how to figure the grade

[keithw37]

How do I figure the percent on a grade . Is it 1inch per 8 feet for a 1 % grade.

[SpaceMouse]

Close. 1" per 100"

[rpbns]

Hey Keith,
I've been working on that myself. The formula I was given is Height in inches divided by length in inches -equals grade.
H/L=Grade
So if you wanted to increase your height to 2" over an 80" length you get a grade of 2.5%.
2"/80"=2.5%
That may be more of an explanation than was needed, but I figured I can actually help with this one, may not happen again for quite awhile. [:)]
Rob

[selector]

2"/80" = 0.025. The answer of 0.025 is meaningless by itself, but you learn to convert it to a precentage by multiplying the answer by 100 to make the answer "out of" 100, or per hundred, or per centum, in Latin. If you multiply the answer of 0.025 by 100, the process moves the decimal point two places to the right, resulting in 002.5. The two zeros are useless, so we just read 2.5, but now as the percent that we wanted with the multiplication of 100.

All this to say that you can convert anything, any two numbers, any two units in relation to themselves as a percent by dividing one by the other, and moving the decimal point two places to the right.

So, what is the grade, in percent, of a rise of 4" over a distance of 146"? Just as before, divide the 4" by the 146" (rise over the run) to get 0.027397. Move the decimal two places to the right (effectively multiplying by 100), and you can read your grade as 2.7%, in rounded figures.

If I have 3578 grey hairs and 12688 coloured hairs on my head, what percentage are grey?

3578/12688 = 0.28198. Move the decimal over two places to get the percent, or 28%

Does that help to explain percentages and how they relate to grades?

-Crandell

[Robert Langford]

kEITHW37, one of the model RR magazines had an article on building a grade tool using a level, I don't remember when it was, but mabe someone on this thread can tell you. Good luck
Bob
Sandy Southern Railroad

[John Richards]

Duhhhhh, what was that again, ;-}

regards,

[claycts]

FREE GRADE CHART under my signature, help yourself

[ndbprr]

I don't want to throw flames here but I am curious. Could the first poster tell me if he is young or out of school? Are our schools getting this bad that this question is asked so many times? If they are it is down right scary what the future holds.

[Anonymous]

Heck I'm 41 and we never learned that in school. I learned it later when I got into the mechanical trades (HVAC).

My school system taught me so little I ended up having to work for them. I always tell people that no one else would hire me. (I hope I'm kidding)

[dickencr]

Everyone has the same message - stated is a different way. Here's my 2 cents...

Remember that the equation is Rise divided by Run. Rise = height, Run = length

In this case 1" over 96" with a resulting grade of 1.04%

Basic math (please don't flame me for this tutorial) KeithW37 stated his problem in two dissimilar units. Inches and feet. They need to be the same. Inches works best here since none of us is dealing in the number of miles that a real railroad encounters.

So Rise divided by Run gives a ratio of these numbers. To change this to a percentage, multiply by 100. 1" / 96" = 0.0104166 x 100 = 1.04166% or a 1.04% grade.

This from professor obvious.

[Anonymous]

NDBPRR ??? Who ever you are dosen't matter,.. but I am going to take it upon myself to make a statement in reply to your negative reply. First of all I am going to assume math comes easy to you, that is great, it comes easy to me as well, but I understand it does not come so easy to others YOUNG AND OLD alike...If ya don't get it, it can be very frustrating. A word of advice don't be so eager to sound full of wisdom, instead share your wisdom especially in this site where we are trying to promote the hobby.
I agree with you to the extent that todays education system is in dire need of attention to more of a "brains on" thought processes experience rather than the all too easy hands on computer or calculator. I am with ya on that one.
My second point is this ...If anyone in this site, young, old, inexperienced, or experienced reaches out and has the courage to ask ANY question and you have the solution, do the right thing and spread the hobbies knowledge. Don't degrade the fella for needing an answer and having the courage to ask for it young or old. Spread some goodwill and give him the answer.. Got something good to say say it...If you don't, keep quiet and move on. No offense intended. Take care and good luck.

[Anonymous]

Keith..if ya wanna keep it simple as stated above by the first reply by space mouse...one inch rise.. over a one hundred inch run.... equals a 1% grade. Try to think in terms of the dollar. The one hundred pennies in a dollar make up one hundred percent of that dollar. So one cent, one penny, equals one percent of a dollar.
If you need to cut it in half due to limited space...1/2 inch rise over 50 inch run of track is one percent grade. 1/4 inch rise over 25 inch run of track is one percent grade, and 1/8 inch rise over 12.5 inches of track run is 1% grade. Good luck to you. I hope all goes well with your model railroad. Its a great hobby. Kepp asking questions and share when you can..Take care..

[BR60103]

Robert: I built a grade tool from a level. I have a 2 foot level. If a 2% grade is 2" in 100, that comes down to about 1/2" in 2 feet. I took a piece of 1/2" thick stripwood and looped a rubber band around it and over the level. If I put the wood at the end of the level, I now have a 2% grade measure. 1/4" of wood gives 1%. Move it to the 18" mark and you have a steeper grade.
You can use a longer level if you have it or a shorter one for grades on curves (Note that the grade calculation will be off on a curve, but in the favourable direction.)
Keep the rubber band out of the way!

[keithw37]

Thanks to all

[ndbprr]

Yes junior high math comes easy to me. I said I wasn't trying to start a flaming war I am trying to figure out why this is such a problem. It makes me wonder if people check their wages, figure the deductions, pay their taxes, mortgages, credit card bills or are the vast majority sheep to be sheared?

[chateauricher]

QUOTE: Originally posted by Jerry M1
Why? Take as an example the sketch shown below. The joists are all spaced at 16" but it could be any equal distance. If I know for example that the track rises 4" in a distance of 4 joists then it rises 2 inches in a two joist distance and one inch in one joist distance. That tidbit of knowledge is used everyday in Surveying real life railroads and highways.

Sketch ?!?! What sketch ???

[tomytuna]

I've just ordered the " Grade Gauge " from Walthers....still waiting for delivery..will let you know how it works out when i receive it ...as we we have long run with grade...
Teachers don't teach typing or spelling either as you can see by my note...LOL
Tom

[rcato]

Careful now.

[carl425]

I've got one of these:

 

It will give you degrees, inches of rise in run of feet (like a roofer would use), and percent grade.

[riogrande5761]

Wow, lots of threads being necro'd lately on MR forums.

[Steven S]

I think it has to do with all those zombie shows on TV.  People feel the need to resurrect something.

 

Steve S

[floridaflyer]

Of course if there is a curve in the grade that has to be factored in as it will increase the %of grade.

[dante]

floridaflyer

Of course if there is a curve in the grade that has to be factored in as it will increase the %of grade.

 

It will increase the effect of the grade on the pulling power of the loco because of the added friction of the curve but it will not increase the actual % of grade: rise/run formula remains the same.

Dante

[farrellaa]

Anonymous

Heck I'm 41 and we never learned that in school. I learned it later when I got into the mechanical trades (HVAC).

My school system taught me so little I ended up having to work for them. I always tell people that no one else would hire me. (I hope I'm kidding)

 

And that is why I keep this reminder around!

   -Bob

[richhotrain]

rcato

Careful now.

 

In the greater scheme of things, I guess that it really doesn't matter, but I have to ask.

What is worse?  Reviving a 9 year old thread or doing so with a totally inane comment?

Rich

[davidmurray]

Bob:

I agree, I don't think that I've used algeba, Calculus, or a few other things since 1975.

My high school general shop classes were much more useful.

Dave

[BroadwayLion]

LION is not math major. LION is not mechanical engineer. LION is not an artist.

LION is a nice, soft, furry felid who builds model trains. So LION takes a simple, straight forward approach to construction.

If LION has a track --> here, and wants it to end <-- there, him simply runs the track from here to there. If the train can go up the grade, all well and good. If it cannot make the grade, him can had helpers, or him can rip things out and try again with plan B. The LAYOUT dictates the grades. If you do not have the space for a 1% grade, it may end up as a 2% grade or maybe a 3% grade.

If making a helix you are, you must have enough of a grade to get the new level above the previous level. If you are using a 48" diameter circle, the grade will be so and such. If you are using a 60" diameter circle, it will be less. But what if you cannot have a 60" circle? Maybe you can use 1/8" hard board for your roadbed instead of 1/2" plywood with a 1/2 combination of cork and rail on top of that. Then your elevation per turn can be less and your grade will be less steep.

LION does not worry about numbers. That is ok if you actually plan your stuff on paper. LIONS do not plan stuff on paper, they keep it all in their heads. It is easier to work with things then ideas.

Oh well, you primates can do what you want to do, the LION will get the job done and the trains will run. That in the end (the TAIL) is all that matters.

ROAR

[mobilman44]

Don't overwork the issue..........  1 inch in 8 feet is 0.96 percent rise.  Round that to 1 percent and don't look back.............

 

[DSchmitt]

mobilman44

Don't overwork the issue..........  1 inch in 8 feet is 0.96 percent rise.  Round that to 1 percent and don't look back.............

 

 

No it's a little over 1.04 percent.

[mobilman44]

EXACTLY my point (made the erroneous count to see if anyone could tell)!  

Be it 0.96 or 1.04, it just is no big deal.

One point that is important.....and to me this applies to the incline going from my below level staging up/down to the main level.  The incline should be measured in rather long increments.  Said another way, the grade should be checked in its entirety to assure consistency - especially if any curved trackage is involved.

Said a third way.......... a two percent grade should be two percent for each fraction of that incline - and not 1 percent here and 3 percent there, etc.

Of course, that is only if you want it that way.