This picture shows 4 GG-1s drawing power….plenty to spare.
photo is from a close friend Bill
Attachments
Images (1)
Original Post
Replies sorted oldest to newest
I don't have my PRR Electric Locomotive Operating Instructions book at hand but I'm nearly certain that it contained instructions that the controller should not be operated beyond a certain notch when 3 GG1s were MUed together.
I can't tell from the photograph whether the motors were pulling a train or running light. Running light would require very little current.
I would tend to believe this shot shows a power-balancing light move, as I have never seen evidence of more that three GG1s on a freight train, and no more than two on a passenger train. If so, probably only one unit in the photo was under power. The others had their pantographs raised but were probably not providing any traction. Whenever I saw light engine moves all rear pantographs were always raised. Pennsys (and other railroads') use of the rear pantograph was strategic. I they used the lead pantograph and it somehow got ripped from the roof it would likely take the rear pantograph with it. By using the rear pantograph, the motor could continue by raising the front one in case of a failure. For some reason the Milwaukee did not follow that convention and seemed to use the front pantograph.
Apart from the grades at the B&P tunnel in Baltimore, where a helper engine was stationed to assist freights, there were no grades that would require more than the 218,000 lbs of TE that a 3 motor consist (with 90 MPH gearing) could provide.
On a related note, I never saw a photograph of more than two New Haven EP-4s or EF-3s MUed together on a train. They were essentially the New Haven answers to the GG1s, in passenger and freight service respectively.
Also note that there is no hyphen in GG1 (or any PRR locomotive) but the New Haven designations used hyphens.
From the title I was thinking you were going to spec current draw. Twelve 385-horsepower (287 kW) GEA-627-A1 traction AC commutator motors, drove the GG1's 57-inch diameter wheels on six axles using a quill drive. Just in straight math, and disregarding the traction motors being put in series, then series parallel and finally parallel, I don' know how or if they transitioned them, the 12 motors could draw under full load a combined 2.4+ million watts, and with a PRR 11,000 volt cantenary that works out to about 313 amps. So, 4 of them possibly when first getting a train moving under full load would be wanting 1200+ amps. (If pushed the right buttons on the calculator)
