This little attic room is exactly 9'-0" (16' long). On the double mainline I opted for 084/096 curve arcs on the far end and 072/084 on the hinged "Drop Gate" entry end. The right side is a Service Yard with Engine House in the foreground. I thought this might give you some idea of what can be achieved in 9' if you favor wide curve arcs for running trains round and round.(photo from Feb 2010, layout was never finished due to illness). Good luck Shane-- you can do a lot of railroading in 9'.
