Network Rail and its team demolished and replaced the bridge over the railway at Lynebeg on the mainline between Perth and Inverness. In continuous working across 78 hours from Friday night until Tuesday morning, the 1884 Victorian masonry structure was demolished and replaced with 660t twin-track concrete box structure.
The completion of the bridge replacement is part of supporting work ahead of the dualling of the A9 between Tomatin and Moy and is seen as a significant milestone in the project’s progress. It has been the culmination of years of planning and preparation by Network Rail, its contractor BAM Nuttall, Atkins Mouchel Joint Venture and Transport Scotland. Transport Scotland had engaged Network Rail to deliver a programme of advance works in the vicinity of the Highland Main Line, includes works to replace the Lynebeg Rail Underbridge and culvert diversion works around Moy Rail Bridge. These advance works are expected to continue into Spring 2022.
The 200-strong team carrying out the bridge replacement included BAM Nuttall, Network Rail, Story, Mammoet, Kelly Electrical Services and SA Evans. BAM's Scottish rail team was joined by BAM teams from Highways and Rail South.
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 the structure several hundred meters along the B1954 and sliding it to its final position.
The new bridge is designed to strengthen, safeguard and futureproof the route for the long-term including dealing with the weight and volume of traffic that passes over it on a daily basis and accommodating any future double-tracking of the line should that be proposed in the future.
During the same 78-hour possession, a 1,200 x 800mm precast box culvert and a 900mm twin-wall plastic culvert were installed under the track to accommodate the forthcoming A9 works.
Minister for transport Graeme Dey visited the site following the complex operation to see first-hand 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.”
Billy McKay, Network Rail’s programme manager for the Lynebeg bridge replacement works, said: “We are delighted that the work to replace the bridge at Lynebeg was completed successfully and the railway reopened 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. As well as upgrading the railway bridge, the team is delighted to have played a part in supporting the future dualling of the A9.”
Huw Jones, Divisional Director, Rail, BAM Nuttall said: Our team faced some really challenging conditions over the course of this weekend, having to deal with some of the worst winter weather we have ever experienced on a rail blockade. The safe, successful, on-time delivery of this project is a tribute to the commitment and close collaboration of our team and the meticulous preparation undertaken in the run-up to this possession. This would not have been possible without the strong collaboration across the integrated team, and I would like to thank everyone for their dedication over the weekend and during the last few months.’
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.