# Highline Safety



## squad143 (Jan 9, 2011)

Been a while since I posted a video.... been more than busy.

This fall I had a buddy (also a climber) doing some work with me. It was great having another climber to trade ideas with, we both have learned quite a bit off of each other.

On this job (removal of an Ash), there was a large cavity in the base of one of the co-dominant stems (stem furthest away from the cottage). We had some concerns of it breaking with the added weight of a climber and some of the rigging forces.

In these situations you can put a safety in an adjacent tree, but even then you risk swinging into your TIP tree if things fail. In this case, there were no trees in close proximity to tie into. My friend came up with this (highline between two trees) to use as a safety.

I shot about 1/2 the video from another tree I was removing using my camcorder (forgot my helmet cam that week) and the other half from the ground.

Ideally a bucket truck would have been the best setup for this removal, but I don't own one.

[video=youtube;JjJILht_aQ8]http://www.youtube.com/watch?v=JjJILht_aQ8[/video]


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## ropensaddle (Jan 9, 2011)

squad143 said:


> Been a while since I posted a video.... been more than busy.
> 
> This fall I had a buddy (also a climber) doing some work with me. It was great having another climber to trade ideas with, we both have learned quite a bit off of each other.
> 
> ...


 
I have done that numerous times on may falls, it is just better than falling.


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## NCTREE (Jan 10, 2011)

Hmmm! I wonder what the mechanical disadvantage is at the middle point of your rope that is tied off to the two trees your using as a safety line? I thought it was 50/1... I could be wrong though. Anyone know?


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## deevo (Jan 10, 2011)

squad143 said:


> Been a while since I posted a video.... been more than busy.
> 
> This fall I had a buddy (also a climber) doing some work with me. It was great having another climber to trade ideas with, we both have learned quite a bit off of each other.
> 
> ...


 
Looked good Chuck, we've done something similiar as well at times this year, as long as the neighbouring trees can take your weight and you can trust em.....the way your going you'll have a lift/bucket soon!


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## squad143 (Jan 10, 2011)

Thanks Devon. Just purchased (December) a used 1 ton 4x4 (dump) that I'm going to convert to a chip truck with tool boxes this spring. Who knows what kind of lift the future may hold. A spider would be nice..... but I may have to find somewhere else to live (with half a paycheck).:hmm3grin2orange:

Here's a quick pic:


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## deevo (Jan 11, 2011)

squad143 said:


> Thanks Devon. Just purchased (December) a used 1 ton 4x4 (dump) that I'm going to convert to a chip truck with tool boxes this spring. Who knows what kind of lift the future may hold. A spider would be nice..... but I may have to find somewhere else to live (with half a paycheck).:hmm3grin2orange:
> 
> Here's a quick pic:


 
Nice looking truck! Yeah you might have to migrate north from the big W with all the equipment and toys you are inheriting! Keep posting the vids!


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## squad143 (Jan 11, 2011)

NCTREE said:


> Hmmm! I wonder what the mechanical disadvantage is at the middle point of your rope that is tied off to the two trees your using as a safety line? I thought it was 50/1... I could be wrong though. Anyone know?


 
I'm not quite sure of what you are asking here.

Are you wanting to know the forces on the anchor points (trees in this case)?

Here is a great site to go to to calculate forces on anchor systems. This is a rigging calculator (Rigging Calculator || Design Tools || CablePick.Com) it is used in the entertainment industry to figure out bridal vector forces (a way to hang heavy lighting and sound equipment over stages and audiences). 

It does not go past 170 degrees. Theoretically at 180 degrees your forces become infinate, however that is only obtainable on paper.

Hope this helps.


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## NCTREE (Jan 12, 2011)

squad143 said:


> I'm not quite sure of what you are asking here.
> 
> Are you wanting to know the forces on the anchor points (trees in this case)?
> 
> ...


 
I guess what i'm try to say is if you shock load the safety line your tied into at the mid point between the two anchor points then that would be a mechanical disadvantage. The further you move away from an anchor point the higher the mechanical disadvantage

Ex. if you weigh a 100lbs then the force your putting on the safety line would be 50/1 which is 5000lbs. 

I'm unsure of this and would like to understand it better.


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## squad143 (Jan 12, 2011)

NCTree,

Sorry.. I've never heard of mechanical disatvantage, but I think I see what your asking.

Lets say a 200lb climber was in the middle of a straight line. Since this is the real world and we have anchors that will move somewhat (trees will bend towards the climber when loaded) and we have rope stretch. We have to consider that the line will not remain straight (180 degrees). For sake of calculations, lets say that the angle (at the climber) will be 170 degrees. The tension force exerted on the rope would be 1150 lbs. or 288% of the original weight.

Now that is just with the weight of the climber. There is going to be an added weight depending on how far the climber drops before the system catches him (the further the fall, the more weight increases substaintally) this is why it is better to have no, or little slack in your climbing system.

If the climber was to exert a 400 lb. load on the line, then the tension force would be close to 2300 lbs. A 1000 lb load would result in 5700 lb. of tension.

Every time we hang off rope, it is a calculated risk. Was this system "bomb proof", absolutely not. Would it have held up had the climber fell due to the branch breaking below him, I believe it would have. I can't be 100%, but I am absolutely positive that had that system not been in place and the branch gave way, he would fall. Gravity seems to work that way.

Here is another site for calculating rope angel leverage: Rope Angle Leverage Calculator

Actually there is a lot of good info here: MyTreeLessons-Trees, Knots, Rigging, Physics, Safety Information


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## NCTREE (Jan 13, 2011)

Ok I think I understand what your sayin, thanks for the mini rigging lesson

BTW thats a neat little rigging calculator you found it could come in handy. Thanks again


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## treemandan (Jan 20, 2011)

NCTREE said:


> Hmmm! I wonder what the mechanical disadvantage is at the middle point of your rope that is tied off to the two trees your using as a safety line? I thought it was 50/1... I could be wrong though. Anyone know?


 
Are you asking in reference to being close to ripping the TIPS out? I would get on thick wood for that.


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## treemandan (Jan 20, 2011)

resent: seriously, What's with these gay smilies Darin? R- U- O- K?

well I can't get you a beer Squad but nice job just the same


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## NCTREE (Jan 20, 2011)

treemandan said:


> Are you asking in reference to being close to ripping the TIPS out? I would get on thick wood for that.


 
yes I am but what i really want to know is if he falls out of the tree hanging from the middle of that line then how far will he drop from the shock load? thats what i meant by a mechanical disavdavantage.


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## Treetom (Jan 23, 2011)

Good work, squad. Neat work by the ground crew laying down the limbs. I've considered 2 climbing lines in separate trees with separate connections to my saddle. You've just given me a new use for that 200' of Husky 5/8" I just bought. Which rope did you use for the skyline?


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## squad143 (Apr 22, 2011)

Treetom said:


> Which rope did you use for the skyline?


 
That was my friend in the tree. I was up another tree (removal) and shooting the video. I believed he used 1/2" PMI easy bend.

Sorry for such a long time replying. Havn't been on here too much lately. Life been getting in the way.


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