JKIL – MEPL’s Terratec TBM Begins Tunneling for Mumbai’s PST-2 Tunnel

J Kumar Infraprojects – Michigan Engineers JV earlier this month commissioned tunnel boring machine (TBM) S116 in Malad for Mumbai city’s 4.7 km Priority Sewer Tunnel (PST-2) of Mumbai Sewer Disposal Project (MSDP) Stage II.

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

S116 (nicknamed Manu-2) is a 3.14 diameter Terratec rock earth pressure balance (EPB) machine and had passed factory acceptance tests in March. Along with another Terratec TBM S80, it’s the smallest diameter earth pressure balance (EPB) machine to be deployed in India.

On July 20, S116 was lowered into Malad Pumping Station’s launch shaft (Shaft 08). Some snaps shared by a follower:

PST-2 tunnel’s route along Link Road between Malad – Oshiwara mostly follows Mumbai Metro’s elevated Line-2A (Yellow Line) between Oshiwara and Infinity Mall, Malad.

Per Terratec’s old press release, TBM S116 is designed to operate under a range of geological conditions, including silty sand, silty clay, boulders, breccia, basalt, clay with gravel and thyolite. It features a mixed type cutterhead, 27 back-loading 432mm disc cutters and a high-speed main drive capable of eight RPM.

The new machine by Terratec has been designed to work with a 4+1 universal segment design, utilizing reinforced concrete segments of different lengths (1000mm and 650mm), to navigate sharp curves in complex geological conditions effectively. This adaptability allows the machine to avoid obstacles, follow specific routes, and accommodate existing structures above ground, ensuring precise and efficient tunnel construction.

TBM S116 was commissioned and started building temporary rings on August 7.

This is the second TBM that Terratec has provided to JKIL – MEPL JV for MSDP project. Last week, their first machine TBM S112 – a 3.85m diameter rock slurry TBM completed building a 1630m tunnel from Malad WWTF (Shaft S07) to Malad Pumping Station (Shaft S06) as part of 5.8 km PST-1 tunnel (Borivali – Malad).

BMC is quietly building a network of 100+ kms of water & sewage tunnels across Mumbai and I’ve posted about at least 3 such projects this month already. The other two posts are:

• APCO Wins Ghatkopar – Bhandup Water Tunnel’s Contract in Mumbai
• JKIL – MEPL’s Terratec TBM Records Breakthrough for Mumbai Sewage Project

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– TMRG