New rail bridge at Pamban likely to open by February end

The 2.1-km engineering marvel will link mainland India with Rameswaram Island.

Bengaluru, DHNS: The new railway bridge connecting mainland India to Pamban Island at the southwestern tip of Tamil Nadu is expected to open for train traffic by the end of February, according to officials.

Built over nearly six years at a cost of Rs 531 crore, the 2.1-km structure has been hailed as an engineering marvel. It is India's first vertical lift bridge, featuring a navigational span that can be raised up to 17 metres to allow floating pontoons, Indian Coast Guard vessels and fishing boats to pass underneath, through the Palk Strait.

Last week, the Indian Railways took a group of journalists to the Pamban Bridge, where officials explained its strategic importance and technological advancements. The new bridge had come under scrutiny after the Commissioner of Rail Safety (Southern Circle) A M Chowdhary, who is based in Bengaluru, flagged deviations in design and welding parameters. However, the bridge received statutory clearance after these concerns were addressed.

Railway officials, along with representatives of RVNL, the contractor for the bridge, and project consultant Balaji Railroad Systems Ltd stressed that the structure was ready for commercial operations, meaning trains can be operated on it.

Prime Minister Narendra Modi is expected to inaugurate the bridge by the end of February but no date has been finalised, according to officials who spoke on the condition of anonymity.

The decision to construct a new bridge was taken in 2019 after the old cantilever bridge — opened on February 24, 1914 — became structurally weak due to corrosion. Train movements on it stopped in December 2022. The old bridge was a historic engineering feat in its own right. It was India's longest sea bridge before the Bandra-Worli Sea Link opened in Mumbai in 2010. It featured a Scherzer rolling lift span, which opened like scissors to allow ships to pass through. The railways now plans to dismantle the old bridge.

The old bridge had several limitations. Its Scherzer rolling lift span had to be operated manually by 16 people, and the process took 45 minutes. The old bridge had only a single, unelectrified track.

The new bridge, constructed between February 2019 and November 2024, addresses most of these challenges. The track is electrified, and features a rail guard on either side to keep wheels aligned and prevent derailment. A sub-structure has also been built to accommodate a second railway track in the future. The bridge includes a cable tray to support signalling and telecommunication (S&T) and electrical cables, according to officials.

But the biggest upgrade is the navigational span, which can be lifted vertically via towers located on either side. This span is 72.5 metres long and weighs a whopping 660 metric tonnes. Together with the track and the 34-metre-tall towers, including counterweights, the weight reaches 1,470 MT. Unlike the manually operated Scherzer span on the old bridge, the new structure's vertical lift span is operated by an electro-mechanical system, which is interlocked with train control systems for the separation of the navigational span. The lifting process takes just 5 minutes and 30 seconds, and can be performed by one person.

Manjunath Kanamadi, Chief Public Relations Officer, South Western Railway (SWR), explained that while the old bridge suffered from corrosion, the new bridge is protected by a painting scheme comprising zinc metallising, Epilux zinc rich primer and Polysiloxane paint. "It's designed to last a hundred years," he said.

K Vel Murugan, a resident engineer at Balaji Railroad Systems, a Hyderabad-based firm which provided project management consultancy for the bridge, said that the painting scheme was expected to last 35 years, and patchworks could be undertaken when necessary afterwards.

The vertical distance between the water level and the bottom of the girder on the new bridge is five metres, compared to just 1.5 metres on the old one. The new navigational span of the new bridge can be lifted up to 17 metres. This will allow ships with an air draught of 22 metres to pass underneath without a hitch. The water depth below the navigational span is 5.5 metres, Murugan added.

While the lifting mechanism has been designed to withstand wind speeds of 140 kmph, trains will operate on the bridge only when wind speeds are at 58 kmph or lower. From October to February, especially during the northeast monsoon, wind speeds frequently cross 58 kmph, according to Murugan.

The new bridge has been designed for a speed of 80 kmph due to the presence of a 2.65-degree curve, though the Commissioner of Rail Safety (CRS) has authorised a maximum speed of 75 kmph. The old bridge had a speed limit of 10 km.

As many as 130 trains can operate on the bridge per week. Currently, trains terminate at Mandapam, 17 km northwest of Rameswaram.