The Monster in the Corner, with test train. . .
Whew. Got the helix constructed, after three attempts. It's pretty solidly built--God forbid what will happen if (knock on wood) I get a plumbing leak in the wall void this thing occupies!
After two abortive attempts at building the thing, I took it down to the bare base and rebuilt it, taking care to measure the gradient on the climb upward, a task made quite a bit easier with my Husky "Professional 9"Multi-Function Digital Level with Storage Bag." This tool really made the helix possible to construct for an idiot like myself. Besides the usual visual bubble levels, this thing provides push-button access to a display that provides level in degrees, inches of rise to foot of run, and grade in terms of percentage.
Another view of the Helix. Sorry for the mess!
Husky digital level--invaluable for building a helix. . .
All that's left is cleaning up a couple of track joints, wiring track wiring feeders, and waiting for the upper benchwork to extend atop the helix towards the large circular sub-terminal. At that point, I'll secure the last 4 feet of upper level helix and work the vertical transition. Eventually, it'll all be encased by fascia panels. I'll likely add infrared detection sensors at the top and bottom of the helix for crews to be alerted when their trains are about to re-enter the visible portion of the layout.