Zipline, thoughts

RegC

RegC

TreeHouser
Joined
Feb 10, 2014
Messages
2,261
Location
Victoria, BC
You might have caught the the previous zipline vid I put out a few days ago. I was back at the same job on monday, and got the inclination to video and explain some of the considerations I have when applying the technique to the tall skinny types that are in the vid. If you're having to deal with similar profile trees as what grow out here then you might take something from it, or be reminded of things you'd forgotten.

There seems to be a trend of zipline videos out there over the last few years, and to an extent sort-of glorifying the concept, without pointing out the potential dangers. Im hardly rehearsed, eloquent or thorough in the vid, but the points are valid at least.

I receive lots of email or on-line messages from people I dont know, telling me how much they've learned, or think they've learned for some of the videos I've put out over the years....and to be honest it worries me at times, because i dont know these people or how they're interpreting or applying this stuff. Anyway, if you have time here it is. Use HD setting:

<iframe width="560" height="315" src="https://www.youtube.com/embed/ahkjhilyCZY" frameborder="0" allowfullscreen></iframe>
 
Seems to make a lot of sense on those types of trees. Hardly ever do it here on our spread out trees.

jp:D
 
first time I ever tried speelining, the guy at the saw shop showed and sold me the rescue pulleys and biners... I was working a monster tulip, backed up to the wires and a rose garden and some dogwoods right below on the front side. Wide open lawn after the bed.... Guy at the saw shop told me the pulleys were rated for 4,000 lbs... This is how ignorant I was ... I'd look at monster limb and think, "this weighs less than a pick up truck", sling it up and cut... Knew nothing about the dangers of side loading, force multipliers etc... We were using high-v, which has a lot of stretch.... I might have been dead otherwise.... Learned everything I know about zip lining online.. rarely use it .. thinking about it for a maple next week.... don't remember the last time I did... thanks for the detail about potential butt brake.. good to know..
 
Cool vid, Reg. I would think that anyone that has followed your vids would know you as a thinking climber, not doing things haphazardly. What was that about not having to clip and unclip with your safety, i couldn't catch it. Would you mind clarifying. Thanks.
 
Great Vid Reg! We do a little speedlining here too because of "targets", mainly on pines. Your point on side loading the the tree is well stated. I have went as far as installing a guy line or simply running the line through a block and anchoring one end 180 degrees from the landing zone, letting the tree column load instead of side load. You say you're not a teacher but I would disagree. Your safe, methodical, forward thinking approach to tree work is extremely educational.
 
If you look at charts that show the different characteristics of wood strength, comparing the resistance to deforming and breakage from force applied parallel to the grain as opposed to force applied perpendicular to it, it really emphasises the wisdom in having your zip line as parallel to the tree as is possible. The inherent risks with force applied perpendicular to the grain are further compounded by the growth patterns affecting direction changes in grain, like with grain runout and around knots and whatnot. What is already relatively weak gets weaker.
 
Zip lines really shine on leaning excurrents over homes n targets when you can zip them out 180 degrees opposite the lean.

The zip line itself can be configured in a manner that both pulls the top over onto the desired path, as well as catch and confine it within its travel window.

But like Reg, I worry about amateur YouTube copycats killin themselves tryin to be as cool as a journeyman with decades of hands on experience.

Zip lining heads by literally pulling them over your way with a high set line requires groundies who can back up as one to suck up slack quickly, but not pull too hard and bounce the climber around unnecessarily.

The go big or go home mentality's exactly what can kill you during zip line ops.

With me anything three groundies can't comfortably pull over and anchor's too big a load, in general.

I've dabbled a bit with long lateral travel ziplining, but it generally requires guy lining the anchor trunk, haul back lines on the zip pulley etc. even with all that done, rope stretch over such long distances kill any hope of a small window of travel. That's why loggers use wire rope to cover long lateral travel reach.

In many ways zip lining's an extremely delicate and complex feat to pull off safely n successfully, even with an experienced crew.

The key's knowing when you can safely do it, and when you can't.

Sure is a thing of beauty when Reg produces, directs, narrates and performs the feat over a sparkling shoreline though!

But I can see the worry in his eyes that someone's going to hurt themselves mimicking his daring do.

You wanna be safe? Don't race formula one cars on a pro circuit...

http://www.washingtonpost.com/news/wonkblog/wp/2015/01/28/charted-the-20-deadliest-jobs-in-america/

Jomo
 
Reg...I appreciate you taking time to show more detail on the thought process used for your speedlines.

The concept that you use the lower limbs to make the load on the top a compression load instead of a side load was new to me...I have not seen that put forth in my reading...maybe I missed it somewhere. But it makes good sense.

I do remember from reading awhile back that it was stressed to not shock load a zip line...the book (Art and Science of Practical Rigging?) stressed to catch the load with a block and then transfer the load to the zip line. I have done that some but it is a time consuming hassle sometimes. I have used a vertical speedline a few times to control the bounce of pieces near a house and that worked well.

I liked the way your top dumped over and the line directed it down...that seems less shock to the tree to me than if you had caught the top with a block and then transferred it to a speedline.

Can you explain (or show) how the butt end of a limb or tope can get fouled up and brake itself (I suppose even jam?) on the way down. I have not wrapped my brain around that one yet. That process does seem like a big" uh-oh" deal.

Thanks for your contributions.
 
  • Thread Starter Thread Starter
  • #11
Thanks all

pantheraba said:
Reg...I appreciate you taking time to show more detail on the thought process used for your speedlines.

The concept that you use the lower limbs to make the load on the top a compression load instead of a side load was new to me...I have not seen that put forth in my reading...maybe I missed it somewhere. But it makes good sense.

I do remember from reading awhile back that it was stressed to not shock load a zip line...the book (Art and Science of Practical Rigging?) stressed to catch the load with a block and then transfer the load to the zip line. I have done that some but it is a time consuming hassle sometimes. I have used a vertical speedline a few times to control the bounce of pieces near a house and that worked well.

I liked the way your top dumped over and the line directed it down...that seems less shock to the tree to me than if you had caught the top with a block and then transferred it to a speedline.

Can you explain (or show) how the butt end of a limb or tope can get fouled up and brake itself (I suppose even jam?) on the way down. I have not wrapped my brain around that one yet. That process does seem like a big" uh-oh" deal.

Thanks for your contributions.
Click to expand...

Sure Gary. It's not so easy to simulate with a short light section. But imagine the leverage of a butt-tied 15 ft limb pressing into the line. Works just like a cam.
2015-10-07 15.30.21.jpg
 
Loved the pep talk at the end...beware Fu*k It Cuts!!:thumbup:
 
Another great video, Reg! I think you accomplished your intended goals perfectly.

I have an off topic question, have you tried one of the Sena communication systems? Seems a hands-free, bluetooth com set would be perfect for everything you do. At under $300 for a set of two, they are a good investment.

About halfway into the vid you make a comment about a foot ascender for taking up slack. Spurring up a tree while an SRT line is self feeding through your hitch, should only take a HUT, no need for a foot ascender. You might need some extra weight on your line if you are less than 50' up. One of SRT's best and most energy-saving uses on removals.
 
From Gerry B, commenting on the Snipe thread that Sean linked today:

"Tree work is so cool. It keeps a person in touch with nature in real time."


That's exactly what Reg's vid made me feel, it took Gerry to find the right words.:thumbup:8)
 
  • Thread Starter Thread Starter
  • #15
DMc said:
Another great video, Reg! I think you accomplished your intended goals perfectly.

I have an off topic question, have you tried one of the Sena communication systems? Seems a hands-free, bluetooth com set would be perfect for everything you do. At under $300 for a set of two, they are a good investment.

About halfway into the vid you make a comment about a foot ascender for taking up slack. Spurring up a tree while an SRT line is self feeding through your hitch, should only take a HUT, no need for a foot ascender. You might need some extra weight on your line if you are less than 50' up. One of SRT's best and most energy-saving uses on removals.
Click to expand...
Thanks Dave.

Nah I much prefer shouting over the noise of the traffic, chipper and saws !

Yeah I could see the benefits on certain jobs.

What is a HUT ?
 
Thanks Reg. I've been telling the guys at work to watch the rigging. Just because they see it done in a great video doesn't mean it works that way in real life. No one shows the "boring" stuff or the mistakes.
 
I love these videos. Beautiful setting. Masterful execution coupled with a willingness to explain the reasons behind the outcome.

Cheers.
 
RegC said:
...What is a HUT ?
Click to expand...

Ha! Sorry about that. HUT stands for, hold up thingy. Basically anything you choose to use to keep your hitch upright and sliding up the rope. Chest strap, neck bungee, nipple ring, whatever.

With the Sena coms you can not only discretely tell your groundsmen to remove that branch from the client's car, but if things really fall apart you can make a call hands free if you have your phone in your pocket.

They add a whole new level of safety.
 
  • Thread Starter Thread Starter
  • #21
DMc said:
Ha! Sorry about that. HUT stands for, hold up thingy. Basically anything you choose to use to keep your hitch upright and sliding up the rope. Chest strap, neck bungee, nipple ring, whatever.

With the Sena coms you can not only discretely tell your groundsmen to remove that branch from the client's car, but if things really fall apart you can make a call hands free if you have your phone in your pocket.

They add a whole new level of safety.
Click to expand...

That'd be nice Dave, but my lines and hitches are constantly pitchy. Not much you can do about it.
 
Reg, do you mean a HUT/ tether doesn't work with your Rope Wrench due to pitch? Have you run a Hitch Hiker? I have pitch friction sometimes, but usually don't have issues.


Just watched the video. Good quality/ advice.

Something that I find helpful where you need to suck up slack in the line with a limb attached opposite the landing zone, is being able to hinge them down, allowing the groundie to pull out slack before you're cutting it free, onto the zip line. I've found western red cedar to hold well with just a top cut at the collar. Doug-fir holds well when cutting into the trunk somewhat (Daniel Murphy dubbed it a Shoulder Cut in a video). Also, a diagonal top cut on Doug-fir will frequently keep it from snapping free compared to a straight down from above cut. Plays into cut and chuck, too.

Hanging the limbs vertically before releasing also reduced the shock-loading on the system. This is usually not necessary, as with your case in the video. A doug-fir that's lost a significant top in the past often gets those large, dense, heavy lower limbs. Hinging them to vertical reduces the load on the tree and the groundie, allowing the groundie to hold and guide a larger limb that possibly with a drop cut. If they can hold the rope rather than anchor it, they become part of the energy absorbing system. One of those situational things.

As you mention, catching the top on the speedline is a questionable thing. I find a convenient thing about a speedline on a conifer is the ability to work the speedline up, leaving you a pull line for the top. You can pop a munter hitch on the rigging rope, lickety-split, for rappelling down to your topping-cut height with one hand, while managing your climbing line and flip line down the spar with the other. You avoid a rope retrieval from the sappy top of the tree, to a degree, lessening pitch issues.
 
  • Thread Starter Thread Starter
  • #25
SouthSoundTree- said:
Reg, do you mean a HUT/ tether doesn't work with your Rope Wrench due to pitch? Have you run a Hitch Hiker? I have pitch friction sometimes, but usually don't have issues.


Just watched the video. Good quality/ advice.

Something that I find helpful where you need to suck up slack in the line with a limb attached opposite the landing zone, is being able to hinge them down, allowing the groundie to pull out slack before you're cutting it free, onto the zip line. I've found western red cedar to hold well with just a top cut at the collar. Doug-fir holds well when cutting into the trunk somewhat (Daniel Murphy dubbed it a Shoulder Cut in a video). Also, a diagonal top cut on Doug-fir will frequently keep it from snapping free compared to a straight down from above cut. Plays into cut and chuck, too.

Hanging the limbs vertically before releasing also reduced the shock-loading on the system. This is usually not necessary, as with your case in the video. A doug-fir that's lost a significant top in the past often gets those large, dense, heavy lower limbs. Hinging them to vertical reduces the load on the tree and the groundie, allowing the groundie to hold and guide a larger limb that possibly with a drop cut. If they can hold the rope rather than anchor it, they become part of the energy absorbing system. One of those situational things.

As you mention, catching the top on the speedline is a questionable thing. I find a convenient thing about a speedline on a conifer is the ability to work the speedline up, leaving you a pull line for the top. You can pop a munter hitch on the rigging rope, lickety-split, for rappelling down to your topping-cut height with one hand, while managing your climbing line and flip line down the spar with the other. You avoid a rope retrieval from the sappy top of the tree, to a degree, lessening pitch issues.
Click to expand...

I tried the HH a few times Sean, and it performed well. I never liked that the whole thing depended on two little stopper knots though....especially if youre taking it on and off. I never found issue with the RW, so I stuck with that.

We suck up slack on ziplines to gain clearance, not so much to reduce loading. Often we add deliberate slack, so the load is almost free falling vertical, so theres hardly any loading on the tree. I drill it home to the guys when and when not to i.e. I hardly felt that top in the vid....Darrel ran it like a champ.

I generally hang limbs for other reasons....so long as that its not too heavy for me to pick up to unclip the carabiner. Failing that you have to cut it loose with the saw. So, it usually needs some pre-thought.

Ive tried and practiced diagonal cuts over the years. I agree, they have their place. Thanks
 
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