It is 75 years today that LNER A4 class locomotive Mallard broke the world speed record for a steam locomotive. And that record still stands today.

Mallard is the holder of the world speed record for steam locomotives at 125.88 mph (202.58 km/h). The record was achieved on 3 July 1938 on the slight downward grade of Stoke Bank south of Grantham on the East Coast Main Line, and the highest speed was recorded at milepost 90¼, between Little Bytham and Essendine.GoG