[Matt D.]

Originally Posted by FattyBoomBatty

you sure bout dat? why does it say 25,000hp engines? Or was it motors? I know it said they cranked up the boost to 31,000 volts, but a 25k hp electric motor would be ginormous.

From Wikipedia...

Originally Posted by Wikipedia

TGVs are all electrified at 25 kV 50 Hz AC. Catenary wires are kept at a greater mechanical tension than normal lines because the pantograph causes oscillations in the wire, and the wave must travel faster than the train to avoid producing standing waves that would cause the wires to break. This was a problem when rail speed record attempts were made in 1990; power wire tension had to be increased further still to accommodate train speeds of over 500 km/h (310 mph). On LGVs, only the rear pantograph is raised, avoiding amplification of the oscillations created by the front pantograph. The front power car is supplied by a cable running along the roof of the train. Eurostar trains are long enough that oscillations are damped sufficiently between the front and rear power cars, so both pantographs can be raised - there is no interconnecting high-voltage cable along the 400-m length of the train. On lignes classiques slower maximum speeds prevent oscillation problems, and on DC lines both pantographs must be raised.