Steam recording meter from dynamometer Car

Steam recording meter from dynamometer Car no 902502, NER, 1906. Detail of meter for recording the amount of steam used per hour by a locomotive, from a dynamometer car built for the North Eastern Railway (NER) in 1906. This dynamometer was used on the record-breaking run of Sir Nigel Gresley's 'Mallard' locomotive, in 1938. A dynamometer car containing technical apparatus enabled tests to be made on railway journeys under varying conditions, obtaining information relating to speed, acceleration, superheater and smokebox temperatures.