Toadmoor Tunnel

From Wikipedia, the free encyclopedia

Toadmoor Tunnel portal showing elliptical shape of bore.

Toadmoor Tunnel (originally called Hag Wood Tunnel) was built at Ambergate as part of the North Midland Railway, which opened in 1840.

128 yards long, it was cut through an unstable hillside on a notoriously difficult line of route. George Stephenson designed it with an elliptical shape so that it had least diameter vertically with most strength at the sides. Braced with steel hoops at its southern end. Due to unplanned earth movements, it took 15 months to build, instead of the planned two.