The cable is anchored to the disabled vehicle, then it passes through a snatch block on the anchor/tow vehicle, back to the load, through another block, back to the tow, etc. until the desired number of strands are strung. Now, let's assume a 1,000 LB. pull is made on the free end of the cable- - - -with 4 strands in play, the total pull is 4K LBS. The progress is slow, but the pull is massive. I used to operate a Grove rubber-tire crane with a 4-line lift capacity of 20,000 lbs. using a hydraulic winch with 1/2" diameter cable. The heavy haul wrecker I operated had 300 feet of 3/4" cable on a PTO drive winch with a 35 ton single line pull capacity. We used lots of snatch block recovery equipment with that one, plus two wrecker booms with 1/2" cable and 5-ton winches.
Jerry
