GP7 / GP9
The GP locomotive series are four-axle road switchers built by Electro-Motive Division (EMD), a division of the General Motors Corporation -- which was evenually purchased by Caterpillar Inc. in 2005. The GP7 line of locomotives were built between October 1949 and May 1954 while the GP9 series were built between January 1954 and August 1963. In total, approximately 2,700 GP7's were built and 3,400 GP9’s – mainly for US and Canadian railways.
The GP7 locomotive was the first diesel produced in the GP (General Purpose) series of EMD locomotives. Powered by a 16 cylinder, 1,500 horsepower motor, the GP7 was a reliable and solid performer. Although the GP’s were designed for both freight and passenger service, they would become an instant success with freight hauling lines. With improved front and rear visibility due to its center cab design, as well as lower maintenance costs, the GP7 was an immediate victory for railroads. In the mid-1950’s EMD increased the output of these units to 1,750 horsepower and were sold under the GP9 series.
Lionel began production of their version of the GP7 diesel series in 1955. It was not until 1958 when Lionel first marketed a GP9 locomotive in their product line. For Lionel, the distinguising feature between the 7 and 9 series was the inclusion of a dynamic brake blister on top of the GP9. On the real railroad, both the GP7 and GP9 came with or without this dynamic brake blister unit.