% Grade calculation

[selector]

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.

[rrinker]

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

[dehusman]

If you have a 24" level, every 1/4" you can put under the low end is 1% of grade.

Dave H.

[cwclark]

" 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

[CBQ_Guy]

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.

[Anonymous]

Thanks for all the information this will help alot.

[selector]

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.

[Anonymous]

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

[turbine682]

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

[jwr_1986]

Regardless of scale the formual is literally rise divided by run. Thus a 10" rise in 100" is a 10% grade.

Jesse

[Anonymous]

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.