PRR GG1 - Technical Information

Technical Information

A GG1 was 79 feet 6 inches (24.23 m) long and weighed 475,000 pounds (215,000 kg). The frame of the locomotive was in two halves joined with a ball and socket joint, allowing the locomotive to negotiate sharper curves. The body rested on the frame and was clad in welded steel plates. The control cabs were near the center of the locomotive on each side of the main oil-cooled transformer and oil-fired train-heating boiler. This arrangement, first used on the Modified P5 class, provided for greater crew safety in a collision and for bi-directional operation of the locomotive. A pantograph on each end of the locomotive body was used to collect the 25 Hz, 11,000 V alternating current (AC) from the overhead lines. In operation the leading pantograph was usually kept lowered and the trailing raised to collect current, since if the rear pantograph failed it would not strike the forward pantograph. Transformers between the two cabs stepped down the 11,000 V to the voltages needed for the traction motors and other equipment.

Twelve 385-horsepower (287 kW) GEA-627-A1 traction motors drove the GG1's 57-inch (140 cm) diameter driving wheels on six axles using a quill drive. Four unpowered leading/trailing wheels were mounted on each end of the locomotive. Using Whyte notation for steam locomotives, each frame is a 4-6-0 locomotive, which in the Pennsylvania Railroad classification system is a "G". The GG1 has two such frames back to back, 4-6-0+0-6-4. The AAR wheel arrangement is 2-C+C-2 meaning two sets of three powered axles that are hinged together, with two unpowered axles on either side.