Thurgoland Tunnel

Maximum clearance was only obtained by reducing the normal six-foot spacing between the tracks.

Because of the clearance problems the original construction caused for the planned LNER electrification, and because opening-out was deemed too expensive, in 1948 a second single-line tunnel was built for the up line and the old tunnel was converted to carry only the down line.

As this project was begun in 1947 just before railway nationalisation (British Railways), each of the up tunnel portals host twin dates, with "LNER 1947" inscribed in the central parapet panel at the top of the portals and "BR 1948" below in the keystone.

Due to the anticipated interim period of steam working before the new electric Woodhead 3 tunnel was completed, a cast-iron smokeplate lined the roof of the tunnel to protect the concrete lining.

The up tunnel, being much newer, has been re-utilised for a walking trail, whilst the down bore has been blocked off.