Namma Metro Reaches Critical Milestone with Erection of Steel Girders for Phase 2A

Namma Metro’s Phase 2A project has achieved a significant milestone with the successful installation of four composite steel girders over the Salem Bridge, located between the Isro and Doddanekundi metro stations in southeastern Bengaluru. The operation, which was described as a “critical milestone,” is a key part of the under-construction Silk Board to KR Pura stretch.

The ambitious task took nearly 70 workers three days to complete. The first 36-meter girder was launched on January 27, followed by two more on January 28, and the final girder on January 29. The girders, each 3.4 meters deep, are part of a 65-meter span (575 metric tons) being installed between two metro pillars.

Before starting the operation, the Bangalore Metro Rail Corporation Limited (BMRCL) received approval from the Commissioner of Metro Rail Safety (CMRS), Southern Circle. The installation presented numerous challenges, as there was no service road available, and the railway underpass had a restricted opening. Additionally, the road’s skewed alignment crossing the railway track made crane operations even more difficult.

The composite girders were precisely aligned and joined to an existing 14.5-meter girder at a height of 14 to 15 meters. To facilitate the work, passenger trains on the Bengaluru-Salem line were halted from 11:30 pm to 3:30 am, and traffic on the Outer Ring Road towards KR Puram was diverted from 9 pm to 6 am, with temporary barricades guiding vehicles.

Unlike typical operations where 400-500 MT cranes are used to block main roads, a single 700 MT crane was deployed to launch the girders, given that only one side of the road was blocked.

The BMRCL stated that the remaining tasks, including the erection of the final girder, deck slabs, and parapets, will be completed within two months, after which road obstructions will be cleared.