wiring a DC 2 rail double X-over on a girder bridge

What you have is basically the same as an oval of track with a crossover in the middle. The main difference is you will have very little space between each switch and the crossover. There should be no problem wiring the frog on each switch. You should have enough room for proper rail insulation and the frog would be wired as per normal for a hot frog. The trouble is with the crossover. If you could use a crossover with insulated frogs it would simplefly things quite a bit but if you insist on hot frogs you will have to establish some absolute rules.

Travel through the crossover will need a primary route and a secondary route. That is, which ever route is selected the control switches for that route must disconnect power from the other route. Both switches for any crossover route must be switched at the same time. One divergent and one streight is not allowed. The crossover route controls power to the crossover. If you can insure these rules than you will need only one switch for each crossover route to control crossover power.

Al

Al,

Yes, thank you. 

I have done this before with isolated dpdt switches on each throwbar.  However I want to make it idiot proof this time so as to preempt a short. 

Plastic or isolated frogs not  good for this installation.  It is a slow order piece of terminal trackage with small wheelbase power. 

I had thought to use pnumatic control for the throws and slave the micros, but hand throws will be so much simpler, however it brings the human idiot factor into play.

Really looking for that special tinkerer who has devised a work around.

This assembly is on a 35" X 9" removable girder bridge.

Fastrack has a moving diagram for the basic isolation with Tortoise power & DCC.