steam locomotive doctor syn at hythe station steam locomotive Doctor syn on the romney hythe and dymchurch railway Canadian Pacific-style locomotives, built in 1931 by the Yorkshire Engine Co The Romney, Hythe, and Dymchurch Railway (RH&DR) is a narrow-gauge heritage railway in Kent, England. It was opened in 1927 and is notable for its small size and charming steam locomotives. The railway runs for 13.5 miles (21.7 km) from Hythe to Dungeness, passing through New Romney and other stations. The RH&DR is often referred to as "Kent's Mainline in Miniature" due to its small gauge and the quality of its infrastructure.