The EMD GT22CUM1 is a narrow gauge diesel-electric 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...

 built by EMD. It has six axles in two trucks, giving it a C-C wheel arrangement. The name means a C-C locomotive, U for metre gauge

Metre gauge

Metre gauge refers to narrow gauge railways and tramways with a track gauge of . In some African, American and Asian countries it is the main gauge. In Europe it has been used for local railways in France, Germany, and Belgium, most of which were closed down in mid 20th century. Only in Switzerland...

 (the rails are a metre apart), 12 cylinder 645 series. They were built for service in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 by the Villares with license of EMD. The Rede Ferroviaria Federal Sociedade Anonima (RFFSA

RFFSA

The Rede Ferroviária Federal, Sociedade Anônima was the state-owned national railway company of Brazil. It was created in 1957, and dissolved between 1999–2007.-Constituent Railways:...

) a state railroad in Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 bought about 55 in the early 1980s in order to expand their locomotive roster. The RFFSA needed a powerful single-engined locomotive with light weight per axle for their metric system, and the GT22 represented the highest-rated model that EMD had to offer at the time.

However, a big locomotive such as an SD40

EMD SD40

The EMD SD40 is a 6-axle diesel locomotive built by General Motors Electro-Motive Division between January 1966 and August 1972.-Design:Like its predecessor in EMD's catalog, the SD35, the SD40 is a high-horsepower, six-motor freight locomotive....

 with its three-axle trucks wasn't readily adaptable to the RFFSA's narrow gauge trackage. The smaller traction motors of the meter gauge locomotive were able to handle the full current capacity from the 2.450 hp prime mover. And so, EMD proposed the metre gauge version of the Flexicoil-C three-axle trucks, similar to those found under the export EMD GT26CUM locomotive model, creating the GT22CUM in the process.

GT22CUM1	GT22CUM2	GT26CUM
2250Hp	2250Hp	3000Hp
108 tons	120 tons	135 tons

The model name "GT22CUM1" deconstructs as follows:

• G - general Use
• T - turbo charged
• 22 - 12 cylinder 645E diesel engine
• C - C-C wheel arrangement
• U - metrical gauge
• M1 - model 1