Derailment-free Curves
- 5 minutes ago
- 2 min read
Having a smooth flow to our curves is essential to derailment-free operation. However, once a curve exceeds 90 degrees, a problem arises. A single, three-foot-long piece of flex track isn't long enough to span the entire distance. At first glance, the solution would be simple enough: just join two pieces of track together. Unfortunately, it's not so simple, and attempting to do so is a recipe for a train in the ditch.
Try as you might, you will, without fail, have a kink at the joint as soon as you start bending the track. The chance of derailments at this point is pretty much one hundred percent.
Here’s the solution. Take two, three-foot-long sections of track and lay them straight on your workbench. Connect them with your rail joiners. Add a drop of flux and solder the connection (both joiners). This is the one and only situation where you solder your joiners. Do not solder them anywhere else on your layout. You need the rail to be able to expand and contract. Note: flex track has one rail that is “anchored” in place and one rail that “slides”. Put both “sliding” rails on the same side and on the outside of the curve.
Here you go: a smooth joint. Problem solved. I would likely make a few quick passes with a jeweler's file on the inside joint for good measure.
If you're running four-axle power and shorter rolling stock (say, sixty feet or less), a 24-inch radius curve is more than enough. In these situations, another option is to use Atlas' 24-inch "sectional track" PN 536. The rigid nature of sectional track will keep the kinks from showing up the way they do with flex track.
Most layout rooms, even fully finished ones, are subjected to environmental changes in heat and humidity. As a result, there will be subtle expansion and contraction in both the bench work and track. If you don't account for this, it's possible that at some point you'll get a "pop-up" on a curve. It won't be on all of them, maybe not immediately, but over a span of several years it's something to watch for. Assuming you laid your track on plywood (many of us use extruded foam), it doesn't hurt to spike down the curves using the center holes you see in the ties. The Atlas track nails above (#2540) work well. I generally don't bother with nailing track down in other areas.
Finally, try to avoid going directly from a curve directly into a turnout. Doing so risks causing the occasional derailment, especially if you're running at any speed. Put a short section of straight section between the two as a transition. Shoot for something in the range of four to eight inches. Whatever your design will allow.
