Larsen & Toubro (L&T) has achieved another major construction milestone on the Mumbai-Ahmedabad High-Speed Rail (MAHSR) Project with the successful breakthrough of Mountain Tunnel-07 (MT-07) under the C-3 package. The achievement marks the company’s third mountain tunnel breakthrough in Maharashtra within five months, highlighting the steady progress of India’s first Bullet Train corridor.
Located at Ambesari village in Dahanu taluka of Maharashtra’s Palghar district, the MT-07 tunnel has been constructed through the Sahyadri mountain range. The tunnel measures 417 metres in length and 12.6 metres in width, and has been designed to accommodate both up and down high-speed rail tracks.
Excavation was carried out simultaneously from both ends using the New Austrian Tunnelling Method (NATM), enabling continuous geological assessment and the installation of appropriate ground support systems, including shotcrete, rock bolts and lattice girders. The tunnelling work was completed over a period of 516 days using 117 controlled blasts, despite challenging geological conditions.
Advanced monitoring and instrumentation systems were deployed throughout the construction process to ensure structural stability and worker safety. Real-time monitoring through 3D targets, surface settlement points (SSPs) and seismographs enabled engineers to track ground movement, tunnel behaviour and vibration levels with high precision during excavation.
The breakthrough adds to the progress already achieved under the MAHSR project, following the completion of MT-05 and MT-06 earlier this year. With MT-07 now completed, three of the seven mountain tunnels being constructed in Maharashtra have achieved breakthrough, while excavation work on the remaining tunnels continues at various stages. The eighth mountain tunnel, located in Gujarat’s Valsad district, has already been completed.
The MT-07 tunnel forms part of the 135.45-km MAHSR C-3 package being executed by L&T, which extends from Shilphata in Thane to Zaroli village near the Maharashtra-Gujarat border. The package includes three Bullet Train stations at Thane, Virar and Boisar, around 124 km of viaducts constructed using Full Span Launching Method and segmental girders, nearly 2.3 km of steel bridges, seven mountain tunnels spanning approximately 6 km, and around 5 km of specialised earth structures.
The successful completion of the latest tunnel represents another significant engineering achievement for the Mumbai-Ahmedabad Bullet Train Project and reinforces the pace of construction on one of India’s most ambitious transportation infrastructure initiatives.