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Grade Easements

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  • Member since
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  • From: Northern Va
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Grade Easements
Posted by rclarkdc on Thursday, December 31, 2009 8:53 AM
I need some help designing easements into grades. I'm starting to build in HO using a 3/4" plywood sub-roadbed. I will be easing from level into grades ranging from 2% to as much as 2.75%. I've looked at several threads here and a couple of benchwork books, and either the info isn't there or, more likely, I simply don't see it. One thread a few weeks back suggested an easement of about the longest car length, about a foot in HO, for every percent of grade change. That seems to make sense to me. I'd appreciation input on how the veterans here actually construct an easement into a grade using plywood (or foam for that matter) as a subroadbed. Many thanks in advance.
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Posted by TomDiehl on Thursday, December 31, 2009 9:45 AM

Grade easment has always been a problem and recently, I found a product that makes it easy and accurate. Woodland scenics makes a product called an "Incline Starter." They're available in several grade percentages, they're 2 feet long, slotted so they can be curved, and made of styrofoam. I got a pack of the 2% grade pieces, they come in a pack of 8 and they're 2-1/2 inches wide, I presume to use in several scales. I just glued them down with white glue.

http://woodlandscenics.woodlandscenics.com/show/Item/ST1412/page/2

It's not expensive and I'm all for something that makes things easier.

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown
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Posted by doctorwayne on Thursday, December 31, 2009 12:53 PM

If you're using 3/4" plywood for your sub-roadbed, it will make its own vertical easement unless you place the first riser for the grade too close to the last one under the level track (provided, of course, that your grade isn't overly steep).

My grades are all about 2.5%, and the risers are placed about 16" apart - I've had zero problems with derailments, spontaneous uncouplings, steam loco pilots striking the rails when entering a grade, or 85' passenger car underbodies dragging on the track as they exit the top of a grade.

In this photo, the track in the foreground begins its descent (at 2.5%) roughly at the point where the speed limit sign is located, while the line upon which the train is running rises correspondingly, making both grades appear even steeper than they actually are (hopefully, trees and undergrowth will eventually de-emphasise this):

It would seem that the prototype, though, is less concerned with this issue Smile,Wink, & GrinLaugh :


Wayne

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Posted by selector on Thursday, December 31, 2009 4:31 PM

Any quality plywood/masonite, or similar laminate, between about 1/2" and 3/4" thick should provide a robust and refined easement for you.  You securely fasten the lower end of a custom-cut length, curved or straight, so that it is level, flush with the surrounding sub-roadbed...which is what you are dealing with.  Use wood screws in several places with the two closest to the onset of the transition set perfectly transversely....across from each other (a line drawn between centrers of the screw heads runs perpendicular to the axis of the wood cut-out/track centerline).  Arch the free end upward until it conforms to the intended steady grade and fasten it to a vertical pylon or a riser.  For thinner subs, you would probably want at least one intermediate support below it at some point, but I would bet you could easily get away with just the one transition-defining riser with subroadbed as stiff as 3/4".

Reverse the process at the top of the grade.

-Crandell

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Posted by markpierce on Thursday, December 31, 2009 4:57 PM

Nice trackside signs, Doc.

Mark

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Posted by markpierce on Thursday, December 31, 2009 5:06 PM

I heartily agree that 1/2 and 3/4-inch plywood is great for forming vertical curves for the roadbed. ... I've always found the need to add additional framework girders so that the vertical risers can be placed where needed. ...  Avoid vertical curves at turnouts.

Published trackplans don't provide for vertical curves, so maximum grades are greater than indicated.

Mark

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Posted by markpierce on Thursday, December 31, 2009 5:15 PM

Extra risers will be needed at ends of the plywood subroadbed to maintain grade where there are gaps such as at this girder bridge (unlike the culvert in the background which is cut through the homasote roadbed but only one layer of plywood roadbed):

 

 

Mark

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Posted by doctorwayne on Thursday, December 31, 2009 5:29 PM

I always enjoy seeing pictures of your layout, Mark, although more would be welcomed.Wink

By the way, thanks for the kind comments on the signs.  Other than a light engine move, not much will reach even 35mph, as the grade extends for about 45', or almost 3/4 of a mile in HO.

Wayne

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Posted by markpierce on Thursday, December 31, 2009 5:43 PM

doctorwayne

I always enjoy seeing pictures of your layout, Mark, although more would be welcomed.Wink

Thanks, Wayne.  But I don't have a "layout," but do have three layout sections in my spare bedroom built for a friend's layout who since changed his plans.  My next layout will require dismantling the three sections to make room.

Edit -- I now wish these layout sections had burned up with the other ones in my friend's layout-room fire.

Mark

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Posted by wsdimenna on Friday, January 1, 2010 7:25 PM

 what I like to do if on a plywood base is subsitue some luan board for cork roadbed about 2 ft from where the grade is going to start. I screw down the track to the luan board and screw one end of the luan down on the plywood. This way I have a flexible way to adjust the easement. Once set I insert foam blocks and fill.

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Posted by Doc in CT on Sunday, January 10, 2010 8:30 AM

TomDiehl
Woodland scenics makes a product called an "Incline Starter."


Tom
My questions is do you need anything in the way of a grade or vertical easement to start the incline? or is the last (first) riser thin enough?
Alan

Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/

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Posted by mobilman44 on Sunday, January 10, 2010 4:17 PM

Hi!

In my current layout, and the previous one - both HO, 2 levels - I utilized the "cookie cutter" method to facilitate vertical easements, and they worked just fine.  Having said that, I learned a lesson - don't put any turnouts on or near a vertical easement.  While it CAN be done successfully, it is an invite to problems - in my case anyway.

One additional comment......  All my grades were a solid 2%.  Unless you have a narrow gauge or logging railroad, I would urge you to keep your grades no steeper than that. 

Hey, for what its worth.......

Mobilman44

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by Doc in CT on Sunday, January 10, 2010 4:32 PM

 Planned grade is 2% (slightly higher on curves); all switches on flat areas.  Hopefully the Nolix will be long enough to get down the 8 inches I am planning on for the staging level (about a 4-5 inch height figuring upper deck thickness).

Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/

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Posted by selector on Sunday, January 10, 2010 5:05 PM

 

Doc in CT

TomDiehl
Woodland scenics makes a product called an "Incline Starter."


Tom
My questions is do you need anything in the way of a grade or vertical easement to start the incline? or is the last (first) riser thin enough?
Alan

I have no experience with this product, but even if it doesn't quite fit your unique situation, it can be sanded to a thickness and angle that helps you out...in all likelihood. 

The idea is to provide an 'acceleration' into a curve vertically the same way a horizontal easement accelerates the lateral conformation to the intended radius.  So you start flat, curve just slightly, but the curve continues to add more and more pitch upward to the rails until that curve is no longer needed because the pitch now conforms to the rate of rise needed to get the elevation you need.  Soon enough, the rails begin an imperceptible pitch down.  You can achieve this with so little expense and effort using the simple technique some of us have described.

-Crandell

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Posted by Doc in CT on Sunday, January 10, 2010 5:15 PM

selector
You can achieve this with so little expense and effort using the simple technique some of us have described.

 

Thanks Crandell for the explanation of sanding the initial grade (forgot that one).  I am not using a cookie cutter approach (at least at the moment) for the layout; thus my interest in WS Inclines.

Alan

Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/

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Posted by markpierce on Sunday, January 10, 2010 5:25 PM

Doc in CT

 Planned grade is 2% (slightly higher on curves);

Don't do that!  You should do nearly the opposite.  Curves add drag, so they raise the effective gradient.  On any significant curve, as one is going up hill, the grade should gradually decline shortly (locomotive length) into the curve and then be gradually raised shortly after entering straight track.  For HO, the rule-of-thumb factor is 32/R, such as a 24-inch-radius curve increases the effective grade by 1.33 percent.  Probably in most circumstances, there should be a 1% or more difference in grade between straight and curved track, as in 2.5+% on straight track, and 1.5-% in the area of major curves.  Ideally, you should have vertical risers which you can adjust while testing trains going up the grade, adjusting for an effective even grade, and then permanently attach the risers to the framework.  Curve length and sharpness as well as train length will be factors.

Mark

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Posted by Doc in CT on Monday, January 11, 2010 6:46 AM

Hi rclarkdc
A 1% grade is 1/4in in 2ft (approx) or 1/8in in 1ft (approx).  So1 you are looking at shimming a 1ft track segment about 0.125in as a lead into a 2% grade. I suppose the first track segment (of 2 segments) could be shimmed 0.06in .
OR  allow the natural bend in plywood subroadbed to form the easement.  Not sure what you would do with foam unless its rather thin.  I know the 2" thick foam does bend on its own in 8ft if supported at one end.  Hopefully someone here has used foam in this manner.

Alan

Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/

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Posted by Paulus Jas on Monday, January 11, 2010 7:19 AM

hi,

the plywood subroadbed will provide you with automatic easements. But you need to leave some extra space for them. You will have an easement at the botom and at the top of the grade,  so you will need at least 2 feet extra length.

Lets say your grade is between riser 11 and riser 27. The trick is to design your grade between riser 12 and 26. So between riser 11 and 12 the roadbed will be theoretically level. With a kink the grade will start until riser 26. You fix the roadbed to riser 11, 13, 14, ect,  and the plywood itself will form an easement, just wait a couple of days and only then fix riser 12. Repeat the same procedure at the top. The heigth of riser 12 is "calculated" by the plywood, not by marth. The heigth of the other risers is calculated by you. When your grade has to rise 6 inches between 10 risers each 18" apart your grade will be

grade = 6 / (10x18) X 100 = 3.3 %

When your grade has to rise 3 inches between 8 risers each 12" apart your grade will be

grade = 3 / ( 8x12) x 100 = 4.1 %

Some one else stated it allready, turnouts have to be in one plane; horizontal or not isn't an issue. So never design a turnout on an easement.

Paul

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Posted by TomDiehl on Monday, January 11, 2010 8:09 AM

Doc in CT

TomDiehl
Woodland scenics makes a product called an "Incline Starter."


Tom
My questions is do you need anything in the way of a grade or vertical easement to start the incline? or is the last (first) riser thin enough?
Alan

The Incline Starter is the vertical transition, but is designed for spots where you'll be starting a grade from a flat table top. I used it for the first time on the track for the coal dump of my coal tower, which is on the flat table top next to my roundhouse. A pack of 8 of them retails for $6.50, so they're not expensive, and are available in several grade percentages. Definately makes life a lot simpler, and at less than a buck each, well worth it.

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown
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Posted by dknelson on Monday, January 11, 2010 8:24 AM

I am making some use of the Woodland Scenics inclines (2%) but also for my plywood and homasote subroadbed in certain situations I have also used the regular wood shims available at any hardware store, sometimes just an inch or two of them.  It takes some mixing and matching to find two that are actually identical and they are then laid side by side to support the subroadbed.

From this website: http://www.sillikerglass.com/glazing_products_and_tools.htm

 

Dave Nelson

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Posted by Paulus Jas on Monday, January 11, 2010 10:56 AM

hi

I just overlooked the way your layout is constructed.

The Woodland Scenics incline starter is meant for and used on TABLETOP- layouts. The "automatic easement" formed by the plywood is used with a COOKIE-CUTTER type subroadbed.

Paul

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Posted by johncolley on Monday, January 11, 2010 11:11 AM

The method I use is to change the grade in increments of 1/16th inch per foot, example a 2% grade is approx. 1/4" per foot so from level I go 1/16 the first foot, then, 1/8, 3/16, 1/4 in suceeding feet of travel, levelling off at the top is the same thing in reverse, so you are talking about an additional six feet added to your grade. hope this makes it clearer, eh? John

jc5729
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Posted by Doc in CT on Monday, January 11, 2010 2:23 PM

 A 1% grade is 1/2 inch in 50 inches, so a 0.1 shim under a 1/2in track section would be a nice easement for a 2% grade, I think.  With possibly a 0.04 or 0.06 for the preceding section?

Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/

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