Designer H.N. Gresly Withdrawn 1942, 1962-1966 (BR Service) Preserved 6 Preserved. 4 in England 2 in Canada & USA Notes: On 3 July 1938 4468 Mallard ; the first of the class to enter service with the Kylchap exhaust, set a world speed record of 126 mph (202.8 km/h), pulling six coaches and