GNR Class O1

The Great Northern Railway Class O1 was a class of two-cylinder 2-8-0 steam locomotives designed by Nigel Gresley for heavy freight work, built between 1913 and 1919. They were meant for the heavy coal trains on the main line from Grantham to London. Five were ordered in 1913 and completed at Doncaster in 1914, but a further fifteen ordered in January 1916 were delayed by the First World War and their construction passed to the North British Locomotive Company, which delivered ten in April 1918 and five more in late 1919. In 1944 the LNER redesignated the class O3 so that the O1 classification could be used for the Thompson class introduced during the Second World War. Seventeen examples passed to British Railways in 1948 and all had been withdrawn by 1952.