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% Grade calculation

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% Grade calculation
Posted by Anonymous on Saturday, March 12, 2005 11:21 AM
Can someone please describe how to calculate the percent grade in HO scale. Is there a standard rise and run rule that works or some other formula for figuring this out. Thanks in advance.
  • Member since
    December 2003
  • From: Sullivan County, NY
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Posted by jwr_1986 on Saturday, March 12, 2005 11:31 AM
Regardless of scale the formual is literally rise divided by run. Thus a 10" rise in 100" is a 10% grade.

Jesse
  • Member since
    March 2001
  • From: US
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Posted by turbine682 on Saturday, March 12, 2005 12:28 PM
There are several MR reference manuals that provide Grade Charts. 4% is considered a steep grade - 4" rise over 100" run as discussed above. Anywhere between a 2% - 3.5% is good. Steeper grade means shorter trains or helper service.

--Ed
Pennsy's Q2's rock and so do C & O's H6's & 8's but the best is NYC's J3a's
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Posted by Anonymous on Saturday, March 12, 2005 2:49 PM
If its a straight run its ok but you need to take curves into account.
I have a 1.82% grade its split between a straight run and two 36" radius curves so engines have difficulty when they jit the curves
  • Member since
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  • From: Vancouver Island, BC
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Posted by selector on Saturday, March 12, 2005 2:50 PM
And, in case you need to be alerted, steeper grades may help you to achieve your goal of getting a grade into your layout. But, it comes at a cost of looking less realistic. If you are attempting to make your layout look highly detailed eventually, and as realistic as possible, I recommend you live with a grade somewhat less than 4%, as advised by Ed.

Mine made me sweat because my little switcher had a very tough time with my initial grade, and I had worked hard on it. Yet, the loco had seemed to have no problems with a similar grade on my kitchen countertop! My eyes told me that the real grade was inconsistent, with deflections upward at points of over 1/2%. I got back to work with a wire brush and evened it all out with long, light, careful strokes. When I finally laid my track and fired up the 0-6-0, up she went!

Good luck.
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Posted by Anonymous on Sunday, March 13, 2005 10:35 PM
Thanks for all the information this will help alot.
  • Member since
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  • From: North Central Illinois
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Posted by CBQ_Guy on Thursday, March 17, 2005 1:10 PM
Also, what may be of help in a general sense is to think of the 1" in 100" part of the rise/run statement in terms of 1" in 8 feet (96"). Not exact but good for "ball-parking" in certain "what if" situations when "imagineering" the layout.
"Paul [Kossart] - The CB&Q Guy" [In Illinois] ~ Modeling the CB&Q and its fictional 'Illiniwek River-Subdivision-Branch Line' in the 1960's. ~
  • Member since
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  • From: Crosby, Texas
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Posted by cwclark on Thursday, March 17, 2005 2:05 PM
" of rise in 100" of track / 100 inches X100 = percent of rise

so if you rise 4 inches in 100 inches of track, than 4/100=.04 and to put it into percent multiply by 100 so .04 x 100 = 4% grade

  • Member since
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  • From: Omaha, NE
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Posted by dehusman on Thursday, March 17, 2005 3:09 PM
If you have a 24" level, every 1/4" you can put under the low end is 1% of grade.

Dave H.

Dave H. Painted side goes up. My website : wnbranch.com

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  • From: Reading, PA
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Posted by rrinker on Thursday, March 17, 2005 7:45 PM
I have several, including a cheapy aluminum one that I've considered threading a bolt into one end to make a tool to lay out grades. Adjust bolt to desired 1/4" incrememnt for grade percentage, then adjust benchwork until the bubble is level.

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
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  • From: Vancouver Island, BC
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Posted by selector on Thursday, March 17, 2005 10:39 PM
Grades, regardless of the application or context, are always calculated on the basis of the 'run' that it takes to get to the 'rise' desired. Rise is divided by run, and will necessarily yield a decimal number that is read at the second integer to the right of the decimal.

So, a 5" rise divided by a track distance (run) of 100" will yield a figure of "decimal zero-five" (0.05). Reading the second number after the decimal point gives you the percentage figure, in this case 5%.

It is never that pretty. Suppose you need to rise 71/2" (or 7.5), and find you must do it in 126"....'cuz that's all you've got. Well, you divide 7.5 by 126, and you get, on your calculator, ".0595238...etc". Reading only the first THREE numbers after the decimal point this time, you will get a 'rounded number', and an approximation of the grade your locos will endure...(and what you'll live with if you continue to built it). So, you will read, starting again at the second number, "Five point nine percent". You can round that easily to an even 6% since 5.9 is so close to it. You can then see that, unless you have a steep grade loco, you have run into a problem.

Hopefully this explanation will assist someone to figure it out.

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