The Fastest Steam Locomotive Ever — Mallard’s 126 mph World Record

The fastest steam locomotive in the world still holds its record after more than 85 years. On 3 July 1938, LNER A4 No. 4468 Mallard reached 126 mph (203 km/h) on Stoke Bank — a mark no other steam locomotive has officially beaten. In this video we break down exactly how Mallard did it, the controversy around the speed claim, the closest rivals (including Germany’s 05 002), and why modern high-speed trains don’t count in the same category. If you enjoy railway history and engineering deep-dives, subscribe for more.