I was wondering what steam trains did for electric power in their coaches. I know that in the early days there was none, and that oil lamps were used. But it doesn’t make sense that steam-powered trains still used oil lamps into the 1930s and 1940s.
So how did steam engines/trains get electric power to the coaches? Did the steam engines somehow have electrical generators included on them, or was it necisary to have a power car on the head end (essentially head end power with steam heat)?
With very few exceptions, until the conversion by Amtrak to head end power, passenger cars had an axle driven generator that was sized to recharge a large box of batteries hung under the car, provided the train operated at a nominal speed. The power came off the batteries/generator. There were receptacles on the side of the cars for “shore power” connections in large stations. Shore power was ac, and it operated a motor that was tied to the generator, so that the batteries could be charged and the lights and any electrical A/C could be operated during layovers. In some cases, the generator and motor were combined as a rotary converter or similar (usually referred to by crews as a “genemotor”).
Clearly the cars with all-electric A/C (as opposed to Waukesha Ice Engines, that ran on propane, ice, or the Pullman Mechanical and steam ejector systems) put a large load on the batteries when the cars were rolling very slowly for long periods or were stopped.
Railroads tried to connect the cars together so that the battery power was shared over the entire train. This practice was and is referred to as “trainlining”. This was done by plugging in large cables to receptacles located on the end of the car just inside the top of the diaphragm. Trainlining required that all cars be at the same battery voltage (which is dc, not ac). One of the big problems encountered when using pool equipment from several lines and when Amtrak came along and permanently reshuffled the car fleet is that not all railroads used the same voltages. Common voltages were 32, 64 and 120 volts dc. Mixing up these cars in a consist meant they could not be trainlined, leading to all kinds of enroute reliability and power failure problems as batteries in individual cars died.
Hope this helps.
That helps a lot. That must have been a pain to maintain, especially with the need for a motor or generator mounted under each passenger car. That must have really been a large expense to maintain, but I think electricity in the passenger cars was a must.
It was. So was the diversity of A/C systems, and the lack of commonality of parts, requiring large inventories and diverse car service personnel. However, remember there was a huge car fleet (over 8000 Pullmans alone in service every night) that led to significant economies of scale, plus shop forces were trained and available to build lots of equipment from scratch or reverse engineer a part, if need be.
That situation can never be duplicated under today’s economic constraints.
While railfans complain about the uniformity and “boring” aesthetics of Amtrak trains, the purpose (at least on paper) of the uniformity was to reduce the parts inventory and simplify maintenance. This has not worked as well as it could, and there is still a lot of diversity in the Amtrak fleet. This runs costs up.
Well, yes, they do. They have turbo-generators. They provide current for headlights, marker lights, number boards, cab lights, gauge lights, ATC, radio, etc.
On the C&NW, for example, steam locomotives in commuter service had additional 12kw turbo-generators fitted to supply the coaches with electricity.
All the best,
Mark.
The B&M also had a lot of steam locos equiped with generators which fed the train lines for lights in the commuter coaches. This practice carried over to the early diesel days when some of the GP7s had a head end generator as well.