The class 2045 was the first mainline diesel locomotive built in Austria. It was designed after the Second World War to resolve the severe locomotive shortage and was a step to move away from steam traction. As the ÖBB now concentrated on electric traction, this diesel locomotive for use on non-electrified lines also got electric power transmission.

It was inspired by American designs, but used as much Austrian components as possible. The locomotive was characterized by a load bearing frame that carried a central cab and two hoods. In each hood there was a 500 hp SGP diesel engine with a generator rated at 302 kW or 411 hp. Each bogie had two 140 kW traction motors which were coupled to the axles via a BBC quill drive. 

Simmering-Graz-Pauker built a total of 20 between 1952 and 1955. As they were intended for both passenger and freight traffic, they had an oil-fired steam generator in the cab. After heavier locomotives had taken over traffic on mainlines, the 2045 was used on branch lines, still both in passenger and freight traffic. The last one was withdrawn in 1993. Seven have been preserved at several locations.