Turkey Hollow Dan filled in some more detail of what I was getting at. My Plans B and C had turnback loops with 042 track. The first concept was to build a rollout section to clamp onto the stationary layout to give me access to the back side of the loop when necessary. The prototype actually worked. The second concept had the same end loop, but two stacked on each other for an out and back. I finally decided I didn't like the depth of either, and went with the around the room with a lift up bridge to get into the center of the layout.
Dennis has done a fine job building his layout in stages, and yes he has to work around his attic room. His addition with a loop into his knee wall has worked out well, and it is surprising how he has good access. I am not like him. Though I only weigh in the 170s, with one replaced knee and lumbar fusion, there is no way I am going to be climbing up on things anymore. Believe me, in my working days, I was always climbing up, over, into tough spots. Those days are done, and I built high enough that I can wire sitting on my little two foot-high padded roll around work stool. 
