A dynamometer car is a railroad maintenance of way car used for measuring various aspects of a locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

's performance. Measurements include tractive effort

Tractive effort

As used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to describe the pulling or pushing capability of a...

 (pulling force), power, top speed, etc.

History

The first dynamometer car was probably one built in about 1838 by the "Father of Computing" Charles Babbage

Charles Babbage

Charles Babbage, FRS was an English mathematician, philosopher, inventor and mechanical engineer who originated the concept of a programmable computer...

. Working for the Great Western Railway

Great Western Railway

The Great Western Railway was a British railway company that linked London with the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838...

 of Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

, he equipped a passenger carriage to be placed between an engine and train and record data on a continuously moving roll of paper. The recorded data included the pulling force of the engine, a plot of the path of the carriage and the vertical shake of the carriage. The work was undertaken to help support the position of the Great Western Railway in the controversy over standardizing the British rail gauge

Rail gauge

Track gauge or rail gauge is the distance between the inner sides of the heads of the two load bearing rails that make up a single railway line. Sixty percent of the world's railways use a standard gauge of . Wider gauges are called broad gauge; smaller gauges, narrow gauge. Break-of-gauge refers...

.

External links

• Testing a Locomotive — Comprehensive details of how a dynamometer car is used for performance testing
• Rail Training & Test Cars photos of some prototype cars.
• Carriages of LNWR: 6-wheeled Dynamometer Car
• Laboratory on Wheels Details (including publicity article from February 1951) of the Victorian & South Australian Railways' dynamometer car
• Esoteric Test Equipment
• National Model Railroad Association, Kitbash Korner: ML&S Dynamometer Car building a model of a dynamometer car.