The Atlas Classic N Scale SD-7 Locomotive is based on the prototype manufactured by EMD from February 1952 to November 1953. Utilizing a 1,500 HP engine and a longer underframe than the GP-7, the SD-7 was the first locomotive to use EMD's Flexicoil truck.
Built by EMD between 1954 and 1959, the SD-9 6-axle switchers produced 1,750 HP and were used primarily for freight service throughout the US, both on main and secondary lines. Many SD-9 locomotives are still in service today, serving as road switchers for shortline & industrial railroads, and as yard switchers for major "Class 1" lines.
- Atlas Silver Sound Ready models are equipped with a speaker for easy conversion to sound with the addition of a decoder.