Townsend Hook is a 3 ft 2+1⁄4 in (972 mm) gauge Fletcher, Jennings & Co. 0-4-0T steam locomotive built in 1880 for the Dorking Greystone Lime Co. as works no.

In the late 1870s the Dorking Greystone Lime Co. of Betchworth, Surrey needed steam locomotives to work the narrow-gauge horse-drawn lines in their quarry.

In 1937 Townsend Hook was hit side-on by a line of wagons descending under gravity, knocking it eight feet down a ledge and dislodging the safety valves.

In 1962 the NGRS acquired a site in a former quarry at Brockham, Surrey, only a few miles from Betchworth, to build a museum dedicated to industrial and narrow gauge railways.

A return to steam is unlikely for the foreseeable future, due to the limited use the loco would receive, and also that many items such as the boiler and water tanks would need to be replaced.

In July 2016 Townsend Hook visited the Talyllyn Railway in Tywyn, Wales, as a static exhibit as part of a gala to bring together all five surviving locos in the UK built by Fletcher, Jennings and Co.[1]