways, in association with Semiconductor Complex Ltd, Chandigarh, has successfully developed - for the first time in India - eight types of Application Specific Integrated Circuits (ASICs) that are used in 108 locations in electric locomotives.

The first electric locomotive where these indigenously-developed ASICs were used was rolled out of the Chittaranjan Locomotive Works (CLW) of Indian Railways in July 2006. With this, the cost of each electric locomotive has come down by Rs 30 lakh.

Besides ensuring financial gains, the project, which was undertaken four years ago, has ensured a continuous supply of these eight types of ASICs .

Pulling people, cargo

CLW manufactures state-of-the-art 5,500-6,000 HP electric locomotives that pull both passenger and goods trains. Each of these electric locomotives costs Rs 10-11 crore.

Six-axle locomotives are driven by six motors while four-axle locomotives are driven by four motors. Last fiscal, 128 locomotives were manufactured at CLW. The target for the current year has been pegged at 150.

Traditionally, CLW has been engaged in the manufacture of conventional locomotives whose wheels were driven by DC traction motors. These locos were easy to control. However, the problem with them was that they were bulky and had lower power-to-weight ratio. Besides, they were more maintenance-intensive.

AC traction motors, though simpler in construction, have higher power-to-weight ratio. But the catch is that they are essentially fixed-speed machines and their use in variable speed calls for complex control stratagems.

Says Sujeet Mishra, Deputy Chief Electrical Engineer of Indian Railways and in-charge of the Traction Solution Lab, Centre for Design & Development, CLW: "If you want an AC motor to work like a DC motor you need switching devices that can switch at higher frequencies.

But for so many simultaneous operations one cannot have a mechanical switch where there is moving contact.

What you need is a static switch with no moving contact. That means you need a semiconductor switch. But to control the switch you need control electronics and the whole thing has to work along with a moving train."

According to him, there are 108 ASICs in each locomotive. Efforts were made to identify components that were likely to get obsolete faster and target them for alternate sourcing.

Developing them indigenously would not only help in cutting costs but also save valuable foreign exchange.

Eight types of ASICs used at 108 locations in a locomotive were identified in this regard. A project to develop them indigenously was taken up jointly with Semiconductor Complex, Chandigarh, a unit of the Department of Space.

The result: these eight types of ASICs are available indigenously, there is no dependence on high-cost imports and manufacturing costs have come down.

And it has provided a big fillip to the R&D capabilities of Indian Railways.

Work is currently on to develop the 9th type of ASIC that is used in 30 locations in electric locomotives.

In this task, Indian Railways has once again partnered with SCL. And, when success is achieved in this project, Indian Railways can rightfully add yet another feather to its colourful cap.

ambar_singhroy@rediffmail.com