A bridge that started to deteriorate almost immediately after it was last replaced in 1969, has been given an HBPW makeover, ensuring its life for at least another 120 years.
The original wrought iron rail underbridge, which runs over the A631 Gainsborough Road southeast of Bawtry in South Yorkshire, was built in the nineteenth century but, in the late 60’s, was replaced with a steel & concrete deck.
But, as Partner, Jon Livesey, explains, the structure began to experience problems soon after completion.
“Cracking began to appear in the concrete and, over time, deterioration has been such that ‘strengthening’ options were not considered to be economical.
“Network Rail’s brief from the outset was to replace the structure and, with that in mind, we used a standard twin U-deck, enabling us to maintain bridge clearance over the A631 whilst also improving the track construction under the east coast main line.
“The bridge is located at the end of Bawtry viaduct which crosses the flood plain of the River Idle, meaning the underlying ground conditions are poor. As a result the abutments had previously been strengthened, hence why our design was developed to minimise any disruption to them and to help keep work in the possession to a minimum”
The work was successfully carried out during a 52-hour bridge possession when the new structure was wheeled into place using a Self-Propelled Modular Transporter (SPMT).
“The project wasn’t without its challenges, however, all works were completed within the possession period which is always positive,” concluded Jon
Client: Network Rail
contractor: AMCO-Giffen