Make Yourself A Winch Genius!

Lean How To Find The Angle Of An Incline Or Ramp.

To find the angle of an incline or ramp with a right angle, 90°.
Using a scientific calculator find the lengths using the Pythagorean theorem:

Adjacent side = A
Opposite side = B
Hypotenuse = C
Θ = angle of incline or ramp

So if A= 4 units long and B = 3 units long then C would be 5 units long.
Look at the trigonometry chart below and select the sine function.

sin Θ = opposite / hypotenuse 3 / 5 = .6

To find the correct angle use the sin‾1 key on the scientific calculator.

.6 sin‾1 = 36.86 °degrees of incline.

Never Use An Atlas® Electric Winch To Pull A Load Up An Incline Of More Than 45 Degrees.
(Always Use Wheel Chocks)

% Percent InclinePulling Capacity
(10,000 LB. Winch)
Level Surface10,000 lbs.
3 Degree Incline6,670 lbs.
6 Degree Incline5,020 lbs.
11 Degree Incline3,400 lbs.
17 Degree Incline2,610 lbs.
26 Degree Incline1,860 lbs.
35 Degree Incline1,530 lbs.
45 Degree Incline1,290 lbs.

Now add the drag coefficient for the rolling surface of your vehicle. Different surfaces provide different coefficient of friction. Use the chart below to calculate the average coefficient of friction of a vehicle on a zero incline (flat road surface).

Standard road surface (zero incline)0.01 to .04
Grass (dry)0.04 to 0.15
Hard packed Dirt or Gravel0.15 to 0.30
Gravel or Dirt0.20 to 0.50
Sand or Loose Gravel0.35 to 0.85
Shallow Creeks, Mud, wet Clay, slick rocks, Swamps or Marshes, Snow, Ice0.50 to 1.00

A standard flat road surface adds as much as 200 lbs. to a 5000 LB. vehicle.
Vehicle of 5000 LB. x .04 = 200 lbs.

Packed Gravel adds as much as 1500 lbs to a 5000 LB. vehicle.
Vehicle of 5000 LB. x .30 = 1500 lbs.

Our 5,000 LB. truck now has a REAL rolling GVW of up to 6,500 LB. on a hard packed gravel surface.