Finally, a bowstring bridge is likely to replace the present Tallah Bridge.
The railways had turned down the earlier bowstring design and suggested a cable-stayed one with larger spans and less number of piers to avoid prolonged blocking of the railway tracks underneath. But now the state PWD has reviewed the design and decided to go for the steel-arch bowstring girder design with certain modifications.
Eastern Railway has given a verbal nod to the amended design and agreed to closing two or three of its lines to facilitate pier construction.
The 51-year-old structure is actually a road overbridge (ROB) and falls within the ambit of Eastern Railways (ER).
TOI was the first to report that even as PWD had sketched a bowstring bridge in the draft masterplan, or the general arrangement drawing (GAD), adopting Research and Standards Organization (RDSO) standardization, ER didn’t approve it, citing technical constraints.
At a meeting on December 26, ER engineers told PWD that construction of multiple piers as shown in the GAD would jeopardize train movement. A cable-stayed bridge, on the other hand, is more feasible here.
On January 16, PWD came up with an amended bowstring design that showed an arrangement of bigger spans supported by less number of piers. The five spans in the earlier design included four bowstring girders, 50m each, along with a 24m composite girder. The 224m deck was supported by 10 piers. The new design will have bigger spans – of 72m length. There will be 5 to 6 piers. “PWD is sticking to railway rules and drawing up the ROB as per RDSO-certified bowstring designs,” a state official said.
Source: Times of India