BENGALURU: An unprecedented and humongous task of erecting a permanent open web girder for Bengaluru Metro above the Bengaluru-Salem railway tracks near Benniganahalli was successfully carried out within six hours on Friday. When the line is ready, Metro trains will pass through this 550-Metric Tonne high steel girder steadied using 14,500 bolts and super high man lifters on a span of 65 metres.
The work is being carried out for a portion of BMRCL’s Reach-1 extension line between K R Puram and Baiyappanhalli which got delayed due to the railway crossing work. The remaining portion of the line from Baiyappanahalli to Whitefield will be launched by March-end.
The launch of this girder running to a length of 63.2 metres had been planned twice but shelved. It was finally carried out by the Bangalore Metro Rail Corporation Limited (BMRCL) through its contractor, ITD CemIndia JV). The job of raising it to a height of 27 metres above the ground by a winch began at 10.30 am and ended by 4.30 pm, with an additional two-hours extension in Line Block taken from Railways.
The girder has been erected above the electrical lines considering the ower trains.
Radhakrishnan Reddy, the project's director, monitoring the operation told The New Indian Express, “The whole process began in July 2021 when the High Steel was transported in 13 trailers from Bilai in Chattisgarh to Bengaluru. A total of four months was spent assembling it all near the launch spot using temporary structures. The process involved tightening the structure with 14,500 High Strength Grip Bolts (HSGB) using Torquing Machines operated by 30 workers.
Cranes and extremely high man lifters that can reach upto 40 metres high were involved in the process. “The man lifters which are used to carry men to the top of the structure used in Metro work so far generally touch 12 metres and these are special ones which are very high. Three people can be sent up using each of them,” he explained.
“By 2.30 pm when the time given to us to complete the work by railways had concluded, we had completed 60 metres. The block was lifted to permit the Kurla Express to pass through and the block was given to us again to complete the remaining 5 metres,” Reddy explained.
Pabitra Roy Chowdhury, General Manager of ITD CemIndia JV said the girder was moved very slowly across the railway tracks as a matter of abundant caution.
The process of dismantling all the structures created using Mild Steel will be carried out within the next six days and railways have given line blocks three hours daily.