Mumbai–Ahmedabad Bullet Train: First 40m Full Span PSC Box Girder Launched in Maharashtra

The National High-Speed Rail Corporation Limited (NHSRCL) has successfully launched the first 40-metre Full Span Pre-Stressed Concrete (PSC) Box Girder using a Full Span Launching Gantry (FSLG) in Maharashtra, at Sakhare village in Dahanu, for the Mumbai–Ahmedabad Bullet Train corridor

The Maharashtra section of the corridor spans 156 km, including 135 km of elevated alignment from Shilphata to Zaroli on the Maharashtra–Gujarat border. Of this, 103 km will be built using 2,575 full span girders, each 40 metres long and weighing about 970 metric tonnes. The section will also feature 17 km of segmental girders, 2.3 km of steel bridges, three stations, seven mountain tunnels covering about 6 km, and special earth structures.

To support construction, 13 casting yards have been planned along the alignment, with five already operational. The proven technology, in use since April 2021, has already contributed to 319 km of completed viaduct in Gujarat.

Each 40-meter-long PSC Box Girder weighs around 970 metric tonnes, making it the heaviest in India's construction industry. These girders are cast as a single monolithic unit—without construction joints—using 390 cubic meters of concrete and 42 metric tonnes of steel. Full-span girders are preferred for Bullet Train project, as they enable construction progress up to 10 times faster than segmental girders.

The full-span pre-cast box girders are being launched using specialized indigenous heavy machinery such as Straddle Carriers, Bridge Launching Gantries, Girder Transporters, and Launching Gantries. To ensure uninterrupted supply, girders are being cast in advance and systematically stacked in dedicated casting yards.