GNR 521 Class

The Great Northern Railway 521 Class was a class of 0-6-0 steam locomotives for goods traffic, introduced in 1911 to a design by Henry Ivatt. From 1912 to 1922 Nigel Gresley built further examples with small changes, known as the 536 Class: the front sandboxes sat below the running plate on the 521 but above it, merged with the front splashers, on the 536, and the boiler and firebox were moved back to give a shorter cab. The London and North Eastern Railway classified both as J6. They had superheaters and piston valves worked by Stephenson valve gear and shared cylinders, boilers and valve gear with Gresley's N2 0-6-2 tanks, so an order for ten more J6s was cancelled to let Doncaster Works build ten N2s instead. The LNER Encyclopedia records that the 95 Gresley-built J6s were built in ten batches at Doncaster. Their fast goods work was short-lived, because the H2 Moguls of 1913 moved them to lighter goods and occasional passenger trains. All 110 passed to British Railways in 1948, withdrawals ran from 1955 to 1962, and none was preserved.