NEW DELHI (Metro Rail News): As a major innovation in construction technology, Delhi Metro Rail Corporation (DMRC) has come up with a specially designed Launcher attached with a Transporter for the launch of U-girders on the elevated section of the 28.92 km long Janakpuri West – RK Ashram Line of Delhi metro.
As per the press release of DMRC, in the earlier phases of construction, erection of U-girders was done with the help of two cranes of capacity 350/400T which were placed at each pier location, and the U-girders were transported at each pier location with the help of a long trailer having an approximate length of 42m. In a congested urban area like Delhi, it used to be very challenging to find adequate space for positioning these heavy capacity cranes which occupy a lot of space. In addition, transporting the U-girders of 28m length with such long trailers was also a herculean task as roads in the NCR are either too congested or have massive traffic volumes even during the nighttime. These limitations often discouraged the use of U-girders in construction in spite of the fact that the U-girders are the most suitable structures for viaducts in terms of cost and time.
According to DMRC, this new state-of-the-art Launcher with Transporter is fully electric with much higher output in comparison to the conventional launchers/cranes. The Transporter carries the U-girder from one designated point and moves forward on rails laid on the already erected U-girders to further add more U-girders from the feeding point to the launcher. As a result, the U-girders are to be transported on trailer only up to the feeding point identified at a suitable location and not for the entire length of work. This results in much less requirement of space.
Through this new Launcher with Transporter, 4 to 6 U-girders per day can be erected on an average whereas, with the conventional method, about 2 U-girders can be done in congested working environments like in Delhi – NCR. The erection work of U-girders with conventional cranes can be done only during the night as it requires blocking of roads to position the cranes. Whereas in case of this new technology, U-girders are transported with the Transporter on the erected viaduct without any interface with road from a single identified feeding point. This technology is being used for the first time in India.
The Launcher today has been made operational for the construction of a 9.5 km long
viaduct from Mukarba Chowk to Ashok Vihar covering four stations namely Bhalswa, Majlis Park, Azadpur and Ashok Vihar and a connection to depot from Majlis Park.