In 1992, GM’s Electro-Motive Division (EMD) introduced the new SD70 Series of engines, which come in the standard direct-current (DC) and alternatingcurrent (AC) models. One glance at the design of this engine reveals the enormous technological gains in railroading. The SD70 boasts a 32-bit 16mHz control microprocessor named the EM2000. This computer works with the Integrated Cab Electronics (ICE) system to collect, analyze, and display a range of accurate-to-the-second information, such as speed, amps, throttle position, air brake operation, and cab signals. All of this information is displayed on fullcolor liquid crystal displays that replace the gauges and indicators found on earlier diesels.
The 70 Series also employs the HTCR (high-traction three-axle radial) truck that reduces rolling resistance in curves and lateral loads and therefore reduces wear on wheels. EMD estimates this will increase wheel life by 20 percent. These innovations have led to brisk sales of both the SD70M (DC version) and SD70MAC (AC version).
