In an all-important development related to the Colaba Bandra SEEPZ underground metro line three, Vaitarna - the Tunnel Boring Machine of package 2 of the Colaba-Bandra-SEEPZ Metro-3 corridor, has completed its longest downline tunnel drive of 3.814-km from Azad Maidan to Mumbai Central Metro Station.

It may be noted that Vaitarna-1, which began its mission on December 4, became the first TBM on Metro-3 corridor to complete its entire drive of tunnelling. It completed its successful operation of 3.814 Km in a time span of 20 months at a mining average of 190 meters every month with 2720 rings. Vaitarna-1 made its way through hard basalt and breccia rock mass with some pockets of very low strength shale bands at average depths of below 20 metres from the road level. It marks an important milestone of the 33.5-km long underground Metro-3 corridor.