I started construction at the beginning of the month. It took a while to decide what benchwork method to use, and on the bottom level I’m using 2×2 legs, 1×3 with 1×2 flange L girders, and 1×3 joists. I’m starting off by building the peninsula, as the walls need to be finished and THERE ARE NO ELECTRICAL OUTLETS IN THE ENTIRE ROOM. This thing won’t even be operable until next year.
Attached photos: I started the 4 sets of 2 L girders by putting together the 2 sections nearest the helix and getting them on their legs. Next up, I did the close set of L girders and legs, then stood everything up and added the final set suspended between them. I eventually added 3 more legs that I thought I didn’t need…such is life. I may yet add two more under the long section, it’s not quite as rigid as I’d like. 3 of the 4 sets of L girders are butt-joined together, but the fourth is underneath the other 3. It is logically a higher one as the railway climbs 4″ to get onto it, but McCormack Creek sits there…and that bridge is over a hundred feet high.
One thing I learned…BE CAREFUL GETTING EVERYTHING LEVEL! I ended up shimming 4 legs, and even that wasn’t enough. My skinny section wasn’t level, and I was lucky to have my joists the way they were – I was able to torque that section until it was level and make 2 butt joints between joists to make sure it stayed that way!
Onto the helix: It’s made from 5/8″ plywood with a 17″ inner radius and 19.5″ outer radius. It’s supported by 3 pillars that come up from the joists and have 3/8″ deep notches cut into them every 3 inches. This gets you a 2.65% grade. The lowest sections are joined with wood blocks, but the upper sections use something else to assure clearance – you’ll see more in a later post! I attached the angled pillars using a section of 2×4 mitre cut to 45° and fastened to the joist.
One thing I did from the very start was number everything. With 6 L girders of differing lengths and 21 joists in this section, they were bound to be mixed up otherwise!
Anyway, the photos show my progress up to now. You can see the different bits of bracing and legs I’ve added as time goes on. Now all my joists are in place and I’m moving on to roadbed!
Full resolution links to plans:
Photos, chronologically ordered: