SD45 Diesel Locomotive

Prototype Information

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 3,600 hp (2,680 kW) on the same frame as the SD38, SD39, SD40, and SDP40. As of 2023, most SD45s have been retired, scrapped or rebuilt to SD40-2 standards.
Design

A total of 1,260 were built for American railroads before the SD45-2 replaced it in 1972, along with the related SD45T-2 ‘Tunnel Motor’.

SD45s had several teething problems. Reliability was not as high as anticipated; the twenty-cylinder prime mover was prone to crankshaft failure from engine block flex. Though it produced 600 horsepower (450 kW) more than the 16-645E3 in the SD40, some railroads felt the extra horsepower was not worth it, even after EMD strengthened the block to eliminate crankshaft failures. At low speeds when tractive effort was adhesion-limited, the SD45 provided no advantage over the SD40.

Reference: https://en.wikipedia.org/wiki/EMD_SD45