The loco was designed by Henry Greenly and was the forerunner of the seven engines that Captain Howe had built for the Romney, Hythe & Dymchurch Railway. Greenly had close connections with Roland Martens who designed the R&ER 1929 4-6-2 Whillan Beck that runs on the line here today and was built by Krauss of Munich
River Esk was designed to haul both stone and passenger trains, however soon found more use on passenger traffic. It was originally fitted with Lentz poppet valve gear, but this didn’t prove to be successful. It was painted works grey in 1924, then LMS red with black and straw lining to 1927. It was then repainted mid-green with black and yellow lining during a rebuild in 1928 by the Yorkshire Engine Co, when the original valve gear was replaced with the current Walschaerts valve gear. At the same time, the loco received a Poultney steam tender, making it a 2-8-2-0-8-0.
This proved unsuccessful and, after languishing at Murthwaite. The locomotive was out of use from 1940 to 1952, survived into the preservation era and was repainted in a new livery of LNWR black in 1967 and received a new tender in 1970. A major rebuild took place between 2011-2018. The engine still carries its black livery and has been very successful on the line.
