The class 5 of the Lancashire & Yorkshire Railway was a 2-4-2T tank locomotive designed by John Aspinall in 1889 for passenger work. As a so-called “radial tank” with radially adjustable carrying axles at both ends and with driving wheels of 68 inches (1.727 mm), they could reach good speeds in both directions. Depending on the year of production, the cylinders had a diameter of 17.5 or 18 inches.

Starting in 1898, they were built with longer frames which allowed larger supplies and increased the service weight by nearly two and a half tons. When George Hughes took over in 1904, he produced these locomotives with a Belpaire firebox and an extended smokebox. By 1911, 310 had been built. All were later taken over by the LMS and in 1948, 105 came to British Railways.

Starting in 1911, Hughes took 46 and superheated them, these were later called class 6. These also got a Belpaire firebox, an extended smokebox and the cylinder diameter was increased to 20 inches. By 1914, 18 more had been newly built in this form. Also these 18 came to the LMS and eight survived until British Railways times. The last ones were withdrawn in 1961.