CHENNAI: Moving ahead rapidly on the target of starting Metro Rail service between Poonamallee Depot and Porur junction by December 2025, the Chennai Metro Rail Limited (CMRL) on Saturday finished the viaduct construction in corridor 4. This stretch will be commissioned first in Metro Rail’s 118.9-km-long second phase.

Wrapping up the viaduct work, the final U-girder between Poonamallee bypass and Porur junction, the 624th on the stretch, was erected in the wee hours of Saturday.

In simple terms, viaducts are the bridge-like structures and u-girders are the precast segments placed on top of the piers/pillars on which the rail tracks are laid.

Speaking to DT Next, CMRL Director (Projects) T Archunan said the final U-girder for the viaduct was launched around 3 am on Saturday so as to ensure that the work was carried out at a time when the vehicular movement is minimal. “By now 80 per cent of track work has been completed between these two locations and trains will be launched on the track before March 25," he said.

The official said the testing of trains would happen in April and added that three-car trains would also be run on the portion in Porur that has the sharpest curve of radius 127.55-metre.

As per the press note, the final U-girder was erected at Kumananchavadi station. With this, a total of 3,202 precast concrete elements and 164 steel girders, including two open web girders, have now been erected across the Tambaram-Maduravoyal Bypass.

The note highlighted that this step has accelerated the progress toward completing the elevated viaduct along corridor 4 (the 26.1-km-long stretch from Lighthouse to Poonamallee Bypass).

"This critical activity coincided with International Women's Day, making the occasion even more significant, as many women engineers and professionals involved in the project were honoured and recognised for their dedicated contributions to the project,” the note read.