Larry: The request you posted sounds deceivingly simple, but it's not. I've been a model railroader for over 25 years and have authored 25 published articles on advanced electronic/electrical control systems for trains. The closest to what you asked for was an article I wrote that was in Classic Toy Trains October 2007 issue. This article described running two trains simultaneously on the same loop of track. Oddly enough, I was in our local train shop about a week ago and a customer voiced the same request as yours. My first reaction was: no problem. But when I got back home to my lab and started to work out the details, I realized it wasn't all that easy!
To do what you and that other guy wanted requires several key steps:
1. You need a detection scheme to know where the trains are.
2. You need to switch the two turnouts which feed the siding at the appropriate time.
3. You need to control the power to the correct blocks at the right time.
I am convinced that this can be accomplished and am working on the approach now. When I finish, I will post the the circuit details.
Bob H. Walker
