September 13, 2025: The Mumbai-Ahmedabad Bullet Train project has achieved a major milestone with the launch of its first 40-meter-long Full Span Pre-Stressed Concrete (PSC) Box Girder in Maharashtra. The National High-Speed Rail Corporation Limited (NHSRCL), implementing the 508-km corridor, carried out the launch on 6 September at Sakhare Village in Dahanu using a Full Span Launching Gantry (FSLG). This marks the beginning of viaduct construction in the state.
The Maharashtra section spans 156 km, of which 135 km will be elevated between Shilphata and Zaroli at the Gujarat border. The elevated stretch requires 2,575 full-span girders, each weighing about 970 metric tonnes, along with 17 km of segmental girders, 2.3 km of steel bridges, three elevated stations, seven mountain tunnels of nearly 6 km, and special earth structures. Thirteen casting yards are planned, with five already operational.
Full Span PSC Box Girder technology, adopted in 2021, has already been used to build a 319 km viaduct in Gujarat. Each girder is cast as a single unit with 390 cubic meters of concrete and 42 metric tonnes of steel, making them the heaviest in India’s construction sector. Their use speeds up construction nearly tenfold compared to segmental girders. Placement is carried out with heavy indigenous machinery, while girders are precast and stored at dedicated yards.
In Maharashtra, 48 km of piers have been completed, and full-span girder launching has begun in Palghar. Excavation of the seven mountain tunnels is underway, with 2.1 km completed. Work is also progressing on river bridges across Vaitarna, Ulhas, and Jagani.
A highlight of the project is the 21 km underground and undersea tunnel between Bandra-Kurla Complex and Shilphata, with 4.65 km of excavation completed so far. At the BKC station, 83 percent of the excavation is finished, and base slab casting at a depth of 100 feet has started.
Source: Swarajya
