Development of The TGV - Electric Power

Electric Power

With the oil crisis of 1973, it no longer seemed economically viable to power the future high-speed train with fossil fuels. The requirements were changed to fully electric operation, which resulted in an extensive redesign and test program. In April 1974, the Z7001 experimental electric railcar, nicknamed "Zébulon", began trials. Zébulon was rebuilt from the Z7115 which had been wrecked. Using this vehicle, the new Y226 long-wheelbase power truck (precursor of the Y230 of the production TGV) was developed and tested, with its body-mounted traction motors and tripod cardan transmission. Body mounting of the traction motors was a major innovation; it allowed a considerable (3300 kg) reduction in the mass of the power truck, giving it a very high critical speed and exceptional tracking stability. Zébulon also served to develop a two-stage high speed pantograph, which later became the AM-PSE pantograph of the TGV Sud-Est, as well as a new type of eddy current rail brake. The eddy current rail brake exerts a magnetic retention effort, without ever making contact with the rail. The promise of high efficiency and low wear was however outweighed by problems with overheating in the rail, and the design was dropped. Zébulon's suspension, of a non-pneumatic design, was completely satisfactory so it was adopted for the new high speed train, instead of the TGV 001's pneumatic suspension.

Over a period of 20 months, Zébulon racked up almost a million kilometres, 25000 of which were run at speeds over 300 km/h (186 mph). The highest speed reached by Zébulon was 309 km/h (192 mph). Prospects were good for project C03, which was fully funded by the French government in 1976. Construction of an electric high-speed line from Paris to Lyon began soon after.