Calcutta: The design of East-West Metro's Sealdah station is likely to be tweaked to construct platforms on both sides of the tracks, a plan earlier drawn only for the project's Howrah and Esplanade stations where the average footfall is likely to be high.
The plan for "double discharge", which will enable passengers to board or get off a train on both sides, has recently been sent to the railway ministry for approval, officials said.
The East-West Metro link will have 12 stations between Salt Lake Sector V and Howrah Maidan, of which the ones in Esplanade, Howrah and Sealdah are likely to have the highest passenger footfall.
The nine others will have the single-discharge system, meaning passengers have to get off or board a train on one side.
In the single-discharge system, the platform is located between two sets of tracks and the doors open on one side. In the double-discharge system, one platform will be in the middle and the other on one side of a pair of tracks.
In the existing north-south Metro, passengers get on and off a train on one side. During rush hours and on festive days, stations witness a stampede-like situation, which many feel could be avoided if there were one more platform for getting on or off a train.
A survey has revealed that the Esplanade station of East-West Metro will handle 55,000 passengers in an hour during rush hours in 2035. The corresponding figures for Sealdah and Howrah are 46,000 and 43,000, respectively.
The average rush-hour footfall at other underground stations of East-West Metro in 2035 will be around 25,000 an hour. The figure is likely to be 15,000 at the overground stations.
Each six-coach rake of East-West Metro can carry 2,068 passengers. The travel time between two stations will be around two-and-a-half minutes.
"We had initially planned a single-discharge system for Sealdah station. We have proposed to tweak the plan and turn Sealdah into a double-discharge station, like Esplanade and Howrah, after calculating the projected passenger load," said Parashuram Singh, managing director, Kolkata Metro Rail Corporation (KMRC), the implementing agency of the project.
"The system will help minimise chaos and ensure faster dispersal of passengers."
A KMRC engineer said the tweak in plan would result in an additional expenditure of around Rs 70 crore.
An official of the construction company Afcons, which is building the Howrah station, said the main or island platform (the one between two sets of tracks) will be 12m-wide. Each side platform will be 6m-wide.
The official said the width of the underground station at Sealdah had to be extended by 20m to make room for double-discharge platforms.
Engineers said two factors had been considered while deciding on the tweak - the level of service and the maximum number of passengers a facility or system can accommodated under a given condition.
"The level of service is rated from A to F. Level A is, say, around midnight when there are almost no passengers. Level F is extreme chaos. Our target is to keep the level of service at C," an engineer said.
"To maintain that we have to have dispersal from trains on both sides at busy stations."
The double-discharge system at a busy station will also ensure that all passengers reach a safe point during a fire or any other emergency within six minutes of a train pulling into a station.
