The EMD DDM45 is a meter-gauge diesel-electric

locomotive A locomotive is a rail transport, rail vehicle that provides the motive power for a train. Traditionally, locomotives pulled trains from the front. However, Push–pull train, push–pull operation has become common, and in the pursuit for ...

built by EMD. The DD in the name means that it has eight axles in two trucks, giving it a D-D

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

, while the M stands for the meter-gauge track it was to operate on, and the 45 represents the

EMD SD45 The SD45 is a six-axle diesel-electric locomotive class built by General Motors Electro-Motive Division between 1965 and 1971. It has an EMD 645E3 twenty- cylinder engine generating on the same frame as the SD38, SD39, SD40, and SDP40. As o ...

that the engine was derived from. They were built for service on the Estrada de Ferro Vitória a Minas (EFVM) in

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. In the early 1970s, the EFVM needed not only to expand its locomotive roster, but to use the most powerful single-engined locomotives available, and the

SD45 The SD45 is a six-axle diesel-electric locomotive class built by General Motors Electro-Motive Division between 1965 and 1971. It has an EMD 645E3 twenty-cylinder engine generating on the same frame as the SD38, SD39, SD40, and SDP40. As of ...

represented the highest-rated model that EMD had to offer at the time. However, a large locomotive like an SD45 with its three-axle trucks was not readily adaptable to the EFVM's meter gauge trackage. The smaller

traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, or electric multiple unit trains. Traction (engineering), Traction motors are used in electrically powe ...

s of the meter gauge locomotive were unable to handle the full current capacity from the prime mover. EMD proposed using a meter-gauge version of the

Flexicoil Flexicoil suspension is a type of secondary suspension for railway vehicles, typically having steel coil springs between the bogies and chassis of a passenger coach, freight car, or locomotive. Suspension systems using steel springs are more ...

-D four-axle

bogie A bogie ( ) (or truck in North American English) comprises two or more Wheelset (rail transport), wheelsets (two Railroad wheel, wheels on an axle), in a frame, attached under a vehicle by a pivot. Bogies take various forms in various modes ...

s, similar to those found under the domestic DD35, DD35A and

DDA40X The EMD DDA40X is a 6,600 hp (4,943 kW) AAR wheel arrangement#D-D, D-D locomotive, built by Electro-Motive Diesel, EMD from 1969 to 1971 exclusively for the Union Pacific Railroad. It is the most powerful diesel locomotive#Diesel–el ...

locomotive models. The two additional traction motors of this design allowed full power to be used. Roster of DDM45s:

See also