I guess it depends on what you’re trying to accomplish with your block control. I’m making my tracks compatible with block detection because I eventually want a working signal system, grade crossing signals etc. I find that most of the folks who run Battery/RC tend to run their trains with some variety of “direct supervision” … meaning if it’s time to stop, someone’s applying the brakes. Whether that’s because you’re using TWC / Form D / Block Stations or an automatic block system of some kind that displays a stop signal, the person running the train has to stop it. That, by the way, is probably the “smartest” form of multiple train control system out there (although, indivisual components have been known to fail inexplicably and cause disasters!) On my railroad, the signal system will require whoever’s running the train to see the signal, and take appropriate action … there is no Positive Train Control planned or expected on the line.
Now, if you mean some kind of PTC system where the signal system, or other block logic directly causes the train to stop as it approaches the occupied section, you end up with larger challenges with battery power than track powered systems (here I include DCC as a track powered system) because when it’s time to start, stop, or change something, you have to do someting to communicate that fact to the locomotive without using the track … not impossible, certainly, but requiring some more creative thinking. DCC at least allows communication with each locomotive individually, but as you’ll see, figuring out who to tell to stop can be a challenge even to DCC users who would implement an automated system.
Here’s one version of human brain controlled trains with a visual signal system involving no track power … the “key” here works more like TWC than anything. (signal stuff starts at about 5:00, but the whole video is worth watching.) http://www.youtube.com/watch?v=dW3mWF2WCyM
Note that he still has to stop manually.
To make this work, your “controller brain” has to know a few things:
1.) Which section is closed.
2.) Which train is approaching the closed section?
3.) How do I tell which train to stop, and which train to move?
This is a little easier with trains than other forms of transportation, because without a passing track, if the line runs from A to B to C, it’s pretty clear if train 1 leaves A, followed by train 2, that Train 1 will arrive at B, and then at C followed by Train 2. So, if the block from B to C is occupied, it’s pretty clear you have to stop train 2 at the entrance. The trouble comes where sidings allow trains to change places on the line. If there’s a passing track at B, and train 2 passes train 1, then the system has to know, now, that when train 2 gets to C that it’s now Train 1 it has to stop as it approaches to avoid a collision. That’s a lot for machines to sort out, especially if there’s no fixed rule on which train will proceed and which will stay … in other words, it’s easy to make “programmed” train running, but a system that’s dynamic and runs without a fixed sequence of events is not so easy if you can’t simply shut down the track. Even trains powered by DCC, without special equipment to report to the system which train is in which section, will have difficulty figuring out which train is approaching which block, and should therefore do something to respond to its environment.
RCS used to make a thing called the “Boomerang” … and there are other similar things around (Del Tapparo also makes one, I think…) where a battery powered train could be programmed to respond to magnets along the track … if you could make the red signal turn on a magnet, you could probably stop a train at the signal … but starting it back up again when the signal cleared might be a challenge.
It can be done … but you’ll have to be very inventive.
Matthew (OV)