The SD7 was General Motors Electro-Motive Divisions' first foray into 6-axle power. The “SD” stood for Special Duty, while the 7 was carried over for the 4-axle GP7 series. This new series of locomotives provided extra tractive effort spread and weight distribution across the six-axle trucks. Production lasted from May of 1951 to November of 1953. A total of 188 units were built for 17 railroads, from class Is to industrial operations. The SD7 would give way to the SD9.

  The Rapido Trains HO scale EMD SD7, SD9 and SD10 Locomotive features:

• Measured from a living SD9
• Road-specific details for each model variant
• Separate grab irons and handrails installed at the factory
• Operating headlights, rear lights, white class lights AND beacons (where appropriate).
• Highly detailed cab interior
• Correct fuel and water tank arrangements per road
• Multiple styles of stepwells
• See-through, etched steps
• High short hood and modified ‘chopped’ short hood where appropriate
• Appropriate cab or nose headlights
• Multiple dynamic-brake hatches
• DC/Silent (21-pin DCC Ready) or DC/DCC/ESU LokSound
• And much, much more!