The LNER class Y10 consisted of two tank locomotives supplied by Sentinel. A special feature was the gearbox, which could be switched between two speeds while stationary. A vertical water tube boiler was also used, which operated at a high pressure of 275 psi (19 bar) and had short response times.
Their intended area of operation was the Wisbech and Upwell Tramway in East Anglia. For this they received two cabs and cow catchers, which were no longer present in the photo. Since they didn't prove themselves there, they came to Yarmouth the year after they were delivered, where they were used in the harbour. They both came to British Railways, but were withdrawn in 1948 and 1952. 