Construction: subroadbed continues

Work continues. I've got most of the main line spline subroaded laid out now. I can't join it to the helix until the helix is built to all 5 levels, and I can't build the helix until I get my order of track in. I also can't exactly position the subroadbed for the sidings and spurs until I get the track in, so I'm a little stuck until the end of the week. Nevertheless, I have experimented with attaching two sections of cork roadbed; one with white glue to plywood in the helix; the other with white latex caulk to the splines. The caulk is admirably tacky, it takes very little effort to keep it in place in the correct alignment.

I attached a rough printout of the planned 4-foot truss arch bridge (to be based on CPR's Stoney Creek Bridge). It gives some sense of the chasm to be spanned. I remember there was an excellent article on building exactly such a bridge in the April 1991 issue of Model Railroader Magazine. Unfortunately I sold my 50-year collection of MR about 10 years ago, now I'll need to find a copy of that issue somewhere (although I can always order from the publisher if the train shows don't yield results).