Author: Elliot Davenport
Date: August 26th, 2013
If you would like your rolling stock to travel through curves at speeds which were previously not possible, and with minimal risk of derailing, then you may want to consider modifying the curves on your railroad through something which is known as model railroad super elevation. Surprisingly, this is an aspect of track planning that is often overlooked or neglected, but can increase the smooth running of your trains to another and satisfactory level.
Super elevation involves raising one rail higher than the opposite rail through a curve. This results in the train tilting more than usual as it travels through the curve, and the effect is similar to what an airplane does when it begins and completes a banking maneuver. What’s the benefit in adding super elevation to your curves? Not only will your rolling stock be able to travel through the curves on your layout at higher speeds, but they will also do so with a higher level of comfortability.
Given that most hobbyist model their railroads after the prototype, there is no exception when modeling a super elevation. When calculating a super elevation which is based on the speed by which a train will travel through a curve the following formula should be used: Height = 4 * Speed * Speed/Radius in Feet.
When designing a super elevation, you should keep in mind that you do not want the elevation change to occur suddenly. Try to imagine what that would be like if you were a passenger and how that would effect your ride.
Therefore, you should plan the increase in the elevation to be gradual. Along this line of thinking, easement changes happen linearly along the track and this should also be the case with your track work. The ultimate goal for smooth operation on a curve is to increase the radius as well as the height uniformly.
So, just exactly how do you accomplish this when laying track on your layout?
To create superelevation, insert small strips of styrene under the ties beneath the outer rail of the curve. You do not need one under every tie. Styrene comes in many thicknesses; .040 to .060 works well for a bank in HO scale. You’re building a railroad not a race track.
It is important to work up to the full bank using progressively thicker strips through the easement section of the curve. Make the transition as smooth and gradual as possible. Start with .010 styrene for a few ties, then .015, etc. As with the lateral easements, the more gradual you can keep the transition to the super elevation, the fewer operating problems you’re likely to encounter. Reverse the transition process on the other side of the curve.
To access a very helpful PDF report which explains what super elevations are and how to build them click here.