GNR Class J23

The Great Northern Railway Class J23 was a class of 0-6-0T side-tank steam locomotives designed by Nigel Gresley for short-haul coal traffic in the West Riding of Yorkshire, work that also required shunting ability. Long side tanks ran to the front of the smokebox, which sloped forward to improve visibility, and the engines were nicknamed Submarines. Forty were built by the GNR between 1913 and 1922, and the LNER added 62 more between 1924 and 1939. Because several spare boilers of two sizes were used, the LNER divided the class into J51 with the smaller boiler and J50 with the larger one, and rebuilt the J51s to J50 between 1929 and 1935. All were built at Doncaster except the last fourteen, which came from Gorton. Withdrawals began in 1958 as diesel shunters arrived, the class was extinct by 1965 and none was preserved.