Decades ago, when I was horselogging on the coast I used something similar to this to load my short logger truck. What I did not have is this slick adjustable stiff arm set-up. With this A-frame I would use two short cables, each with a log-dog end, on the other end were loops which I hung from the block hook. I would hammer the log-dogs into each end of the log. I would use a team, or tractor, to pull the lifting cable and raise the log. Then the truck would be backed in under and the log lowered. Worked slick. Took a little time, but what is time to an arrogant young man in the woods?
These portable A-frames can be used for lots of lifting projects. Great homemade tool. LRM