PRR class GG1

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Pennsylvania Railroad GG1
PRR GG1 4935 at the Railroad Museum of Pennsylvania in Strasburg PA
PRR GG1 4935 at the Railroad Museum of Pennsylvania in Strasburg PA
Numbering: 4800-4938
Number: 139
Manufacturer: Baldwin , General Electric , PRR Altoona
Year of construction (s): 1935-1943
Retirement: until 1983
Axis formula : (2'Co) - (Co2 ')
Gauge : 1435 mm ( standard gauge )
Length over coupling: 24,232 mm
Service mass: 208.6 t - 216.3 t
Wheel set mass : 22.9 t
Top speed: 161 km / h
Hourly output : 3442 kW - 3680 kW
Power system : 11-13 kV, 25 Hz
Power transmission: Overhead line
Number of traction motors: 12

The class GG1 of the Pennsylvania Railroad (PRR) was at its emergence as one of the fastest electric locomotives . Due to its extraordinary design, it is also considered one of the most beautiful. The locomotives were almost fifty years the backbone of the people express service in the Northeast Corridor of the United States .

Emergence

The Pennsylvania Railroad was looking for a replacement for the P5 series electric locomotives in the early 1930s, as they were not suitable for fast passenger train traffic. Before the construction contracts were awarded, two prototypes were built . One locomotive received the wheel arrangement 2'Do2 'and was designated as the R1 series, the second locomotive , based on the EP-3 of the New York, New Haven and Hartford Railroad , with the wheel arrangement (2'Co) (Co2') received the series designation GG1. Both vehicles had a largely identical streamlined structure with central driver's cabs . After the tests had been carried out, it was decided to get the locomotives with the wheel arrangement (2'Co) (Co2 '). The chief designer of the PRR, Raymond Loewy , got the order to redesign the locomotive. Since not much could be changed on the locomotive body, his only corrections were that the locomotive body of the series locomotives was welded instead of riveted. He also created a color scheme with five longitudinal stripes.

Technical information

A GG1 was 24.3 m long and weighed around 216 tons. The locomotives had a frame that was clad with welded sheet steel. The driver's cabs were moved to the center in order to offer the crew greater safety in the event of an accident. To improve visibility, the front nose was designed to be narrower at the level of the front window. The vehicle had the same height over its entire length in order to be able to position the pantographs in optimal positions due to the lateral deflection in the arch. The entire structure was aerodynamically rounded.

The six driving wheel sets were arranged in two bogies with cast steel frames. They carried the pulling and pushing devices at the ends and were coupled together. Each of the two motor bogies was additionally equipped with a two-axle running bogie at the ends of the vehicle . According to the PRR locomotive classification, 2'C locomotives were given the series designation G. As a result, the locomotives were designated as "GG".

GG 1 in action at Amtrak

Each axle was driven by two GEA-627-A1 drive motors with an output of 288 kW each. The power was transmitted via reduction gears and Westinghouse spring drives . The GG1 were designed for the PRR power system of 11 kV AC voltage with a frequency of 25  Hz . In the middle of the vehicle was the transformer with which the voltage for the drive motors, cooling fans and all other equipment was provided. The power control took place via a switch system. The output voltage could be regulated by varying the number of secondary transformer windings.

The locomotives had a total output of 3456 kW at 78.8 km / h (peak output). For express train traffic, the locomotives were translated for 161 km / h (100 mph), although 177 km / h would have been possible. For freight train traffic , the locomotives were given a top speed of 145 km / h (90 mph).

A GG1 accident

One of the most interesting events in GG1 history occurred on January 15, 1953 at Washington Union Station . Due to an incorrectly positioned brake valve , the brakes on part of the 'Federal Express' passenger train could not be operated. The unbraked passenger cars pushed the locomotive and two other cars over the platform through the station to the luggage compartment. The locomotive no. 4876 was then dismantled into three parts and refurbished in the PRR repair shop in Altoona, Pennsylvania . It then returned to service and was one of the longest-running locomotives of this series.

Retirement

The GG1s were largely replaced by the AEM-7 locomotives , and the last GG1s were decommissioned in 1983. The main reason was cracks, which after almost fifty years of operation appeared more and more frequently in the cast steel frame and required extensive repairs. Increasing difficulties in the procurement of spare parts and the planning to change the mains frequency from 25 Hz to 60 Hz accelerated the decision. Only the late-built machines with rectifiers could have continued to be used; the older vehicles would have had to be converted.

Today none of the GG1s are operational, restoring a machine to an operational condition is highly unlikely. The machines contain large amounts of asbestos , especially in the insulation of the wiring. The oil containing PCBs used to cool the transformers has also been disposed of in the meantime. The locomotives that still exist are in more or less good condition in museums or on the siding.

Existing copies

Web links

Commons : PRR class GG1  - collection of images, videos and audio files