Metro rides just got cooler. Seventy-seven per cent of the trains that ran this month were air-conditioned and the count is likely to rise to 80 per cent soon.

With increasing use of newer trains, Metro Railway also plans to retire the last of the first batch of non-AC rakes that had joined the fleet 33 years ago.

The new rakes supplied by the Integral Coach Factory (ICF) in Perambore are finally operational after the initial technical glitches, Metro officials said.

“We are hoping to add three more new AC rakes by March, so that 90 per cent of the services can be covered by AC rakes,” a senior Metro official said.

“The ICF engineers have been able to fix the problems. So, we have been able to run five new AC rakes every day. Earlier, we could run three and that, too, on short stretches,” the official said. Three more new AC rakes are undergoing trial and are expected to be put into service by March.

Metro trains covered a total of 1,38,912km between Kavi Subhash (New Garia) and Dum Dum and at times up to Noapara from January 1 to 21. Of the total distance covered, the five new AC rakes clocked 31,812km and the 13 old AC ones 75,341km, the officials said.

The number of AC trains has gone up since December. Before that, only 60 per cent of the Metro fleet was air-conditioned, sources said.

As more AC rakes are added to the fleet , the old non-AC rakes will be phased out, said the official. By March, the last of the seven rakes produced by BHEL will be taken off, the official said.

Metro services in the city began in 1984. Seven non-AC yellow rakes had been procured between 1984 and 1988. Six of those rakes have been withdrawn.

The last one, numbered B6 by Metro Railway, had been upgraded twice over the past six years, officials said.

“Condemned rakes are usually sold as scrap. But this rake can be kept in the railway museum,” said an official.

Six more rakes produced by NGEF (New Government Electrical Factory), that became part of the fleet between 1988 and 1992, would continue to be service for now.

The demand for rakes is expected to increase once the Noapara-Dakshineswar stretch is commissioned and frequency of trains is increased.

A rake manufactured by CNR Dalian Locomotive & Rolling Stock Co in China is also undergoing trial.

Once the prototype is cleared by the railway safety agency, 13 more will join the fleet, said officials.