Superelevating model train track curves is the process of raising the outer edge of a track curve to help improve the stability and the appearance of trains as they round the curve. This is not really required for operation of the train, nor does it necessarily prevent derailments, unless the train is moving pretty fast. In that case, the train does take the curve better with less likelihood of tipping over. It looks more realistic and prototypical as well.
A recent article in Model Railroader by Andy Schnur, titled “Superelevating Flextrack” (October, 2008, pp. 44-45), describes a fairly easy method of doing this that will surely be helpful to those who are considering this as they plan for laying track.
The first thing to do is make sure you have easements going into your model train track curves. The article describes using a long thin spline of wood, and bending it starting at the outside edge of the straight track where the curve will begin and ending at the next piece of straight track where the curve will end. Place a small nail about 6-9 inches into the curve to provide a point around which to bend the spline. Then mark the surface of the layout along the inside of the spline. That should be the mark you follow as you lay your flextrack for the curve. The easement has already been figured out for you by the difference in the tension of the spline as it rounds the curve, with the tighter radius in the center and the gradual increase in the radius as you get closer to the straight track on each side.
To start the superelevation, you have to form a ramp under the outside rail at the beginning of the easement to gradually increase the incline of the outside rail to a level of about 1/32 inch for HO scale, or about half that for N scale (1/64”). To form this ramp Andy describes his method of using masking tape on a sheet of clean glass, starting with a 6” strip of ¾” masking tape, placed sticky side down on the glass. Then take a 5” strip of tape and place it over the first, lining up one end with the end of the first strip. The next strip will be 4” long, again lined up on the same end. Then use 3”, 2” and 1” strips. For N scale, you may only need to use 3 strips to make the ramp rather than 6. When you’re finished putting the strips down, cut the stack of strips lengthwise into ¼ inch wide strips. Use one strip as your ramp on one end of the curve and a second strip for the other end of the curve.
In between the 2 ramps, for the middle of the curve, you can either use a stack of 6 strips cut to ¼ inch wide or you can use a strip of cardboard as Andy describes, using a sheet of 1/32 inch thick cardboard cut into ¼ inch strips about 11 inches long. The cardboard strip can be centered down the sticky middle of an 11’ long piece of masking tape. This combination of cardboard and masking tape can be gradually bent to the radius of the middle of your curve and fastened with the sticky side down.
Next, fasten down the flextrack lining up the outer rail along the elevated strip of masking tape and cardboard combination. Now you have a smooth transition with a gradual elevation along the outer rail of track as you enter into the curve, a continued elevation throughout the middle of the curve, and a smooth gradual decline of the outer rail back to level track.
This will look awesome when you start running trains on your superelevated model train track curves!