WOW!
i'm sew sorry, as i wove on web and not everything got printed. But eye saw fit to answer all questions methodically. Actually, in depth, squeezing these things out from myself and assembling them to answer the diffrent queries that might result. Trying to trim back as i became self concious as to length, repetition, politeness while being comprehensive. But, a-lass; after all that the power flashed from a storm; and it was gone! So, revisiting all that and making previous post was all that i had the time and spirit for at the time. Also i was leaving room for other responses! i do that sometimes, back off to see if someone else would like to speak, sometimes waiting a few daze...........
We don't pull everything down with a truck, sometimes don't do it for months, sometimes a few times a week. We just don't rule it out. Sometimes it is the quicker set up, less fatigue way to pull, needs no anchor, it is mobile power, present on job etc. It also has a wealth of power in reserve, quickly accessible in a pinch if right at the wrong time that mystery wind did catch ya wrong, or other miss-calcualtion.
i usually use 5/8" line on truck pulls, and go gently. We generally drive forward, with a man at 90 degrees to the drop watching me (i generally nod when the tree starts 'breathing' some), and top, while directing driver. Sometimes another man watching all, but specifically watching truck's path, so driver can specifically watch the previous man's command. Pre-stretching the line, set brake and brace tree, can take more time and effort manually, prior to even backcutting any.
i think with the more power available you can bring down larger, more off balance things safer, with less air time. Basically by invoking a superior hinge to usher the drop. Even in climbing, sometimes i will have the guys pull down on the end of a horizontal rigged limb, pulling the limb into the facecut with more hinge, some times getting 180degress of hinging almost horizontally. We do it the same way as a takedown, by pulling on the end of the lever, so the hinge folds earlier, with more fibre, giving more support and braking through the arc the hinge ushers. This gives some control over direction and speed, as long as the hinge hangs on.
So, having a wide face to allow a wider sweep, and a hinge that can achieve that too, can impact the ground less, with the most directional control; in the air, or on the ground. Sometimes to compound this, we use 3' tall tight stacks of brush at the calculated initial contact points. Sometimes, knotching the top of the first leading levers on the removal, then slightly undercutting them. The idea is not to make them dangerous, but to have them fold at so much force, dissipating it. This keeps them from being loaded springs trapped under tons of force, digging into the ground, absorbs a lot of shock; while maintaining their pull in the favorably in the felling direction! Sometimes if we want the head to roll left, we can set it so that an even fork hits the ground first, and the right leg ends up being the longer of the 2 after folding, serving to the left, of course a block or face dutchman can help some here too.
With more positive hinge control, we can also lessen shock by not laying into the lean as much, whereby, that would be feeding directly into gravity. So, less impact i think on the same drop! Even without a truck as the pulling force, we do try to maximize the leveraged pull, and the hinging to reap all these benefits. With more pull, we can get more hinge control, sometimes to reach this, we use the truck.
Sometimes i will bring a driver to the sideview of the tree and show him we are dropping this straight up and down stick, it is 20' lever. If we are pulling with 50#, that would put 1 ton of force at the hinge on a balanced load. It will go over! But we want to bring it over earlier, with a thicker hinge for slower fall. So he can put together a 3/1 while i quiz him on it, then bust hemaroids with 2 other guys, as i take my time to cut the tree, or he can use the 'mule' to pull it. If he wants to do that, and he pulls too hard, he will hand pull all future trees over by hand; with 2 other cussing guys........ So the only way he can screw up is to go too hard! Really, just setting the line and pulling (bow stringing) sideways can be quite powerful too.
We don't really try to bend the top, that kinda got started with discussion of bowlining a ring to the top, or lacing line over it to snake down back of tree. Insamuch that you could bend with either hitching setup, but, the bowline would continue pulling on the same point, while on a flexing top there would be more forgiveness and strength in the other method. But, we do look for movement at the back of the backcut,and the top of the tree, for earliest percievable motions of each during cutting, as they are strategically the most leveraged points of each to witness this readily.
Whether in a self torquing rig in the tree, or lacing the line over and down the back spine of the tree, i think the pull goes to the knot/first hitch. That means that, just like a line going over your head, down your back and tied to your ankles, would push your head down and try to pull you forward from the ankles flippinng, so does the same force act on a tree! Though it might not be able to flip a tree or limb around, it is a diffrent pull than a line pulling you under your armpits forward! i think that bend in the rig, or top of the tree, wants to 'dump' its bucket as it straightens out, and this is more apparent with an acute angle; ie closer to the tree. i think this delivers somehow additional urging and force, but don't know how to examine, test and prove it, beyond observation. i think that the more acute the angle, the more pronounced that is, like in the example of standing closer to the tree, with line high; another one would be as the line snakes over the top over a rear leaning flared point. This seems to be like cocked back to me (more acute angle?), and the the line seems to want to open out and be straight more.
The bark strips that came off with these pines i spoke of, seemed most notably strong and leathery above all else to my forensic observation, that is why i offered it. In the centerpunch hinge, we might be weakening it some, but we are after flexability of younger fibre. i watched an Eric Sorenson film produced by Stihl so many times about how the center fibres where stiffer, that i beleived these 2 experts. i think it is more pronounced in some trees. When pushing flexability and depending on hinging it to the max, i consider that imagery that they offered, for it seemed to fit with some of my experience. This included the leathery, younger strips of pine; philosophy examples of flexable saplings making it through storms, where stiffer trees didn't etc.
Hope i answered 'em all that time..................
