Required Tractive Force

[malaycobra]

This may be too vague a question, but here goes:

I have to get a 420 tonne (GVW Load & trailer) load up a 13% grade. How much tractive force would the tractor unit need to have?

Not much I know, but that's all the information I have for now.

 

[rmw]

Draw yourself a simple right triangle with the slope that you have to pull as the angle opposite the short side. The truck is shown as a weight and the rest is simple trigonometry. Once you determine the force at that angle, then you need to determine the coefficient of friction of the drivers and figure the weight you will have to have on those axles (and maybe how many axles will be required as drivers.)

rmw

 

[malaycobra]

While I appreciate your taking the time to answer, you say "Once you determine the force at that angle" and "then you need to determine the coefficient of friction"
If I know how to do that, I wouldn't have asked the question.

Anyway, thanks for your time, I got my answer elsewhere...

 

[MiketheEngineer]

Use better brush up on Trig 101