Truth be told, sectional track is the main reason I stayed awake in high-school math class. Once I realized that mathematics could answer important questions like “how close to the edge of the plywood will this loop be?” and “how long do I need to cut that fitter section?” it became much more relevant to me. To this day, I carry a calculator with trigonometry functions everywhere I go, just in case a track-planning emergency crops up. Thanks to my enhanced geometry skills, my first book—about track planning, naturally—was well along by graduation time. (I self-published it a year later.) When the time came over the winter of ’21-22 to design a replacement for the Covid-19 Emergency Railroad, I was rarin’ to go.

I wanted the new railroad to be longer, of course, but that’s easy: just keep adding straight track. I wanted an over-and-under figure-eight with a modest grade. I wanted it to be asymmetrical. I wanted a long siding for staging an extra train. I wanted as short a list of track components as possible, with maximum use of the pieces I already had. I reached for Kato’s list of available Unitrack components, my trusty calculator, and a pencil, and got to work. The process is straightforward—lay out locations of the curves, determine the length of the longest straightaway, and calculate lengths of the remaining straight runs.

Whenever a loop of sectional track becomes more complicated than a basic oval, the question of “closing the gap” inevitably comes up. The geometry is almost never perfect, so what, then, do you do? There are several strategies:

• Cut custom-sized fitter sections (or use expandable sections)
• Replace or relocate individual components to achieve a better fit
• Rely on the inherent looseness in the track joints to enable closure

For this impermanent railroad, I didn’t want to cut fitters. I was able to get things reasonably close by tweaking the lengths and locations of straight track. I could have gotten even closer by resorting to Kato’s extra-short straights (they’re now available in 29, 33, 38, and 45.5mm lengths). Swapping in a set of 447/480 transition curves for one pair of 381/414 curves also helped close the gap. I just happened to pick up a package (Kato 20-186) for cheap at the RIT show. All that left me with about a 1-inch gap remaining—not bad for a 40-foot loop of double track. In practice, it closed up just fine.

I had one double-track truss bridge that had seen use on the old railroad, but trying to squeeze three tracks (on 66mm centers) underneath proved to be too much. Luckily, my neighbor Steve, who has progressed from interested bystander to full-on N scale co-conspirator, had also purchased a bridge, so we used that until I picked up another of my own. Kato packages their truss bridges with an additional top chord for connecting multiple bridges together. It goes against good civil engineering practice, but two Kato trusses connected together this way form a remarkably rigid structure that does not need the center pier. That simplified matters considerably.

Once the plan was settled, it was time to fabricate a roadbed. As you’ll recall, the original Covid-19 Emergency Railroad was assembled from short pieces of MDF, assembled with pocket screws and laid out on coffee cans. Crude as it was, it exceeded my expectations, and saw over a dozen sessions across two summers. It did have some shortcomings, though.

• MDF is not weather-resistant, so it had to be taken down after every session. I once left it out overnight, to find the next morning that some light overnight showers had made the panels sag a little.
• MDF also tends to split easily, and the pocket screws driven into the panel ends stripped out over time.
• There was no easy way to compensate for the slope in the driveway. The driveway is “level” for automotive purposes, but not for railroading. As it was typically set up in the summer of ’21, one end of the railroad had a 3%-plus grade, which was too much for my lighter locomotives.

The driveway-railroading concept had proven itself viable to my satisfaction. It was time for a different approach, and I was willing to invest some real money into materials this time. I opted for a semi-permanent roadbed milled from 3/4″ pressure-treated plywood, supported on 4×4 legs (also pressure treated). I drew up the plan, and Tetrised the roadbed pieces onto a single sheet of plywood as best I could. It would have been easy enough to lay out the cuts on the plywood with a yardstick and trammel, and cut them out with a jigsaw. For me, it was even easier to CAD it all up at work on lunch hours, and CNC the parts on the big table. From there it was a simple matter of cleaning up the edges with a coarse sanding block, and cutting some legs to length.

Did I say simple? Did you believe me? Actually, it was anything but. I laid out the roadbed pieces in their intended location, a little further up the driveway, alongside the house. I determined the locations of each supporting leg. I established the desired elevation of each point on the track plan, to ensure desired gradients of 1% (on the long side) and 2% (short side) leading up to the bridge. I set up a laser level, measured the actual elevation of each leg location, and added the gradient offsets. Then I cut the legs to length, and installed them, one by one.

Yeah, too much math. But it was worth it. In the end, I got a nice level straightaway with a siding, and even slopes. The heavier trains go on the inside loop, and the 1% ruling grade doesn’t tax the power too much.