Published Date: 07-09-2025

The National High-Speed Rail Corporation Limited (NHSRCL) has successfully launched the first Full Span Pre-Stressed Concrete (PSC) Box Girder of 40 meters length using a Full Span Launching Gantry (FSLG) in the Maharashtra section of the Mumbai-Ahmedabad Bullet Train corridor. The launch took place at Sakhare Village, Dahanu in Maharashtra on 6th September 2025.

The Maharashtra section of the Bullet Train corridor spans 156 km, which includes 135 km of elevated alignment from Shilphata to Zaroli village at the Maharashtra-Gujarat border. Out of this, 103 km of elevated viaduct is planned to be constructed using 2,575 full span girders, each 40 meters long and weighing approximately 970 metric tonnes.

Other major structures in this section include 17 km of segmental girders, 2.3 km of steel bridges, 3 stations, 7 mountain tunnels (approximately 6 km), and special earth structures.

A total of 13 casting yards are planned along the alignment between Shilphata and the Gujarat-Maharashtra border, out of which 5 casting yards are currently operational.

This advanced full span girder technology has been in use for the Bullet Train project since April 2021 and has contributed significantly to the completion of 319 km of viaduct in Gujarat.

Additional Information on Full Span Girders

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.

Bullet Train Project Progress in Maharashtra

(As on 05th September 2025)

• Work on all three elevated stations — Thane, Virar, and Boisar — is progressing rapidly. The first slab for Virar and Boisar stations has been cast.
• Pier foundation and pier work is underway at multiple locations, with approximately 48 km of piers completed so far.
• Viaduct construction using full span box girder launching has commenced from the Dahanu area in Palghar district.
• Excavation work for 7 mountain tunnels is ongoing in Palghar district, with a cumulative progress of approximately 2.1 km out of 6 km.
• Construction work has started on Vaitarna, Ulhas, and Jagani river bridges.
• A 21 km long underground/undersea tunnel is under construction between Bandra-Kurla Complex (BKC) and Shilphata, including a 7 km undersea stretch beneath Thane Creek.
• Out of 21 km tunnelling, 16 km is being executed using Tunnel Boring Machines (TBM) and 5 km through the New Austrian Tunnelling Method (NATM).
• Approximately 4.65 km of tunnel excavation has been completed from Shilphata and ADIT portal using NATM.
• Base slab casting is completed at Vikhroli (56 meters depth) and Sawli shaft (39 meters depth).
• Sludge treatment plants are being installed at shaft locations, and the Mahape tunnel lining casting yard is producing tunnel segments.
• At under construction Mumbai Bullet Train station at Bandra Kurla Complex, 83% excavation work has been achieved. Base slab casting at 100 ft below ground level has already started at both ends of the station site.