JKIL – MEPL’s Terratec TBM Records Breakthrough for Mumbai Sewage Project

J Kumar Infraprojects – Michigan Engineers JV on Friday celebrated the first tunnel breakthrough in Malad West for Mumbai city’s 5.8 km Priority Sewer Tunnel (PST-1) project.

Mumbai’s PST-1 tunnel project by Brihanmumbai Municipal Corporation (BMC) connects Don Bosco Junction in Borivali West and Malad Waste Water Treatment Facility (WWTF). Along with PST-2 tunnel (Oshiwara Bus Depot to Malad Pumping Station), it aims to improve the quality and reliability of wastewater collection, treatment, and disposal processes, while minimizing the environmental impact caused by wastewater.

Today’s major milestone was recorded by Terratec tunnel boring machine (TBM) S112 nicknamed Manu 1. This 3.85m diameter machine is India’s smallest diameter rock slurry TBM.

S112 was launched in January 2024 from Malad WWTF (Shaft S07) and arrived on Friday afternoon at Malad Pumping Station (Shaft S06) to complete a 1630 meter long tunnel.

Per Terratec’s press release from June 2023, S112 is designed to handle various geological conditions along the tunnel alignments consisting of weathered/fresh breccia and basalt. The TBM has 23 rings of 15” replaceable disc cutters and a high-speed main drive which is capable of turning the cutter head at up to 8 revolutions per minute. The TBM is equipped with an active articulation system to accommodate a minimum curve radius of 250mR. The TBM’s main drive is hydraulic due to size constraints and the installation of a shield integrated man lock.

Manu 1 will now be relaunched towards Don Bosco Junction for its next tunneling assignment of roughly 4100 meters.

Terratec is the sole supplier for Mumbai’s sewage segmental tunnels and has provided 2 TBMs – S112 for 5.8 km PST-1 (Don Bosco to Malad WWTF) and S116 for 4.7 km PST-2 (Oshiwara Bus Depot to Malad Pumping Station). S116 (Manu 2) is a 3.14 diameter EPB machine and had passed factory acceptance tests earlier this year – see details and pics.

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– TMRG