The first A11 was built in 1925, by Sir Nigel Gresley and son of S.D. Holden as an experimental hybrid. A further seventeen were built between 1925 and 1928. All eighteen members survived to British Railways ownership in 1948. Withdrawals went from 1958 to 1966. Three have been since preserved, including the first of the class, No. 1400, "Stephen D. Holden", after one of it's two designers. He is painted blue with red stripes, the number "34" on his cab side and the letters "NWR" on his tender sides. The actual description of Robin is boiler, smokebox without neck holders from Gresley A3, drive wheels, side rods, cab, footplate steps, tender, dome from Holden B12 and footplate, funnel, splashers (wheel arches) from both hybrid.