New Delhi, 04 May (H.S.): A significant engineering milestone has been achieved under the Mumbai-Ahmedabad Bullet Train project in Ahmedabad. In the Maninagar area, over the Ahmedabad-Vadodara railway line, a total of five precast-prestressed heavy portal beams (girders) were successfully launched in just 22 days.
The National High-Speed Rail Corporation Limited (NHSRCL) stated on Monday that this launching activity was completed in a planned sequence on April 8, 13, 19, 24, and 29, exemplifying swift and precise execution over active railway tracks. The heaviest beam, weighing approximately 1,360 metric tonnes, was launched on April 8. The other beams weighed between 1,170 and 1,360 metric tonnes, making this one of the most complex operations on railway infrastructure.
The bullet train alignment in Maninagar passes at an elevated height and oblique angle over existing railway tracks, rendering the structural planning highly challenging. The span between the two pillars here is about 30 to 34 meters, necessitating robust and stable portal beams.
These heavy portal beams are designed to securely span multiple active tracks, including the Ahmedabad-Vadodara railway's up, down, and third lines. Their large size and weight ensure structural stability with minimal deflection, guaranteeing track precision and safe operations.
A 2,200 metric tonne capacity crawler crane was employed for the launch—the first such use in India over active railway tracks. Each beam was installed in approximately 3.5 hours, significantly faster than the previous 9-hour blocks. This was accomplished in coordination with Indian Railways, stringent safety measures, and continuous monitoring.
Notably, each portal beam measures 34 meters in length with a cross-section of 5.5 meters × 4.5 meters. These beams were fabricated on-site and installed as heavy units.
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Hindusthan Samachar / Jun Sarkar
