Французские двухсистемные электровозы серии BB 20000

Class of 234 French electric locomotives

The class were built to fulfil both freight and passenger roles; the specifications included the ability to haul 16 Corail coaches at on a 0.25% gradient, and to haul a freight train at on a 0.88% gradient. The locomotives are a two cabin design with the body built out of steel, two pantographs are fitted; one for 1500 V operation, the other for 25 kV operation. three phase inverter circuits are connected in parallel, with the two three phase supplies per motor being series connected. For speeds below one supply voltage reducing chopper circuit (French:hacheur) per motor bogie is used to assist control. The power electronics of the two motor bogies are connected in parallel, with helical spring primarily suspension. Drive from the traction motors to wheel is via a floating ring vibration isolation element (French:anneau dansant) and hollow shaft drive. Two locomotives SNCF BB 20011 and 20012 were used to develop and test the dual voltage traction system, microprocessor control systems and auxiliary motors, BB 20012 was used to develop and test the pneumatic and electrical braking system.

264 of the class were ordered by SNCF, only 234 were built, the last 30 of the order were instead built as a new triple voltage design capable of also operating on 3 kV DC; these used asynchronous electric motors and became the SNCF Class BB 36000 (Asytrit). The class have been used in most regions of France. Other liveries carried include the Fret SNCF green livery, the red and grey multiservice and TER Alsace liveries and the purple and silver En voyage livery.

The locomotives have been reproduced as models in HO scale by Roco, Märklin, Jouef and Trix, and by PIKO in HO and N scales.