Bullet Train Project: Heavy Portal Beams Launched Over Railway Line in 22 Days

The precast-prestressed beams were launched in a planned sequence on April 8, 13, 19, 24, and 29, with the entire operation completed within 22 days in coordination with Indian Railways.

Each installation was carried out in approximately three and a half hours, reducing the duration compared with the earlier nine-hour traffic blocks.

Addressing the development, officials said: "All five (5) precast-prestressed heavy portal beams (girders) have been successfully launched over the Ahmedabad-Vadodara railway line in Maninagar... within just 22 days."

The first launch on April 8 involved the heaviest beam, weighing about 1,360 metric tonnes.

Officials said it was "one of the heaviest lifts ever undertaken over operational railway lines."

The remaining beams weighed between 1,170 and 1,360 metric tonnes, making the operation one of the most complex structural exercises conducted on railway infrastructure.

The Maninagar section involves the high-speed rail alignment crossing existing tracks at an elevated level with a skewed geometry and limited working space.

The span between piers ranges from about 30 to 34 metres. "The space between the two piers is also relatively large... which further demands a strong and rigid supporting system like portal beams," they noted.

Each beam measures 34 metres in length with a cross-section of 5.5 metres by 4.5 metres and was precast on site as an integrated unit before erection.

The portal beams are designed to span multiple active railway lines, including the Ahmedabad-Vadodara up, down and third lines.

Their size and structural capacity help limit deflection and maintain alignment, ensuring safe railway operations beneath the elevated corridor.

The launches were carried out using a 2,200 metric tonne crawler crane as the primary equipment, deployed for the first time over Indian railway tracks.

Despite challenges such as restricted space, overhead electrification systems and ongoing train movements, the work was completed with officials describing it as "high precision, strict safety checks, and continuous monitoring."

Officials said the operation reflects detailed planning and coordination required to execute heavy engineering work over a high-traffic railway route without disrupting regular services.

- IANS