EMD SD70 series

The EMD SD70 is a series of diesel-electric locomotives manufactured by Electro-Motive Diesel. This locomotive family is an extension and improvement of the EMD SD60 series. Production commenced in late 1992 and since then over 5,700 units have been produced; most of these are the SD70M, SD70MAC, and SD70ACe models. While the majority of the production was ordered for use in North America, various models of the series have been used worldwide. All locomotives of this series are hood units with C-C trucks, except the SD70ACe-P4 and SD70MACH which have a B1-1B wheel configuration, and the SD70ACe-BB, which has a B+B-B+B wheel arrangement.

Superseding the HT-C truck, a new bolsterless radial HTCR truck was fitted to all EMD SD70s built 1992–2002; in 2003 the non-radial HTSC truck (basically the HTCR made less costly by removing radial components) was made standard on the SD70ACe and SD70M-2 models; the radial HTCR truck remained available as an option.

Models

SD70 (1992–1999)

The EMD SD70 has the smaller spartan cab, typical on preceding SD60 models, instead of the larger comfort cab used on later models. Notable differences between the SD70 and SD60 are the radial steering EMD HTCR truck instead of the older HTC truck, and the SD70's overall length of 72 ft 4 in (22.05 m), with the older SD60 being 2 inches shorter. The SD70 also rides higher as its frame is approximately 1⁄2 inch (13 mm) higher than the SD60. This model is equipped with direct current (DC) traction motors, which simplifies the locomotive's electrical system by obviating the need for computer-controlled inverters (as are required for alternating current (AC) power).