Independent Yard Wiring and Operation
Using two SPDTs, what's the proper way to wire them so that that one yard (south) can be operated independently of the other yard (north) - and independently of the mainline direction center-off DPDT?  Note: The double reverse loop operations are controlled by a mainline direction DPDT and a reverse loop DPDT, an operation that functions flawlessly.  I realize I could probably use SPSTs for this, but SPDTs are what I have, so no need to mention them. My layout is DC.

As you can see from the attached PDF diagram (a single red line = one rail gapped; two red lines = both rails gapped), I've gapped one rail of each yard between the end of turnout #10 that leads directly into the yards and the end of the yards.  However, when I connected a wire from the center-off SPDT's center lug to the gapped rail in its respective yard and a wire from one end lug of a SPDT to the track power and flipped the SPDT switch, the loco moved in only one direction.  I had to flip the switch on the mainline direction DPDT to get the loco to move in either direction within the yard - an extraneous motion I want to eliminate so that I only need to flip each yard's SPDT switch. 

My objective: to make each yard either "dead" or "alive" and electrically separate from the other - and the mainline DPDT.    

Earlier, in addition to the above two-wire trial, I had also connected a third wire from the other end lug of the SPDT to the center, power supplying lug of the reverse loop's DPDT, which resulted only in a current spike and no movement of the loco.

Obviously, there's interference from the mainline DPDT.  How do I break free of it?

Thanks for your help!

Attached Files
.pdf   Great Northern Wiring Schematic (Sept., 2018).pdf (Size: 474.68 KB / Downloads: 313)
Without studying your diagram too closely, I'm going to suggest that you gap BOTH rails to BOTH yards and use the DPDT switches to switch the yards from mainline power to yard power.

Then, you are going to need two or three power packs or controllers so that you can keep things moving on the mainline and both yards.
Ron Wm. Hurlbut
Toronto, Ontario, Dominion of Canada
Ontario Narrow Gauge Show
Humber Valley & Simcoe Railway Blog

So, if this small layout (5' x 7') and diagram were yours and you wanted to set it up exactly as I wish to do and for the objectives I wish to obtain to be able to run two locos simultaneously (in and out of the yards and for a short distance within a loop) and the yards operate independently of each other and the mainline, how would you wire it? What you suggest seems like overkill. I also don't have the need or space for additional power packs.
I have always found that it's far easier to gap both rails and use DPDT switches.
Also. if you use one controller you'll still only be able to move 1 loco at a time, since they all move at different speeds.
~~ Mikey KB3VBR (Admin)
~~ NARA Member # 75    
~~ Baldwin Eddystone Unofficial Website

~~ I wonder what that would look like in 1:20.3???

That, however, is not the question. I successfully wired an identical yard configuration on an identical layout exactly as I'm trying to do again here - with two SPDTs, one for each yard - but have torn it down and can't get what I believe to be the same wiring scheme to work here. Can you help with this?

Problem solved!

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