Silver Jubilee (train) in the context of "LNER Class A4 4468 Mallard"

LNER Class A4 4468 Mallard is a 4-6-2 ("Pacific") steam locomotive built in 1938 for operation on the London and North Eastern Railway (LNER) at Doncaster Works to a design of Nigel Gresley. Its streamlined, wind tunnel tested design allowed it to haul long-distance express passenger services at high speeds. On 3 July 1938, Mallard broke the world speed record for steam locomotives at 126 mph (203 km/h), which still stands today.

While in British Railways days, regular steam-hauled rail services in the UK were officially limited to a 90 mph (140 km/h) "line speed", before the Second World War, the A4s had to run significantly above 90 mph (140 km/h) just to keep schedule on trains such as the Silver Jubilee and The Coronation, with the engines reaching 100 mph on many occasions. Mallard covered almost one and a half million miles (2.4 million km) before it was retired in 1963.