To eliminate the oscillations and the hammer blow of steam locomotives, Jean-Jacques Heilmann was the first one to develop an electric transmission for steam locomotives. His first design of 1890 included some sort of generator car that used a boiler that powered a triple-expansion compound steam engine. This turned a 360 kW generator that delivered its power to three carriages with four traction motors each.
The first working prototype of a similar design was completed in 1893 and called “La Fusée Electrique” (“The Electric Rocket”). The steam engine now only had two-stage expansion and was designed with the help of the Swiss SLM. A BBC generator rated at 500 kW powered eight traction motors in the two four-axle bogies of the locomotive. Trial runs over approximately 2,000 km were successful, since they showed very smooth running characteristics and a top speed of 107 km/h.
There was some interest from different countries, but initially there were no orders. Frequently raised points were that these locomotives were too complicated, too expensive and too heavy. Finally, the French Ouest ordered two locomotives which were somewhat heavier than the prototypes. These were completed in 1897 and numbered 8001 and 8002. On test runs, these had no problems hauling a 250 tonne train at 100 km/h. Nevertheless, there were no further orders and these two were scrapped. Similar types of power transmission were only implemented later with internal combustion engines.