This pretty much sums up EMD’s first GP series models, the GP7, GP7B, GP9, and GP9B. In EMD’s nomenclature, GP stands for general purpose. These series of EMD locomotives were very popular with railroads large and small. They certainly were popular on the railroads that became Penn Central, all except the GP7B, which none of the merger partners had on their rosters.
EMD started producing the 1,500 horsepower GP7 in October 1949 and May 1954, with a 567B 16 cylinder engine. GMD of Canada also produced these early GP units. Total production number of GP7’s was 2,734. If my roster and research figures are correct, PC had 301 GP7’s on the railroad. Below is my GP7 model on the layout.
Next in line following the GP7 models was the GP9 and GP9B models, produced between January 1954 and August 1963. The last two were built by GMD in August 1963. The GP9 was again a four axle locomotive, this time with a 567C 16 cylinder engine generating 1,750 horsepower. Production totaled 4,112 units, including the GP9B’s. Below is a freight with a GP7 as lead unit, with a GP9 trailing.
Penn Central rostered 377 GP9’s plus 40 GP9B’s, all ex-PRR. Again, if my calculations are correct, Penn Central rostered 718 of these models. Quite popular to say the least. Of course, Penn Central inherited or purchased just about every diesel locomotive produced, up to the time of its demise and folding into ConRail. As well, many of these GP models lasted into CR, being rebuilt into GP8’s. Below are photos of the prototype GP9B 3806, and my model #3839 on the layout.
Along with other four axle power, including later GP models, the geeps were ideal for lighter rail found on many lines throughout the system. Early, and later geeps for that matter were used on the Secondary, and the Hitop branch, due to lighter, less maintained rail, as well as the tight curves on the branch itself. As I’ve posted elsewhere, six axle power was eventually banned on the Secondary due to just plain worn out rail.
Of course, geeps are pretty much the mainstay on the layout. As with the prototype I worked on, these early geeps had a sound of their own being cranked up to notch 8. Same on the layout today. There is nothing quite like the sound of an early GP locomotive.