Over the last few years, I've had the opportunity to design a number of multi-deck layouts. Sometimes one of the major challenges is figuring out how to hold the dang thing up. The areas around the walls are straightforward, of course, some sort of bracket usually works well. But the island and peninsula areas can be a bigger puzzle.
This becomes even truer when I'm working with upper and lower decks somewhat independently. It's easy to make a change on one deck, forget to reflect it in the other at the moment, and only discover much later that you've created "no visible (or invisible) means of support".
There are oodles of doodles on the Internet where layout design neophytes posit extensive gravity-defying multi-deck islands and peninsulas. Not only does the 3D model railroad layout design CAD allow these folks to draw untenable decks, but also to view them from impossible angles. This makes these unbuildable designs appear deceptively practical.
But it's not just limited to layout design tyros. I've been involved now in a couple of large layout projects where an otherwise innovative design lacked only one thing: a way to support the upper deck! Eventually, these layout owners resort to all manner of skyhooks and other appurtenances when the ¼" wide masonite backdrop on the lower deck proves unable to bear the weight of a few hundred pounds of plywood and plaster. How much easier it would have been to design in proper support from the beginning – but even experienced designers hate to give up lower deck real estate for upper deck stability.
For my own part, I've learned to use CAD to my advantage. I often use a straight or curved studwall to support backdrops and upper decks in island and peninsula areas. Once the general footprint of the design is defined, I'll draw in a rough location of the studwall in its own CAD layer. By keeping this layer visible and on top of the other layers most of the time, I avoid paining myself into an overhanging corner (to mix my metaphors.)
Multi-deck designs have been a great addition to the layout designer's toolbox. But applying multi-deck concepts thoughtfully includes always keeping track of what's holding them up.
I've written before about one of my favorite streaming Internet audio channels, Devlar Surf Sessions on Live365. Modern instrumental ("Instro") Surf music includes such subgenres as Spy, Space, and Tiki along with terrific band names such as the Atomic Mosquitoes, the Aqua Velvets, and the X-Rays. I thought this stream was being discontinued, but I've had the good news that it will carry on. So an even heartier "Thanks for the cool waves, Dude ", to programmer Ray Dukes. Definitely worth a listen.