Electric steam locomotive
An electric steam locomotive is a special form of steam locomotive in which the boiler water is heated electrically.
Two such locomotives were used in shunting operations on the Swiss Federal Railways (SBB) during World War II because there was a lack of coal and a lack of electric locomotives. The electric steam locomotive can - when its boiler is heated up - run for up to 20 minutes without an energy supply, like a fireless steam locomotive .
History and structure
The two locomotives were converted from existing E 3/3 “Tigerli” shunting steam locomotives . They were the numbers 8521 and 8522. The SBB locomotives received two electric evaporators, each of which was fed by an associated transformer. The pantograph was on the roof, the main oil switch in front of the driver's cab on the boiler. The two transformers and the evaporators were located on both sides of the circulating sheet. The boiler water was taken from the lowest point of the boiler and driven through the evaporator with circulation pumps. The steam was then returned to the steam dome from the evaporators. The flow rate was 5 l / sec, the hourly amount of steam generated 300 kg with 12 bar per evaporator (together 600 kg). Since the heating current was passed directly through the heating pipes, the voltage was limited to around 20 volts.
The power of the transformer was 480 kVA. A current of around 12,000 A flowed through the heating pipes. Regulation was carried out by adding water using injectors or by interrupting the power supply. The circulation pumps were supplied with direct current of 36 volts from a normal vehicle battery, which in turn was charged via a rectifier connected to a transformer. The entire electrical system weighed seven tons, which made it necessary to reinforce the suspension springs. The actual firing was not changed and a small coal fire was usually preserved so that catenary-free tracks could be operated for more than 20 minutes. The coal savings were still 700–1200 kg per day or around 300 tons per year (300 tons corresponds to a wartime value of approx. 36,000 francs ). Another positive side effect of the electric steam generation was that a cold locomotive was heated up and ready for use within an hour. The conversion costs were around 100,000 francs per locomotive.
The locomotives were used in Zollikofen (8521) and Brig (8522). The electrical equipment was removed around 1951. While the 8521 was canceled in 1963, the 8522 came to the Sursee-Triengen-Bahn in 1964 and is still in place today.
literature
- Alfred Moser: The steam operation of the Swiss railways 1847–1966 . 4th updated edition. Birkhäuser, Stuttgart 1967, p. 269.
Web links
See also
- Steam-electric locomotive by Jean-Jacques Heilmann , picture