Chennai Metro Rail has completed its tunnel from Nehru Park to Egmore, a distance of 948 meters. This work which was done by a tunnel boring machine (TBM) was launched in July 2012.
The TBM reached the Egmore station last week. The other TBM has completed about 720 metres, and it may be a while before it arrives at Egmore. The assembling of another TBM that will tunnel from Pachaiyappa’s College to Kilpauk has begun.
The two TBMs employed at the Nehru Park station were shipped from China, and Chinese workers are also here to operate these machines as part of an MoU signed between CMRL and joint ventures, Larsen & Toubro and Shanghai Urban Construction Group.
The TBMs are usually operated at a speed of 6-10 metres a day and soil conditions play an important role in determining their speed. If the soil is loose, then the speed of the TBM may be reduced.
Chennai Metro Rail, built at a cost of Rs. 14,600 crore, will span 45 km. Of the 32 stations, 19 will be underground and the others elevated.