Break test results of various rigging slings constructed of 12 strand hollow braid

[evo]

3/8 dead eye with locking brummel from teufelberger t rex instructions

This one has the most bunching at the Brummell?

 

[evo]

It occurred to me that a better test of the dead eye would be to have a straight pull of opposing, but the same, dead eye construction with space in between the buries.

Can you clarify? Are you talking about just an eye to eye with normal buries? Vs the hollow braid hitch cord splice that retains equal rope diameter?

 

[john.massing]

Can you clarify? Are you talking about just an eye to eye with normal buries? Vs the hollow braid hitch cord splice that retains equal rope diameter?

Yes, an eye and eye with normal buries that allow for full bury and taper that do not overlap.

 

[john.massing]

This one has the most bunching at the Brummell?

No. That is from jostling around prior to lock stitching and a small amount of the bury working out. I knew about this and sent it anyway to see if it affected the strength.

 

[john.massing]

This one has the most bunching at the Brummell?

...forgot to attach this

 

[john.massing]

...forgot to attach this

While I had that one out, I am pointing out that it is flat and glazed where I assume it went around the bollard and also broke well below the bury and closer to this point.

 

[john.massing]

Given the break test numbers with respect to the dead eye slings, I don't think they are worthless. They are irrelevant to the strength of the eye splice other than showing it is stronger than the cordage in a turn on a bollard.

I plan to make a 100' dead eye with locking brummel sling for a remote retrievable rigging point. This test illustrates similarly with breaking force data what I would imagine is most similar to real world loading of such a device; where the sling bends over a branch or union.

 

[evo]

I’m curious on why it broke at the bollard. Bear with me, we have been told that a Brummel reduces the strength but is much better than a knot. A straight bury is stronger but less secure and requires a longer bury.
If your tests are showing consistent breaking at the bollard how can the actual strength of the splice be tested? Other than ‘welp’ it’s stronger than the part of the rope that broke.

I’m curious on how many wraps, how tight the wraps were and if there was any slack left before locking off the tail.

 

[john.massing]

I’m curious on why it broke at the bollard. Bear with me, we have been told that a Brummel reduces the strength but is much better than a knot. A straight bury is stronger but less secure and requires a longer bury.
If your tests are showing consistent breaking at the bollard how can the actual strength of the splice be tested? Other than ‘welp’ it’s stronger than the part of the rope that broke.

I’m curious on how many wraps, how tight the wraps were and if there was any slack left before locking off the tail.

I don't think the dead eye splices were sufficiently tested. I think opposing dead eyes would be a better test.

It would interest me to have high speed video of the breakings.

That being said, I think the ultra/pocket, loopie, and whoopie slings tests are sufficient.

 

[Njdelaney]

This is great info. I made up a small 3/8 T-rex ultra sling that I use for tons of things like rigging down smaller pieces, attaching the Maasdam to for pre-tensioning during cabling, etc, and now I feel better about it's strength relative to those tasks. It also seems that the ultra sling requires less nuance in the way you use it to achieve good strength numbers.

 

[Brocky]

I’m curious on why it broke at the bollard. Bear with me, we have been told that a Brummel reduces the strength but is much better than a knot. A straight bury is stronger but less secure and requires a longer bury.
If your tests are showing consistent breaking at the bollard how can the actual strength of the splice be tested? Other than ‘welp’ it’s stronger than the part of the rope that broke.

I’m curious on how many wraps, how tight the wraps were and if there was any slack left before locking off the tail.

Perhaps it wasn’t milked, or pulled tight, before wrapping around the bollard.

 

[evo]

Perhaps it wasn’t milked, or pulled tight, before wrapping around the bollard.

These are my thoughts, some type of human testing error?
Either that or the friction of the rope stretching around the bollard generated enough heat to weaken the fibers. And/or this was in conjunction with the rope flattening around the bollard.

 

[john.massing]

Perhaps it wasn’t milked, or pulled tight, before wrapping around the bollard.

It is 12 strand hollow braid. I think, video may confirm, that there is friction in the strands where the cordage is rounder in free space and flattened on the bollard. This is speculation.

All of the cordage tested is a relatively loose braid.

I am curious to actually 'know'. The consistency of break location at a distance from the bury accompanied by a flattened and glazed on one side of the rope, leaving all splices intact is not speculation.

I have since messaged the break tester this information and shared these results with many people and encouraged them to carry the torch if the so choose. After seeing that Tree Fund does not award grants to individuals, I have halted my personal funding of this project.

Positively, I have learned things and appreciate all of the questions and input. There is testing left to be done and I would love to see more results. Thank you for your interests.

 

[SeanRuel]

Do you think that the reason for the 3rd brummel is to lock brummel 2 in place in lieu of a bury? It would be interesting.

I have heard that as the explanation for why they are built with 3 crosses. I made one years ago w 2 that we beat the hell out of, pockets shifting was never an issue.

I wonder if having the pockets not locked could equalize load better? It just seems unnecessary to do the 3 crosses, but I'd be curious to see numbers on it

 

[Matias]

I have heard that as the explanation for why they are built with 3 crosses. I made one years ago w 2 that we beat the hell out of, pockets shifting was never an issue.

I wonder if having the pockets not locked could equalize load better? It just seems unnecessary to do the 3 crosses, but I'd be curious to see numbers on it

I have made some in 3/8" with out the 3rd cross through, and they let you know when you have pushed to much weight because the eyes shift a little. it isn't horrible, and would bet that it would break at least 3 times higher force than where I start to percieve some distortion. I did it that way to keep the pockets closer together for a sling that I use with a big Pinto.