Lynebeg rail bridge installation marks A9 Dualling milestone

NETWORK Rail has announced it has demolished and replaced the bridge over the railway at Lynebeg, south of Inverness on the Highland Mainline between Perth and Inverness.

The move is part of supporting work ahead of the dualling of the A9 between Tomatin and Moy.

The 1884 Victorian masonry structure has been replaced with 660ton twin-track concrete box structure.

The construction team used a Self-Propelled Modular Transporter (SPMT) system to carry the structure from the site compound, where it was constructed offline over a 10-week period, before manoeuvring it several hundred metres along the B1954 and sliding it to its final position.

Two 750-ton cranes then lifted seven concrete wing walls, which were also constructed on site, into position.

The new bridge is designed to ‘strengthen, safeguard, and future-proof’ the route, including dealing with the volume of traffic and accommodating any potential future double-tracking of the line.

During a 78-hour window, a 1,200 x 800mm pre-cast box culvert and a 900mm twin wall plastic culvert were installed under the track at two locations to accommodate the A9 works.

Scotland’s transport minister Graeme Dey, visited the site following the operation to see the new rail bridge. He said, “The success of the Lynebeg rail bridge installation marks a significant milestone for the A9 Dualling: Tomatin to Moy project, as the first tangible improvement to the transport infrastructure as part of the project’s advance works.

“Not only is this new structure safeguarding and improving connectivity on Scotland’s Highland Mainline, these works will help to deliver the ongoing A9 Dualling programme and will enhance the local infrastructure for the benefit of the surrounding communities.”

Whilst visiting the new bridge, Mr Dey revealed the shortlisted contractors for the £115 million project to upgrade 9.6km of the A9 to dual carriageway between Tomatin and Moy. Balfour Beatty Civil Engineering Ltd; John Graham Construction Ltd and Wills Bros Civil Engineering Ltd are the names in contention for the construction contract for the third section of the A9 Dualling, which will be awarded in the second half of 2022.

Billy McKay, Network Rail’s programme manager for the Lynebeg bridge replacement works, commented, “We are delighted that the work to replace the bridge at Lynebeg was completed successfully and the railway re-opened to traffic as planned – despite terrible weather conditions and the impact of Storm Arwen. The installation was complex due to requirement to remove the existing railway infrastructure including cabling, track and the embankment, before the concrete bridge could be pushed into its final position. And all against the clock due to the need to reinstate and re-open the line to traffic at the end of the possession.”

Works will continue on site for several weeks to complete the new structure, including cladding the concrete wing walls with the recovered stone from the original stone arch bridge which was constructed as part of the Highland Mainline in 1884.