speed line technique

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dfdavis

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Several times recently I could have used a speed line to remove limbs. I saw the section in Sherrill catalogue, but was wondering if anyone had additional information on technique and hardware required. A good diagram or internet source would be appreciated.
 
THe Art and Science of Practical Rigging book and video series has excellent examples.

Key thing to remember is not to dump the load onto the speed line, lower it on.

A recent experiment we did on a tight speed line (which it has to be) showed the weight at the anchor points of the speed line was up to 5x the weight of the load.

So, imagine the speed line is 10,000lb breaking strain rope, you've tightened it up at say a 45 deg angle, you lower a 500lb limb etc onto it, the force at each end of that speed line is around 2,500lb.

That equates to 25% of breaking strain which exceeds safe working load requirements.

Now if you dump a load the force equates to 5x the weight for every 5 feet the load falls. So imagine you dump that 500lb load 5 feet, force of load is now 2500lb, multiply that by 5 again to get the force at the anchor points of the speed line = 12,500lbs you have just exceeded the breaking strain of your rope.

So, small sections, lower them.
 
Thank you, that sounds like a good source. Is that book available through arborist suppliers? Or where might I get a copy? Thanks, D
 
Ekka said:
THe Art and Science of Practical Rigging book and video series has excellent examples.

Key thing to remember is not to dump the load onto the speed line, lower it on.

tried speedlining years ago taking down some big lawson cyppress. we had some time on our hands, and nothing to damage below. Got a bit cocky and dumped a whole 20'' top onto the speedline(about 300kgs). it did'nt snap the line, but it ???? near uprooted the tree. i think the movement in the top anchor point saved the line, and the fact that the top swung onto the line, rather than just dropping.
never bothered with it since :D
 
The input force needs to be low, and not impacted as Ekka relates. The bend in the line at that loading will give potential loading by this Bent Line Leverage Calculator ; how much of that loading is achieved depends on the angle of the line from anchor to anchor. The input force, bend in line and angle of line are all multipliers to produce the line tension. The support trees then each get loaded with the line tension pulling at angle to further multiply leveraged force on the tree. The higher all that happens, the more leverage must be further multiplied for length from hitchpoint to roots; to consider roots as final support.

You can evacuate wood over obstacle, leaving less dragging mess etc., free travel towards truck. i call it a gravity bender, and might have lowering line that lowers on that new gravity path. Plus i just want to see if same guy that got sent after the blue sky hook yesterday, will even move to get something called a gravity bender. Dave Spenscer did the base for the calculator above, and also this animation on Efficient Transitions and Use of Speedline

i've been guilty of using a Speedline as 2/1 to Start , so crew pulls something around on the hinge that couldn't be speedlined easily from it's present position. Then as line straightens out, power of 2:1 is gone and ready to tearoff and slide on line.
 
Thor's Hammer said:
Ekka said:
Key thing to remember is not to dump the load onto the speed line, lower it on.
tried speedlining years ago taking down some big lawson cyppress. we had some time on our hands, and nothing to damage below. Got a bit cocky and dumped a whole 20'' top onto the speedline(about 300kgs). it did'nt snap the line, but it ???? near uprooted the tree. i think the movement in the top anchor point saved the line, and the fact that the top swung onto the line, rather than just dropping.
never bothered with it since :D
Sooo you tottally understand the forces on a load, you completely disregard all prudent rope and rigging procedures just to check out what happens when you overload systems. THEN you abandon use of the system altogether. And you almost destroy, (I assume the roots are damaged or the cambium effected) a client's property in this experiment.
I would respect your experiment if you learned anything from it. On the face of it sounds like just another yahoo. sorta like "hey if I redline my car will it blow up? Oh gosh, my car blew up maybe i'll only drive a truck from now on".
Speed lineing is a by far more effecient way to move brush out and away from the rigging point.
Nothing seems so dumb as seeing tree guys ropeing out trees directly into a bad landing zone when they could zip it right into a better landing zone.
My advice to you is dont brag about being unskilled about your job.
Frans
:dizzy:
 
Frans-c'mon man lighten up a little. Have used the speedline (also called zipline ) on big Doug. firs. Only used it when lowering branches would have been impractical, used an old climbing line 1/2". It has to be tight to work good. We had one end tied in the tree being removed, the other end we tied to a tree past the chipper, tightened it with a poormans comelong (bowline on the bight ). You need at least six-ten biners to make it work, just be carefull not to put one through the chipper in all the excitement.
 
TS that animated demo was excellent.

Frans, I hope I dont get on the wrong side of you! ;)
 
Hey frans, lighten up...
its was about 16 years ago when i was young and silly, and it was a yard below. to the best of my knowledge, it was another 5-6 years before i heard the term speedline used. The idea of doing it came out of our heads, and we rigged it with stainless yachting equipment and 25mm terelyne line. yeah it was pretty stupid in hindsight, but sometimes you have to push the envelope... ;)

since then we have dismantled thousands of trees in tight situations and have never really felt that we needed it. Possibly using a crane on a regular basis on tree work has been better for us, although i wouldent knock an arborist who uses the system efficiently. the thing with the crane is you can lift and place your brash and timber wherever you want within the cranes working radius

really liked that animation though :cool:
 
Lifting/lowering device, Greg Good put a Harkken winch on a steel frame that can be strapped to a tree like a hobbs, and used tolift loads up to a ton, and lower them as well. A must have for anyone serious about med/large removals. :umpkin:
 
TheTreeSpyder said:
Plus i just want to see if same guy that got sent after the blue sky hook yesterday, will even move to get something called a gravity bender.

TS, I don't claim to always understand all of your explanations related to items you decide to expound upon. But when you sneak some good humor in there I can really appreciate it. We often send new Scouts to find the left handed smoke shifter...your sky hook/gravity bender is a hoot.

Excellent animation of swinging that limb.

MB, great video of speedlining limbs...that guy wasn't messing around...zip, zip, zip.
 
clearance said:
Frans-c'mon man lighten up a little. Have used the speedline (also called zipline ) on big Doug. firs. Only used it when lowering branches would have been impractical, used an old climbing line 1/2". It has to be tight to work good.
O.K. O.K. I'm sorry, I'll lighten up just a bit :)
Hey, by the way the 1/2" old climbing rope is a real bad idea for this application. I'm not a brainiac but the forces on a speed line are up to (5) times greater even with just a small shock load then with simply lowering the branch. The tighter the high lead (zip line), the more forces applied to it... That prob. jumps the load up to levels your rope has not seen before.
Ekka (what kind of name is that? just curious) No offense intended, thanks for the check)
Frans
 

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