I know this is a little off topic, but how much power would you need? It shouldn't be too hard to engineer something like that. Right off hand, I can think of a few options (probably quite obvious ones, but it's certainly a possibility, and maybe this will help get you started):

1. Motor-generator combination, driven at fractional speed (of course, you'd have to find a generator that would give you the correct voltage at that speed, and not overload it). Not real good with motors (digital electronics and microcontrollers are more my thing), but I think a 50Hz generator (or motor) driven at half speed should give you 25Hz, at half the voltage and current (or possibly less). You could then use a resistor, a very powerful voltage divider, or (icky solution, but easy) chop peaks using a zener diode to get the correct voltage, if you can't find a generator that outputs that voltage already.

2. Build an inverter for your voltage and frequency:
http://www.discovercircuits.com/C/co-dctoac.htm
(of course, depending on your power levels, the schematics may have to be modified)

3. I don't know if this was covered at the site above, but you could always rectify the AC to DC at the peak output voltage (which is different than the normal RMS voltage) and modulate it by a weak sine wave oscillator. In fact, you could even modulate the sine wave by another sine wave (or some other wave source) to have the lights gradually fade between bright and darker. Or, use a couple long-cycle pulse waves (at different frequencies) to flicker it. There are a lot of possibilities.

If you're referring to the Clean Energy Act of 2007:

http://en.wikipedia.org/wiki/Clean_Energy_Act_of_2007

...I think they've got an exception for specialty bulbs.

Even then, regular incandescent bulbs aren't explicitly "banned", per se. They just need to become 25% more efficient by 2012 and 200% more efficient by 2020. And I'm sure that's going to happen. :)

The most important thing is to get the thing running. At the Trolley Museum where I reside the trolley is run off 240VDC with 2 motors instead of 600VDC with 4 motors do the visitors complain no, and the lower power draw doesn't put as much of a strain on the equipment. And the wiring is not excitedly what I would call vintage ether although what vintage parts were on hand were used in the restoration others were bought off the shelf. I don't know where people expect us to get all the money to do this stuff, as I say if you don't like it volunteer your time and money to fix it.

I'm glad that some people got my point about building a low cost "demonstration" of how the shops were illuminated.

As the owner of an RS-1, and having worked on some other vintage equipment, I have infinite respect for the engineers, designers and technicians that came up with the electrical systems used on the older equipment. They did some pretty amazing things without transistors, diodes, SCRs, PLC,s and many other things that we take for granted today.

However, the units I most recently worked on are intended for use in today's railroad enviornment, and I don't want any inspecting mechanical department types taking exception to older style insulation. They are also getting 26 air, for the same reason; i.e. historical appearance on the outside, but more up-to-date and operator friendly inside.

Finding vintage and proper electrical gear does not have to be expensive - it just needs to be searched for. From my experience with railroad museums as a lurker, it appears to me that many guys limit their searches to the local electrical supply house, or even worse, Home Depot. They will look under every rock in the nation for the proper valves/steam fittings/bolts/whatever, but very quickly give up looking for proper switches/wire/relays/whatever.

Here are some examples that really bug me:

Plastic wire ties. Cheap and easy to use, fast - but they were not used back then. What is wrong with doing a proper job with cable lacing, using the waxed twine? The stuff is still made, and pretty cheap. A 20 dollar roll will last a long time. Dressing up cables with the stuff is no lost art - if you were a boy scout, you have more than enough knowledge about the knots. As a bonus, nobody gets their arm scratched open from ends of wire ties that someone did not cut flush. I think there are even still a few places making the metal ties - or a pair of tin snips and a punch will do in a pinch.

Ring terminals. All that colored insulation on the modern ones really sticks out like a sore thumb. The older types, without it, are still around on this Earth in huge quantities - just ask an old timer electrician, and he will probably give you a bucket load he has had for the last 50 years. Or, if the restoration is for something really old - yes, there are places that still make brass grommets for other uses, but can be very easily adapted for the very old style wire terminations.

Relays. Sure the modern ones are more reliable, but remember that back in the 1920s and 30s, relays were really high tech, and should be treated a bit better than lowly worker drones in the electrical cabinets that hey are now. Most of those old relays are fairly modular, and with a bit of skill, can be repaired by swapping in and out parts. The same can be said about vintage circuit breakers.

Electrical boxes and fittings. No, the stamped metal ones from Ace really are not the same, are they? See my comment above about ring terminals, and bugging old electricians to get them. In addition, old style cast boxes for thickwall conduit can often be reused from buildings that are getting torn down. Ask the foreman if you can pick through the building or rubble for boxes, but say it nice with flowers, beer and doughnuts for the guys.

And there are more things that bug me, but I will refrain from bringing them up. But, with the above three items, note that big money does not really enter into the equation.

As for me and my volunteer time - I spend it mainly with old radios and ships, but am looking to branch out into the railroad restoration world. However, I have mostly been discouraged by the electrical departments.

--
Will