The LNWR 5ft 6in Tank was a class of 160 passenger 2-4-2T locomotives manufactured by the London and North Western Railway in their Crewe Works between 1890 and 1897.

The design featured a boiler pressed to 150 lbf/in2 (1.03 MPa) delivering saturated steam to two 17 by 24 inches (430 by 610 mm) cylinders connected by Allan valve gear to the driving wheels.

They were effectively a tank version of the LNWR Webb Precursor Class,[1] which were then being withdrawn.

Forty-two locomotives were fitted up between 1929 and 1932 by the LMS for push-pull train service.

[4] Forty-three survived to British Railways service in 1948; their numbers were increased by 40000.