Skinny rope on base anchor leg?

[evo]

In theory if it’s strong enough it’s just that. But it’s a bad idea.
Like others have said if it matters that much just use a retrieval line and canopy tie. I can think of a number of reasons not to do what you’re talking about.
Abrasion or cutting is one big one. And it’s in error to think the base tie side only sees half the load:

 

[Webfoot]

And it’s in error to think the base tie side only sees half the load:

Should I be seeing something embedded below or is that colon just a typo?

 

[southsoundtree]

Are you using the bigshot sections as trekking poles?

 

[Webfoot]

Are you using the bigshot sections as trekking poles?

No..... I suppose the base pole could be used that way given the rubber cap, but doing that with the extension's open ends sounds like trouble.

 

[southsoundtree]

Make a trekking 'foot pad' for it.

 

[Crimsonking]

Text format will make this sound harsher than I mean it, so please consider that-

If an additional 6-7 lbs of line is too much for your back, is climbing in the woods alone a good idea? If you’re not alone, can someone else carry the lines and you carry the conversation?

Rather than expose myself to greater risk (known and unknown) with below-rating lines, I would look to solving the strain issue in other ways. A quick trip down will multiply back issues in a hurry.

As was mentioned above, a canopy anchor with a light retrieval line sounds best.

 

[Brocky]

V.elo Ropes has 6mm DyTech, has a break strength of around 5100#. Core is dyneema, with a Technora and polyester cover

 

[moss]

Started climbing 20 years ago, my back was a mess from an injury in my early 20's. I built a a rolling cart based on 16" bicycle wheels. I rolled my tree climbing gear anywhere I wanted to go on or off trail. Eventually tree climbing built my core strength so well that I didn't need the cart anymore. I still use the cart when I need to carry saws and climbing gear or when I'm carrying other people's gear.

When I want a super-lite climbing kit I use my 85' 11.7mm Yale double braid and an 8mm accessory line of the same length as a canopy anchor pull down.

My issue (of many) with a "low strength" back leg basal anchor is the variability in upper anchor limb diameter and friction per tree. It's already a fair amount of skilled assessment to determine the overall condition of a tree and upper TIP without adding in more variables effecting safety.
-AJ

 

[Webfoot]

Text format will make this sound harsher than I mean it, so please consider that-

If an additional 6-7 lbs of line is too much for your back, is climbing in the woods alone a good idea? If you’re not alone, can someone else carry the lines and you carry the conversation?

I do not take it harshly. I appreciate that you care enough to say something. People far more capable than I am end up dead from a variety of mishaps in the wild so I would be a fool not to think about it. I am pretty cautious in general but I may take greater risks than I realize where my evaluation is poor. To date I have only climbed trees in city parks where cell reception is good. I will need to feel significantly more competent before climbing in the woods alone.

Rather than expose myself to greater risk (known and unknown) with below-rating lines, I would look to solving the strain issue in other ways. A quick trip down will multiply back issues in a hurry.

I regret mentioning Pur Line as it did not produce the conversation I hoped to have. I forget that I am not my own audience. As illustration if someone inquired about rappelling on 550 cord, since two strands should hold 1100 pounds and hypothetical person weighs only a fraction of that, I might reply with a essay on:

Dynamic and static load
Derating from knots and bend radius
Common friction devices
Thermal dissipation
- glass transition temperature
Susceptibility to abrasion and cutting compounded by:
- per-fibre tension
- increased pressure at point of contact
- fiber volume
Rigor in manufacturing and certification
Difficulty of creating a "third hand" backup

Others might rightly reply don't be a dumbass, you'll surely die.

As was mentioned above, a canopy anchor with a light retrieval line sounds best.

My first climbs were on a canopy anchor but they were 20 feet off the ground and it was trivial to isolate a limb. At 40 feet it is easier to base tie. At Big Shot range I don't know that I could do it at all, but I have only used double bagging once and I hope to improve. I am under the impression that most Big Shot users are not creating a canopy tie from the ground even if they convert to one aloft. Is this mistaken?

 

[Webfoot]

V.elo Ropes has 6mm DyTech, has a break strength of around 5100#. Core is dyneema, with a Technora and polyester cover

That's right there with Edelrid Hard Line as the strongest sheathed 6mm I've seen, though it is slightly heavier. Are you "just putting this out there" or implying something more?

 

[DSMc]

@Webfoot , you would be well advised to stick with traditional tree climbing lines and equipment until you gain more experience. Their use and safety have been well tested for what you plan on doing.

And no, it is not hard to set a canopy anchor high within the tree. It just takes practice, which is something that must be done.

 

[Webfoot]

@Webfoot , you would be well advised to stick with traditional tree climbing lines and equipment until you gain more experience. Their use and safety have been well tested for what you plan on doing.

I acknowledge that.

I do not understand where the stated abrasion and/or cutting hazard to the back strand is coming from and I wish I did. No one has actually articulated that yet.

 

[Njdelaney]

I can explain it to you. If your base anchored, often your base leg is on the back side of the tree and out of sight. That alone makes it more dangerous if you're using a saw or even hand snips, and often it can be redirected around a stub and you won't even know it unless you make a point to check all the way up. Your base leg is under tension both above and below your body, unlike the climbing side of your line, so that is additional exposure to danger. Frequently your base leg is up against the trunk, near where you need to make finish pruning cuts. The other day, one of my partners who is still getting comfortable climbing and cutting, had to remove a limb in this scenario. I walked him through how to hold the base leg away from his initial cut, and despite being told exactly what the danger was, when the limb started to go, he had a fear response to move himself away(which was not necessary) and in doing so he let go of the base leg and it snapped against the top of the chain before the chain had stopped moving. He cut 1/4 of the way through his base leg, and that just happened last week.

 

[Njdelaney]

Let me also add that this discussion has been had recently on the Buzz in response to another experienced climber nicking his base leg. Many climbers who are more experienced than I weighed in about the dangers of a base tie in a removal scenario and I poo-pooed that as simply blaming a technique for a human error, but the truth is your exposure to a cutting hazard is definitely increased in this scenario. There are other safety concerns that offset this for a rec climb only, like the idea that if your TIP fails, you'll be caught by any limbs/unions below that when base tied, but the danger of a cutting hazard is definitely increased with a base tie. I acknowledge this reality and you should too.

 

[Bart_]

Couple points. Pulling 2:1 tension ratio out of the base tied thread is kind of cherry picking a data point. Smoother bark and the difference is less. 2:1 is very rough bark. (forgive me if you're right about 2:1 nominal - I'm too old and decrepit to go back and re-read the data - but you shouldn't rely on best cases)

Life support is based on a safety factor. Diminishing that factor opens the door for a "freak" event/defect to cause failure/fall.

Don't cut your bridge, saddle, self, lanyard, uo line, down line, tail, or either DRT line with your hand saw or chainsaw while pruning(?) during your rec climb.

I agree a canopy cinch tie is great bang for your buck losing weight from full sized rope to robust(!) pull down cord per Moss.

Look into fishing line/weight/reel rigs the rec climbers use, use that to pull throw line, then rope. Trade carrying poles for extra -relaxing- set up time on your rec climb. Hand slingshot probably good for 80+ ft tip. Earlier I probably misspoke - fireline not trilene

If you go canopy cinch be damn sure its good because it has no redundancy. If you go base tied you can gain tree structure tip redundancy - but then you have to carry more rope.

 

[southsoundtree]

I acknowledge that.

I do not understand where the stated abrasion and/or cutting hazard to the back strand is coming from and I wish I did. No one has actually articulated that yet.

A broken branch stub

 

[Webfoot]

@Bart_ Thanks for the correction. Sorry for citing incorrectly.

Safety factor in the simplistic form I see most often does not seem adequate here, e.g. the Pur Line I regretfully used as an example provides a 15:1 safety factor for a single person load. Are you operating with a more complex and nuanced definition of safety factor? (I hope from prior conversation you know I am not so ignorant as to believe laboratory tensile strength is the complete measure of a rope.)

I don't carry a saw of any kind while climbing.

I did not realize a hand slingshot and fishing line was a viable option or I might not have bought the Big Shot. So much to learn.

I presently favor the base tie for that reason, as well as the ease of setting. I cannot use binoculars while manipulating line so I expect difficulty at greater height but I'll have to try it and see I suppose. I will be using them to evaluate any TIP over 40 feet up.

 

[Webfoot]

A broken branch stub

If this represents a real hazard to ropes that is just what I need to learn from this. I am well aware of the damage that rock can do to rope, up to full cutting in a single loaded slip of a few feet (or less) across an edge. I simply haven't given wood the same respect. I see none of the rope projection tools used by cavers and urban rigging in use by arborists, and I don't recall this being addressed in The Tree Climber's Companion or other references, so I am somewhat taken aback by this.

How much damage and how quickly can sharp wood features do to rope? Why haven't I seen this addressed in introductory literature, and why don't I see edge rollers, rope mats, rope wraps etc., being employed of this is a serious hazard?

 

[DSMc]

... How much damage and how quickly can sharp wood features do to rope? Why haven't I seen this addressed in introductory literature, and why don't I see edge rollers, rope mats, rope wraps etc., being employed of this is a serious hazard?

It's an anomaly. A mere possibility that is negated by proper equipment selection. Use tools and techniques that have been proven to work in diverse conditions.

You have set yourself on the journey of learning a new skill that has strong mental and physical requirements that can not be separated. Take your time. Mistakes that involve gravity and height can become quite costly.

 

[moss]

My first climbs were on a canopy anchor but they were 20 feet off the ground and it was trivial to isolate a limb. At 40 feet it is easier to base tie. At Big Shot range I don't know that I could do it at all, but I have only used double bagging once and I hope to improve. I am under the impression that most Big Shot users are not creating a canopy tie from the ground even if they convert to one aloft. Is this mistaken?

It takes time to get better at isolating. Once you have some experience with that it doesn’t matter if you’re isolatiing a limb at 40’ or 90’, problem is the same. Binoculars are very helpful to figure what’s going on with your throwline and bag at greater heights.

A climber has to do a lot of throwbag moves after a big shot throw. You can easily send a throwbag through the tops of adjacent trees. Pulling a bag back through branches to establish a good rope path can be very tricky, many opportunities to get hung up.

Which is why I prefer to hand throw if possible, the bag is likely to stay much closer. For basal anchors you still need to “isolate” each leg to a certain degree so that the rope path won’t give you any surprises during ascent.
-AJ