After several years of construction, the 5th and 6th rail line project on the Central Railway has reached a crucial stage where the authorities will now have to build parallel tunnels and viaducts as the construction crosses over from Mumbai to Kalyan.
The railways are building a separate corridor for outstation and goods trains between Kurla and Kalyan under the Mumbai Urban Transport Project.
While work between Kalyan and Diva has been completed, the work from Thane to Kurla is more than 70% complete. Work on the crucial link between Thane and Diva that will comprise tunnels and viaducts has now begun. The railways have finalised two tunnels in Parsik hills and three small viaducts over the Thane creek to complete the project by 2014.
The Mumbai Rail Vikas Corporation that is coordinating the project said that it will have to bore through the Parsik hills and build viaducts similar to the existing ones over the Thane creek bridge. The original line was built by the British in 1853.
“The slow line will have an additional pair of rails so that the fast train tracks can be exclusively used by outstation and goods trains. For this, we will have to bore through the Parsik hills to construct a tunnel, adjacent to the old tunnel between Mumbra and Kalwa.
Currently, the slow trains take a detour along the hills whereas the fast trains take the Parsik tunnel route skipping Kalwa and Mumbra stations. Both these lines get separated before Kalwa station and meet each other few metres before Diva station.
“We have done a geo-technical study and found that the rock in the mountains is very solid and can easily bear its weight. The tunnel will be made through controlled blasts and boring,” he added.
The tunnel will be about 165 metres long and 13 metres wide, just to accommodate two lines and bear all features for air-circulation with ventilation shafts.
The viaducts will be built parallel to the existing lines over the Thane creek with the latest engineering technologies. The three new viaducts one after the other between Thane and Kalwa will allow segregating suburban trains from outstation trains, to avoid delays, detentions and mixing of traffic.
The next phase of the project will be to take this out-station train corridor all the way to Mumbai CST. Planning for it has begun.
