vertical transition

[leon]

how would you figure the vertical transitions for any given percentage of a grade? How much length would this add to the grade?

Thank you; Leon

[Sumpter250]

Percentage = rise, in inches Divided by the run, in inches, multiplied by 100.

A 3" rise in 48" run is, 0.0625, multiplied by 100 is 6.25 percent. Or h / l X100 = percentage of grade where h = the height,
l = the distance over which that height is reached.
The vertical transition: is the percentage ( in this case, 6.25/100= .0625 ) times the horizontal distance ( run ) 48" which equals 3".

Given the percentage, and the desired rise, it would be:
the desired rise, divided by the decimal equivalent of the percentage, in this example: 6.25% divided by 100 = .0625 ( the decimal equivalent of 6.25% )
3" (the desired rise) the run is 3/.0625 = 48"
A desired rise of 5", at 6.25% would be 5/.0625= 80" ( 6'-7.25" ) run
A desired rise of 5", at 4% would be 5/.04 =125" ( 10'-5" ) run
Hope that helps
Pete

:o Why do I have to learn all this "math"? I'll never use it in real life!!!!

[teejay]

...and if you're Canadian , double it and add 32 ....applies to everything here .

T

[Sumpter250]

Law of Physical Surfaces - The chances of an open-faced jelly sandwich landing face down on a floor,and still being edible, is directly correlated to the newness,and cleanliness of the carpet or rug.
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:oops: :oops: :oops: :oops: Times two with 32 added

[leon]

Thanks to all! All of you must have known the math in order to accomplish something on your layouts. Now I know the math also, but what I am concerned with is the transition from the flat surface to the grade at the bottom and also the transition from the grade to the flat surface at the top so as to hopefully have all the drive wheels on the locomotive keeping in contact with the track at the bottom and the top of the grade.

[Sumpter250]

The smaller the percentage of grade, the less problem you'll have at each end.
That said, a very gently curved " entry into the climb / up ramp", and "leveling out after the climb ", "easement" should take care of "driver contact" problems.
The radius of those easements should be based on the longest wheelbase,and amount of vertical movement of the driver axles in the loco frame, that will be operated on that incline.

[leon]

Sounds to me that the ideal answer to this problem would be sprung axels!! This mite be able to be accomplished with the proper tools; the knowledge of using them and having the time and firm desire of accomplishment. I think I would be better off running my long wheel base loco (2-10-0) on the level and keep on dreaming.

[santafewillie]

Keep it simple. I don't use anything more than a 2% grade in HO; that' about 1" in 4 ft. I add about a foot of transition at each end. That works for all of my 4 & 6 axle diesels. So if I want to go up 12" I go 48 ft + 2 ft for transition = 50 ft. If I only want to go 4", that works out to 16 ft + 2 ft for transition = 18 ft. Like I said, keep it simple. If you're coming off curves such as helix's than add some more transition...there's no magical formula; just common sense.
willie

[BR60103]

I'll go about with willie. I look for about 2 coach lengths -- one each side of the target grade start. If you do it on a straight, take a long piece of roadbed -- Homasote is probably best -- and tack it down flat before the first bit, then tack it down to the grade after the transition and let it form the transition by itself.
I've also considered (but not tried!) taking a sheet of 2" foam insulation and drawing the flat and the grade on it, then joining it with a 60" radius* and cutting it out so that it sits on its side.
* I have a 60" radius template.

Your worst problems will be locomotives and steam locomotives are the worst. On one transition the pilot and the overhang under the cab will touch the rails or the center drivers will be raised up; on the other the loco will sit/rock on the center drivers and all the others will be off te track.

[leon]

Thanks Willie and Dave. Seems that you two have given the best advice of all. I have 2-10-0 steam locomotive that I am sure would give me a problem with a grade. I haven't the room for a 1 or 2 percent grade and will probably try a 3 to 4 percent grade. I know I am trying to fit a back yard layout onto a postage stamp but that is the fun of it all. So once again--Thanks Leon

[TinGoat]

Here's a general Rule of Thumb:
   

The second item is important.
Grade Transitions adjusted for Percentage of Grade. Note that transitions at the bottom and top of grades are different. Longer rolling stock will uncouple at the top of a grade as one coupler rises above the next over the transition.