In 1888, Holden experimented by removing the side rods of T19 No. 721 to form a 2-2-2.[1] In 1889 the first of a new class appeared: initially No. 740 (later 789 and 780) which had been built on a 'Locomotive and Machinery' account. This was followed by two batches of ten on the more normal 'Letter' account.[2] in 1893. They were built with 18 in × 24 in (457 mm × 610 mm)[3] inside cylinders powered by a 140 lbf/in2 (965 kPa) boiler. They were later rebuilt with 18 in × 25 in (457 mm × 635 mm) and 160 lbf/in2 (1,103 kPa) boilers.[2]
One of their main spheres was on the Joint Line working expresses to York. In 1896 the class inaugurated the epic making non-stop run to North Walsham using oil-firing. Rous-Martin[4] found that the singles climbed Brentwood Bank more rapidly than the 2-4-0s. See also Ahrons (1951).
Nine locomotives were withdrawn between 1901 and 1903. The surviving eight locomotives in the 770-series were transferred to the duplicate list in July 1904, and had their number prefixed with a "0". The remaining fourteen were withdrawn between 1904 and 1907.[5]