Key Points

A tunnel is being constructed beneath the creek between Mumbai and Thane, under the sea.

He reviewed the breakthrough of the tunnel between Ghansoli and Shilphata (4.881 km) in Maharashtra, saying that it has been a major achievement for the Mumbai-Ahmedabad Bullet Train corridor.

The Union Minister pushed the button and triggered a controlled dynamite blast to break through its final layer, completing five kilometre of excavation.

Calling it a "landmark achievement", Minister Vaishnaw said that the first phase of the high-speed corridor on the Surat-Bilimora section will start in December 2027 covering Thane in 2028 and the Bandra-Kurla Complex in 2029.

He told reporters in Ghansoli near Mumbai that the bullet train will be the "transport for the middle class", and the fares will be "reasonable".

"Now, nearly 320 km of the viaduct, that is, the bridge portion, in the Mumbai-Ahmedabad project has been completed. Very good work is underway at all stations. The bridges being built over the rivers are also being completed very rapidly," he said.

According to the Union Minister, the people will be able to cover the distance between Mumbai and Ahmedabad in two hours and seven minutes on the bullet trains against nine hours as shown on the Google Maps app.

He said that the services are designed such that a train will depart every half an hour during the morning and evening peak hours.

Once the entire network stabilises, there will be a train every 10 minutes during peak hours, he added.

Minister Vaishnaw said that there will be no need for ticket reservations to travel between Mumbai and Ahmedabad, and passengers can arrive at the station and board the bullet train.

The National High Speed Rail Corporation Limited (NHSRCL) said that the tunnel, excavated using the New Austrian Tunnel Method (NATM), is part of the 21 km underground stretch between the Bandra-Kurla Complex (BKC) and Shilphata, including a 7-km segment beneath Thane Creek.

With the latest breakthrough, the bullet train tunnel now connects the Savali shaft to the tunnel portal at Shilphata, linking it to the viaduct portion of the Mumbai-Ahmedabad High Speed Rail (MAHSR) project, the NHSRCL added in a statement.

The NHSRCL said that excavation of the tunnel began in May 2024 in three phases, and the first breakthrough of a 2.7-km continuous section was achieved on July 9.

An additional intermediate tunnel was built to allow simultaneous excavation from both Ghansoli and Shilphata sides.

The NATM tunnel has an internal width of 12.6 metres and was constructed using drilling, blasting, survey works, and support systems under challenging geological conditions.

According to NHSRCL, the next phase will involve waterproofing, lining, finishing, and equipment installation, while the remaining 16 km of tunnelling will be executed using tunnel boring machines.

The completed tunnel will be a single-tube, 13.1-metre diameter structure accommodating twin tracks for both up and down lines.

The 508 km-long Mumbai-Ahmedabad high-speed rail corridor is India's first bullet train project.

NHSRCL said that work has been completed on 321 km of viaduct, 398 km of pier, along with 17 river bridges, nine steel bridges, and the installation of over four lakh noise barriers across 206 km.

The track bed construction has been finished on 206 km, and more than 2,000 overhead equipment masts have been installed covering 48 km of the mainline viaduct, NHSRCL added.

- IANS