Reliable Main Bearings for Mumbai Metro TBMs

In India‘s metropolis, Mumbai, a new metro line is currently under construction. It is aimed to improve traffic and rail congestion of the city. In this giant project, the Robbins Company has been entrusted with parts of the tunnel boring work. To do the job, the TBM manufacturer relies once again on Liebherr‘s main bearings.

Since June 2018, the twin Robbins Crossover TBMs have been excavating two 2.8 km long tunnels for the new metro line 3 in Mumbai in parallel. The twin 6.65 m diameter machines were built for the application in mixed geology. They combine features of a hard rock Single Shield TBM and an Earth Pressure Balance machine and are not only able to bore in hard rock, but also operate in soft ground, using a screw conveyor at each machine’s centreline with a bulkhead gate and discharge gate. The mixed grounds in Mumbai consist of basalt, shale, tuff and breccia. Water pressure can reach up to 2 bar during the excavation works. Such mixed geology pose particular challenges to both machines and material. This, in turn, places high demands also on the components in the tunnel boring machines.

Main Bearings Designed for High Continuous Loads

Liebherr main bearings are specially designed for high continuous loads and reliable, fail-safe drilling. “Liebherr is a partner we can depend on to supply the most critical components on our machine”, says Mike Kolenich, Director of Supply Chain at Robbins.

The three-row roller bearing with a diameter of 2640 mm (114 in) ensure an even rotation and a stable load transmission on the cutter shields to achieve highest bore quality. Also the ring gear was supplied by Liebherr for the project, measuring the diameter of 1924 mm.

“In general, Liebherr has provided an excellent product within the schedule restrictions given by the customer. We visited Liebherr facilities in Germany and remained impressed with the overall organization of the production line, the clean and efficient working environment,” explains Matias Iovine, Project Manager Mumbai Metro at Robbins.

The most recent breakthroughs for the two Crossover machines were on October 3 and October 22, 2019, when they completed 499 m of tunnelling between Vidhan Bhavan and Churchgate stations. Starting from January 25 and February 15, 2020, correspondently, the machines are now boring their third drive and are expected to break through in May 2020 on a 700 m drive. The project is expected to be finished in December 2021.


Related articles:

Issue 02/2015

Marathon Machines

From abrasive rock to fault zones to water inflows, geologic challenges become more common as tunnel lengths increase. In rock tunnels over 15 km long, a host of challenges may meet a TBM, requiring a...

Issue 02/2015 India

Delhi Metro, Phase 3: 19 TBMs simultaneously engaged

A total of 19 Tunnel Boring Machines (TBMs) are simultaneously engaged in constructing Metro tunnels across the length and breadth of the national capital, Delhi, today, thus emerging as one of the...

Issue 07/2015 Qatar

Doha’s future Metro Network

21 Herrenknecht tunnel boring machines (TBMs) are operating or being got ready in Doha, the capital of the Arab Emirate of Qatar. The Metro network is being further developed here at breakneck speed...

Issue 02/2021 China

China’s Largest Robbins Crossover TBM Launches on Pearl River Delta Intercity Railway

The largest ever Robbins Crossover (XRE) TBM in China launched in late March 2021 in Guangzhou for contractors Sichuan Jinshi Heavy Equipment Leasing Co., Ltd and CREC Bureau 2. The 9.16 m diameter...

Issue 07/2016 USA

Veteran TBM is boring 28 km of Wastewater Tunnels in Indianapolis

In early September 2016, one of the longest-running Robbins TBMs embarked on its most extensive project yet. The Main Beam machine with a diameter of 6.2 m, owned by the Shea-Kiewit (S-K) JV, is...