The Centre has turned down a proposal to install automatic platform screen doors at Metro stations in the city because of high costs.

The doors would have prevented suicides and kept platforms cooler by stopping the cool air generated by ACs from flowing into the tunnels.

The Calcutta Metro authorities had sent three proposals over the past three fiscals to the railway ministry but are yet to get a reply.

"At present, we have no plans to install platform screen doors at Calcutta Metro," a senior railway board member told Metro from Delhi.

It would have cost almost Rs 150 crore to build floor-to-ceiling screens on platforms at all 24 stations.

Platforms screen doors slide open/close simultaneously with train doors, allowing movement of passengers.

In India, the Delhi Metro Rail Corporation started installing platform screen doors at six stations on the Yellow Line this year. A DMRC official said all stations in the upcoming Mukundpur-Shiv Vihar (Line 7) and Janakpuri West-Botanical Garden (Line 8) sections would have platform screen doors.

Apart from being a security feature, the doors would generate revenue through advertisements, he said. Screens facing the platform would have LCD display panels while the doors would have advertisements on them.

In Singapore, all Metro stations have platform screen doors.

A railway ministry official said the proposal was not sanctioned because "it wasn't financially viable". "Now, the ministry's policy is to complete pending projects before sanctioning new ones."

The doors would have been the only effective way to stop suicides, a Calcutta Metro official said. Since 1984, when Metro started operating in the city, there have been 289 suicide attempts and 149 suicides. This year since January, there have been 11 attempts and four suicides.

"Apart from a person losing life, services get disrupted for nearly 30 minutes every time a person attempts suicide," a Metro spokesperson said.

Also, the screens would have stopped the cool air of ACs from flowing into the tunnels. "The ACs at several stations are old... they need to be revamped. We have already started work at some stations," the official said. But passengers would continue to suffer if the cool air escapes into the tunnel, he said.

"It's like switching on the AC in your house with the doors and windows open.... In the past, tunnels needed to be kept cool because of non-AC trains. But now most trains have ACs."

Metro Rail spends Rs 35.08 crore annually on non-traction power consumption, which excludes the power to run trains but includes air conditioning at stations. Setting up screens would have saved power consumption considerably, the official said.