Building A Model Railroad Super Elevation



Author:  Elliot Davenport

Date:  March 26th, 2014

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.

By incorporating super elevations into your track plan you’ll accomplish another element which is vital to your model railroad, and that is another highly realistic detail.

The next time you’re out for the express purpose of viewing a prototypical railroad you’ll observe that super elevations are present on more curves than you may have noticed before.

They’re added because they, as previously mentioned, allow trains to travel through curves at much faster speeds than a standard curved track, and just as important, they reduce wear-and-tear on the cars themselves.

Why add a super elevation to your railroad? Consider this: The real trains your\’re modeling yours after are quite heavy and they really only want to travel in a straight line. Subsequently, just as with your models which have to travel through even tighter curves, trains will fight this unnatural centripetal force which increase the possibility of derailment, and certainly makes it necessary for the engineer to slow the train down, as you will have to do with your locomotives and rail cars.

Given that you’re fighting a similar problem with your model railroad, the inclusion of some super elevations will significantly reduces these potential problematic issues (derailments)for you as well.

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.

How To Create A Super Elevation For A Model Railroad

Start out by determining where you want to add a super elevation on your layout which may include more than one location. Having made this decision, the next step simply 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.

This can be done by using styrene strips which come in varying sizes (typically .040 to .060 works well for the HO scale as an example). Take the styrene strips and insert them under the ties underneath the outer rail of the curve. Note that it isn’t necessary to place styrene strips under every tie.

What you want to keep in mind is to gradually use thicker strips of styrene through the easement section of the curve. The goal is to make the make the transition as smooth and gradual as you possibly can. Finally, as you work through the curve or transition reverse the process.

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.
A Word About Easements

Easements are part of and play an important role in the curves on your layout because they gradually decrease the transition form curved to straight track. However, they are a little difficult to lay out. With that said, one solution is to use flex track which makes this task much easier.

To form a functional easement, and one that looks good as well, begin by finding the centerlines of the curve you’re making and the tangent track which is to be connected to the easement.

Now, mark the tangency of the circle. You should see that the easement is halfway between the circle and the line. Using a measuring device such as a yardstick bend it so that it follows the circle at one end.

The yardstick should be tangent to the tangent track at the other end, and it should also fall halfway between the two at the point of tangency. You can also do this by creating a template through the use of your personal computer as another alternative. This whole track laying process can also be made much simpler by using flex track for the easements only.

To access a very helpful PDF report which explains what super elevations are and how to build them click here.