Reached another milestone yesterday–the main helix between the main and upper levels is now complete! I have track reaching to 58″ off the floor. Like the helix between staging and the main level, I used what I call the “double pinwheel” method of building a helix (click here for a full write up on the double pinwheel helix). It requires only straight-line cuts, it’s very forgiving of non-precise cuts, and it’s rock solid.
The helix joins the town of St Charles to the towns of Turners Siding, Kemmergem, Monarch and Benedict on the upper level. The grade (3%) starts at the RR-west end of St Charles yard and continues up three turns of the helix. There will be another 15 feet of hidden track before the line emerges, so that’s effectively a fourth turn’s worth of elevation gain after the helix. Of course, when I built the base supports for the helix, I miscalculated something that had the initial grade into the helix closer to 4%. At first I was like, “well, maybe it will work.” I test ran a few locomotives up the first loop (all I had constructed upon discovery), and while my lightest locomotive could still pull 11-12 cars up the grade, I finally wised up and decided to fix it before it became unfixable. After dropping to 3% (lowering all the supports by 3/4″), the lightest locomotive could again haul 14 cars and a cab from a dead stop up the grade, the same limit as the helix from staging. I’m sure I will be glad I made this adjustment in the future! Measure twice, cut once… thankfully it just required loosening and reattaching some screws and only a few new cuts of supports to fix it.
It will be a little while now before I start the upper-level benchwork, but finishing the helix will allow me to install the lower-level backdrop, so the beautiful insulation pads will no longer be visible on the main level. I know that will be a big disappointment to many of you who feel the insulation just adds an extra layer of realism… ok, enough sarcasm. Building helixes isn’t fun for many modelers (including me), so I’m very glad this portion of the layout is now complete!
