GN W-1

The class W -1 of the Great Northern Railway consisted of two built by General Electric electric locomotives with axle formula ( Bo'Do ') ( Do'Bo '). With each 3.7 MW, it was the most powerful electric locomotives that have ever been used in North America.

History

Increased traffic on the transcontinental route of the Great Northern Railway making the procurement of additional locomotives for the traffic on the electrified with 11 kV, 25 Hz single-phase AC voltage 117 km long part of the network between Wenatchee and Skykomish in the U.S. state of Washington and the 12.5-kilometer long tunnel Cascade required. A use of diesel locomotives was severely restricted in this because of the lack of ventilation.

The two vehicles with the numbers 5018 and 5019 were built in 1947 at the plant in Erie ( Pennsylvania) by General Electric. Due to their size, the machines were referred to as " Big Boys of the North American electrification ". In passenger locomotives reached a speed of 105 km / h A 1,814 -ton freight train could carry without additional sliding on the slope of the locomotive locomotives. On the downhill braking performance of the locomotive was enough to slow the train without the air brakes of the train.

After 1956 an improved ventilation system in the Cascade tunnel was installed, the Great Northern ended on July 31, 1956 Electric traction on this section. Both locomotives were retired. Locomotive 5019 was scrapped in 1959. Locomotive 5018 was sold to the Union Pacific Railroad, which used the chassis to build on their experimental coal dust turbine locomotive UP80.

Design features

It was Converters locomotives in which the alternating current from the overhead line was initially stepped down to 1350 volts and two 25 -hertz synchronous motors drive. This in turn drove at each two DC generators that supplied the twelve silent GE 746 DC traction motors. The traction motors were alien energized, thereby regeneration from braking energy to the catenary was possible. The exciter system served two exciters on the shaft of the synchronous motors. The smaller main pathogens ( engl. main exciter ) was about self-excited and provided the excitation current of the synchronous motor, direct current generators and a larger excitation (English regenerative exciter ), who supplied the excitation current to the traction motors. The braking performance, including the regenerative brake was 5750 hp.

The frame of the locomotive consisted of cast steel and was in two parts. In the middle of the engine, both parts were connected. The streamlined -designed structure was welded. The locomotives had two cabs. These were equipped similarly to diesel locomotives. The transformers, the main generator units, fans and control units were arranged in the center of the vehicle. In the noses of the vehicles, the air compressor and the auxiliary generators were housed.

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