Clayton Tunnel is a 1,057 yard brick-lined tube which formed part of the rail connection between Bradford and Queensbury.
During construction in 1874, Thomas Coates (20) and William Elliot (27) lost their lives when their lifting cage fell down No.1 shaft. The man in charge of the winding engine was found to be under the influence of alcohol. Both casualties are buried in the graveyard of Clayton Parish Church where a headstone commemorates the accident.
Since closure, the eastern approach cutting has been completely filled-in and a housing estate built on the surrounding land. A bungalow sits directly above the portal - its conservatory recently suffered subsidence, possibly due to the void beneath it.
Infill has also claimed much of the cutting at the tunnel’s west end but it stops short of the portal by about 50 feet, allowing access for inspections which take place annually.