southsoundtree
Been here much more than a while
- Location
- Olympia, WA
Tirfors/ Griphoists mean slow pulls. The higher your anchor crotch, the slower the tree will move over-center enough for gravity to overcome the remaining hinge strength. The lower the anchor crotch, the sooner the tree will come over at the same pull line-speed.
During the hinge bending and breaking, you can lose the tree to side-lean. If they are spars, there is way less leverage sideways on the hinge to consider.
All else being equal, the faster the steady, non-jerking pull, the more likely you will be to get it to the lay, without losing it to the side.
Log skidders tend to pull low because they have the power, and its easy to stand on the arch and set a choker, compared to climbing. Down low, they move the tree fast. Let's you do things you can't when pulling at a creep.
A faster, longer pull can be achieved by a mid-line load, such as a log, being hoisted up. This keeps pressure on the pull line until the log lands on the ground. Increased chance of barberchairing the tree, because it's preloaded to an unknown level, judged only be human effort of pull and judgment of line deflection, unless you have a load-cell. But, useful in some situations, all the same.
Pics inform a lot for the purpose of suggestions or discussion.
POWs are cheap. Being able to have a controlled release under load can save the day.
During the hinge bending and breaking, you can lose the tree to side-lean. If they are spars, there is way less leverage sideways on the hinge to consider.
All else being equal, the faster the steady, non-jerking pull, the more likely you will be to get it to the lay, without losing it to the side.
Log skidders tend to pull low because they have the power, and its easy to stand on the arch and set a choker, compared to climbing. Down low, they move the tree fast. Let's you do things you can't when pulling at a creep.
A faster, longer pull can be achieved by a mid-line load, such as a log, being hoisted up. This keeps pressure on the pull line until the log lands on the ground. Increased chance of barberchairing the tree, because it's preloaded to an unknown level, judged only be human effort of pull and judgment of line deflection, unless you have a load-cell. But, useful in some situations, all the same.
Pics inform a lot for the purpose of suggestions or discussion.
POWs are cheap. Being able to have a controlled release under load can save the day.
