Quick VS Delta Link and knots questions/options

[luckylakes]

Mitchellfarmer1,
The cross load on a delta or oval climbing quick link have way higher KN than a screw gate biner. I see now why so many use them for 1 sticking. All the pic's I see show never to allow a screw gate carabiner to get cross loaded but when you use it in 1 sticking in conjunction with a tree, the smaller the dia the tree the more the cross load pivots across the center even when the rope is tight @ both ends. I'm new to all this but that is my understanding.. The gridlock screw gate biner specs are below and are 22kn (224lbs x 22kn = 4928 lbs) w/a 7KN (1568 lbs) cross load and from what I read guys have stated use nothing less than 24KN. If you note many use a nite ize gear tie wrapped around the delta link and then around the outboard side of the tether to make sure the setup is captured against the tree keeping the loop tight and also keeping the rope pulled straight away from a cross load incident. Either way is is gonna be cross loaded in the sense that the tree pivot point is across the center. A fatter tree gives more of a straight pull and less pivot cross load.
My Kong SS delta link is 40kn with a cross load of 25kn. One hella difference. After looking this delta link over I like the old ovals I have used for my standard tree harnesses to attached my back strap to the prussic on the tree tether but that is a different application. In actuality the delta is better in that case too cause the 2" strap would lay totally flat and no way for a cross load on a fall because its a pyramid w/ the prussic rope @ the top. A smaller oval with a scaffold knot might not be the best either due to possible pull through and why I think /guess more guys use Delta's for a wider base to prevent this.. All in all the delta is a win win in my book now!! This is my own observations and research only..
I still would like to know what is the most strength saving dia round stock sized delta link for a 9mm rope

Best Use	Climbing
Carabiner Type	Locking
Gate Type	Screw-lock
Gate Open Clearance	21 millimeters
Strength Major Axis Closed	22 kilonewtons
Strength Major Axis Open	8 kilonewtons
Strength Minor Axis	7 kilonewtons
Dimensions	110 x 65 millimeters
Weight	76 grams

 

[luckylakes]

Zacrowsl,
The kong delta as I pointed out had cross loads of 25kn, way stronger than those other competitors mentioned and the video Kevin2 had a link to showed with a torque wench the delta or oval link only needs 5 foot pounds to be secure and you can do what depending on your strength with just your hands or just cut off an old open end wrench or buy a baby crescent. The scaffold knot maintains 75% of the rope strength. I would like to find a knot that has a higher strength to attach to the delta link.

 

[raisins]

Technically a good hardened steel carabiner is stronger than a quick link or delta link. I been doing a ton of research on this. Plus to get the full strength of a quick link or delta it must be completely 100% screwed shut. You aren't doing that without a wrench. Neither are meant to be used in our application. But a fall hard enough to kill you (in a saddle) on any of the listed devices won't break any of them either. My opinion.

Petzl oxan
Major axis strength : 38 kN
Minor axis strength : 16 kN
Open gate strength : 15 kN

Petzl Delta specs
Major axis strength : 25 kN
Minor axis strength : 10 kN

Petzl Quick link specs
Major axis strength : 25 kN
Minor axis strength : 10 kN

Also a video for thought:

Here's some quick link tests (posted earlier in thread).

The quick link ratings are significant underestimates, it seems.

 

[raisins]

Is there a reason not to use these? Isnt the whole purpose of the design to stop cross loading?

Also edge loading, which can't be totally eliminated in a tree, I don't think. It's much better than the rock ledge edge loading shown on the brochures.

 

[Zacrowsl]

Here's some quick link tests (posted earlier in thread).

The quick link ratings are significant underestimates, it seems.

The reason I chose those 2 links, is bec they are what I hear of being used the most. But this video is a great example of why we use steel. A aluminum and steel carabiner with the exact same kn rating, the steel almost always has a much higher minimum breaking strength. Steel can be rendered useless but still hold you, where when aluminum fails it snaps.

I'm going to use a carabiner and not worry with it any more. I do NOT think that any fall we take will break any of these listed. For me @200lbs to generate 15kn I'd have to fall 5ft. At no point in my climb do I have 5ft of slack.

Not only that....I'd like to see how 15kn of force (while using static rope, in a saddle,)would affect the climber. I have a feeling we will break before our gear.

 

[luckylakes]

I have 2ea steel auto lock biners from my gunners belt that were cycled out when I used to fly aerials in old H-1, jolly greens and blackhawks for 14 yrs. as a cameraman specialist @ the CCAFS/NASA, FL. They are 21 yrs old now & I will still stake my life on them. I was also trained in full restraint harnesses with inertia reels for film retrievals from the MLP and the 115' levels off the UT on complex 39 and all the other umbilical towers on both sides of the river.
While I have no experience in rock climbing I do know what a fall can do and a tree saddle is definitely not made to do what a hunters fully body harness can do.
I totally agree w/ Zacrowsl, you fall any real distance in a saddle for what ever the reason you most likely will be busted up. Don't do it!

 

[arm breaker]

Good info on this thread about that product and that concern is mentioned:

Link on loop for girth hitch (notch quickie)

I know many folks like a link on their tether/SRT/rappel rope as it’s easily hooked and prevents cross-loading a carabiner. I am curious if anyone has tried these? https://www.treestuff.com/notch-v3-quickie/ Costly but seems to be made for the job.

saddlehunter.com

I started that thread and can give an update. I now use these exclusively for SRT and absolutely love them. I’ve had very little issue with orientation and have never come close to losing the pin for the reasons mentioned. I can see why you might think these would be issues, but also keep in mind the quickie was designed by some serious treefolk with more experience and risk exposure than most of us have.

 

[valerio024]

I started that thread and can give an update. I now use these exclusively for SRT and absolutely love them. I’ve had very little issue with orientation and have never come close to losing the pin for the reasons mentioned. I can see why you might think these would be issues, but also keep in mind the quickie was designed by some serious treefolk with more experience and risk exposure than most of us have.

The only problem is that they are out of stock everywhere.


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[luckylakes]

I did a quick search on climbing knot strength's to say compare a bull hitch, a figure 8 to a scaffold knot and its impossible to find a side by side chart wet or dry on such because all rope materials have different materials and characteristics to different knots and when wet it all changes again. Either way the quality rope we all use I believe is fine its just the knot strength and selection is the interesting part to me.. Pretty interesting discussion...

 

[tailgunner]

I have 2ea steel auto lock biners from my gunners belt that were cycled out when I used to fly aerials in old H-1, jolly greens and blackhawks for 14 yrs. as a cameraman specialist @ the CCAFS/NASA, FL. They are 21 yrs old now & I will still stake my life on them. I was also trained in full restraint harnesses with inertia reels for film retrievals from the MLP and the 115' levels off the UT on complex 39 and all the other umbilical towers on both sides of the river.
While I have no experience in rock climbing I do know what a fall can do and a tree saddle is definitely not made to do what a hunters fully body harness can do.
I totally agree w/ Zacrowsl, you fall any real distance in a saddle for what ever the reason you most likely will be busted up. Don't do it!

this is afact right here from lucky....there is a huge difference between fall arrest systems and fall restraint systems.a saddle is a dont fall system.only made for sitting in

 

[raisins]

I did a quick search on climbing knot strength's to say compare a bull hitch, a figure 8 to a scaffold knot and its impossible to find a side by side chart wet or dry on such because all rope materials have different materials and characteristics to different knots and when wet it all changes again. Either way the quality rope we all use I believe is fine its just the knot strength and selection is the interesting part to me.. Pretty interesting discussion...

http://www.paci.com.au/downloads_public/knots/Knot-Testing_Thomas-Evans_2016.pdf

 

[luckylakes]

Yes that was the report I read. Pretty hard to digest.. and not clear to me..

 

[raisins]

Yes that was the report I read. Pretty hard to digest.. and not clear to me..

Check out table 3 on page 11 of 18. First column gives the % of the original strength of material retained after the knot, with the numbers hyphenated being the range of values across the several studies they reviewed.

I was glad to find that figure 8 on a bight, overhand on a bight, and double fisherman's bend are all quite strong. I'd extend the strength of the double fisherman's to a scaffold, since the knot part is the same with the scaffold just being doubled back onto itself. Those, along with friction hitches, are the only knots I currently use.

 

[tmattson]

The only problem is that they are out of stock everywhere.


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So which one y'all think, the more expensive milled or the cast? Big price difference.

 

[valerio024]

So which one y'all think, the more expensive milled or the cast? Big price difference.

Cast is fine for me.


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[luckylakes]

that funny, when I down loaded it for review it stopped @ page 10. I didn't catch it was18 pages... go figure! Yes it makes more sense now.. knot is strength fair, not as good as I hoped across the board..

 

[luckylakes]

BTW if you are concerned about getting 5 foot pounds of torque on the oval or delta link here is what I did. WE all have friends with ladder or fixed position stands. Just get one of the cheapo tools that come with one. I had to put mine in the vise and hit the opening about 10 strokes on each side with a file to make it fit the hex on my Kong delta as the link is some odd ball size as none of my metric or english size wrenches fit. This modified wrench is ultra light.

 

[DMTJAGER]

Know this ain’t gonna untie or pull thru. And if it does. It was my time and No knot was gonna save me. Hahaha

I doublbled wrapped the bight around the biner. Tied a regular scaffold and the loosened up the main limb. Pulled it back thru to make a figure 8. Out the link back in and pulled. Same knot. Just more bit in the link

Doubled bight

Regular way

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No offence meant what so ever and maybe I just don't know that much about knots, (and I don't) but why not just use a figure 8 on a bite and be absolutely safe? Trying to educate myself on knots.

 

[CooterBrown]

BTW if you are concerned about getting 5 foot pounds of torque on the oval or delta link here is what I did. WE all have friends with ladder or fixed position stands. Just get one of the cheapo tools that come with one. I had to put mine in the vise and hit the opening about 10 strokes on each side with a file to make it fit the hex on my Kong delta as the link is some odd ball size as none of my metric or english size wrenches fit. This modified wrench is ultra light.

What do you do when you come to a limb. Got to be a slow process getting up a tree.

 

[luckylakes]

Yes a figure 8 is fine, would be no difference on limbs,, then you would technically have to use your tether or a second Lineman rope.. in either situation