Freelance 2013

[FCIN]

It is my dream to have a room large enough to have two "ISL"

Reinhard;
I'm also thinking about having a second (actually it would be a third) ISL, based on one of two prototype short line railroads that I'm familiar with and both only have two turnouts on them!

But I admit even in that case I would swap structures etc. to glide on the timeline as I do today

I also like your concept of switching structures, railroads, and timelines. I currently switch railroads when I operate my yet to be completed industrial branch (depends on which of the locomotives I want to use on an operating session), but the idea of changing industries and even era's is appealing.