Clay Cross Tunnel
Clay Cross Tunnel is a tunnel on the former North Midland Railway line near Clay Cross in Derbyshire, England, now part of the Midland Main Line. Construction It was designed by George Stephenson with an estimate of £96,000 for construction. The tenders for the work were issued by the North Midland Railway in December 1836. The contractors appointed were Messrs. Hardy, Copeland and Cropper of Watford for the sum of £105,400 (). The tunnel was to be wide and high with a bed of broken stone at the base deep to form the rail bed. The tunnel was to be arched completely round with brickwork laid in Roman cement deep in the roof and walls, and deep in the floor. Approximately 15 million bricks were required for the tunnel lining. The greatest depth below the surface was about . Construction began on 2 February 1837 when the first sod was turned for the sinking of the ventilation shaft in the centre of the tunnel. The boring of the tunnel was not straightforward, eventually costing £140,000 (equivalent to £ in ), instead of the expected £98,000 (equivalent to £ in ), with the loss of fifteen lives. It was reported in