Hi fffrank, your topic caught my interest as your proposed railway has some similaries to my own. My railway is in a loft but the space has to be used for other purposes not exclusively for my railway. I took inspiration from those shelf type railways popular in America, only mine is a landscaped version of. I just wanted a sceanic line for running my collection of BR Blue, and thats all it is. No station, yard, shed or any of the other usual suspects. The two long sides are only 12' the ends 24, but you could just do angled or curved corners. Mostly trees and telegraph poles etc are to the back so less vunerable. The two signals at the near edge are not fixed down so would knock over rather than break. I've used peco points at the crossover so this obviously sets the track spacing. This of course is wider to scale than the prototype, (but what most of us use?) if not using really big radius life like curves. The picture is an overall view which is not it's most flattering aspect, but gives an idea what the aforementioned track spacing is like on 12'.