Grade Math help

[woodlandfarms]

Just real quick. One area that I am interested in mowing has a rise of 40ft every 100. It is not the steepest part of the property, but one that I need to clean up soon .. Is this a 25% grade? I looked around TBN and I know someone had posted the math, just can't seem to find it.

Carl

 

[NJBill]

Hope this will help you understand Carl.

Not my best blueprint drawing, but it should give you the basics.

All the best. Bill

 

[roxynoodle]

Slope equals rise over run. A rise of 40 feet over a run of 100 feet would be a 40% grade. I don't think I'd want to mow that!

 

[Gatorboy]

Just real quick. One area that I am interested in mowing has a rise of 40ft every 100. It is not the steepest part of the property, but one that I need to clean up soon .. Is this a 25% grade?

That angle is 21.8 degrees

Inverse Tangent of 0.4 (Opposite / Adjacent) = 21.8

 

[Egon]

Is the run measured horizontally or on the slope?

 

[woodlandfarms]

Is the run measured horizontally or on the slope?

It is Horizontal, not on slope. I am using a high quality Topo the county has. It is pretty accurate.

Really, what I want to do is find out what a 40 or 45 degree slope feels like. And what a 30 degree slope is like... May not need the 1845 after all....

Carl

 

[MossRoad]

Just real quick. One area that I am interested in mowing has a rise of 40ft every 100. It is not the steepest part of the property, but one that I need to clean up soon .. Is this a 25% grade? I looked around TBN and I know someone had posted the math, just can't seem to find it.

Carl

I go up and down stuff like that with my PT425.
40' up in 100' forward is the same as:
up 4' in 10'
up 2' in 5'
up 1' in 2.5'
up 6" in 15"

I have to transfer the weight of my brush mower to the front tires when I go up the hill by taking it out of float and lifting it about a half an inch. Then I have plenty of traction.

Here's a quick reference for you:
A 100% grade is 1' up for 1' forward = 45 degree slope.
A 50% grade is 6" up for 1' forward = 22.5 degree slope.
A 25% grade is 3" up for 1' forward = 11.25 degree slope.
A 12.5% grade is 1.5" up for 1' forward = 5.625 degree slope.

So you can see that your 6" up in 15" forward slope is less than a 22.5 degree slope. You should have no problems with a PT on that slope.

Hope this helps.

 

[woodlandfarms]

I found another spot that needs attention. It is around 27 in slope (110 ft vertical rise for every 400 feet horizontal). Think the 1430 with a brush hog or grapple bucket can handle this slope?

 

[NJBill]

That's 15.4 degrees

Almost any model of P T is supposed to be able to handle that one.

 

[woodlandfarms]

I found another spot that needs attention. It is around 27 in slope (110 ft vertical rise for every 400 feet horizontal). Think the 1430 with a brush hog or grapple bucket can handle this slope?

Ooops 110 over 300....