This is a Churchward designed tank dating from 1906 and was a development of his earlier Class 44xx, which it closely resembled. The most noticeable difference was the larger driving wheels. Early members of the class were the last to be built at the Stafford Road Works in Wolverhampton between 1906 and 1908, the rest being built at Swindon. Several batches were built up to 1929, bringing the total to 175. They were used for branch line duties on both freight and passenger trains and were found in many parts of the system, although uncommon in the London area. In 1953, fifteen were fitted for push-pull work in the Cardiff area. Taunton allocated members of the class, operating on single track routes, were fitted with an automatic staff changing apparatus. The last of the class was withdrawn in 1965 and fourteen have survived into preservation.