Jump to content

Question about stitched eye strength.


tpcollins

Recommended Posts

I have a 30" Beal dynamic rope lanyard with a small and a large stitched eye on the ends. The Beal instructions approve of a Lark's Foot knot tied with the larger loop to the climbing harness - which is what I currently have set up. The small eye would be connected to a 7/16" round Petzl carabiner.

 

Where would the strongest and weakest areas be when loaded:

 

- the eye's stitching

- the smaller eye's rope around the carabiner

- the larger eye tied via Lark's Foot to the harness

 

Thanks.

Link to comment
Share on other sites

  • Replies 12
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

I can't speak to this specific piece of gear, but can give you some insight from a previous job designing and testing parachutes. Stitching is usually designed to be stronger than what is being stitched. The failure point during testing is almost always the point where the material goes from double to single thickness. On this piece of gear, that would be just toward the center from the stitching. That, combined with knowing that knots are weak points, would lead me to believe that the stitching should be the strongest of the three you have listed.

Link to comment
Share on other sites

I know this has been beaten to death, but I can't resist. Learn how to tie a clove and carry an extra locker. No PAS type device is worth carrying in any situation. For raps tie an overhand midway along a doublelength runner to put your device on, and clip into anchors with a locker on the free loop, takes 15 seconds to set up and you'll be carrying it anyway.

Link to comment
Share on other sites

I had to look up a Lark's Foot which is referred to as a Girth Hitch by most climbing nomenclature. Regardless, any knot is considered the weak link of the rope. There has been a lot of testing and internet reporting of how much each knot actually weakens the system if you're interested. Hope that helps.

Link to comment
Share on other sites

If you guys look at his other posts, the OP has been talking about various roofing and tree stand safety applications. Not climbing.

 

I would think people helping people is the American way regardless of the forum or it's application. Please forgive me.

 

you don't understand what he is trying to say. the answer to your question is different between rock climbers and tree climbers. Most people are assuming you are asking in regards to rock climbing. You are assuming a negative purpose to Bronco's comment.

 

Link to comment
Share on other sites

If you guys look at his other posts, the OP has been talking about various roofing and tree stand safety applications. Not climbing.

 

I would think people helping people is the American way regardless of the forum or it's application. Please forgive me.

 

I don't think he's criticizing your question, just pointing it out that this is not being used in the typical application that most of us are used to. You might get lucky and find someone on here who is a professional rigger, or more likely you'll get someone who is a SAR member and has extensive rigging experience that can answer your questions outside of a climbing context.

 

Again, since the same kind of comments come up in everyone of these rigging threads, I'd suggest using only one of the threads to ask questions in the future so you don't get a bunch of confused climbers asking about what you're doing with a lark's foot or why you're using a sewn eye-to-eye instead of clove hitching in with your rope.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...