Vital maintenance work between Taunton and Exeter St David’s in Somerset has been sped up thanks to the use of concrete-spraying robots.
‘Ivy and Holly’ relined the walls of Whiteball Tunnel with 830 cubic metres of a specialist concrete mix designed to safeguard against loose masonry and bricks falling on the railway.
Specialist machines constantly stirred the mix to stop it from setting before the robots could get on with the job.
Network Rail said it is one of the first times this cutting-edge technology has been used and meant the work could be done more safely and quickly than if it was done by hand.
Programme manager Scott Pillinger said the team had worked day and night during the three-week closure and that the robots “really helped speed up the time the work took”.
Scott added: “Whiteball Tunnel is over 100 years old and this work will make sure that it stays safe for use for another century, ensuring passenger journeys won’t be affected by falling masonry inside the tunnel.
“Everything we can do to get the trains back on track is great news for us.”
Before the line re-opened on March 9, engineers of the human kind made the most of the closure by completing track renewals further down the line in Marley tunnel in Devon.