I’ve been completing the patterns for the laser work. These are pulled form the 3d model, and exported into 2d autocad.
The actual files will be cut in cardstock, .17 acrylic, .03 styrene. The 1" foam will be cut per cardstock templates.
Lots to be done, but I wanted to show some progress… And sometimes it’s all on the computer.
Of course …He’s Devoning … 
Here’s the final design / install plan. I’m posting this to have a place to come back to when I forget what the heck I’m trying to do.
It’s much simplified, mainly in the removal of railings and refuges.
As-is
Structure rework / post removal
First set of pier jigs & piers (suspended from existing plywood deck)
Second set of pier jigs & piers, all posts removed (1st set is holding up existing plywood deck)
Piers done; jigs and plywood deck removed
Meanwhile, indoor construction of the trestle (on a foam base replicating the in-place piers)
Bents installed on the layout
Deck installed on the bents
At least, that’s the plan…
More to come in 2023… 
Some notes on what I just wrote.
I’m trying to finish a number of yard and lighting projects, which take precedence. But I really need to get this trestle done! So the interchange here helps motivate me.
This process has been all about forcing everything into known geometry, from both the site side and the workbench side, to the degree possible. I can’t afford 3D laser scanning of the site, but have tried to get a reasonably good data set with template-based measurements.
The 1/2" nominally thick cedar slabs beneath each bent will be adjusted to suit the tolerances.
The pier jigs are greatly simplified, basically down to pieces of acrylic representing the pier top surfaces, all suspended from the existing (and still quite accurate) plywood deck.
For the pier form, I’m planning on using Precision Plastic sheet, cut in ~2" tall strips and bent around that suspended acrylic rectangle. The PP sheet will be from stock obtained from both Bruce and Ken.
The benchtop build base will be cut from lasered cardstock patterns (you can’t cut that foam directly with a laser).
Bent jigs will have lasered parts. The deck will have a laser cut / marked template.
ALL wood parts will be hand-cut and assembled, from ripped cedar. The 100’s of feet of cedar ripping will be done by a Grizzly 14" bandsaw, now on order.
Joints will be using TiteBond II (I’ve read it’s better than III for outdoor use??) and a pin-nailer.
Rail will be code 332; no guard rails; hand spiked with a spiker tool Bruce gave me (thanks Bruce!!) and steel spikes Rooster gave me (thanks David!!).
Well, that’s the plan.
Cliff
But, WHERE is the band saw??? 
It’s ordered, but no tracking info yet. For all I know it’s talking to the traveling outhouse…
[next day edit] It’s in St Louis now, woo hoo! Which reminds me, I should install a heavy eyebolt in a garage ceiling joist for a come-along. This thing weighs a ton (well, 200lbs) and I’ll need to set it on its wheelbase (which is shipping separately).
Be sure to buy a cast lifting eye, not just a bent one. I’ve had the bent ones open up on me at the most inopportune moment 
Ooohh, yeah, great point Jon, thanks.
I made the base assembly jig today. It’s in 3 sections for convenience now, but the 2 curved sections will need joining when the bent stringers and outer braces go on.
Also did the template for the deck (foreground, in two sections) and pier jig placement (coiled up).
The deck template is upside down, and has very faint lines for stringer placement (not sure if they’re visible here). But the plan is to sick the ties into the slots and install the stringers per this template.
This could have been done on a 1:1 print form a local printer, but I had the cardstock on hand and the laser to cut and engrave it, hence the cutouts for the ties.
I’d like to make this in two sections, and install it onto the bents after they’re parked on the layout. Not sure where to make the joint yet though, since all the stringers leapfrog past each other.
If I have to make the deck all one assembly, I might make a plywood build-base for it, to get it out to the layout without breaking to bits.
Cheers,
888:> Cliffy
All good ideas! Following along to keep the pressure on!
That’s why I don’t post the “to do list” here any more. 
Thanks Jon. 
I lasered the parts for the 3 bent jigs after work today, here they are loosely arranged. I predict lots of stripping and bonding time ahead. Referring to the plex, of course.
That far sheet started its second life as a scrap from your shop Jon, which travelled to my digs by way of the generous Mr. Marconi.
Finished gluing up the bent jigs yesterday, and wiped in some india ink to make the engraving stand out better.
Today I finished most of the part peeling and pre-assembly of the pier-casting jigs just now. Need to cut a bunch of 3/4 pvc pipe for them, and that’ll be it for those.
For the record, all this sheet stock was scrap from other projects.
Bruce, the bandsaw came in late yesterday evening. Since they had to bring it on a big rig and do a curbside drop-off, I horsed it onto a dolly there and eventually got it down our long driveway and in the garage. So here it will abide until probably the weekend.
And yeah, it is heavy! 200 lbs.
After the 3/4 pipe cutting, the other jiggish thing needed is the OSB “J” for the deck template.
Then it’s bandsaw time. Except that has to fit between concrete block curb laying time, which I’ve not belabored the thread with since it’s not directly related to the layout.
Cheers,
88::> Cliffy
Maybe this will help
Thanks Sean. That and Jim’s links will certainly be helpful.
The pier-setting jigs are now done. They’ll hang from the existing plywood “bridge” and locate and set the elevation & boundaries of the piers, hopefully with reasonable accuracy.
After the trestle is done, you can build a pipe organ!
Just amazing stuff!
Very nice!
If you do, I’ll send O.D. to play it!
OK, you guys made me look… and yep, it’s a thing…
About those piers. The plan is to set the tops of them using the plex jigs. Each has a 2-layer (.34" total thickness) plate being lowered into place.
Around those, I’m intending to make little boxes of Precision Plastic “coursed stone” patterned sheet. Held together with painter’s tape, cut to suit the concrete terrain when needed. Sounds so easy…
Then pour the plaster through the obround holes in the plex, and later removing the PP plastic. It won’t be pretty, since the PP backside isn’t meant for use as a form. But it’ll be close enough I think.
Bruce, that’s your plastic there. I needed 2 more sheets, and fortunately found some at oakridgehobbies.com. Got their last 2 sheets of this particular pattern!
