The Saturday gang was over to test out all parts of the new extension to Curlew and Darestof following the installation of the DCC auto-reversers and other wiring. Many thanks again to John for capturing the day in pictures.
In May, I attended the NMRA Pacific Coast Region convention in Sacramento, followed by the joint UP/SP historical societies’ convention in Ogden Utah commemorating the 150th anniversary of the completion of the US transcontinental railroad. It seems that while I was gone the Saturday elves were hard at work in my absence, working to get the portable end of the line section known as Darestof installed in preparation for VanRail in September. What is not evident in the photos is the amount of stuff that had to be moved to make room for the new L-girders and benchwork to support Darestof. The event was recorded once again by John.
They did leave me to install the track to connect Darestof to Curlew. I didn’t want to compromise the design of Curlew just for VanRail, so the very end of Curlew was left unbuilt so that we could join it temporarily to Darestof. Once we continue along the wall and move Darestof to its next location, the south end of Curlew will get finished. For now, there is lots of track that has just been nailed down instead of glued.
Darestof was not the only location where the elves were working. The sawmill in Curlew needs some sort of a log pond, so the trusty sabre saw was put to good use to cut out the plywood. They installed another piece lower down for the pond bottom.
Many thanks to the guys for doing this to advance the construction, and to Suzy for inviting them over in the first place! . There was considerable consternation amongst the group that I may be mad at them, but why would I be, after they did so much to help me.
Once all of the cork roadbed was in place, the track was installed using the normal latex caulk as a glue. The mainlines are Peco code 83, and some of the sidings and spurs are Shinohara code 70 from way back when.
One corner of the layout just begged for a mine to fill an otherwise empty space, so some ideas where tossed around. It quickly became clear than a simple spur off of the mainline simply would not do, as it would be rather boring to switch. Stop, pickup a couple of cars, drop off a couple of cars, and carry on. Ho, hum.
An alternative presented itself in the idea of a short branch line heading back north from Curlew to the mine. This would represent a distance great enough to require a dedicated train, complete with caboose, to switch the mine. Even though the distance is not great, and the number of cars low, all of the elements of a branch line train would be there, to add operational interest.
Once again, the CAD program helped to plan what could actually be done in the small space, without sacrificing too much on curves and grades. It quickly became apparent that a small run around track plus the mine spur itself could be squeezed in, resulting in about three cars to and from the mine.
After all of the work that went in to installing the joists and risers so that the section would be level, the stars conspired against us in the form of warped plywood. This is the tale of that pursuit.
But first, a bit of background on my usual construction methods. All of the sub-roadbed so far on the layout is composed on two layers of 3/8” fir plywood, laminated together from narrow arcs and straight bits that fit under the tracks. With this approach there are no splice plates per se, as the plywood pieces form a continuous two layer sandwich all around the layout. This has proven to be a very good approach as can be attested to by the lack of running issues on the rest of the layout. One problem with it, however, is that the areas between the tracks are wide open, and more bits have to be pieced together to fill in for buildings, etc. This was quite a job under Grand Forks, as it seemed that I was always adding another bit to support something or another.
And then the bright idea hit me! For Curlew, as it was all going to be completely flat so as to facilitate switching and not having cars roll away from the operators, I decided to try laminating two layers of large sheets of the same 3/8” plywood, in the hope that I could get a nice flat area for both the tracks and the town, all at once. All of the plywood these days seems to be warped in one way or another, and the best that I could find locally was no different. I have always glued the layers back to back, so that any warps should cancel out. This has worked very well on the thin strips used before, so I assumed that it would be similar for the larger sheets. Well, it seems that I was wrong. Once everything was glued and dried, I noticed that there were in fact a few places where it went up and down, and not just a tiny bit. My guess is that the dynamics of the wood are different along the edges than in the middle of the sheet as the worst spots are where there is a joint on one side or the other. The three big main pieces were all offset from one another to avoid having adjacent joints on both layers. While this works well with the thin strips, it seems that it doesn’t for large sheets. At one spot the two top sheets curl up a bit making a cusp, even though they were screwed and clamped together as flat as I could make it. Earlier posts show the lengths I went to to clamp them flat.
Ok, I thought, no real problem, as we can sort it all out when the plywood gets screwed down to the risers. They can be adjusted upwards and downwards to fix bumps or dips. John’s pictures show the effort that went into getting the many risers attached at just the right elevation, by using the laser level (thank you very much!). Again, it seemed like a good idea to all of us at the time…
I quickly realized that I needed some specialized tools to see just how warped the plywood was. I devised some targets for the laser level that show if any point on the plywood is at the correct height or not. I realized that using the laser on the edge of the plywood is not good enough when it is wide and may be cupped. I came up with a two step block idea where the goal is to split the beam on the edge, with the upper half of the beam hitting the second block. That one is set back a bit, so it is easy to see if the beam is only on the lower block, (too high), only on the upper block (too low), or split between the two (just right). I will make up some from high grade birch plywood so that they are all the exact same thickness. I had to hunt through many pieces of my 1×4 supply to find a bunch that were the same thickness, so it’s time for a special tool.
The first task during the week was to glue the two layers of plywood together so that they all formed one big continuous sheet right around the corner. Sounds simple enough… It was at this stage that it became apparent that the warping in the plywood was quite strong and even though the plywood was weighted to try to remove the warping as the glue dried, this was going to be a problem. More about that later.
The next step was to locate the permanent joists so that they would not interfere with the track switch machines. Gordie’s marvelous paper layout drawing was again taped to the plywood, aligned with the registration marks, as it would be placed and removed many times.
Early February 2019 saw the real start of construction for Curlew with L-Girders and joists, followed by plywood sheets cut to fit the corner and the curved wall. Thanks again to our trusty recorder, John, for many of the photos.