An EMD SD45-2 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division beginning in 1972. Power was provided by an EMD 645E3 20-cylinder engine which generated 3,600 horsepower (2,680 kW). Part of the EMD Dash 2 line, the SD45-2 was an upgraded SD45. The main spotting difference between an SD45 and an SD45-2 was the long hood configuration and the rear radiator assembly. On the SD45 the long hood is flared whereas on the SD45-2 it is vertical and the rear cooling fans are more spread out over the top of the rear of the long hood. This unit shared the same common frame with the EMD SD40-2 and EMD SD38-2. The largest owner of the SD45-2 was the Atchison, Topeka, & Santa Fe with 90 units, the Clinchfield had 18 units, Seaboard Coast line had 15 units and Erie Lackawanna rostered 13 units.
A few cabless SD45-2Bs also existed; these were rebuilds of wrecked units by ATSF. In most cases, as in the example shown, the dynamic brakes were moved to the opposite end of the hood from the radiators; they were originally near the center of the hood. These B Units are designed to be run with other locomotives. Santa Fe acquired more B units throughout their time with diesels than any other railroads in North America.