Climbing Sling Myths

Arent those rating more for a shock instead of a gradual pull

You put the stitches in the same place, but not the labels.

Try a clove hitch instead of a girth hitch.

Great. Thanks

On the 4 wraps it looks like one (or more?) section of the sling is twisted to enable the wrap, which must cause uneven forces on the sling. I’m guessing it puts more force on the edges of the sling than the center, which might be the reason why it breaks at a lower strength than anticipated. I’m not sure but I think it looks like it’s breaking in the twisted spot

It probably melted from the friction lol. Also Nylon I think the material is weaker if you heat it up, so it's not only cutting itself it becomes weaker than it's normal rating.

Girth hitch: you used a big pin. Of course it was stronger. I think the CE standards use 12mm pins in most places. The +30% on the baseline tests might be from using the big pins.

I'm very late to the party but, in practice a nylon sling that is twice as long should be able to take a higher dynamic load before breaking even if the static break force is the same due to the higher amount of work needed. Seems like a fun test for the drop tower considering that the results have to vary depending on how the test is set up, will the impact be after the same fall distance or will the longer sling get a longer fall due to the extra length.

Wow, this intro where a man jumping from the mountain is very cool!

I do not understand why you keep calling a choke a "girth hitch." Or why endless straps are "slings."

A little history on this heavy industry vs recreation thing would be cool.

Pointless test.. when climbing you're always going to include a 22kn carabiner so that's your absolute limit.

I haven't made it through the video yet, so they might have already explained this, but I'm guessing the ones where they overlap across the bar break earlier because the friction is preventing them from evenly distributing the force between the loops

Edit: The ones in the video didn't seem to overlap that badly, so my current guess is that they tear earlier because of the wider angle, basically the wider the angle the more stress you put on the slings compared to the weight they're holding. At a 45 degree angle you would account for losing about half of the capacity from what I remember learning.

Kilonew-ton literally breaks my brain when I hear it I don’t know why, it didn’t start popping up in this video until after the 4 minute, before that I was all kilonewton.

For the 3rd method tried (the 4th picture) as well as the 4th tried (3rd picture) I think the main reason for the results it's because the force exercised on the string is not the same on all sections. And 2 big reasons for this I think are:
1. More friction and imperfect sling contact makes some sections receiving more force than other sections. Also it makes the force direction being misaligned with the expected pulling force (because of the sling contact and twisting the pulling force is't perfectly vertical anymore -> the sling breaks easier)
2. Is is also probably kind of impossible to have the 2 ends perfectly splitted and, because it's wrapped multiple times one end might receive more force than the other (while if the sling is not wrapped multiple times it will probably equalise itself at some degree).

When climbing, we need to be fast and simple. That is the more important, so you don't waste your muscular strength in hold positions, while you build a bomber placement. Interesting tests, but if you do things correctly, slings and fixed anchors will never be a problem in climbing. But for industrial uses, when you must move heavy weights, these informations are gold. Here in Brazil, while climbing Pão de Açucar in Rio de Janeiro, a climber died hanging on the rope. He fell down maybe 60 meters when a fixed steel cable broke. The rope, anchor, carabineers and slings holds, but not his body. He died from internal injuries. The weaker point will always be your body. If you generate more than 8 KN or 10 KN forces while climbing, then I guess you did something terribly wrong.

Fortunately, most of us weigh less than a few thousand pounds so this is cool from pure curiosity.

Dan Merrick here. One issue I've had with testing is that the shackle pins rotate pretty freely. Rubbing seems to reduce sling strength pretty significantly so I am curious if the girth hitch would perform as well if the pin didn't rotate while loading. I think the result should be close to the same but I am not certain.

Basically if solo climbing just tie whatever, you are probably not fat enough

All of the lifting slings we use at work have similar but far more conservative diagrams on the label, IIRC they only show the multiplier for a basket hitch and a girth hitch and you actually get two different ratings for the basket hitch depending how large an object you are going around, i.e. you get a lower rating if the angle it creates is larger, but its only like 1.2x-2x max I think

I was thinking the same thing re the drop tower as a sharp shock load shouldn't have such a large friction burn and may have a higher Kn. Being nylon and using the 1 inch tube tape for speed lining branches down in tree removal. We buy 100 metre rolls and tie to what ever lengths we require. I have broken numerous over the years but never had one break at the knot. Being nylon and having a bit of slippage in the knot, hmmmn I wonder.
Love the Vids. Cheers

Cows tails with sling

im just glad we have these people around.😂😂😂

Not sure if there is a video somewhere, but what would happen to a nylon sling if you girth hitched it to your harness and then on the other side girth hitched it to a carabiner so it stays in place. The use is just for resting. Would the strength loss of two girth hitches double to end up somewhere 18/19kN?

you put the 3 on wrong. you used the wrong configuration. if you look at the image again and the video you'll see the difference between the two. there is also a small image on the side to show how to wrap the slings

The problem with knots should be on dynamic loads. When you take a fall, knot tightens up fast and heat generated that way can melt the sling, weakening its rated strength.
On static loads, like in this test, that is not the case, so it is probably the reason numbers are much higher with girth hitch.

please do a video of an 11mm Metolius sling lifting a car.

Your tests are awesome! The practical is what maters, not the theoretical. And the reason the chart is crap is because they assumed that the load share is going to be perfect for those 2x, 4x setups. It's not. And they assumed the knot strength of a girth hitch would reduce the strength 50%. It doesn't. Assumptions = bad. Testing = good. Theory = good. When testing proves theory? Then you're good to go.

Can you do this test with the drop tower? It would be really interesting for me (-:

Just like when you braid 3 ropes together you only get 2 x the strength because the rope isn't straight and turns converts 30+ percent of the tensile load into shearing load .
Same applies to knots in dyneema they usually reduce strength by 30-50 percent so splicing is important .
Also the low stretch character of dyneema likely contributes to sudden failure like comparing a electrical tape to a box clear tape in character.

Your "double double" is tied incorrectly. To recreate the pictured 112kn anchor, you first need to secure the sling to your 2:1. Next, you want to wrap you sling "doubled" around the shackle and back to the 2:1 shackle. Do this three times and finish by locking the last bit of the sling back on your 2:1 shackle as you started. Along with the overlapping of the webbing, that is the reason you aren't seeing the correct results.

It is widely accepted that 12kN of force may cause possible death or dismemberment. I think it would be good content to provide the audience with a little bit of context there. Maybe a pig carcass or something? Primarily to demonstrate that if a body does generate the extreme forces that (quality) climbing gear is capable of surviving, said body might be better off not surviving, for lack of a less graphic point...

I am a little bit confused, actually the sling MBS is 22knand it broke at 82kn which in reality it is +/-7% deviation, not that bad. Might affect the friction of the sling since you packed it pretty tight.

Girth hitch is not halved because it only manipulates the sling in a manner that does not create any tearing motion or place more stress on a smaller area. The math not wrong. The presumption they started from is.

Multiple wraps is forcing the sling wide putting force mostly to the inside edges lessening the resistance by tearing.

Look to the construction industry for heavier slings. Possibly the origin of that image too.

The drawing shows the wraps not overlapping i believe this is because as the overlapped straps pull against each other as the tension increases and the build of and friction and heat it shears itself.

I watch this channel and now understand why I have a hard time keeping a climbing partner

How a climber breaks up...

Interesting video . I appreciate the effort You all put into the videos .

That picture was of an asian elephant, not an african elephant. Jeeezzeeez!

What about slings linked by lark hitch? I always thought what was a big no no. The radius is a lot less than your shackle

I think the 4x sounds good in theory but i think the friction on itself causes it to fail sooner ?

That’s from an early edition of Freedom of the Hills.

ANY squeezing, folding, overlapping, disturbance is going to cause a weaker point and thus detract from doubling. Girth hitches are variable but essentially you're gripping the nylon onto the surface and running it flat. Thus your ideal condition for the girth hitch is kind of expected. The more interesting aspect was to see pinching and non-ideal set-ups severely affect the results.

I am so glad that the girth hitch holds up with nylon. I use them all the time for belaying anchors and such!