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Winching
Guide
Estimating Load
The ability to determine the load that the recovery will take is an important skill to
learn. It allows you to properly setup rigging for a successful recovery the first time
and reduces the chance of equipment damage and danger to bystanders.
Resistance Types
• Grade Resistance:
The resistance
of pulling a vehicle up a slope.
• Mire Resistance:
The resistance
of pulling a vehicle from soft terrain,
such as mud, sand or snow.
• Tackle Resistance:
The added resistance
of snatch blocks during winching.
Grade Resistance
For recoveries or applications that pull a vehicle up a slope, grade resistance is a factor in the
recovery load. This is because there are many other variables to consider off-road that add
resistance. For example, the ground is not smooth or solid like pavement, the vehicle’s wheels
may not turn smoothly, the vehicle’s steering may be broken, and a host of other factors.
For the majority of off-road recoveries, the grade resistance
can be equal to the gross vehicle weight (GVW).
For smooth ramps used to load a trailer or other
situations that are not as varied, you can use the
following to estimate the recovery load. To
estimate load you will need the gross vehicle
weight (GVW) and the grade of the terrain.
• GVW can be found on the nameplate of
the vehicle, or by a weigh station scale.
• % Grade = Rise / Run
Example: Rise 4 ft / Run 10 ft = 40% Grade
Reference the chart to find the estimated
recovery load resistance.
Example: GVW of 6000 lb on a 60% grade =
recovery load of 51% of 6000 lb = About 3060 lb
Grade
Angle
% of GVW
20%
11
20%
40%
22
37%
60%
31
51%
80%
39
62%
100%
45
71%
