Delhi Metro has started the launching work on the Janakpuri West – RK Ashram Marg corridor with a state-of-the-art launcher attached with a Transporter for the launch of U-girders on its elevated section. For the very first time, such a technology is being used in the country. According to DMRC, the new launcher with Transporter is fully electric with a much higher output compared to the conventional launchers or cranes. The U-girder is carried by the Transporter from one designated point and is moved forward on rails laid on the already erected U-girders to add more U-girders further from the feeding point to the launcher. The U-girders, as a result, are to be transported on trailer only up to the feeding point identified at a suitable location and not for the work’s entire length. This results in much less space requirement, the DMRC stated.
This new specially designed Launcher is 62 metres long and has a total weight of 230T. According to Delhi Metro, it can negotiate gradients up to 4 per cent and 200 metre radius curves. The Transporter is 41.75 metre long and has a total weight of 35T. The Transporter can travel with a speed of 3 km per hour at no load and 2 km per hour at full load.
Compared to the conventional method of the launching U-girders, the output of this new innovation is quite high. On average, this Launcher can erect four to six U-girders per day whereas with the conventional method, around two U-girders can be done in congested working environments like in Delhi-NCR. As U-girders’ erection work with conventional cranes requires blocking of roads to position the cranes, it can be done only during the night. But in the case of this new Launcher with Transporter, the transportation of U-girders are done with the Transporter on the erected viaduct without any interface with road from a single identified feeding point.
According to DMRC, the total load of U-girders that are to be erected is as high as 160 ton and a total of 462 such U-girders are to be erected in the contract. This state-of-the-art launcher has been made operational for a 9.5 km long viaduct’s construction from Mukarba Chowk to Ashok Vihar covering four mero stations namely Majlis Park, Bhalswa, Ashok Vihar and Azadpur and a connection to depot from Majlis Park, the corporation added.
