The first scenario we are going to explore is the most common one that leads to confusion and that is a snatch block pull back to the rig to "double" the power of the winch.

Essentially the way it works is each line at the snatch block will have the load of what the winch is putting out. If it is pulling at 5000 lbs, each leg going through the block is 5000 lbs x 2 for a total pulling power of 10,000 lbs.

Here is a diagram from firejeep and then my redneck rigging to illustrate a rig with a winch on it and the anchor points. We will be exploring these three scenarios.

I needed to show the obvious which is the load the rig has against it. The best way to show that was to rig an anchor line with a scale to show it.

Essentially this scale model shows exactly what was predicted and we won't get too nitpicky over frictional issues adding or taking away from the totals.

My version of the second diagram.

1- load moving rig

2- 1st line load

3- 2nd line load

4- anchor load

Load at 1-

Load at 2 and 3

Load at 4