> Whoa !!! Slow down a bit.

I'm well aware that the AMTRAK specs are overkill for most tourist operations. Northwest Railcar have quite a bit of info about the system, but nothing with real meat in it unfortunately.

I'm involved with a tourist railway that runs the same sort of services as described, and the design of the system interests me. We're having quite a debate about what is "safe". No system that does not have a "train line complete" circuit can be truly safe - if a cable pulls out of a jumper, live wires could be exposed. Admittedly the hazard at 110v is less than at 480v, but I'd rather not be exposed to either.

FWIW, we run two power busses - one at 24vdc that feeds into the lighting circuits from what were the battery terminals - a battery bank at each end of the train provides protection for lighting if the generator fails or the train parts. The cooking and entertainment power is distributed via a separate system that has a TLC circuit and a switchboard and fusing between the bus and the vehicle appliances and outlets.

I'm interested mainly in what AMTRAK etc have to say about mechanical protection, cable types and protection circuits.

I'm interested in what others use also.

>Take a tip from the airline industry. Airliners have a large number of passengers in a long narrow box in a noisy environment.

You will get better results from a number of small loudspeakers distributed throughout the car than from a single loudspeaker. Four loudspeakers is probably the absolute minimum number for a railway coach. You can put the loudspeaker enclosures in the parcel racks if you don't want to attach them to the ceiling.

THIS IS VITAL: Multiple loudspeakers must be polarized identically. You don't want one speaker cone to move in when the next one is moving out.
You can get sound cancellation and intelligibility problems. The same wire must go to the same terminal on all loudpeakers and matching transformers. Different makes and models of loudspeakers may be polarized differently. You can confirm polarization by using a small battery and observing which way the cone moves. You're probably better off using identical loudspeakers in the same car.

fkrock@pacbell.net

Whoever suggested the 70 volt system is correct. That's what the commuter car manufacturers use, and that's what has been used on PA systems on tourist lines which worked well. Multiple speakers is good. I think we put 6 speakers in the body of the coach, plus one in each vestibule. Also, the inter-car jumpers should be considered almost sacrificial. You want them to stay in as the train rock and rolls down the track, but you want them to be the weakest link when (not if...) somebody uncouples without removing the PA jumpers... Pulling wires out at the terminal strips creates a lot more work than replacing or even making a new jumper cable.

prr8404@aol.com

> Are you trying to make an authentic
> restoration or just fixing up some cars to
> "play" with?

32VDC systems, Get a 32v buck boost transformer, and 4 100 amp diodes on heatsinks. handful of wire, and viola, one nominally 32v dc system.

Trainlines from generators, there should be some sort of protection for it, a circuit breaker or something, that would trip if the train pulls apart and something shorts.

The Strasburg has 3 sources of power for the first class cars, land line, trainline and onboard gen. all interlocked and protected.

Also if you run a 240 volt four wire system, put a small 240/110 transformer at each car to take care of any load balance issues. That way you don't have to pay attention to which car is in the consist as far as which pulls off of which phase. Your power source "sees" the transformers and the phases are loaded equally.

If you have any specific questions feel free to email me.

steve

steve@strasburgrailroad.com

> We have a couple of old passenger cars here
> at the Nevada Northern that we are planning
> to refurbish.

The cars we'll be working on are old SP bunk cars and at the same time I want to update the ex-IC commuter coaches.

NN Ry Coach 5 will be in very limited daylight service only this year.

Thanks

Nevada Northern Railway Museum
nnry1@mwpower.net