Duplex stainless steel to protect Pamban Bridge
Railways’ ambitious project of a second bridge parallel to Pamban bridge is set to take off in another few months.
CHENNAI: One of India’s century-old iconic structures – the 2.34-km railway bridge over Palk Strait connecting Rameswaram island, with the last station on mainland of Indian peninsula –Mandapam – is entering its final phase of use.
Railways’ ambitious project of a second bridge parallel to Pamban bridge is set to take off in another few months. The new bridge will cost `250 crore and come up at a location which is known as the second most corrosive region in the world after Florida in the US.
In order to tackle the problem of corrosion and other maintenance-related issues, Railways has decided to use duplex stainless steel as an integral component for the fabrication of four girders of the new bridge.
To this effect, the Rail Vikas Nigam Limited (RVNL), an engineering arm of Railways, which has been entrusted with the task of building the bridge, has invited bids to procure 120 tonnes of stainless steel.
“The duplex stainless steel has high corrosion resistance capacity with minimal maintenance,” said a senior official from RVNL.
The new Pamban viaduct will have 100 spans of 18.3-metre steel girders (1.83 km) and one navigational span of 72.5 metres. It will be three metres higher than the existing bridge with navigational air clearance of 22 metres above sea level. Because of vertical lift, full horizontal width of 72.5 metres will be available for navigation of ships and vessels.
“We have already completed the soil test at a few locations. The new bridge has been designed suitably for double lines, including navigational lift span, parallel to the existing bridge. The civil works for construction of a new bridge will begin in another few months,” the official said.
The existing Pamban bridge was one of longest sea rail bridge when was built in 1904. It remained as the only surface connectivity between Rameswaram island with mainland till a road bridge was built in 1988.
Metre gauge trains transported hundreds of pilgrims daily to Sri Ramanathaswamy temple on the island. The bridge has 144 girders measuring 13.30 metres in length, 2.35 metres in breadth and 1.25 metres in height and weighing 11 tonnes with rails.
In 2016, as part of strengthening of Pamban bridge the Railways decided to replace manually-operated 65.23 metre two leaf structure with another vertically operated electronic span to enable ships to pass under the bridge.
As the replacement works required cancellation of trains on Pamban bridge for six months to one year, Railways decided to proceed with construction of second bridge.