4x10 FasTrack Layout Wiring

Maybe a dumb question here, but if you want the two loops isolated, I don't understand the need for the SPST toggle switches? What would they do and when would you use them? I run only command control and have 2 isolated loops and no toggle switches.

I am not all that knowledgeable on conventional operation, but my understanding was to try and get the two loops set to nearly the same voltage before crossing them with a train. Once crossed you could then run different voltages (speeds) on each loop without problems.

Having a toggle on your two spurs makes sense as you could then park engines there and power them down with the switches. I think you would really need one switch per spur to have it work correctly though. I do that on my layout too.

I would only use them if I was operating one train and wanted to go back and forth between the 2 loops.

Maybe I am missing something here, but I still don't see the need for the SPST switches between loops? You just set the two handles to similar voltages and run the train from loop to loop.  

KW posted:

I would only use them if I was operating one train and wanted to go back and forth between the 2 loops.

You only need insulated gaps, then.

If you are going to run like you propose, you are much better off using a 2 station version of Cab Control using SPDT center off toggles to select which side of the ZW-L powers which loop... inside, outside, both or none.

All toggles up, all power comes from "A", all down from "D", or choose any combination as you wish.

Red is center rail, black outside rails, the breaks in the red rails indicate insulators for block delineation. This shows three districts(loops), you can start with just two as you have pictured & add as many as needed.

Thanks.  If all the "U" posts on a ZW-L transformer are connected internally, can I use one common bus wire for ground?

I think that's what the diagram is showing. 

Can any 14 volt accessories with power from the "B" or "C" terminals also connect to that ground?