The Mallard is an express locomotive with a wind-tunnel tested, aerodynamic body that allowed it to reach speeds of over 100 mph. Designed by Sir Nigel Gresley and built in the 1930’s, Number 4468 Mallard is a London and North Eastern Railway Class A4 4-6-2 Pacific steam locomotive. Mallard is the holder of the world speed record for steam locomotives at 126 mph (203 km/h). The record was achieved on July 3, 1938. She was in service until 1963 when she was retired after a lifetime of more than 1.5 million miles of service.