Central Railway takes another short at DC-AC conversion between CST and Thane

Mumbai: One of India’s last bastions of the 1,500 volt director current (DC) – the rail lines between CST and Thane – have been converted into the efficient 25,000 volt alternating current (AC). The Central Railway was scheduled to carry out the switch between midnight on Sunday and 6 am on Monday and, early on Monday, the Central Railway has finally converted its electric traction between Thane and CST from direct current (DC) to alternating current (AC), despite showers hitting the city on Sunday.

With this conversion, only the Harbour lines between CST and Panvel and the Thane-Vashi trans-harbour lines will be still running on DC traction making them an island in the vast AC-powered Indian Railway network.

Calling the process a ‘psychological’ feat rather than a technological feat, a top-ranking CR official said, “For the past three years, we have spent countless man-hours debating how to go about this conversion. As one solution after another failed, the issue of DC-AC conversion was becoming more of an albatross around CR’s neck. Just about every other project on CR had been put on the backburner and the only one we were all concentrating on – the DC to AC conversion- was just not taking off.”

CR general manager Sunil Kumar Sood said that the rains would not be an issue and the conversion would happen late on Sunday night, with the officials operating a block from 12 am to 6 am.

He said, “Rains will not be an issue for us as we have planned the conversion accordingly. The spots with restrictions have been brought down to only three from nine. They are at Mumbra tunnel, Hancock Bridge and the viaduct at Byculla.”

The Commissioner of Railway Safety (CRS) had earlier given a speed restriction to 15 kmph at nine spots between CST and Kurla due to lack of vertical clearances. CR then negotiated with the Railway Board on Saturday and Sunday and now the restriction will be there at only three spots. CR had conducted a test trial on Friday with the restrictions and found that around 180 trains would need to be cancelled per day.

Mr Sood said that with the restriction limited to only three spots, the delays would not be as severe. “We expect that there will be a delay of only three to four minutes during peak hours in the morning and evening and only of two-minutes during non-peak hours,” he added.

Currently, Hancock Bridge, which is due for demolition in two to three months, has the slowest speed at 15 kmph. An official said, “Hancock has a limit of 15 kmph, which is okay because we expect it to be demolished soon.” Officials have also said that the system will have teething problems for about a week, after which they will be resolved.

The advantage of the switchover to AC is that CR will now be eligible to get new rakes since manufactures have stopped making trains that run on DC for about 10 years, due to which new trains would go to Western Railway (WR) which is already on AC by default.