In 1900, John Aspinall introduced a new class of 0-8-0 locomotives for heavy mineral traffic. Their drivers measured 4 feet and 5 7/8 inches and their cylinders measured 20 by 26 inches. They could haul trains of up to 60 coal wagons, but usually the number was only 27. By 1908, a total of 110 had been built at Horwich.
20 of these locomotives had been built with Henry Hoy's corrugated steel inner furnace. Since this was no success, these received standard fireboxes between 1911 and 1914. Later this class was rebuilt with new superheated boilers and modern side-window cabs. The LMS put them in power class 5F and the first ones were withdrawn in 1926. British Railways only received two which had already gone in 1950.