Grade % questions

[Handy]

Hi all. This is my first time posting here, I've lurked around for a couple days though. I'm pretty new to layout design and wanted to ask about grades.

I've seen others say 2-3% is normal, with 9% being an extreme. What does the % refer to- the angle? Also does this change in regards to scale? I'm in the way early planning stages of an N scale layout.

Thanks.

 

[Paul Davis]

Probably the easyest way to explain it is to put it this way:

A 2% grade means for a section of track 100 units long* one end is 2 units higher while for a 9% grade a peice of track 100 units long* would have one end 9 units higher.

What scale you model in doesn't make a difference. A 2% grade in Z has the same steepness as a 2% grade in the real thing

*Ok technically this isn't true.as the 100 units should be the horizontal distance. The sloped peice of track 100 units long is actually slightly less than 100 units horizontaly but the difference is so small it really doesn't make a difference unless the grade is really really steep.

 

[ezdays]

Handy,

First of all, welcome. I've been coming here less than two months and have found everyone here friendly and very helpful. Like you, I'm new to layouts as well and just into my first one. I started the other thread that you've been reading about grades. Paul defines it very well. Basically, measure the rise and divide by the distance and you have your %. One thing I did was to pick up a package of Woodland Scenics foam inclines. They come in 2, 3 and 4% and are about 24" long, which means the 4% ones that I bought have a rise of one inch. I had already made a few inclines out of board material, but these are neat since you can bend them to fit curves. Four to a package for under $5. I tore out some of the inclines I made and replaced them with these.

Don

 

[jon-monon]

Welcome aboard Handy! Sounds like the other folks have explained it well. Your right normal people run 2 or 3% grades and get nervy when it gets up to 4%, but loggers go up to 9, 10, even 11% grade and enjoy every minute! A rough figure, if you want to stay on the normal end of the scale, is you can go 2 inches up/down every 8 feet. IMHO you'll have more fun if go for a steep logging layout

 

[interurban]

Welcome Handy, the folk have already boogled ya mind with %
or at least this old mind .
The way I was taught was simple, 1inch elevation every 3 feet.
Unless ya want ta live dangerous
Have lots of fun

 

[Handy]

Thanks All!

As I understand it- the equation is as follows....

(hight of high point minus hight of low point) over distance between points = percentage over 100

So- (not actual example) - if the high point is 7cm and the low point is ground level(0), and the distance between each is 70cm, then the grade is a whopping 35% .

As I get more into the planning I'll be posting more in the N forum since later Q's will most likely be N specific.

Thanks again.

 

[ezdays]

Handy,

I don't know how you did your arithmetic, but if you're going up 7 cm in a 70 cm distance, the grade comes to 10%.

7 cm / 70 cm = .1 = 10%

Which is really steep., unless you wanted to go logging......

Don

 

[Handy]

Doh!

When I did the math, the 70 morphed into a 20.
You right.

A better example-

You want to get a train up 10 cm form ground, using a 3% grade. How far apart would the points be?

10/x = 3/100
using cross multiplication...
10 * 100 = 3x
1000 = 3x
333.3333~ = x

You would need a little over 333 cm to acomplish this.

It's nice to have this, it helps with many things.