The unique Scherzer’s span of Pamban railway bridge, India’s first cantilever bridge, is all set to pave way for a new span as the Ministry of Railways has sanctioned Rs 20 crore for its replacement. Southern Railway has begun designing the new span.
The manually operated 65.23-metre-long rolling-type lift span, which opens like a pair of scissors for vessels to pass through the channel, was designed and built by German engineer Scherzer and it has completed its life span.
“We are planning to have an elegant and unique type of span and working on four different types,” Southern Railway Chief Engineer (Bridges) M. Suyambulingam told The Hindu after inspecting the ongoing re-girdering work at the bridge on Tuesday.
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“We are for the best option with optimal cost and will probably go for the vertically lifting type on the lines of Bacalan-Bastide lift bridge in France, a road bridge, ” Mr Suyambulingam said.
The replacement work would begin in January-February next year and would be completed in a year’s time, he said.
As most of the activities would take place outside, the bridge would remain open for train services, he said. “There will be least disturbance to train services when the new span with pre-fabricated structures is erected,” he added.
Polymer alloy coating
Fighting to maintain the 2.06-km-long bridge with more than 140 spans and located in the world’s second highly corrosive environment, Southern Railway has decided to try polymer alloy coating for girders.
“We have selected six spans in the mid-sea for application of three different varieties of polymer alloy coating on a trial measure to enhance the life of the girders and reduce the frequency of painting,” Mr. Suyambulingam said.
Three manufacturers had claimed that polymer alloy coating would not only enhance the life of the spans but also reduce the frequency of painting to once in 15 years. “We have got clearance for the application and the three varieties will be applied in two spans each on a trial measure,” he said. The tender process had been completed and the work would begin in June, he added.
