I am no logger and I am sure less tractor experience than most people around here, but I safely pull and control the slide of large objects using a Hi-Lift jack.
By large I mean between 4-8 thousand pounds. I have no idea what a log weighs, but I have used my jack as a manual winch to pull docks made of wood. out of the water and onto high ground. I have also used the setup to move full size telephone poles (sometimes two at a time!) all by myself.
It is especially easy to "lower" docks down a slope because you actually release the weight by lowering the jack one click at a time.
These jacks (also called "farm jacks" or "lift-alls" in Eroupe) are absolutely the best (and cheapest - $60!) piece of equipment.
I wrap good quality chain around the poles (heavy ropes work, but stretch is a problem, creating a huge danger - just be sure to drape a rug or blanket over it when under tension in case it lets go) and never stand "in-line" with the load.
You hook the chain(with plenty of extra chain on the end) to the lifting arm of the jack and start out at the top of the jack.
Simply tie the top of the jack off to another tree or anything heaver than your load (a tractor with the wheels chocked works very well).
You can now lower the load as if you were lowering a car down off a jack.
When you get to the end of the jack (mine is 60"...I think they come up to 72" long) you simply hook a spare piece of chain with grab hooks to to the loaded chain and the tied off chain.."lift the load one click to take the strain off the chain, (temporarily placed on the short extra chain. You can now slide the jack arm back up to the top. Hook the chain up again and lower the load another length of the jack, one click at a time.
I am a complete idiot with very little mechanical skill - I can safely lower or winch a substantial load down a long slope (100 feet?) by myself in probably 10-15 minutes.
It is safe, entirely under control and cheap. (The chain, not withstanding)
I learned to do this winching surf fishing 4x4s stuck on the beach - there we have nothing to tie off to - we bury the spare tire as a ground anchor. I have pulled fully loaded hummers and even an RV out this way (When the tide is rising you have to be quick!)
I hope this isn't off topic, but this $60 "winch" has pulled out more bushes and small trees (root ball and all!) - but it lowers weight best of all, which I hope helps you.
