Yea, control but it's a little bit more then that. You yard down hill the log runs ahead goes on the wrong side of a stump you have a hangup, virtually assured with a turn of logs. One of them is bound to run the wrong way and hang up or even run out of the choker. if you are yarding up hill the choker stays tight and follows along the intended path instaed of taking off where you don't want it. Also it is much easier to get lift yarding uphill. Keep the ends of the logs off the ground, bigger turns, more wood, less hangups, less work. Easier layouts too. A lot more work to pack rigging up a hill then down plus you usually have to rig tail trees on a down hill show and a haulback is mandatory, more rigging then shotgunning which you can do yarding uphill and it's faster too.I'm not a pro logger, either, but I've sent some to a mill. For me, it's all about control. Logs that roll down a hill and hit hard things can be damaged/splintered and even drag your equipment with them (yikes). Damaged logs = little/no money from the mill. Logs that you drag up a hill are in your control (for the most part).
Moving the yarder is no big deal. Not to often you get a full 360 degree setting anyway. The roads are usually built so you can get the best logging which means uphill. The exceptions are because of rough terrain that makes the road building to expensive or property boundaries and access problems.I assumed that most of it was because of access. If you have your landing at the peak you can work the logs up to you from the north, south, east, and west, but if you set up at the bottom of the west slope you can only get the logs from that side before you had to break it all down, build a road, and head to the next slope. I could very well be wrong though.
:agree2: Damn good explanation! right on the money. Anyone that's ever spent some time downhill logging, would like not to have to do it again. It also makes it real interesting when You pull a tailhold that's uphill from You, lines attached to a rootwad coming at You, powered by logs continuing on down, get You moving, and looking for that perfect stump.
There isn't much scarier than a piece of equipment that doesn't like to go uphill.Decades ago I help do skidder logging on a nasty little side slope that a skidder could barely make it up. So we set out with a long cable to pull to the bottom and skid them out that way. With the second draw of the skidder we had pretty well figured out that it was a VERY bad idea. Once any log was lose it came down the hill and it ALWAYS went to the opposite side of any tree between where it was and the skidder, thus hanging up.
We ditched that plan and cut a skidder trail along the top of the ridge and winched to that ridge and then skidded down to the landing. No problems, no hassles and no rolling logs. Winching and skidding down hill was such a bad idea that we figured it out in less than 15 minutes, which means it was stupid in epic proportions.