In March 1949, British Railways ordered a final 20 from Brighton works despite a pressing need for smaller tank locomotives. This imbalance was rectified by building forty-one examples of the LMS Fairburn 2-6-4T for the Southern Region. Also at this time Brighton works staff were embroiled in the difficulties associated with Bulleid's experimental and problematic Leader class. As a result, Brighton sought assistance from the other Southern Region works to complete this final order. Ashford works cut the frames and constructed the tenders, and Eastleigh works constructed six of the final batch of locomotives.