New layout plan for 2008, revision 4

Staging deck revision 4. Goes with main-deck revision 2. Back to a clockwise-climbing spiral helix. Ditched the reverse loop in favour of a yard lead. Top left corner, the disconnected track is an alternative ladder, same length lead, but it intrudes onto the room by the amount marked by the black diagonal line next to the connected ladder Bottom right corner, helix supports are numbered, entering low at #1 and orbiting at least 4 times, before exiting higher at 5 or so. The clearance at 7 is going to be 1.3", depending on the yard ladder. Red box this time is Workbench, situated about 16" below staging.