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The New Haven chose the 11 kV 25 Hz system, later used by the PRR, in addition to working with Westinghouse to develop AC/DC electric motors (locomotives) to run on both AC overhead lines and DC third rail. The main line, now Metro-North Railroad's New Haven Line, was converted to 12.5 kV 60 Hz in 1985.
Most overhead supply systems are either DC or single phase AC, using a single wire with return through the grounded running rails. Three phase AC systems use a pair of overhead wires, and paired trolley poles. Electric overhead cranes and gantry cranes may use a current collector system to provide power over the full length of their operating ...
[citation needed] The additional rail carries the electrical return that, on third-rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420 V DC , and a top-contact fourth rail is located centrally between the running rails at −210 V DC , which ...
The overhead wiring, generally having two separate overhead lines and the rail for the third phase, was more complicated, and the low frequency used required a separate generation or conversion and distribution system. Train speed was restricted to one to four speeds, with two or four speeds obtained by pole-changing or cascade operation or both.
In this system, the current is mainly carried between the overhead line and a feeder transmission line instead of the rail. The overhead line (3) and feeder (5) are on opposite phases so the voltage between them is 50 kV, while the voltage between the overhead line (3) and the running rails (4) remains at 25 kV. Periodic autotransformers (9 ...
Since 1940. Used both third rail DC (1200 V) and overhead line AC (6.3 kV 25 Hz) until 1955. Also uses German standard 15 kV AC 16 2/3 Hz overhead electrification on the section between Neugraben and Stade on line S3, opened in December 2007.
This vehicle is capable of operating either under 1,500 V DC overhead wires or on battery power alone for a distance of up to 50 km on tracks without an overhead power supply. [34] The batteries can be charged via the pantograph while running on tracks with an overhead wires or at a specially built recharging facility at a station. [34] [35]
Where an external electric supply is provided, this is typically with overhead conductors or above-ground rails or (rarely) sub-surface electro-magnets. An all-electric vehicle typically requires one or more on-board energy supply elements or devices for autonomous operation, most commonly by chemical batteries , less frequently via electro ...