I found the article in Model Rail April by Robin Green (The trials of Treoch) very interesting involving the use of the "Atmospheric Railway" technique to move model trains by suction.
The only thing that was glaring in its absence was mention of how points are supposed to work. I don't know if anyone knows how the real railway proposed to do this!!!
My proposed layout has massively complex points and I can't imagine how to switch tubes properly although the general idea of the system is certainly very interesting.
Luke