Construction activity on the 5 Km stretch of the 21 Km tunnel on Maharashtra section of the Mumbai–Ahmedabad High-Speed Rail corridor has advanced to the structural stage, with lining, waterproofing and drainage works currently underway, according to a statement by the National High Speed Rail Corporation Limited (NHSRCL) on Thursday, 2 April.
NHSRCL is the implementing agency for the 508-km Mumbai-Ahmedabad bullet train corridor.
According to the agency, the 5-km section of the 21-km tunnel has been fully excavated using the New Austrian Tunneling Method (NATM).
As per the NHSRCL, drainage systems are being installed using a Drainage Casting Gantry to ensure that seepage water is collected and channelled through a dedicated system within the tunnel.
Waterproofing operations are also in progress, with specialised gantries installing protective membranes to prevent water ingress and enhance durability.
Reinforcement bar cages are being prepared and installed along the tunnel profile, forming the steel framework required ahead of the final concrete lining.
The lining process is being executed using a Lining Gantry, which casts the permanent concrete structure of the tunnel, providing both strength and a smooth internal finish.
In parallel, dedicated equipment rooms are being developed within the tunnel to house critical systems required for operations and maintenance.
The 21 Km tunnel is a key component of India’s first bullet train project, the 508 Km Mumbai–Ahmedabad High-Speed Rail corridor, which will connect Maharashtra and Gujarat with trains operating at speeds of up to 320 Km/h.
The tunnel includes India’s first 7 Km undersea rail section beneath Thane Creek and is being constructed using a combination of NATM for 5 Km and Tunnel Boring Machines (TBM) for the remaining 16 Km.
The corridor, being implemented by NHSRCL, is designed to reduce travel time between Mumbai and Ahmedabad to about 2 hours on limited-stop services, while connecting major industrial and urban centres such as Vapi, Surat, Vadodara and Anand.
