In order to get swappable loads, I need to not only get the stake pockets all aligned, but also the side sills the same distance apart and aligned relative to one another. I should count my blessings that these cars do not appear to have end pockets!
I had thought that simply building all cars with identical side and end sills would achieve this alignment, but then I realized there could be minor errors in width or squareness that would throw everything out. What I really need to do is to build the flat cars so they all fit the same load. Likewise, all the loads should be built around a single flatcar.
So, I put together two jigs that I am pretentiously calling the canonical flat car and load (proper engineers probably have a name for such things). These jigs fix the locations of the stakes in the case of loads, and of the stake pockets in the case of cars. The “flat car” is, of course, not an actual flat car, but merely a piece of styrene with the pockets in the right locations. Similarly, the “load” will never travel the rails.
Now, I don’t have any issue with loads having to always be aligned in one direction – I can mark their orientation on the bottom. However, I was tickled when I was able to put the “load” on the “flat car” backwards, and it still fit.