Thanks for your kind remarks. I had a loft layout when a child, so this was my first thought, especially as we had the roof re-done last year. However, owing to the truss design, it would mean climbing over a 3' high bracing timber in the middle, the hatch is only about 2'-square, and there would have to be major spending on installing power. I thought a smaller layout, more accessible, would be more likely to be finished, although I would dearly love to have a big 'continuous run'.
The double-slip I considered, but was not sure they were that common in little shunting yards. I wonder now if they are better for short-wheelbase locos than 3-way Insulfrogs. More to post when I can get another few yards of track and finish the sidings. Thank you for giving this your attention. Best wishes.