Directional pull line for felling

[hobby climber]

Would this work ? What if you tie a rope to the upper part of the spar and its other end to mid trunk. Then run the rope through a block that is attached to your truck. This would equalize the pull force exerted on both attachment points of the tree as it's pulled over with truck. Your thoughts...

 

[Gord]

Yes, splitting the crotch is one possibility. Another is that the stem, if not straight, will be induced to bow more so than it would when pulled solely from the top.

I disagree here...a fishpoled line will produce no more 'bowing' than a line tied on directly. The crotch still has to exert the same forces regardless of how the line is tied. However, if a fishpoled line is passed around the trunk a few times before it's tied to the base, it will add some rigidity to the tree.

edit: I rethought this. The only way that the fishpoled line will produce more downward force on the crotch is if the pull is near to vertical so that the 'doubled' line will give somewhat of a mechanical advantage. Given that a pull line should pulled from at least a tree length away, and that the pull point will be below the top of the tree (unless it's a spar) the angle will almost always be more acute than 45 degrees (more so for a back leaner), also given the friction in the crotch, the MA will be very little above 1.

 

[arboromega]

hobby climber, pulling a tree with a truck is usally bad news in my opinion, too much to go wrong.

 

[glens]

I disagree here...a fishpoled line will produce no more 'bowing' than a line tied on directly. The crotch still has to exert the same forces regardless of how the line is tied. However, if a fishpoled line is passed around the trunk a few times before it's tied to the base, it will add some rigidity to the tree.

edit: I rethought this. The only way that the fishpoled line will produce more downward force on the crotch is if the pull is near to vertical so that the 'doubled' line will give somewhat of a mechanical advantage. Given that a pull line should pulled from at least a tree length away, and that the pull point will be below the top of the tree (unless it's a spar) the angle will almost always be more acute than 45 degrees (more so for a back leaner), also given the friction in the crotch, the MA will be very little above 1.

Think it through some more.

If you "fishpole" the line, it will pull <i>between the upper interface and the lower</i> with the same amount of force you exert on the "free" end of the line (discounting friction).

If you pull from 70' away to 70' up, you're pulling straight down to the ground at a level of 71% the force you're exerting on the line.&nbsp; That will be the case in either scenario.&nbsp; If, however, you've got the line "fishpoled" down the tree, you're also trying to compress the top interface to the bottom attachment with the same (100%) force as you're pulling (ignoring friction at the upper point) for a total downward force (as the upper point sees it) of 171% if the stem were plumb.

Why stress the upper interface that much?

If you wind the line around the stem on the way down before anchoring it back to the stem below you'd indeed decrease any "bowing" effect to the extent of the number of wraps along the way, but you're <i>still</i> trying to compress (and now twist) it.&nbsp; Remember, the line is going to do everything it can to become as straight and short as possible when you pull it.&nbsp; In any event, that sounds a bit more difficult than simply isolating the upper point with your throwbag, etc. and using a running bowline.

Glen

 

[Gord]

Reading these over I understand that you're right with the math Glen. However, aside from the math your post doesn't show a good grasp of real world tree work.

 

[a_lopa]

 

[glens]

Thanks for the half-a-nod, Gord.&nbsp; I used a 45&deg; angle of pull to illustrate the best worst-case scenario.

I only use a pull line in situations where the tree (or parts thereof) can be felled but they exhibit notable side or back lean very near and threatening stationary targets.&nbsp; I don't do it every day, but it doesn't occur extremely infrequently either.&nbsp; Are you saying I should cease using my throwline to isolate high points and running bowlines up to them?

Regarding use of a vehicle of some sort to pull, I dislike it very much due to the lack of delicacy/feedback, but when I do it, the pull is redirected from a stationary object with a low-mounted block.

Glen

 

[hobby climber]

So Glens, what you are saying is if you have to use a vehicle to assist in pulling over a tree, it should be stationary? I do understand your logic but what about the what ifs ... Last year I took on a job to TD seven dead/dry "carolina poplars" situated about eight feet inside a white pine stand along a field. The pines -25-30' & the dead trees -55-60'. The dead tree could only be drop ed in the field and not into the pines. What I did was secure a bull rope to the upper (stable) part of the trunk and the other end about half way down. Then ran the rope thorough a block that was attached to my truck. I notched the base of the trunk for direction and had assistant back cut as I gently pulled the tree into the field. With this set up it gave equal pull force to the attachment points on the trunk and reduced (I believe) the risk of snapping the spar. It worked out fine for me is this situation. I know this may not have been the best method but its all I could think of at the time given that there was nothing else in the field to anchor to. If there is a better way to have done this...I'm all ears. Blocking down the wood was not an option, the tree I don't think would have supported it. Thanks HC

 

[John Ellison]

I use a truck regularly to pull with and see nothing wrong with it in some situations because it is so much faster. If I have a dozen pine trees to pull away from an old fence and they are sound green trees I will use the truck every time if I can easily set up redirects to where I can see the tree.
True, it is a receipe for disaster if you are talking about two guys, unfamiliar with tree work in a hopped up 4w drive yelling and waving at each other, but I am sure that does not apply to any of us on AS.
In a sticky situation I use one or two Maasdam rope pullers. If it is real sticky I dont touch any thing and turn around and walk away. I regularly tell people that they need an arborist.
To get back on topic I would rather tie at the top instead of the fishing pole method to eliminate what I consider the foul holt of the line running over the crotch, the line would not move much there but it is the weak link and could damage or burn the line. If it is going to be a hard pull and I cant isolate the top I use 3/8 wire rope to avoid any chance of burn right in the middle of the rope.

John

 

[NeTree]

Hobby, coupla things:

When pulling trees over using a vehicle, consider: If the tires start to slip and you break traction, the tree (if it's heavy enough) can actually pull you back further than where you started, risking snapping the tree off at the hinge when the kerf closes.

In your example of using a block, you actually INCREASED the force required to pull the tree over; since the pulling force was effectively applied (roughly) in between the two attachment points on the tree.



Dan,

In your example I may have used the 3:1 MA system tied to the cedar and gunned for the target with tapered hinge, to be fancy. Since that would pull the tree slightly towards the cedar, it would ensure counteraction to any lean towards the house. More likely, I just would have attached my come-along to the cedar, and then a bullrope directly to the tree being felled. With 20 feet of pull at 4,000 swl, the tree would have to have one helluva lean to not have enough cable to pull it over center.

 

[glens]

HC, the only time I'll pull directly to the tree with a vehicle is when the vehicle is on a hill and the resultant pull is nearly horizontal.&nbsp; Any other time I'll affix a block to a very low point and pull through that.&nbsp; If there isn't a suitable fixed location for that block, I'll set another vehicle there and use the trailer hitch to fasten the redirect.&nbsp; I don't want any upward pull on the "mule" which might serve to reduce traction, with the problems that can cause (as Erik mentioned).&nbsp; I also keep the back cut filled with wedges (in fact, try to actually wedge the stem over merely using the rope as an assist) just in case the rope or stem suddenly becomes ineffective for whatever reason.

Dan, what can I say?&nbsp; That must have been some sight!&nbsp; My math shows an angle of 25.6&deg; with 2000# direct pull resulting in a horizontal component of 1801#, hahaha!&nbsp; Also, I very much prefer to use a Ford.

Glen

 

[arbortec]

I think that the direct tie to the top of the tree would be most efficient(no force lost to friction)- also if you rigged a rescueceder to your rope and added a fiddle block(say 5 to 1) tied back to a solid anchor point you couldn't lose. The force generated with that sort of rig would pull over a tree with a good lean even.

 

[hobby climber]

NeTree...an interesting point. Your saying that because the block (on my truck) pulls equally on the two attachment points on the tree, it would be as if I had attached only one rope to the tree between the two attachment point. This would make my example less efficient than if I had attached the rope higher. That makes sense...thank you for the eye opener. :Eye: (Ya learn something new all the time on AS.com)!!!

 

[John Ellison]

Dan, I think he was refering to HC's situation. I could'nt read your diagram on my screen, looks interesting though.

John

 

[John Ellison]

Dan, No its a Mozilla browser. I think I answered your question. I looked in the help section a bit and tried to match your key words up with Mozillas but figured that supper sounded better. Thanks

John

 

[arbortec]

my drawing sux but maybe this will better illustrate.......

 

[NeTree]

Also, I very much prefer to use a Ford.

Glen

 

[geofore]

rope/wedges

I've seen Glens work with wedges, not often that he would have the need for a truck or rope to do a pull with his ability using wedges and notch placement to direct a tree. Any of you guys using 4x4trucks or 2x4trucks to pull, you'll have much less wheel spin if you load the truck (fill the bed with wood) with some weight for more traction before you pull. Once the wheels spin you have no traction and the tree can pull the truck backwards. So make sure the guy in the truck doesn't floor it for a good take off. What is your back up if the rope/cable breaks?
Dan, I liked your pulley set up, I've done setups like that and gotten comments that it looked like something from outerspace. When the tree lands where I said it would all the comments stop and they ask," How did you do that?" Even seeing it done they don't believe it works.
All you new guys, heed the warnings about useing a pickup truck to do the pulling, the trees weigh a lot more than a pickup truck. You need to learn how to use wedges and pulleys. It's good to have more than one trick in your bag. There's more than one way to skin a cat.

 

[glens]

Dan, No its a Mozilla browser. I think I answered your question. I looked in the help section a bit and tried to match your key words up with Mozillas but figured that supper sounded better.

John, does your cursor appear as a magnifying glass with a central plus sign while over the image?&nbsp; If so, left-click once and it should jump to full size.

The detail level in the image is quite poor because it was saved as JPEG.&nbsp; If it had been saved as GIF or PNG it would have much better resolution and would be probably 1/10 the file size.

Glen

 

[glens]

NeTree...an interesting point. Your saying that because the block (on my truck) pulls equally on the two attachment points on the tree, it would be as if I had attached only one rope to the tree between the two attachment point. This would make my example less efficient than if I had attached the rope higher. That makes sense...thank you for the eye opener. :Eye: (Ya learn something new all the time on AS.com)!!!

Actually, I think that method was a fine idea.&nbsp; I somehow envision the forces being split proportional to the length of line in each leg, the shorter of which would act the strongest.&nbsp; If that's true, using a movable block as the pulling point would redirect the forces toward the top as the tree falls toward you, and there's nothing wrong with spreading the load out like that.&nbsp; It just seems a bit extra work, is the only down-side as I see it (well, that and the fact that the initial median pull point would then lie closer to the lower point, requiring maybe greater pull for the same effect).&nbsp; I'll probably ponder the math on that one while sleeping...

Glen