Bangalore Mirror writes that Bengaluru will witness the race of two tunnel boring machine giant brands in the coming months.

Total of 9 slurry tunnel boring machines will bore the Phase 2 section of Bangalore Metro Rail Corporation's (BMRCL) 13,87 kilometre tunnels.  5 Herrenknecht TBMs and 4 CRCHI TBMs. Interestingly in addition to 4 CRCHI TBMs, also the 3 Herrenknecht TBMs have been manufactured in China.

For Phase 2, BMRCL insisted on Slurry tunnel boring machines because in Phase 1 Earth Pressure Balance (EPB) TBMs performed very poorly. Phase 1 boring only 9 kilometres took 5 (FIVE) years to bore with EPB TBMs.

For Phase 2, it is a first a China brand tunnel boring machine (CRCHI) will be used for BMRCL tunnelling and hopes are high for CRCHI to perform better than  other brand TBMs in Phase I.  Expectations for advance rate for both Chinese and German TBM in Phase II is 3 metres per day. This is average advance expectation. It can vary over time.

Geology on route is known to be 34% hard rock, 46% soft soil and 20% mixed ground.

Everybody is curious how CRCHI versus Herrenknecht race will come out.

https://bangaloremirror.indiatimes.com/bangalore/others/metro-to-dig-deep-with-german-chinese-boring-machines/articleshow/76901452.cms