Here is a photo of the recently installed 'final link' in the mainline sub roadbed, with staging below, and Onondaga Yard on the far side of the studs (which will eventually be backdrop):
And an overview of the Onondaga Yard area, with new roadbed just installed for both mainlines as well as some track and switches with which I was experimenting for yard layout:
Roadbed is now continuous from staging up to the top level. Here is the back staging ramp west of CP 282 and the protective wall (aluminum flashing, stapled to the studs):
I have decided to use traditional cork roadbed instead of foam under my mainline interlockings. The issue with the foam is that it is relatively compressible, and as such does not offer the best support for the switches. While the ride will be a bit rougher on the turnouts over cork, the whole structure will be more firm and I think that will be better in the long run.
Looking 'railroad east' we see the road bed of CP280, ready for mainline track:
And this time, with some loose track placed on top so we can see the general interlocking plant at CP 282. The yard leads are to the left here, and the connector to the eventual shortline to the right:And a few the other way, 'railroad west' of CP282. None of the track here is secured in place, it is just placed atop the roadbed:
Finally, too, with all main line subroadbed down, it was time to place the thru-truss for Nine Mile Creek. I selected a spot on a short tangent, quite a distance from any interlocking, out on the raised portion of the inner curves. The river will come through from behind the bridge to the edge of the layout and flow east along the mainline. I really like the way this looks so far:
The track across the bridge will be Micro-Engineering Code 83 'bridge track' which includes the oversize timbers as well as ribbon guard and guard rails. It comes in 36" pieces, and I won't cut it down until I am ready to finish the track through the area. It's going to look awesome.
I used some scrap lumber cut to size to temporarily support the truss; these will soon be stone abutments, set in place on the plywood. Track laying cannot be finished until the bridge is weathered and permanently in place.
More to come - winter is a great time for layout progress!