The Gresley designed, Pacific A4 class, Mallard is the  holder of the world speed record for steam locomotives at 126 mph, achieved on July 3, 1938 on the slight downwards grade of Stoke Bank, south of Grantham, on the East Coast Main Line. The Mallard is currently housed at the National Railway Museum, along with many other fine examples of railway history. Who’s your favourite Record Holder? Answers in an Email, Subject line, Record Holder.