The Great Northern Railway Class J23 was a class of 0-6-0T steam locomotive. They had long side tanks that came to the front of the smokebox, which sloped forwards to improve visibility and had a recess cut in to aid maintenance. Forty were built by the Great Northern Railway (GNR) between 1913 and 1922, with a further 62 being added by the London and North Eastern Railway (LNER) between 1924 and 1939. There are plans to build a new J50/2 as of April 2013.