Due to an urgent need for freight locomotives, Worsdell developed the Y14, which, with its very low axle load and simple design, could be used almost anywhere and was inexpensive to maintain. Because the design was so successful, Worsdell's successors also had a total of 289 locomotives built by 1913.
Locomotive Magazine, October 1912
Changes during production included a sloped instead of a straight grate or a different chimney. Number 127 was the only one built as a compound, while another locomotive was built and under fire in just nine hours and 47 minutes, which was a record. On the LNER the Y14 class became the J15 and 127 were still in use until the formation of British Railways in 1948. Although these locomotives never received a superheater, the last ones lasted until 1958.