Crude oil prices in the international markets may have cooled considerably in recent months. But concerned about the earlier record increase in prices and in an effort to go green, Indian Railways is developing technology to run trains on compressed natural gas. In fact, it has set up the Indian Railways Institute of Alternate Fuels to devise technology to tap into compressed natural gas and biofuel.

Two research projects have already been commissioned by the railway ministry for using compressed natural gas to not only run suburban trains, but also to haul trains over long distances. Some 200 diesel multiple units fitted with compressed natural gas engines have already begun trial runs. ?If the pilot project is successful, we will launch it commercially soon,? a railway ministry official said.

Initially, in the modified engines about half the diesel will be substituted with gas, which will gradually be increased to 70%. The initial cost of developing the engine is around Rs 40 lakh.

Meanwhile, the Indian Railways? research and design arm, the Rail Design & Standards Organisation (RDSO) is also working to modify the existing diesel locomotive engines and adapt them to run on compressed natural gas. ?Our plan is to have loco engines that have a retrofit kit, which will allow them to run on compressed natural gas, like it is done for cars,? the official said.

The RDSO?s initiative was sanctioned Rs 22.3 crore in the Rail Budget for 2008-09 and the ministry is hopeful that a compressed natural gas compatible engine would be ready by next year.

Switching over to compressed natural gas from diesel will help the railways cut costs, an issue that has become especially important given the contraction in its freight business and volatile oil prices. The railways spent Rs 8,560 crore on diesel last year, which it expects would go down by 60% once it makes the transition to compressed natural gas.

However, sourcing the fuel would be a tricky proposition. Compressed natural gas is at present sold only in select cities, unlike diesel, which is freely available. Running diesel multiple units on suburban routes like Mumbai and Delhi, where compressed natural gas is sold, will not be difficult, however. Unless compressed natural gas is freely available across the country, using it for long distance trains will not be feasible.

Though the railways has been working towards using biodiesel to run its trains for some time now, it has so far not been commercially viable. The key deterrent was sourcing of biofuel as the railways? plan for jatropha cultivation along its tracks found few takers.