Mark,

Where I live, all the train cars come from coal mines. There are red cars,
grey cars and black cars, and all have a giant CPR logo on them, yet at the
same time, they are all black (dust). The shutters would work for the first
week, then they would be plugged with dust, and the solar panels coated with
dust (Most likely smashed to pieces too!). Go into an office 'on the hill'
with an open pit mine. Open up anything (photocopier, computer, etc.) and
you will find coal dust.

Have a look beside a coal train track in winter. Have you ever seen black
snow?

Also, I imagine there would be people that would be happy to 'liberate' all
those solar panels and batteries :)

- Keelan Lightfoot

>Why make an electrical connection?  (Assuming you have power on each car
>- use a small solar cell to top off a small Lead-Acid battery pack,
>would probably work rather well.)  Use IR for connections, with an IR
>I/O port on the front and rear of each car/engine/caboose, right next to
>the coupler - have a simple shutter that opens when the couplers lock
>together, and you're probably set.  Photodiodes & LED's are pretty
>low-maintenance.  Shutter could be pretty easy to make, actuated off the
>coupler's movement...  I suspect the same location could be used for
>electrical connections, also, using a large spring-loaded plunger for
>each contact, possibly.)  If the shutter's closed, have it connect the
>In and Out pins together, so you know you're at the end of the train.