The EMD SD70 is a series of diesel-electric locomotives produced by Electro-Motive Diesel in response to the GE Dash 9-44CW. Production commenced in late 1992. All SD70 models were delivered with the self-steering HTCR radial truck. The radial truck allows the axles to steer in curves which reduces wear on the wheels and railhead.
Washington Northern ordered 10 SD70s from EMD in 1995. These represent the newest 6-axle power in active duty on the WN, and can occasionally be seen running through the tideflats district.