Archive · 15 Aug 2026
Thane-Borivali second tunnel work begins amid 15-minute travel promise
Workers are building a very long underground road tunnel in Mumbai, India.
Two giant digging machines called tunnel boring machines are being used.
The first machine, named Nayak, started working about two months ago.
The second machine, named Arjuna, has just started digging its own tunnel.
Now both machines can dig at the same time, which speeds things up.
The tunnels will be about 10.25 kilometres long and will go deep beneath a big park called Sanjay Gandhi National Park.
Right now, driving between Thane and Borivali takes about an hour or even an hour and a half.
When the tunnels are finished, the same trip should take only around 15 minutes.
Less time stuck in traffic also means less fuel used and less smoke in the air.
The people in charge say this will be India's longest and deepest city tunnel.
TBM-2 'Arjuna' began excavating the second tunnel of the Thane-Borivali Twin Tunnel Project from the Thane side.
Arjuna joins TBM-1 'Nayak', which started about two months earlier, so excavation of both tunnels can now proceed simultaneously.
The two machines will dig 10.25 km of twin tunnels forming part of the 11.84 km Thane-Borivali corridor beneath Sanjay Gandhi National Park.
MMRDA expects travel time between Thane and Borivali to drop from roughly 60-90 minutes to about 15 minutes.
MMRDA calls it India's longest and deepest urban tunnel project, with a maximum overburden of 320 metres, expected to reduce congestion, fuel consumption and emissions.
Chief Minister Devendra Fadnavis said obstacles to starting work from the Borivali side have been resolved, with TBMs to operate from both sides.
- Who
- Mumbai Metropolitan Region Development Authority (MMRDA), Chief Minister Devendra Fadnavis, and the tunnel boring machines TBM-1 'Nayak' and TBM-2 'Arjuna'.
- What
- Excavation of the second tunnel of the Thane-Borivali Twin Tunnel Project began with the launch of TBM-2 'Arjuna' from the Thane side.
- When
- Recently announced via MMRDA posts on X; Arjuna was launched about two months after TBM-1 Nayak (specific date not given in the articles).
- Where
- Between Thane and Borivali in the Mumbai Metropolitan Region, with the tunnels passing deep beneath Sanjay Gandhi National Park.
- Why
- To shorten road travel between Thane and Borivali from about 60-90 minutes to roughly 15 minutes and to ease congestion while reducing fuel consumption and emissions.
- Project
- Thane-Borivali Twin Tunnel Project
- Twin tunnels length
- 10.25 km
- Total corridor length
- 11.84 km
- Expected travel time
- About 15 minutes (currently 60-90 minutes)
- Maximum overburden
- 320 metres
- Tunnel boring machines
- TBM-1 'Nayak' and TBM-2 'Arjuna'
- Arjuna distinction
- India's largest single-shield hard rock tunnel boring machine for an urban tunnel
- Route beneath
- Sanjay Gandhi National Park