A 16-day closure of a key part of the Midland Main Line and Derwent Valley route from May 27 to June 11, has seen the replacement of track in two tunnels – Milford between Duffield and Belper, and Clay Cross tunnel, south of Chesterfield. The closure also meant Matlock was without a train service, with a rail replacement service operating.
In Clay Cross tunnel, as well as new sleepers and ballast, specially coated rails were installed under the 10 tunnel air shafts to make them more resilient during poor weather conditions. The 855-yard Milford tunnel had both tracks and ballast replaced.