Thornhill was built in 1880 as builders number 2028 for the Manx Northern Railway on the Isle of Man by Beyer, Peacock and company. It operated on this railway until 1905 when it was taken over by the Isle of Man Railway and renumbered 14. It was withdrawn from service in 1963 and put on display at St John Station from 1967 to the next year. It was later displayed at Douglas Station until 1978 when it was sold to a private collector. In July 2021 it was photographed under retoration at John Fowler Ltd.