The marvellous Pamban bridge

Restoration work on the existing, iconic Pamban rail bridge and the construction of a new one are taking place simultaneously in the coastal waters of the Bay of Bengal, off the state of Tamil Nadu. The iconic, 108-year-old Pamban cantilever rail bridge was commissioned in 1914 bridging peninsular India and the Gulf of Mannar, interconnecting Mandapam in Rameswaram mainland with Rameswaram Island. It was the only link connecting the two locations until a new road bridge was built parallel to the sea link in 1988. Serving more than its codal life, the rail bridge was getting heavily corroded and was being repaired regularly by Railways in order to carry train traffic safely.

Finally, rail traffic on the bridge was suspended from December 2022 after a red alert was received from the sensor-based health monitoring system installed by IIT Madras and Southern Railway officials assessed that the bridge had to be repaired due to heavy corrosion, to be made safe for rail operations. The Research Design and Standards Organisation (RDSO), the R&D wing of the Ministry of Railways that functions as technical advisor and consultant to the Railway Board and the Zonal Railway, had been advised to inspect and suggest possible repairs required to put the old bridge back in service.

The new Pamban bridge is being executed by Rail Vikas Nigam Limited (RVNL) with whom the Southern Railway is actively engaged. While the existing bridge structure has a total length of 2058 metres comprising 146 spans of steel girders, 145 spans of 12.20m length and one navigational span of 61.0m length, the new bridge being constructed will have 99 spans of 18.3m length and one navigational span of 72.5m length. It will be 3.0m higher than the existing bridge with navigational air clearance of 22.0m above sea level. Because of vertical lift, full horizontal width of 72.5m will be available for navigation. This will be India’s first vertical lift Railway sea bridge, once the work is completed.

The substructure of the new bridge and navigational span are being built with the provision for double line and designed with the Railways’ plan for electrification. In comparison to existing manual operation and control, the new bridge will have electro-mechanical controlled systems which will be interlocked with train control systems.

The construction of the new vertical-lift railway bridge has faced a number of engineering challenges due to the 2.65 degree of curved alignment of the bridge in its length complicating the movement of the lift span, besides its mechanical peculiarity and a rough sea. The 550-ton lift span has been moved only 80 meters due to the curved alignment of the bridge, with more challenges ahead in reaching the final fixing point. The lift span has been designed by a Spanish firm and assembled near the coast due to its massive size, contributing to the complexity of the project.

While the new rail bridge is yet to get operational, it allowed the passage of three ships under its central part early this year, attracting numerous tourists who enjoyed the spectacular view. The suspension bridge was opened and one ship passed travelling from Goa to Visakhapatnam, the second from Lakshadweep to Cuddalore in Tamil Nadu and the third ship from the South to the Indian Coast Guard Station at Mandapam in the North.

The great Pamban bridge attracts thousands of tourists from all over the world. It transports scores of pilgrims visiting the famous Ramanathaswamy Temple.

(Technical details courtesy: Southern Railways)