# Easement/transitions curves



## george (Jun 18, 2013)

We all need to save space (HO scale). So, in your experience, is a well-constructed easement/transition arrangement with 18" radius as effective as a non-easement 22" radius in (a) saving space and (b) satisfactory operation where the longest coach is 60' ?


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## DavefromMD (Jul 25, 2013)

I've had no issue running 60 foot coaches on 18 inch radius curves. No easements.


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## riogrande (Apr 28, 2012)

DavefromMD said:


> I've had no issue running 60 foot coaches on 18 inch radius curves. No easements.


That's right, 60' coaches should operate OK on 18-inch curves, however, it is worth adding easements - see below for comments based on John Armstrong;s track planning book.



george said:


> We all need to save space (HO scale). So, in your experience, is a well-constructed easement/transition arrangement with 18" radius as effective as a non-easement 22" radius in (a) saving space and (b) satisfactory operation where the longest coach is 60' ?


Don't take it from me, take it from John Armstrong, author of Track Planning for Realistic Operation, sold by Kalmbach. On page 45 of my edition, John has a diagram showing the "offset" between long cars on two different examples. One is an 18-inch radius curve to straight track with an easement, and the other is a a 24-inch radius curve to straight track without an easement. The offset is significantly much greater for the larger radius curve without and easement. The easement only costs you roughly a half inch of extra space. I used them most definitely!

In John Armstrong's book, he classifies 18-inch curves as "sharp" and says the following: "Sharp curves are really suitable only for cars up to about 60 feet long, and on passenger cars some careful adjustment may be required to avoid diaphragm troubles unless easement are provided. .... "


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## george (Jun 18, 2013)

Thanks guys: easements it will be.


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## Joefrumjersey (Apr 16, 2013)

I have had layouts with 22" radius curves, and no easement in the past. 60' cars will run on these without issue, but may look funny. You may try using 24" curves to ease your transition to the 22" curve. That will make the spiral more gradual. 

Joe


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## riogrande (Apr 28, 2012)

Joefrumjersey said:


> I have had layouts with 22" radius curves, and no easement in the past. 60' cars will run on these without issue, but may look funny. You may try using 24" curves to ease your transition to the 22" curve. That will make the spiral more gradual.
> 
> Joe


I had a layout in my garage years ago and was watching my Walthers 89' auto racks going around a 36-inch curve. A 36-inch curve sounds very broad to many folks, but those auto racks looked funny going around them and the curves appeared sharp in that situation.

This all goes to underscore that in model railroading, you can almost never have broad enough curves. On my smallish 10 x18' layout, I've opted for 32-inch minimum curves, and have already noticed how 89' TOFC flat cars and auto racks look less than desirable but you gots do the best you have with the space available.

Anyway, I digress. Easements are a way to help make operation more reliable as the spiral into curves makes for a smoother; they are not difficult to add once you learn the basic technique. I use an approximate offset of a half inch and then let the flex track "spring" naturally out to the curve centerline I draw, with the transition portion about 9 inches on either side of the offset point. John Armstrongs book has a nice diagram and gives some different offset figures depending on the radius of the curve. It might be a little more difficult if you use "stiff" flex track like Micro Engineering or others like it.


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## Joefrumjersey (Apr 16, 2013)

riogrande said:


> This all goes to underscore that in model railroading, you can almost never have broad enough curves. On my smallish 10 x18' layout, I've opted for 32-inch minimum curves, and have already noticed how 89' TOFC flat cars and auto racks look less than desirable but you gots do the best you have with the space available.
> 
> Anyway, I digress. Easements are a way to help make operation more reliable as the spiral into curves makes for a smoother; they are not difficult to add once you learn the basic technique. I use an approximate offset of a half inch and then let the flex track "spring" naturally out to the curve centerline I draw, with the transition portion about 9 inches on either side of the offset point. John Armstrongs book has a nice diagram and gives some different offset figures depending on the radius of the curve. It might be a little more difficult if you use "stiff" flex track like Micro Engineering or others like it.


I totally agree that easements are the way to go. I also strongly believe that using the broadest curve possible for the space available. I have found that if you can build your layout to eye level, at least eye level while seated, the long cars don't look as silly going around the curve.

I do use Micro Engineering Code 70, so nothing really springs into place. However, once the curve is plotted I create a new starting point ½" from center and re-plot the spiral until they meet. When I was using sectional, rigid track (Kato) I started the curve with the next widest size. It worked quite well.


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