Another ATSF Admirer

Helix Construction, drawing spirals

Inked in black the "cut out" lines, including between each track centre for the spiral proper, as well as around the inside of the spiral. The outside requires a little more thinking to see where the exits lead off and where the door will hit if it is too wide!

Helix Construction, drawing spirals
Another ATSF Admirer, Apr 26, 2008