Tether Hooks

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Neeves

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As a change from Anchors (and anchoring) :)

I wondered how people's perceptions of tethers and tether hooks, on safety harnessses, might have developed over the last 12 months.

Pertinently I further wondered if anyone had retired (destroyed, ensured they were never used again) any item of 'tether equipment' (whole tether, jacklines, hook, jackline securement point).

Jonathan
 
I took the old webbing jackline and made a set of straps to tie my dinghy on its trailer.
Our tethers still look like new. They don't see a lot of wear or sunlight.
 
My tethers have spent the last year or two in a cupboard onboard. They have not been used for years.
In normal weather I consider they are more trouble than they are worth and therefore only come out in a gale or worse.......and I try hard not to "do" gales these days.
 
mainsail1 said:
My tethers have spent the last year or two in a cupboard onboard. They have not been used for years.
In normal weather I consider they are more trouble than they are worth and therefore only come out in a gale or worse.......and I try hard not to "do" gales these days.
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We get ours out so they are immediately available at night or if expecting anything rough, particularly short handed.
 
lw395 said:
We get ours out so they are immediately available at night or if expecting anything rough, particularly short handed.
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Was there not an article last year in PBO ( I might be mistaken) but how certain makes of tether hooks did not open or got jammed , or was it they opened (brain fog)
 
Jacklines on new-to-me boat are kaput and condemned. I always used to take mine below when I left the ex boat on her mooring but maybe that's a bit fussy. Even so, when laying up you would expect them to be taken off. Tethers last a long time but I would't trust either the tethers or the hooks on the early 1970's harnesses that for some reason I still keep.
 
Minn said:
Yes, they can twist open if snagged on a deck fitting. Forgot the details.
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The MAIB reported on an accident in the Indian Ocean, in which a Gibb-style harness hook released after lateral loading caused it to deform. See http://www.mysailing.com.au/gear/sa...e-of-safety-harness-tethers-on-sailing-yachts

Practical Sailor did an article on harness hooks - see https://www.practical-sailor.com/blog/Check-Your-Safety-Tethers-12344-1.html

I use, and like, the Gibb-style hooks, as they are easily used one-handed, even with gloves on. With care, I hope that the circumstances in which they might be subjected to lateral loading can be avoided.
 
I started the thread because there was a failure on a Clipper yacht (MAIB report still to come) and a man died (even though he was quickly retrieved). The early case, outlined in the PS report linked above, pointed the finger at the hook.

I believe the information was 'edited' by Morgans Cloud and added to their subscription website AAC.

But both PS and AAC are N Am centric - that's obviously where the big english reading market is located - and I wondered how much of the investigation into the Clipper failure filtered through to the UK.

It does not seem very much.

But moving from the specific to the general - tethers and jacklines do not last forever and there is no indication that people think of retiring them. Ours are all date stamped. We store ours away if we are not on passage - but if offshore they hang from the cabin roof, ready for immediate use, along with LJs. The jacklines are installed when we go offshore.

The Clipper yacht death occurred in the Southern Ocean - but it was a text book retrieval - he was sadly still dead. The hook failed - hoping yours might not fail is wishful thinking (if you don't know which hooks are suspect. I suspect you could go overboard in the N Sea with a similar result - except it is unlikely we leisure sailors would enjoy a textbook retrieval - increasing the chance of a retrieval of a body.

The answer is obvious, don't fall off the boat.

We have had one MOB, scariest time of my life.

Hopefully Thinwater will be along soon - he did all the work on the PS investigation.

Jonathan
 
I, and a couple of mates, followed the reports with more than normal interest. Several of us hoisted in the 'lesson', and made some changes.

I've switched to a triple-hooked tether for going forward, after the fashion of the very well proven 'Via Ferrata' usage. I have several tethers on board, and make use of them in different places.... such as when seated at the tiller, on watch solo.

I use climbers' webbing slings, built to international standards. I use the old-pattern Gibb snaplinks as they're the best I can get.

The probability of TWO of these being prized open simultaneously is vanishingly small.
 
My understanding is that the the hook 'simply' bent, maybe after being prized open. To me the chance of being prized open is not remote - it is a yacht, anything can happen (and does).

We, like Zoidberg, have doubled up on tethers - we use 2 x 'double ended' (i.e. 3 hooks, 2 at one end, 1 at the harness and use 2 of tethers for one person). The reason for the 2 tethers - simple - we have 6 harnesses, we only sail the 2 of us offshore - no use carrying spares and not using them. I actually use a climbing harness, the rest are chest harnesses.

Without starting another, or different debate, we have had seas breaking over our cabin roof and if you were working on the foredeck in such conditions - belt and braces seems the way to go (or not go :) ) as you could slide at considerable speed - and go straight over the lifelines

Our jackstays are secured to the bow and transom horn cleats and we have 2 further jackstay from each bow, diagonally to the mast (its a cat). We have 4 'U' bolts in the cockpit roof and one each at chest height either side of the 'patio' doors.

Jonathan
 
a. The tether standard was re-written in 2009 to include impact standards. If the tether is older than that it probably transmits excessive impact force and will either fail or injure the user. The changes were made in response to several failures. If your tether is older than 2009, RETIRE IT. Most older tethers failed the new ISO 12401 standard when new. http://www.ussailing.org/wp-content/uploads/DARoot/Offshore/SAS%20Studies/safety%20tips.pdf

b. The Spinlock/Gibb failure was at a mere 500 pounds. This can be either a cross load OR the jackline hooking in the gate area (nose-hooked). Judging from the direction of the Clipper fall, this latter is actually quite probable (see second video, below).

c. The Spinlock hook also has a problem with opening on U-bolts. This is a failure to meet the standard. Watch the first video on this page. It unclipped at about 20 pounds.
http://sail-delmarva.blogspot.com/2018/02/a-locking-carabiner-that-isnt.html

If you asked a climber or industrial worker to use a Spinlock hook they would laugh at you. It does not meet any of the required standards. This is sad, because MANY clips do, such as the new Wichard Proline and Kong hooks. AND these are even easier to use one0handed, with gloves, than the Spinlock hooks (they are climbing designs--climbers never have two hands free!).
 
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