Pull Rope Tie Off

Discussion in 'Rigging and Roping' started by KevinS, Nov 22, 2017.

  1. KevinS

    KevinS Well-Known Member

    Joined:
    May 10, 2009
    Messages:
    1,535
    Location:
    ontario
    So for a pull rope to tip a tree set from the ground typically set a running bowline around the main stem or a rope through a good crotch and basal tie it.

    Using the basal tie off if you put a rope over a branch it can run straight down putting 200% force at the crotch.
    If you candy cane the rope down the trunk it twists/pulls sort of into the trunk/branch collar. Does it help or spread the force at all etc into the trunk instead of just the single limb?

    I know it still gets the 200% instead of the 100% of force with a runner. But does it help relieve some tension on the branch you’re isolated over.

    Thanks
     
  2. TCtreeswinger

    TCtreeswinger Well-Known Member

    Joined:
    Feb 8, 2014
    Messages:
    412
    People say the same for a questionable TIP basal anchor I've found it's more about angle of deflection than anything. Not much help I know...
     
  3. rope-a-dope

    rope-a-dope Well-Known Member

    Joined:
    Nov 5, 2015
    Messages:
    289
    Location:
    Asheville
    I could see it being a good move for a w. pine so you don't rip the limbs off with any mechanical advantage. They are hard to get the main stem isolated.
     
  4. NE Tree

    NE Tree Well-Known Member

    Joined:
    Feb 2, 2015
    Messages:
    887
    Location:
    fremont, Ne
    It's all about the angle. When pulling a tree, you're not going to be at a 180° angle, closer to 120 or so. This angle will determine load minus any friction. Also, when pulling a tree over, tip failure isn't as big of a deal with a basal tie because you usually have another branch that will catch it. With a canopy tie, if it breaks, you're S.O.L.
     
    Tom Dunlap likes this.
  5. KevinS

    KevinS Well-Known Member

    Joined:
    May 10, 2009
    Messages:
    1,535
    Location:
    ontario
    I totally agree but even with a basal tie off day in a black walnut or something if your TIP breaks and the rope drops 8 or 10 or 15 feet to the next crotch once it’s moving you could lose you pressure and if you are pulling with say a b&t there’s no way you can get the slack recovered to not be mid air f’d.

    Just another point that either way it’s better if your TIP stays whole.

    I agree about the white pines as well even if branches are smaller or weaker spreading the load makes less branches break.

    So I can see if the rope is candy caned it grabs/pulls the main stem as much as the TIP crotch/limb. Therefore reducing the weakness likelihood seems logical.
     
  6. evo

    evo Well-Known Member

    Joined:
    Mar 26, 2009
    Messages:
    2,131
    Location:
    My Island, WA
    I don't see much if any MA when pulling trees over using a base tie vs a running bowline. The strength is in the leverage applied. The closer to 90* your pull is the more leverage force you can apply. Typically the speed of pull is the limiting factor, hinge wood has a limited amount of time to function before it breaks with any torsion on the stem or crown weight. It's a balance of power and speed which can pull hard enough and fast enough to over come the gravitational forces, and shear weights.
     
    colb likes this.
  7. Tom Dunlap

    Tom Dunlap Longest registered member

    Joined:
    Jun 1, 2001
    Messages:
    14,825
    Location:
    Retired in Minneapolis
    There is soooo much reading material that arbos need to look at.

    Read Don Blair's Arborist Equipment

    Read The Art and Science of Practical Rigging by Pete Donzelli

    The mythical 200% load is only found when you're lifting unicorns

    Once the enemy of work, Mr. Friction, enters the arena all bets are off

    To reduce the load on the TIP spiral the rope around the branch and down the trunk.spread the spirals between branch and trunk to have the most efficient use of Mr. Friction on that leg.

    Wtih the wraps you can reduce the load to a theoretical 1:1 or 100%

    Next, like others already said...rope angle is key

    Next, rope stretch

    If iwas ever concerned about limbs breaking off and my TIP sliding, for rigging or climbing, I would STOP and change. No guess work or it will becomea Utube FAIL!
     
  8. KevinS

    KevinS Well-Known Member

    Joined:
    May 10, 2009
    Messages:
    1,535
    Location:
    ontario
    Tom I’m glad to hear I’m not the only one slinging unicorns around lol.

    This was never a worry about breaking out a tie in we were working with sufficient TIPs. No danger there and rope angels on this job were also no problem all of these trees were pulled over by hand with 1 or 2 guys.

    My curiosity was just if by candy caning the rope and that gets the rope nicely seated into a crotch and helps it stay snug to the main stem and not roll out what if any extra strength does that provide? Compared to up over and straight back down not necessarily snugged into the main stem.

    Load distribution may be a better description of what I’m looking at compared to strength.

    We were working safe ample room no problems arose it was a why do you do that question posed to me and I was looking if there was a good breakdown on the idea of it
     
  9. Tom Dunlap

    Tom Dunlap Longest registered member

    Joined:
    Jun 1, 2001
    Messages:
    14,825
    Location:
    Retired in Minneapolis
    Trees/wood is so strong in compression. Doing a trunk wrap takes advantage of that

    When I was learning about this stuff I'd find a small flexible tree like a crab apple, and put ropes in it different ways. Then add a pull load and watch the flexing. This is a good way for the whole crew to learn. Walking on the ground with the rigging at eye level is a great way to dissect the setups

    Or have that unicorn pull...
     
    colb and kiteflyingeek like this.
  10. rope-a-dope

    rope-a-dope Well-Known Member

    Joined:
    Nov 5, 2015
    Messages:
    289
    Location:
    Asheville
    I think the question of pull strength is more about the tree conditions. The rope path might shift the forces slightly towards the tree center of mass, but if the main concern is a failure of the limb/union/branch supporting the pull rope, the best option is probably a second pull line set lower and using both lines together.
     
    colb and Tom Dunlap like this.
  11. grappleyarder

    grappleyarder Active Member

    Joined:
    Aug 3, 2010
    Messages:
    156
    Location:
    Gatineau, QC
    Analysis via physics/mechanics requires we create an imaginary section at the pulling side and the tie-offside at the branch and determine the forces.

    For the branch, no change if we have trunk wraps or not...
     
  12. Daniel

    Daniel Well-Known Member

    Joined:
    Jul 1, 2006
    Messages:
    2,784
    Location:
    Suburban Philadelphia (Wayne)
    good falling technique is a synthesis of setting pull line(s) , proper pre-tensioning, good cutting technique and coordinated pulling.... I pull with equipment 95%+ of the time, often overcoming extreme back lean and side lean.... I prefer high pull lines, so setting the pull line is very important.. In crucial scenarios, if there is any question about placement, its best to take the time to set the line by hand. Either way in critical situations, a test pull to see how the tree reacts and make sure the tip can take the load is needed.

    Getting a wrap on the trunk is not much of a concern , and generally not practical when setting lines with a throw line. You are better off focusing on setting a high pull line and cutting technique..

     
    mjp, chiselbit, NE Tree and 3 others like this.
  13. TheTreeSpyder

    TheTreeSpyder Well-Known Member

    Joined:
    Jan 15, 2002
    Messages:
    1,499
    Location:
    Florida>>> USA
    i've always felt there is an elusive quality/quanity in the over the top/end and back to base type pulling.
    .
    Basal tie: 1 thing for sure;generally can tie on the back side; knot up, easy for feller to find after drop, untie, let groundies pull out; sometimes w/truck; as opposed to hitch buried someplace in pile of brush at top of spar, knot side down!
    .
    In a full tree compression i don't think line gives anything in power or ratio;
    As we go into top flexing; i see a more of a gradual bend by line over top and cradling spar curling top forward
    >>than a hitch around 1 point for a 1 point pull/less gradual that can't take as far as safely
    >>more flexxed top can then store more spring loading into system
    Also note, pulling spar forward with either strategy, but over top is also pushing the head down somewhat
    >>for more rotational input on the target trying to rotate
    i will note it is best to sweat/swig HARD (and vibrate) as much purchase as possible over/thru the friction buffer made at top
    >>part of reason for different 'faiths' in this; maybe in subtle handling differences and practices that 1 does and another doesn't
    >>Like hard sweating/swigging in of the rear side of pull
    .
    Depending on scenario, over top is often highest leverage point to grab,many times also the most centered pull.
    Turning vertical felling sideways to horizontal rigging, can throwline thru strong crotch before Center of Gravity
    >>bring end to climber to hitch or sling to basal (of cut).
    >>i think the more cradled, rotational nuances are easier seen hear.
    .
    Quite simply,besides the pull on target in either strategy
    >>i think i see the over the top strategy's bend, trying to pop out and 'dump it's load' and relax to a straight line pull
    >>as all pulls try to be straight lines
    >>there is an extra line of force that is not in the 'direct' to hitch pull
    Craning a horizontal log up to lift (my final rigging direction choice is to drop it up!) on hinge
    >>over end thru V notch to hold then tied on back once again gives most leveraged and rotational force i think
    >>also further rotation torque/later stopping than if tied to top
    >>very much prefer, cuz seems easier to then force tearoff event at cleaner vertical, defter handling
    >>this move is not a basal tie to get it to work,but then less loaded elastic storage length too fairly
    .
    if both ends of line lace over yours shoulders, around under armpits and back to selves
    >>then pulled as 1 to pull you forward vs.
    over shoulders,under armpits and tie to front of chest>> to me i imagine the pull force forward,and the push down on shoulders too, for a more rotational input; not singular force to calc at any rate!
    .
    Overwhelming with by bulldogging with power gear surely is strong way to go
    >>but i see double edged sword as in all, the strength of overcoming wood, can also overcome constitution of wood for possible disaster of higher loaded order
    >>i trust that is metered judiciously to target; generally lower forces in equation that get job done are safer
    .
    Sometimes perhaps must fall back and respect :
    "Not everything that can be counted counts.
    Not everything that counts can be counted."
    >>And fact that it was a favorite quote on the wall of a real "number's man" (Einstein)
    .
    Of all the stuff i've instinctively followed up on from such feeling;
    >>been called out on etc. here and theres, to me this over the end/top lacing would be the unproven
    >>but i guess must be true to my instincts and models on this, as they have been so absolutely true to me please.
     
    Last edited: Nov 28, 2017
    SomethingWitty likes this.
  14. Daniel

    Daniel Well-Known Member

    Joined:
    Jul 1, 2006
    Messages:
    2,784
    Location:
    Suburban Philadelphia (Wayne)
    The up and over basal tie -off is not a 2:1 MA system. you need to pull 2 feet of rope for every foot of movement for 2:1 MA
     
  15. treehumper

    treehumper Well-Known Member

    Joined:
    Apr 23, 2006
    Messages:
    6,453
    Location:
    Ridgefield, NJ
    Where a good union exists the over the top basal tie is an easy set and, as Dr. John Ball pointed out, safer set up to untie. Nobody has to get up into a suspended canopy to untie or leave the rope and risk it being cut.
     
  16. TheTreeSpyder

    TheTreeSpyder Well-Known Member

    Joined:
    Jan 15, 2002
    Messages:
    1,499
    Location:
    Florida>>> USA
    i'm not sure chasing this mythical windmill around again; will find magic unicorn force at the end of rainbow
    >>But let's stir this around some more please.......
    Let's squint to not just be blinded by measuring forces;
    >>to draw focus on another possible multiplier:the force directions the forces work, how many directions that is
    >>And if these directions/vectors miss/confront/add to / OR LEVERAGE each other
    >>then consider elastic spring storage as a force resevoir consideration
    .
    Preview:
    .
    If we basal tied ; up over the top; and stood at base of tree pulling downward.
    >>If Zer0 frictions, this would be 2/1 force>> it would try , though unsucessfully to compress top with 2 legs of pull
    Introduce friction at top; we'd have 1xPull
    >> + whatever force made it thru the friction buffer, to tension the rear leg/basal tie.
    If we sweat/swig a line length purchase from the rear leg side to the control leg side that we pull
    >>we raise the tension contribution on the rear leg, and the friction buffer now helps maintain it
    >>The longer the rear line/'leg'; the more we can work this leveraging
    >>and the more elastic length to store it in
    As we now hold the control leg and walk backwards; the angle over the top opens up
    >>now even with Zer0 friction, would not have 2/1
    .
    Leave force behind, and look at directions inflicted:
    BUT; let's not chase the 2/1 this round:
    In straight forward/ Bowline around the top type pull
    >>the rope itself pulls in 1 direction on the target
    In over the top/basal tie
    >>the rope pulls forward AND pushes down
    How does this extra direction vector play in?
    .
    Sift out the forward pull in either scenario
    >>focus on the downward push of over the top (that happens as also being pulled forward)
    if downward part of force in over the top/basal tie is straight down into spar, no/minimal effect
    >>but if getting downward pressure as top is already leaning forward>>that would tend to help rotation
    If rotating on hinge/pivot; and both systems pull forward same force
    >>and 1 system puts in extra portion of force in way that would assist rotation>>should be more favorable
    .
    Also:force resevoir consideration>>
    ESPECIALLY if we can deform and /or put spring force in top i'd think; gives another quanity
    >>if pull forward with simple tie on static rope >>your pull stops>>line pull stops
    >>if pull forward with simple tie on elastic rope>>your pull stops>>line keeps contracting
    >>this pull on target continues then >> if you are still anchoring line
    .
    If flex top in felling or branch in rigging
    >>can present another point in system for elastic storage/follow thru pull
    BUT: a simple Bowline pull would flex top/branch at 1 point
    >>be more sharp a bend, more risky>>can't push as far
    VS. a gradual bend that would be more positive, and trust to spring more for more elastic response
    >>over the top/basal tie etc. give this bracing/gradual flexxing with the extra added line of force pushing and bracing from behind in a more gradual arc
    >>i'm not sure if the better 'feel' i see is from the more follow thru on the pitch>> but seems different
    .
    time for work.....to be continued!
     
  17. Daniel

    Daniel Well-Known Member

    Joined:
    Jul 1, 2006
    Messages:
    2,784
    Location:
    Suburban Philadelphia (Wayne)
    Definitely has its advantages and is SOP for most whole trees... but we didn't need Dr Ball to tell us that!

    The footlockers will tell you that they can feel the difference when footlocking... but that is a different scenario than using a pull line and while there is definitely compression created, it does not add to the force of bending moment. Any changes that arise out of the fishing pole effect spreading force over the bending top, rather than isolating it at a single point are minimal and only a consideration when using a huge amount of force, which rarely happens
     
    Last edited: Dec 4, 2017
  18. TheTreeSpyder

    TheTreeSpyder Well-Known Member

    Joined:
    Jan 15, 2002
    Messages:
    1,499
    Location:
    Florida>>> USA
    i get this chained in Plato's cave feeling sometimes..
    My instincts have been pretty good to me on all else; i must say,
    >> and so be so true to them on this even after much consideration;
    i can't define as both the same; which generally leads to 1 greater & 1 lesser.
    .
     
  19. Daniel

    Daniel Well-Known Member

    Joined:
    Jul 1, 2006
    Messages:
    2,784
    Location:
    Suburban Philadelphia (Wayne)
    I agree with this in theory.... in practicality it doesn't make much difference in the field wit the equipment and techniques I use... and I think we a re better off focusing on improving other aspects of our game, and teasing out the physics involved there... in other words this effect doesn't make enough of a difference to matter much..

    Mostly just use this technique because its easier to set up and tear down, and is good enough to get the job done 99%
     
  20. KevinS

    KevinS Well-Known Member

    Joined:
    May 10, 2009
    Messages:
    1,535
    Location:
    ontario
    This is what I was looking for thanks. I found my unicorn
     

Share This Page