Assembling of steel girders for the proposed bowstring Railway Over Bridge (RoB) atop Mangaluru-Mumbai railway line of the Konkan Railway Corporation at Indrali — between Udupi and Manipal — started on May 16.
The Malpe-Tirthahalli NH 169A was widened to four lanes between Udupi and Manipal. However, traffic was choked over the RoB at Indrali, near the Udupi Railway Station, which was restricted to two lanes. A proposal to build an RoB parallel to the existing one underwent clearances from the Union Ministry of Road Transport and Highways (MoRTH) and the Ministry of Railways.
A senior engineer with the National Highways division of the Karnataka Public Works Department that is executing the four-lane work told The Hindu, “The worksite has been levelled to facilitate assembling and dragging the girders to their position. The prefabricated elements, including long beams and arch-beams, are being assembled. The process might take about two months.” One more component — cross girders — will arrive from Hubballi in a week.
The oncoming monsoon will not impact the work, as it involves assembling prefabricated steel elements. However, concreting the carriageway surface upon assembling the elements can be done only after the rains abate, which will have an impact on movement of vehicles, the engineer said.
Bowstring bridge to cover right-of-way of railways
The bowstring steel bridge is estimated to cost ₹9 crore. The 54-metre structure will cover the entire 48 metre right-of-way of the KRCL line. Initially, MoRTH had approved a proposal for a 33-metre bridge at a cost of ₹6 crore while the KRCL wanted the RoB to cover its entire right-of-way so as to accommodate further expansion of railway lines. This difference of opinion caused a delay, the engineer explained.
An estimated 476 tonnes of prefabricated galvanised steel will be used to erect the bridge. The prefabrication is done using submerged arc welding process in a workshop while the prefabricated material will be brought to the site after assembly. Concrete will be laid after all the elements are placed in their positions, parallel to the existing RoB. The abutment work to erect piles for the bridge on both the ends is complete.
