Jan posted:Go with the largest curves you can fit in. Here is a double mainline with O81/O90 curves. The right side restricts using larger curves. The 90 degree curves could be replaced with larger curves.
Jan
I like Jan's double-track concept. And concur with his suggestion on using the largest diameter than can fit.
I would drop the idea for the jut-out in the center, as you will need space for operators and builders to move around comfortably. The 3'-wide aisle width is good, but you need more than just aisles IMO, you need space for two or three operators and visitors to move around the layout. So retaining a larger open operating and train-watching area in the center will add value and enjoyment, more so than the added scenery or industry area.
