For the past three years now I’ve been bringing O Gauge model trains to the local museum. In addition, for the last year, I’ve been doing it as a member of the local railroad club. This will now be the fourth year. I discovered that setup is becoming quite a tremendous task, given the overall complexity of the display. For example, here’s this year’s display.
So, I came up with a new plan: build a fairly small railroad that can be carted out to any location and set up easily. Here is the track plan:
As you can see, I’ve managed to cram quite a bit into a small space. Note the overhead loop–that is missing a section because Trax is broken (still); it’s supposed to be complete. I have a somewhat complex method for wiring it that is largely designed to make it simple to operate. You see, the other day I found three real neat gang switches. They’re the kind with a mechanical label that declares whether they are on or off, and are set up so that when one is pushed down any others that are down go up, thus meaning that it can be in only one position at once. The tracks in the diagram are color-coded by blocks, and I suppose that you’ve immediately spotted an apparent flaw in my plan. If only one block can be selected at once, then a train won’t be able to make a seamless loop even before it runs into deselected trackage, causing it to stop and cycle its reverse unit. Ah, but I thought of that already! My system is that the individual switches select not blocks but instead routes. For example, one button will cause block 3 and block 2 to be controlled by the throttle, thus allowing a train to be run in that circle. This will simplify operation somewhat and is definitely not an excuse to let me use the super cool gang switches.
Anyway. One potential issue is if the same route or some of the same blocks are selected at once for two different throttles. At best, this leads to confusion, and at worst, it leads to short-circuits. Not good! Here’s my simple solution: wire it so that one throttle (the one of the left side of the Type VW) has priority over the other one. That way, when both are selected for the same block, then only the left throttle controls the block. In order to make it clear what throttle is actively controlling what block, indicator lights on the control panel will be color-coded. I’ll use bicolor LEDs: if the left throttle is on the block, they’ll be red, if the right throttle, they’re green (thus corresponding to the lights on the transformer itself), and if neither throttle is on the block then it will be off entirely. This has the convenient side-benefit of showing yellow if both blocks are selected.
The trolley line will be controlled by the thumb dial on the VW, as will the overhead line. I might hook them up to that 18B that I ordered, provided that it works and that I can find somewhere to fit it in. More details coming soon when reality kicks in and ice hits the snowblower (in other words, when I begin work).
