Bullet Train Project: Portal Beams Launched Over Delhi-Mumbai Rajdhani Main Line in Vadodara

Vadodara: The Mumbai-Ahmedabad Bullet Train project has achieved a key milestone in Vadodara with the successful launch of all 14 portal beams over the Delhi–Mumbai Rajdhani main line, the National High Speed Rail Corporation Limited (NHSRCL) said in a press release.

The completion of all 14 portal beams marks a major construction milestone and an important step towards integrating the Mumbai-Ahmedabad Bullet Train corridor with Vadodara’s existing railway network while navigating one of the busiest railway routes in the country.

The 14 portal beams have been strategically constructed along the complex Vadodara stretch, where the Bullet Train alignment crosses multiple operational railway lines. Their completion clears a major structural requirement for launching the 40-metre composite girders over the Rajdhani main line and advancing the elevated corridor through this critical section.

The Vadodara stretch, approximately 8.3 km long, passes through a densely developed railway and urban environment and crosses five Indian Railways lines, including two main lines. The alignment also crosses diagonally over the Delhi–Mumbai Rajdhani main line, requiring specially engineered structures to maintain the necessary clearances and ensure safe integration with the existing railway system without disrupting operations.

To address these engineering challenges, 14 portal beams have been constructed over the Delhi–Mumbai Rajdhani main line. Of these, 10 are located between Vadodara Bullet Train station and Vishwamitri Railway station towards the Surat end, while four are located between Vadodara Railway station and Chhayapuri Railway station towards the Ahmedabad end.

The portal beams form the structural framework for constructing the superstructure of the Bullet Train viaduct. Composite girders spanning approximately 40 metres will subsequently be launched over the 14 portal beams at the Rajdhani main line crossing, while the span-by-span (SBS) launching method will be used at the remaining portal beam locations.

The portal beams have been constructed using the cast-in-situ method, necessitated by the highly constrained locations and the need to work around operational railway infrastructure. Each portal beam constructed over the railway tracks weighs approximately 1,500 tonnes upon completion, making conventional precast launching impractical at these locations.

Each beam measures approximately 4 metres in height, 4 metres in width and 37 metres in length, requiring around 590 cubic metres of concrete. The reinforcement cage alone weighs approximately 55 tonnes.

The construction of these structures involves specialised high-capacity cranes, hydraulic jacks, long-boom concrete pumps and precision surveying equipment. As several structures are being built above operational railway infrastructure, the work requires detailed sequencing, continuous monitoring, close coordination with Indian Railways and controlled railway blocks wherever necessary. DeshGujarat