Video footage showing the construction of the first major structure as part of the £500m M8 M73 M74 Motorway Improvements Project has been released by Transport Scotland. The completion of the Braehead Rail Bridge marks a significant milestone in the progress of the M8 M73 M74 Motorway Improvements Project and has been the culmination of months of meticulous planning and preparation between Scottish Roads Partnership (SRP), the contractor responsible for delivering the project, and its construction joint venture, Ferrovial Lagan.
The time lapse footage reveals the new rail bridge, weighing in excess of 2,000 tonnes, sliding into its final position over what will become the new M8 motorway, to join the existing Cutty Sark rail bridge at Bargeddie, Glasgow. The three minute video footage shows the complex engineering challenge beginning with the onsite construction of the bridge, the possession of the railway line and the bridge slide, and concludes with footage of the first passenger train successfully crossing the new bridge as scheduled.
The first phase of works involved the closure of the railway line over four weekends in April 2015, allowing the construction team to lay the foundations by installing eight piles (each two metres 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 new bridge will carry the Rutherglen and Whifflet rail line over the new M8, which is currently being constructed to the south of the existing A8.
“The installation was complex due the strict limit on time as a result of the railway closure. “The operation included the removal of the existing railway infrastructure including overhead lines, rail tracks and the embankment, before the steel and concrete bridge could be pushed into its final position over the pre-cast piers to carry the weight of the structure.”Dario Saavedra, construction manager for Ferrovial Lagan Joint Venture
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 50 metres north, in an operation that lasted approximately four hours.
“The bridge push has been the culmination of many months of intricate planning, detailed engineering, and consultation with all the key stakeholders and is a credit to the teams involved. It’s successful completion demonstrates the level of engineering excellence on this scheme and we are delighted that the first major milestone has been achieved. We look forward to many more key milestones in the months ahead.”Gavin McKevitt, Regional Director Scotland and Northern England, Lagan Construction Group