25 kV 50 Hz railway electrification
Electrificación ferroviaria a 25 kV y 50 Hz
- Date
- 1936-1955 · confidence medium
- Place
- Höllentalbahn, Freiburg im Breisgau, Baden-Württemberg, Germany
- Credited to
- Deutsche Reichsbahn and SNCF (Louis Armand)
- Field
- Matter & energy
⚠️ Disputed: the sources disagree.
What was discovered
The Reichsbahn tested industrial 20 kV 50 Hz current from the grid in the Höllental in 1936, with no converter. SNCF developed it in Savoy (1950) and in the north (1955) at 25 kV, and it became the world standard for high-speed rail.
The 1936 German trial was interrupted by the war, and SNCF resumed it under Louis Armand and made it a standard. The date and 'origin' place depend on which step is counted first.
What it led to
- TGV, newer Shinkansen lines and AVE
- cheap electrification without rotary substations
- rectifier and thyristor locomotives