Edward Thompson designed the B1 as a mixed traffic locomotive and building started in 1942. Construction of the class went on for a number of years, ending with a final batch in 1950. Some of the work was contracted out to the Vulcan Foundry and the North British Locomotive Co. The rest were built at Darlington, except for 10 at Gorton. The last was withdrawn in 1967 and two have been preserved.

The B1 is similar in many ways to Gresley's B17 'Sandringham' Class but with slightly smaller wheels, two cylinders and a higher pressure boiler. 410 were built, making it the largest class of LNER designed locos. They were used throughout the LNER network and had good route availability. In BR days they were also found on the LMR while some used in Scotland were fitted with tablet-catchers on their tenders. 59 of the class received names - consisting of types of Antelope and directors of the LNER. Possible liveries include: wartime NE black, LNER lined black, LNER lined green, apple green with 'British Railways' on the tender and BR lined black with early or last decals.

The models were first released late in 2010 and had been developed over the last two years by Bachmann, building on the success of the recently introduced Blue Riband locomotives. The B1 includes the successful Farish tender drive unit and has a 6-pin DCC decoder socket. The model has an all new body design, with options for welded or flush riveted smoke box detail as well as variations, including door radius, steps and lamp brackets. The tender and locomotive are fitted with separate handrail details and the loco has a fully detailed cab interior including seats for both driver and fireman and a hinged drop plate between locomotive and tender. Other details include a steam generator, AWS battery box and air cylinders.