China Railway Construction Heavy Industries’ (CRCHI) industrial park in Changsha, China, has recently packed India’s largest diameter TBM. The TBM will be passed through Shanghai Port to Mumbai where it is going to be used for a costal road project.
The excavation diameter of the slurry TBM is 12.19 m, it is 80 meters long, 2300 tons wights, and has an installed capacity of 7.280 KW and a gradeability of 5%.
It is said that this TBM is going to be the largest diameter tunnel boring machine of all Chinese TBMs which has been exported to India, and also the largest TBM ever in India itself.
The Mumbai Coastal Road Project is a significant project in India, a 29.2km coastal road which connects Marine drive to Kandivali.
The introduced Slurry TBM will bore a tunnel section of 1,920m. There will be some complicated geological conditions in constructing the tunnel that require excavation in deep overburden and will pass through a compound stratum of basalt, breccia and shale.
The CRCHI Slurry TBM is designed to solve the challenges. It is represented with a mixed cutter head with eight spokes and eight panels, which will enable the machine to bore in the mentioned complicated strata for a long distance.
The TBM is fitted with a big-diameter slurry feeding port and a number of slurry flushing lines (to increase the flow rate of the slurry), to solve other probable problems such as mudcakes forming on the cutterhead and slurry discharge blocking.
Moreover, many innovative systems have been adopted by this CRCHI Slurry TBM, such as dual-circuit automatic pressure system, dual-chamber indirect slurry control system, high-power slurry circulation system as well as high-torque and retractable main drive.
This is the 5th CRCHI TBM in India. The other four slurry TBMs is being used in the Bangalore Metro Rail Project.