MEIL Group is creating history with India’s biggest-diameter and longest urban tunnels through the Thane–Borivali Twin Tunnel Project. This engineering milestone will cut the 1–2 hour commute to just 15 minutes while protecting the Sanjay Gandhi National Park ecosystem. A 13.34-metre TBM, the largest in any metro city, will build twin 3-lane tunnels. On 29 November 2025, MEIL completed the Thane-side portal excavation and safely lowered the massive cutter head—bringing Mumbai closer to a new era

In order to safely operate in all of the MetroLink tunnels, the trains have to be smaller than the tunnels themselves. But you’ve also got to have a buffer in the clearance — a safety mechanism. So that with the high voltage, there’s no dangerous arcing or buildup of static electricity. But because of a measuring mistake, the new trains, as ordered, didn’t have enough of that buffer. Full story in the comments. | KMOV