As part of a £13m programme to support new housing in Stirlingshire, the two companies tunnelled under the main Glasgow to Stirling railway line and M9 motorway to install two 0.5m-diameter pipes across 4km of land between Plean and Cowie. The pipes will carry pressurised waste water for treatment.
Two different methods were deployed to install the pipes. Pipe ramming was used for the 4m-deep, 56m-long section beneath the motorway, while for the 46m stretch under the railway line, the harder ground and greater depth of 8m required rock augur drilling.
Work was carried out around the clock to ensure a smooth drilling operation beneath the railway line.
Scottish Water team manager Steven Greenhill said: “This is an important project addressing one of our key strategic priorities to meet the demands of Scotland’s growing and shifting population.
“The twin challenges of drilling underneath both the motorway and railway line required a co-ordinated multi-agency approach to avoid causing major disruption. We are grateful to all involved for their help and support and I am particularly pleased tunnelling operations have been successfully completed.”
