Dynamic Rope for Lanyard?

[Bart_]

You could get 2x softer by using a Moss style SRT cinched lanyard - only one leg of rope instead of two with a normal DRT lanyard.

 

[Vicente]

The idea that leaning back on a rock climbing rope is going to weaken it is absolutely ridiculous, people take small falls and hang on them all the time. If you take a big fall like 15 ft than yea it's probably time for a new rope but this things get abused way more as far as repeat shock loading than our ropes ever will.

 

[Shadowscape]

I just spoke with a Beal rep. Despite all these people who don't know what they are talking about above but feel the need to give their opinion anyway, Beal does make a dynamic rope lanyard, "The Dynaclip" rope lanyard. I was told by him that it is rated for 20 impact forces of 80 kg, at which point it must retired. Give that a thought when you think about leaning back against it a couple of hundred times a day. 80 kg. That is 176 pounds. 20 times and Beal says it is no longer safe.
No matter what those above say, I don't think any of them know a tinkers damn about rock climbing or dynamic ropes.
I won't be returning to this thread. To many ignorant people giving advice. Just want you to be safe, my friend.

 

[Brocky]

The difference is in static verses shock loading the nylon line. Some of the stretch might be lost, but very little strength. Mooring lines for boats are generally nylon.

 

[flushcut]

I just spoke with a Beal rep. Despite all these people who don't know what they are talking about above but feel the need to give their opinion anyway, Beal does make a dynamic rope lanyard, "The Dynaclip" rope lanyard. I was told by him that it is rated for 20 impact forces of 80 kg, at which point it must retired. Give that a thought when you think about leaning back against it a couple of hundred times a day. 80 kg. That is 176 pounds. 20 times and Beal says it is no longer safe.
No matter what those above say, I don't think any of them know a tinkers damn about rock climbing or dynamic ropes.
I won't be returning to this thread. To many ignorant people giving advice. Just want you to be safe, my friend.

Yes but that is 20 times at fall factor 3. Also known as the hardest fall possible given a fixed length of rope in a drop test tower. And that is also the safety margin that they and their insurance underwriters are willing to allow for life support line. A fall of fall factor 3 is very rare in real world usage and is virtually impossible to achieve when using dynamic cordage as a positioning lanyard.

 

[southsoundtree]

I am only familiar with fall factor 2... a lead climber falling directly into the belay anchor= 2X feet of falling on X feet of rope.

 

[Brocky]

You can achieve a higher fall factor if the lanyard slides down also before stopping on a branch. Happens in via ferrata climbing.

 

[Webfoot]

I can't imagine any difference in a 12 ft long piece of cordage in terms of stretch compared to an arborist rope. Not that I've ever used dynamic rope, because I haven't, and not that my powers of imagination are particularly good, because they aren't. Stretch requires distance to play out. So in that sense, I can't imagine any benefits either.

Dynamic rope and knots both significantly reduce impact forces in short drop tests.

Cow Tail Drop Tests

HOW bad is it to fall on personal anchors? It's obvious-ish that it's not a good idea to fall on a short rope since there isn't much there to absorb your fall, especially if it is really static. We drop tested cow's tails, which are personal anchor systems (PAS) that cavers use. We were hoping...

www.hownot2.info

https://www.cavediggers.com/files/lanyardtest.pdf

 

[Tom Dunlap]

ike the 4" tie in system:

What is the source of this illustration?

 

[Tom Dunlap]

I think I missed this thread in its first life

To be compliant with Z133 I do believe that the ropes must be sanctioned by the manufacturer for arbo work. Simple matter to find that out

In practice most lanyards are used in a hip-hip configuration. This reduces loads in half [theoretically]

There is so little rope length in a lanyard that the actual stretch would be negligible. These numbers can be calculated with basic math...no algebra or calc, etc.

If a climber needed to climb above their TIP then there might be a good reason to use a dynamic rope.

Above TIP for things like:

Seed collection
Animal rescue/renesting
Storm damage
Tip die-back

In the thousands of hours that I climbed I might have spent a dozen hours above my TIP. That is negligible exposure in the grand scheme.

[Except in VERY specific conditions]

 

[Webfoot]

What is the source of this illustration?

Found it.

 

[Tom Dunlap]

Found it.

National Tree Climbing Guide I have a previous edition and it looked familiar. TY

 

[Webfoot]

You could/should use dynamic rope for a lead climbing lanyard, like the 4" tie in system:


View attachment 87594

Is not cinching the spine of the bottom carabiner against a 4" stem against manufacturer guidelines for all common carabiners? Plenty strong nevertheless for moderate loads seen in rope ascension or abseiling but this instruction is being given for climbing above the anchor where impact forces could be quite a lot higher. I am surprised to find contraindicated use in an official USFS publication.