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2% starter incline on a curve

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2% starter incline on a curve
Posted by kasskaboose on Sunday, March 21, 2021 5:06 PM

I've finally decided on using the WS 2% foam starter incline on my HO pike. Any problem in adding that on a 30 degree curve?  My plan is to have one 2% starter incline, 84" of 1/2" foam that the straight track will sit on before there's a 1/2" descent on another WS 2% piece to a zero grade.

The configuration has NO turnouts.

For those unfamilar with the WS 2% starter incline, it's 1/2" rise along a 2' run (2%).

I found an earlier post about that and thought to include it to see if applicable to my setup. If so, from the below, that would mean the 2% incline becomes 3%.  Correct and any issues? 

 https://www.trainboard.com/highball/index.php?threads/incline-and-curves-question.79025/

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Posted by rrebell on Sunday, March 21, 2021 8:40 PM

It dose not change the incline but has the effect. Any curve has an effect, even on flat track. Now I don't know if it would have as great an effect as stated though.

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Posted by wjstix on Thursday, March 25, 2021 9:49 AM

kasskaboose
I found an earlier post about that and thought to include it to see if applicable to my setup. If so, from the below, that would mean the 2% incline becomes 3%.  Correct and any issues?

   https://www.trainboard.com/highball/index.php?threads/incline-and-curves-question.79025/

If by "30 degree" curve you mean "30 inch radius" curve, then yes (if my quick calculations are correct) it would add a degree. The WS 2% riser is really 2.08% (.5 divided by 24), and using John Allen's formula in your link (32/R) a 30"R curve would add .9375%, so it would have the effect of a 3.0175% grade.

Stix
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Posted by riogrande5761 on Thursday, March 25, 2021 9:55 AM

Do those WS inclines also take into account vertical easements?

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by rrebell on Thursday, March 25, 2021 10:59 AM

Lastspikemike

 

 
riogrande5761

Do those WS inclines also take into account vertical easements?

 

 

 

No, they don't. We tried various methods. Adding filler to the bottom ends of the inclines  and filing off the little "hump" at the top and also then fairing in the vertical easement with filler seems to work.  

Woodland Scenics is a tad optimistic about how much easier their foam riser system is than traditional benchwork. 

 

Very much easier. For the bottom you strech out the cork, you can put shims here and there if needed. For the top a hot wire will make short work of the easement and any fine tuning can be rasped away from the cork. When using them it is best to install them, then install the cork, then landforms and plaster cloth up to the cork.

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Posted by riogrande5761 on Thursday, March 25, 2021 11:20 AM

As an alternative, if you use open grid you can use risers and calculate any grade you wish and control it with the height of the rises:

This is the steepest planned grade on the mainline at 1.8% grade, or a rise of 1.8 inches over 100 inches distance.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by doctorwayne on Thursday, March 25, 2021 2:35 PM

riogrande5761
As an alternative, if you use open grid you can use risers and calculate any grade you wish and control it with the height of the rises...

Jim is correct and if you use plywood as the sub-roadbed, it will naturally form the grade easments at both the top and bottom of the grade.

I have a grade from the main level of my layout, up to a partial second level...it begins just past the water tower at left....

...it climbs up a peninsula....

...to reach the partial upper level of the layout here...

The grade, fully supported only at the bottom and the top, started at point 44" above the floor and reached an elevation of 59.75", a difference of 15.75", over a run of 47'.
After marking the mid-point of the run, I added a riser there, placing the track height at that point 51.875" above the floor. 
I added a couple more risers at the 1/4 and 3/4 points of the grade, keeping the rise constant, then, since the sub-roadbed was 3/4" plywood, simply added additional risers as needed, matched to neither raise nor lower the sub-roadbed.

The three original risers added to the grade allowed the plywood to self-create the vertical easements at the top and bottom.

The grade, without compensation for the many curves, is 2.79%. 

However, a train 47' long would be struggling with an equivalent 3.79% grade in the first 32" radius curve, a 4.79" grade in the second 32" radius curve, and then, when navigating the "S"-bend nearing the summit, grades equivalent to 5.68%, 6.57%, and 7.41%.

Now that the second level is in place and operational, it's tempting to try a 47'-long train just to see how many locos it would take, but I've some other projects to complete before that happens.

Wayne

 

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Posted by kasskaboose on Thursday, March 25, 2021 3:11 PM

Great hearing from others.  Thanks! Total difference between wood and cork for sub-roadbed (which is what I have). Thanks for the clarification about what I wrote earlier.

Even with a 2% rise on a curve, I avoid having the sectional track connect at the bottom and top of the elevation.  Additionally, there are no turnouts.  I think 2% on a curve is suitable esp. since I have a long amount of track before the decline.

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Posted by riogrande5761 on Thursday, March 25, 2021 4:26 PM

kasskaboose

Total difference between wood and cork for sub-roadbed (which is what I have). Thanks for the clarification about what I wrote earlier.

Hold the phone.  Cork is not subroadbed.  It is roadbed.  Subroadbed is part of the support structure.  You generally don't equate cork to wood.  

In this discussion, WS foam is the subroadbed with cork on it for the roadbed.

I think 2% on a curve is suitable esp. since I have a long amount of track before the decline.

Grade equivent is closer to 3% when you combine the actual grade plus the drag due to the grade being on a curve.  As long as you have sufficient power for the train length, you should be ok.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by kasskaboose on Thursday, March 25, 2021 6:39 PM

Thanks Rio for the clarification.  I meant that cork is the roadbed and my 2" foam is the sub-roadbed.

I think a consist of 8-10 cars in HO scale of about 8" each pulled by an SD 40-2 should be fine on that curve. 

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Posted by kasskaboose on Thursday, March 25, 2021 8:13 PM

The cork isn't going down to risers, but I'm using the 2% WS starter inclines.

https://www.walmart.com/ip/Woodland-Scenics-WS-1412-Foam-2-Percent-Incline-Starter-8-Package/230750821

 

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Posted by aj1s on Friday, March 26, 2021 5:09 PM

I model in N scale, so is the 32/R ratio scale dependent?

I believe it should be, since friction, derived from the the amount of slippage between wheels on an axle in a curve is also dependent upon the length of the axle, which is the distance between rails.

Stated another way, the length of the outer rail in a curve, relative to the inner rail, is dependent upon not only the true/non-scale radius of the curve, but also upon the true/non-scale distance between rails, and is therefore scale dependent.

As such, for N scale (1:160), the numerator of the ratio should be 32*88/160=17.6, and thus the ratio should be 17.6/R for N scale.

-- Andy - Arlington TX

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