The Delhi Metro Rail Corporation (DMRC) introduced a specially-designed launcher attached with a transporter for the launch of U-girders on its elevated section.
A senior DMRC official said that the output of this innovation is quite high as compared to the conventional method of launching of U-girders. On an average, four to six U-girders per day can be erected with this launcher whereas with the conventional method, about 2 U-girders can be done in congested working environments like in Delhi–NCR, he said.
The launcher started work near Majlis Park in the presence of DMRC’s Managing Director, Dr Mangu Singh and other senior officials.
“In the earlier phases of construction, erection of U-girders was done with the help of two cranes of capacity 350/400 tonnes 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 42 metre. 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,” the official said.
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 has massive traffic volumes even at night, he added.
“This new state-of-the-art launcher 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 trailers only up to the feeding point identified at a suitable location and not for the entire length of work,” he said.
The official further said that this technology is being used for the first time in India. “The total load of U-girders to be erected is as high as 160 tonnes and 462 such U-girders are to be erected in the contract.