How do electric carriage lights on steam trains work?

Question

I do not know whether somehow the steam engine generates the electricity or if it is a battery? And how do they come on automatically when entering a tunnel??

Answer 1

The carriages have bogies under them that is the framed section that holds the wheels the axle is connected thru a gear box to electric generators and the train driver switches them on at the entrance to a tunnel

Answer 2

Quite simply. Often by a generator driven by a dynamo. They would not nomally be automatic but would be operated by the guard.

Answer 3

The carriages have belt driven dynamos which charge batteries so that lights will still operate when the train is stationary. In the UK where we only have "preserved" steam trains running, they always carry a Guard, and it is HIS responsibility to operate the lights as necessary, just as it is the job of the train "captain" or whatever fancy names the operating companies have for what was always called a guard on ordinary main line trains in the UK.

On the London Underground, since they are all "one-person" (driver) operated, the lights are left on permanently whilst the train is in passenger service, thus avoiding the embarrassment of a driver forgetting to turn the lights on as the train entered a tunnel.

Answer 4

The earliest setups had a steam-driven turbine generator mounted right next to the locomotive's headlight.  Passenger cars had, as described, belt-driven generators which served to keep batteries in each car charged up; the lights ran off the batteries.  

You're right about the lights coming on in the tunnels, but it never occurred to me to find out how this is done; perhaps there's a photocell on the switchboard of each car that does this when it gets dark inside the car.

Answer 5

In the British Isles the carriages carry dynamos and battery sets hung from the underframe. The steam locomotives very rarely carried generators, if they did it was for their own running-lights (headlamps).

Some steam engines carry generators these days for main line running to power their running lights and cab accessories such as train-signalbox radio, automatic warning systems and other safety systems etc. They do not supply electricity to the train itself.

When steam trains were in regular main line use it was normal for carriage lights to be lit all the time unless there was a guarantee of no tunnels or night running. Individual seat reading lights have always been under passenger control.

These days the guard will control the lights as appropriate. It would be wasteful of energy to leave them on all the time on a private preserved railway.

Diesel and Electric locomotives, and modern coaches, have very different electrical systems so be careful about making comparisons.

Foreign railways may have many quite different systems.

Answer 6

I can only speak of trains in the US, but here the answer would be all of the above.

Steam engines of the 20th century did have a dynamo but that only supplied the electric needs of the locomotive for lighting.

The coaches' heating and cooling were provided by steam from the locomotive.  This continued ight up until the time the US passenger trains became equipped with "head end power" supplied by the diesel electrics.  The electricity runs through the train supplying all of the power needs.

Prior to this, passenger cars had their own power source mounted underneath, where gasoline powered motors would turn generators supplying that car's electrical needs.

The now long gone caboose operated on battery power, where the generator to recharge the batteries was belt driven off of one of the wheels.  This supplied power for lighting and radio.  Heating was still done the old fashioned way, by means of an oil or coal fired stove.

Answer 7

Hi,

it is most common that each car has its own generator driven by the wheels, and a battery to bridge times, the car is not moving.

Control of the lights in modern trains is by light detectors.

Answer 8

With magneto batteries.

Answer 9

the steam engine has a generator

Answer 10

By a dynamo underneath the carriage