The first member of the class, no. 3292, was completed in December 1897 with a domed parallel boiler, a raised Belpaire firebox and an extended, built-up smokebox similar to that used on the Duke Class. The outside frames were curved over each driving wheel axle. It was named "Badminton" in April 1898. A batch of eleven locomotives, nos. 3293 to 3303, were completed between April and July 1898, with a further batch of eight, nos. 3304 to 3311, between September 1898 and January 1899. The class were the first locomotives on the GWR to be fitted with copper Belpaire fireboxes. The penultimate example, no. 3310 "Waterford", was fitted with a domeless parallel boiler, a steel Belpaire firebox, and an enlarged cab.