Mark- I like the yard in the middle with a Wye connection to the mains. This gives you better access to the yard and a bonus spot to turn trains around. Your call on the narrow isles though.
A smaller yard on the bottom as @ctr suggests would be an option. I know it would sacrifice scenery that you were planning but the trade off of wider aisles may be worth it. The yard tracks could be longer so you may wind up with the same linear footage of track.
I don't have SCARM on my computer at work but if you swap the main and passing siding (purple lines) so the main is on the top edge, then the yard may work. I'm sure Dave can whip up a plan for us to look at.
Bob
