PRR GG1

The PRR GG1 was a class of electric locomotives built for the Pennsylvania Railroad (PRR) for use in the northeastern United States. Between 1934 and 1943, General Electric and the PRR's Altoona Works built 139 GG1s.

The GG1 entered service with the PRR in 1935, and later operated on successor railroads Penn Central, Conrail and Amtrak. The last GG1 was retired by New Jersey Transit in 1983. Most have been scrapped, but several remain in museums.

Technical information

The 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.