Do Easements Matter?

Functionally I think that easements are less important as the curve radius increases.

I have a 62 inch minimum radius on the mainline and don’t think that the

Lack of easements makes any significant difference in operational performance.

Easements are most functional when trying to run long cars around smaller

Radius curves because of the coupler offset between long cars.

Another issue regarding easements is appearance. The give the track a smooth

Flowing look.   I suggest you acquire John Armstrong’s book “track planning for

Realistic operation”. This book explains easements for model railroad.

Super elevation is a very noticeable feature to have on curves and its well worth

The effort but is for appearance only as functionally it’s not necessary on model

Railroads.

Good points. I'm stockpiling track now with lots of the Atlas flex track however I'm also starting to pick up the 49.5 and 54 inch radius Atlas curve track.

If space is not a factor am I going too small on the radius? Running MTH modern locos and some big steam.

Thanks.

Chuck

Easements become more important as speed increases. In a model context, this can be exaggerated on steam because the pilot wheels usually don't have .torsion springs to actually steer the locomotive into a turn. For large radius (60"/O-120) and above this doesn't matter as much. A true easement isn't of a fixed radius -- as you enter it, the radius at a given point gets smaller and smaller until it reaches the fixed radius of the main curve. Exiting the curve, the process is reversed -- increasing until the radius is infinite (straight).

All that said, you should be fine.

Easements matter more in a model context with respect to the beginning and end of a grade as your steam locomotive pilot can dig in at the base and your pilot wheels can lift off the track (long diesel and freight car frames can touch the rails) at the top if the grade easements are too small.

Easements can make a tremendous improvement in the way your track looks and how the trains run. But simply using different diameters of sectional track in a curve is NOT an easement.

A true easement is a spiral curve, which gradually spirals from the tangent track into the needed radius in the curve. By definition, sectional track cannot do this. When your train reaches the first section of "eased" curve using sectional track, it is instantly in a curve...it is not "eased" into the curve via a spiral. There is a big difference.

As Matt pointed out, easements are also very important in vertical curves at the bottom and summit of grades.

I second the endorsement of John Armstrong's Track Planning for Realistic Operation - IMO it is the best single reference on the subject of layout design. The book has easy to follow info on how to lay out eased curves.

I use easements and super elevation on all my visible mainline curves - it just looks neat!  I didn't use easements in hidden staging yards for space reasons (it effectively adds 3/4"  offset to the radius) and haven't had any operational issues.

Ed Rappe

If space is of no concern, go for very large radius.  Do not over-do superelevation (like I did) because a lot of models cannot handle the twist.  A long passenger car will need to have one truck with considerable roll freedom.  But superelevation looks great, even on very large radius.

If space is really no consideration, 80" minimum radius with spiral easements and mild superelevation will look great, and give smooth, realistic operation.

If you don't want to do the mathematical gyrations to plot an easement for your curves, you can use the tried-and-true "Bent Stick Method" which is basically a piece of lattice staked in on your fixed radius and bent to your tangent track which you offset outward by at least an inch from where your fixed curve would normally be. The bend in the stick will be an elliptical shape and form a very nice easement. Then you lay your flex along the centerline.

As Ed mentioned, if adding super-elevation, you have to add an easement to that, too, so that the trains will transition into and out of it cleanly, especially with rigid-framed steam locomotives.

Easements do matter even if you use a large radius curve.  I ease and super elevate my 72" radius curves and the effect is worth the effort.  I also eased a 108" radius curve.  My point is that all curves need easing.

If everyone would get John Armstrong's book, we would have far fewer questions on the Forum.  The book is that good.

Ed

We used the "Bent Stick Method" when building our layout.  It was easy to do and effective.  Our previous layout was build with sectional track and the visual difference between an engine easing into a turn over jerking into a turn is vast and well worth the effort. 

We also used John Armstrong's book.  His insights and examples allowed us to build a much better and more enjoyable layout than we would have otherwise. 

Nathan

Space is always a concern, even to real railroads or they wouldn't have speed restricted curves.  If space is really not a concern then your mainline curves should be ~200" radius or larger for unrestricted speeds anyway.