Of what use is a vest-side tether “quick release” safety shackle that cannot release

[BigNut]

As I am setting up our jacklines afresh, I am also revisiting the tether end of things.

From what I’ve read, even a pricey Tylaska shackle needs a device to release under significant pressure. Most “quick release” shackles on commercially available one-and-done solutions are not able to release under pressure at all.

Would I really be able to find that fid for the Tylaska, and use it under the circumstances that would require me to even consider doing that in the first place? I am thinking in the dark, under water, bring beaten against the hull.
This leads me to consider foregoing a shackle at the vest end completely (the things are clunky and uncomfortable, destroy gelcoat and hurt when you fall against them), and simply hitching in, coupled with a line cutter (my deckvest comes with one ready to go). This might be a simpler, more likely effective, way to go.
Leave the shackle for the other end of the tether.
It makes releasing as “simple” as “Locate cutter -> Cut line”.
Not a pretty thought, as Kris Kristofferson might bemoan, but still thoughts that need to be thunk!
My partner is a dainty lady. Not powerful, even when terrified.
Anybody with real-world experience of releasing a trigger shackle under tension while drowning?

[psk125]

You would definitely not want to use a Tylaska shackle on your harness tethers. They're for spinnaker guys where the foredeck crew has a fid tucked behind his ear. This type: https://www.shopsoundboatworks.com/w...BoCNpQQAvD_BwE has a large hook that requires a squeezing hand action to open so it will not open accidentally. The other end has a pin-release snap shackle that also requires a specific motion to open, but which will release under tension. Most people get a long and a short tether with two hooks that attach to the harness, so that one hook can always be attached when moving about the boat. https://www.landfallnavigation.com/w...BoCO0QQAvD_BwE
Releasing the pinned shackle, if necessary, would be a lot faster than pulling out a cutter and trying to cut a tether while bouncing around in 20' waves somewhere under the boat.
This is a time when racing regulations can set an example, even for a cruising boat.

[Marathon1150]

I agree with PSK125. Finding the line cutter on a Deckvest, in the dark, underwater, would not be easy (we use Spinlock Deckvests which have the line cutter). Cutting the tether would be the next challenge.

Our tethers are bifurcated with Kong shackles at the point where they attach to the boat/jacklines and a quick release pin shackle at the PFD/harness end. I note that Spinlock does not supply this kind of tether (at least in Canada). The pin shackles release quickly even under load (I have simulated the "load" part).

The photos show a Kong attached to a folding padeye in the companionway (one of the places where things often go wrong and people find themselves in the ocean if they are not tethered). The other photo shows the tether with the unused arm clipped on to a harness (it became too hot to keep the Deckvests on during the day) next to the quick release snap shackle.

[BigNut]

Thanks for responding.
The shackles you show are NOT designed to release under pressure though! This is exactly my concern.
The hand squeeze shackle will NOT release the line, but merely open the gate. The line remains captured under tension.
Looking at the pin release, this is NOT designed to release under pressure. How sure are you that you will be able to release it? Maybe on deck. But under a boat, in the dark, dragging at 8 knots?
Add:
I do see statements for some pin shackles that they will release under pressure. Here, eg: https://www.westmarine.com/buy/west-...91?recordNum=1

[BigNut]

Originally Posted by Marathon1150

I agree with PSK125. Finding the line cutter on a Deckvest, in the dark, underwater, would not be easy (we use Spinlock Deckvests which have the line cutter). Cutting the tether would be the next challenge.

Thank you.

I totally agree with that thinking. Hence my quest.

How much pressure did you apply to test that it will be openable by someone who is not particularly muscular or big?

Those Deskvests ARE hot! And then, when you wear them shirtless, they are hard to clean too!
How safe are those harnesses you show in the second picture? For example, there are no crotch straps?

[thinwater]

Originally Posted by Marathon1150

Have her raise her arms, as though she were in the water, and I bet you can side that harness over her head with 3 fingers. It is way, way, way too loose. crotch straps are another topic, but if nor straps it MUST be tighter than that.


he has her spare tether clipped back to the harness. A big no-no if you believe in quick release (which I do not). No quick release function, since the second will still hold.

[BigNut]

My other concern, after all the whining about a pin being too hard to release, is that it would release too quickly!
Aaargh!
Am I just being paranoid?
Does anyone have any links to test data? I presume the ORC would have such data, perhaps.

[BigNut]

This article https://www.practical-sailor.com/saf...-harness-tests from 2000 mentions in passing testing tethers for release under load but does not give any details at all.
It does say that 47% of tethers failed dynamic testing. 1 in 2.

[BigNut]

The study mentioned in the previous article, from 1999. https://www.sfbama.org/fs/Safety%20A...999.pdf#page11

[BigNut]

I missed this thread from 2017: https://www.cruisersforum.com/forums...fd-193721.html
Just in case anybody is still reading. [emoji6]

[Marathon1150]

Originally Posted by thinwater

Have her raise her arms, as though she were in the water, and I bet you can side that harness over her head with 3 fingers. It is way, way, way too loose. crotch straps are another topic, but if nor straps it MUST be tighter than that.


he has her spare tether clipped back to the harness. A big no-no if you believe in quick release (which I do not). No quick release function, since the second will still hold.

Absolutely agree - the harness will be less than useful in some/many situations because it will go over the head if the tether pulls over the head (very likely in a COB situation). The Spinlock deskvests have crotch straps and we used them at all times and had the vests on whenever outside of the cabin (ditto for harnesses and tethers). At some temperature point however, additional risk became acceptable as a way to stay cooler. There is no perfect system other than watching other people's adventures on Youtube.

I do disagree however re the value of a quick release. I recently purchased a Spinlock tether which was available either with no hardware at the PFD/harness end, or a carabiner at the PFD/harness end. I chose the latter but after thinking about it, I should have purchased the no hardware version and added a pin shackle.

[BigNut]

Originally Posted by Marathon1150

There is no perfect system other than watching other people's adventures on Youtube.

That’s not only funny, it is also a reminder that, for us at least, this discussion about releasing a tether if being dragged under after going overboard comes at the very end of our mantra:
If you go overboard, consider yourself dead.
So we spend almost all our efforts toward avoiding that in the first place.

But then, the night-weasels come.

[Marathon1150]

Originally Posted by BigNut

Thanks for responding.
The shackles you show are NOT designed to release under pressure though! This is exactly my concern.
The hand squeeze shackle will NOT release the line, but merely open the gate. The line remains captured under tension.
Looking at the pin release, this is NOT designed to release under pressure. How sure are you that you will be able to release it? Maybe on deck. But under a boat, in the dark, dragging at 8 knots?
Add:
I do see statements for some pin shackles that they will release under pressure. Here, eg: https://www.westmarine.com/buy/west-...91?recordNum=1

The Kong "hand squeeze" shackle in the photo is only being stored on the harness. Next to it, is the quick release shackle that is important piece of equipment. To test it, I leaned back with much of my weight loaded onto the shackle and tether and pulled the pin. As per my original post, I would prefer to remove the pin release shackle while under the water in the dark at eight knots over finding the blade on the Deckvest and then attempt to cut the tether.

Regarding the Kong shackle - I previously had tethers with Wichard shackles. They are extremely hard to get on and off jacklines or other attachment points, particularly with cold hands. It was "easier" to not use the tether. Fortunately, Westmarine recalled those tethers and replaced them with the Kong version at the boat end and the same quick release at the PFD/harness end.
Actually, if everything is set up right, it should not be possible to fall overboard if tethered. We spent several days reworking our jacklines after a safety audit prior to setting across the Pacific from Mexico. Our objective was to be sure that we could move from the companion way to anywhere in the cockpit and forward to the bow, without being able to go over the lifelines. It was very challenging but we feel confident that much of the time, in most places on the boat, with the right tether attached (long vs short leg) we cannot go over the lifelines. If the boat is moving through the water and a crew member goes overboard wearing a tether, the probability is very low that that they will be able to get themselves back on board. A highly motivated skipper/crew member still on board, might be able to get them back.

A tethered single hander who goes over the stern rail is likely a goner. Anywhere else, they have a low probability of self-rescue (see: Singlehanded Sailing: Thoughts, Tips, Techniques & Tactics. A. Evans. The author interviewed a couple of single handers who lived through the experience).

The quick release on the tether is, at least in my thinking, for when the boat is sinking. The Spinlock knife might as useful in such a situation.

[Marathon1150]

Originally Posted by BigNut

That’s not only funny, it is also a reminder that, for us at least, this discussion about releasing a tether if being dragged under after going overboard comes at the very end of our mantra:
If you go overboard, consider yourself dead.
So we spend almost all our efforts toward avoiding that in the first place.

But then, the night-weasels come.

Night-weasels! argghhhhh!

[thinwater]

Originally Posted by BigNut

This article https://www.practical-sailor.com/saf...-harness-tests from 2000 mentions in passing testing tethers for release under load but does not give any details at all.
It does say that 47% of tethers failed dynamic testing. 1 in 2.

The standards that harnesses and tethers must meet have changed since then to include dynamic testing.


The only item I know to be questionable are the Spinlock Race clips, which cannot withstand side loading and may not lock properly. They have been taken out of production.
Sail Delmarva: A Locking Carabiner... That Isn't
The Spinlock replacement uses a better clip, solving the problem.