The Duffield Bank Railway was built by Sir Arthur Percival Heywood in the grounds of his house on the hillside overlooking Duffield, Derbyshire in 1874. Although the Ordnance Survey map circa 1880 does not show the railway itself, it does show two tunnels and two signal posts.It was more than just a garden railway. In a century of technological innovation in the railways, Sir Arthur wished to explore the possibilities of such railways for mining, quarrying, agriculture etc. He believed that they would be relatively easy to build, and to move. He saw possibilities for military railways behind the lines carrying ammunition and supplies. Some other small railways had been built to two foot gauge, but he wished to use the minimum practical, and settled on 15 in (381 mm). Wikipedia>>