An extensive cutting face alongside the Chiltern main line in Warwickshire has been stabilised to remove the threat of landslips that could block the line.
On 31 January 2015, 350,000 tonnes of earth moved on the north side of Harbury tunnel, forcing the route between the Midlands and London to close for six weeks.
This was only the latest problem at Harbury. Ground conditions in the area have caused problems for the railway ever since it was built in 1852, and engineers from the Great Western Railway made the slopes of the cutting at Harbury shallower to prevent landslips as far back as in 1884.
Having stabilised the cutting at the north end of the tunnel following the slip in 2015, Network Rail and its contractors started to work on the cutting at the southern end in December 2019. The £9 million project took 15 months to complete, and work finished on 5 March 2021.
Emma Gray, scheme project manager at Network Rail, explained: “The ground here, made up of layers of limestone and shale, can be unstable and could potentially cause issues for the railway running through it. This preventative work will stop future slips and make it much more secure.
“We know Harbury very well after the huge landslip in 2015, and I want to thank the local community for their patience while we carried out this important work to protect the railway.”
Soil nails and piles were driven into the slopes to stabilise them and a new retaining wall was built at the bottom of the railway cutting to prevent soil movement. The work was carried out during the daytime, while passenger and freight trains continued to run below, meaning no disruption to services and no noisy overnight work.