The EMD DDM45 is a narrow gaugediesel-electriclocomotive built by EMD. The DD in the name means that it has eight axles in two trucks, giving it a D-Dwheel arrangement, while the M stands for the meter gauge track it was to operate on, and the 45 represents the EMD's SD45 that the engine was derived from. They were built for service on the Estrada de Ferro Vitória a Minas (EFVM) in Brazil. 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 represented the highest-rated model that EMD had to offer at the time.
However, a big locomotive such as an SD45 with its three-axle trucks wasn't readily adaptable to the EFVM's narrow gauge trackage. The smaller traction motors of the meter gauge locomotive were unable to handle the full current capacity from the 3,600 hp (2,700 kW) prime mover. EMD proposed using a meter gauge version of the Flexicoil-D four-axle trucks, similar to those found under the domestic DD35, DD35A and DDA40X locomotive models. The two additional traction motors of this design allowed full power to be used.