That said, friends, here I’m !
I take the occasion of my last weekend experiences ( and very slow progress ) to announce you :
I’ve discover the wheel again!
Then I’m thinking to a “cost effective” (how the marketing peoples call the “cheap” one) and at same time sturdy solution, for the backdrop wall in the middle of the peninsulas. This will be in my mind a “Thin wall” (as Bruce Morden call it ) that separate the outside visible tracks from the inside loop. As a drawing is better than thousand words… see what I’m speaking here right :
I take the idea from the walls of caravans and campers: basically a simple multi-frame made by 1 cm deep wood, covered by a (well two, one each side) masonite layer, and the empty gap filled by the expandable foam.
Here is a sample of what I'm speaking :
You will find this on several home repair shops in a spray big can.
When you spry the foam is soft and you can shape it, but when dry it become “solid-soft” and contribute to the strength of the wall.
The result is a very light but sturdy backdrop wall than , if properly fixed to the bench work, is self-supporting.