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.

[2][3] Nigel Gresley succeeded Ivatt in 1911,[4] and soon identified a need for engines to work the short-haul coal traffic in the West Riding of Yorkshire; the nature of which required that the locomotives also be suitable for shunting.

Thirty of these were used in the construction of the new goods tank engines between 1913 and 1919;[5] when ten more were built in 1922, these again used secondhand boilers, but 4 feet 5 inches (1.35 m) in diameter.

[5] Each of the two main classes exhibited variations: locomotive brakes could be operated by vacuum or steam pressure; the driving position could be on the right- or the left-hand side of the cab; and there were three sizes of coal bunker.

[11] Withdrawals began in 1958 with the arrival of diesel shunters and ended in 1963 for the normal stock.