Video footage shows the new rail bridge, weighing in excess of 2,000 tonnes, sliding into its final position over what will become the new M8 motorway. The timelapse footage can be accessed from Bridgeweb's video section (link opens in new tab).
The completion of the bridge slide has been the culmination of months of planning and preparation between Scottish Roads Partnership (SRP), the contractor responsible for delivering the project, and its construction joint venture, Ferrovial Lagan.
SRP took possession of the rail line on 11 July, and returned it to Network Rail on 26 July as programmed, with rail services resuming the following day.
Graeme Reid, project sponsor for Transport Scotland, said: “The success of the bridge slide marks a significant milestone as part of the M8 M73 M74 motorway improvements project and is the first tangible improvement to the transport infrastructure. The time lapse gives a real sense of the challenges involved in delivering a project of this scale and encourages a greater understanding of civil engineering schemes and the benefits they can bring.”
The first phase of works involved the closure of the railway line over four weekends in April, allowing the construction team to lay the foundations by installing eight piles - each 2m in diameter - and reinforce the ground on either side of the bridge. The three-span steel bridge was then built adjacent to the existing railway prior to the slide.
The construction team used a self-propelled modular transporter (SPMT) system to slide the 2,000 tonne structure into place. Six SPMT platform vehicles, fitted with row upon row of rubber wheels were moved into position under the structure to carry the weight of the bridge to the ground. A computer controller was used to simultaneously drive the six SPMT platforms carrying the bridge structure 50m north, in an operation that lasted approximately four hours.
