Tether Clip Update - Practical Sailor

[jackdale]

As promised, here’s an update of what we know about the recent failure of a safety tether during the Clipper Round the World Race. This is latest in several accidents in which the use, misuse, or failure of tethers have been linked to fatalities.

https://www.practical-sailor.com/blo...ml?s=FB_010118

[StuM]

That linked article was posted by Thinwater a couple of days ago in a related thread.

http://www.cruisersforum.com/forums/...ml#post2546890

[jackdale]

Originally Posted by StuM

That linked article was posted by Thinwater a couple of days ago in a related thread.

http://www.cruisersforum.com/forums/...ml#post2546890

merci mucho

[Jeanneau 45.2]

Thank you for the post and link. The title of the other post (why do sailors die being dragged) did not prompt me to open that post, but your title caught my interest so the "duplicate" is most appreciated. FWIW, I have the West Marine with Kong tethers ... guess "lucky" is sometimes better than "good". Alan

[Mike OReilly]

Yes, thanks Jack. Like Jeanneau 45.2, the other thread didn’t draw me in.

Reading the report makes me think about my tethers. We have two, both three-legged. One is an older version with just gibb-style clips (forget which brand, perhaps WM). The other is a Wichard with a quick-release snapshackle for the harness attachment.

I find the gibb clips are easily snagged on our nylon jacklines, just as is shown in the PS photo:



I’ve learned to take extra care when clipping on to make sure they are hooked and running properly.

We use our tethers whenever we’re on passage (off shore), or when we’re running watches overnight. Good to keep thinking about how to improve them.

[FabioC]

Thank you for the pointer to the article, very interesting reading.

However, I read the article, and I am a bit confused by its findings. It seems to me that the observed failures originate primarily by incorrect or partial clipping of the hook on the webbing. While it is certainly true that proper clipping is not a given, especially at night, these failures do not seem to have much to do with the specific brands of hooks, but seem more intrinsic to the accepted operation/design of the hooks.

The problem seems coming more from the fact that the webbing by definition is flat and wide, so it is very possible (or even likely) to clip the hook while snagging in the webbing. To me, this is a strong argument in favor of wire jacklines, rather than webbing. With wire, I do not see much reason for this type of failure to happen. So the take from the article should be: change the webbing to wire, rather than change the hooks to a different brand. Am I missing something?

The other source of failure in the article, i.e., the snagging of the clip on other hardware on deck, it is more the result of poor planning in routing the webbing on deck, and should be solvable with more careful planning. Again, the take from the article should be: pay more attention to the relationship between the jacklines and the other hardware on deck. What am I missing?

Thank you!

[SV DestinyAscen]

From the clipper event testing the tether clip, made from stamped metal, will fail at significantly lower than rated loads if angled/leveraged wrong.

Focus should really be keeping tethers short. Once you're overboard the loads change significantly.

[Maka]

Excellent topic.
Cant wait to hear more opinions

[thinwater]

Originally Posted by FabioC

...The problem seems coming more from the fact that the webbing by definition is flat and wide, so it is very possible (or even likely) to clip the hook while snagging in the webbing. To me, this is a strong argument in favor of wire jacklines, rather than webbing. With wire, I do not see much reason for this type of failure to happen. So the take from the article should be: change the webbing to wire, rather than change the hooks to a different brand. Am I missing something?...

No, you arn't missing anything, and you bring up a very good point. Once the snagged webbing issue was posted, more and more sailor report having the same problem. Another part of the problem is having the locking mechanism inside the hook, where it will always rub against the jackline.

This issue may or may not relate directly to the accident. Unknown.

[Steadman Uhlich]

Excerpt from the PS article linked above:
"According to our testing so far, only one of the popular locking tether snap hooks on the marine market—the Kong double-action safety hook (formerly used in West Marine tethers)—is built to withstand eccentric loads (loads that do not align with the anticipated load paths) that can induce this type of failure. (We’ve not yet tested the clip used on the Wichard Proline tether, which, like the Kong, is based on climbing via ferrata clips used by climbers and is tested to a higher standard than sailing clips."

The Kong Double Action Safety Hook is the type I selected for my own Safety Tether and what I have been recommending to others to purchase for their offshore safety gear.

Before getting the Kong, I had another type of safety tether/hook and was shocked to see it open more than once when used, in moderate conditions, due to something happening (unseen) as the hook twisted the jackline or came up against a hard point (cleat or padeye). In short, I no longer trust the older style hooks.

FYI: The Kong double hook tether shown below can be found at a significantly lower price than some of the other brands that failed the testing by PS. So, price should not deter you from it.

Here is a photo of the Kong Double Action Safety Hook and Tether I recommend:

[SV DestinyAscen]

Definitely a good pick Steady Hands - while it isn't sexy and light like some "racer" models, playing with it for a few minutes was enough. I don't understand why "safety" devices are manufactured with stamped metal, rated in a particular orientation - then advertised as safe. Other industries do not allow this, and it sailing tethers won't pass any sort of OHSA falling harness requirement.

[thinwater]

Originally Posted by SV DestinyAscen

... while it isn't sexy and light like some "racer" models, playing with it for a few minutes was enough. I don't understand why "safety" devices are manufactured with stamped metal, rated in a particular orientation - then advertised as safe. Other industries do not allow this, and it sailing tethers won't pass any sort of OHSA falling harness requirement.

The Tango is actually lighter. I've seen them on Volvo boats.

Spinlock Race Hook 135 grams
Kong Tango 131 grams

(I've weighed them)

[check327]

I may be missing something, but it seems to me that there would be no safety issues with using BD Maglock(or similar) carabiners on the ends of two daisy chains or PAS's clipped into your harness with another locking carabiner. Pretty much the same system an aid climber uses for ascending a fixed rope. Plus you can clip short somewhere if need be. Same price or cheaper than a sailing specific unit.

[mitiempo]

Originally Posted by FabioC

The problem seems coming more from the fact that the webbing by definition is flat and wide, so it is very possible (or even likely) to clip the hook while snagging in the webbing. To me, this is a strong argument in favor of wire jacklines, rather than webbing. With wire, I do not see much reason for this type of failure to happen. So the take from the article should be: change the webbing to wire, rather than change the hooks to a different brand. Am I missing something?

If wire is stepped on it rolls under foot while flat webbing does not. This was the reason for a change to webbing.

[thinwater]

Originally Posted by check327

I may be missing something, but it seems to me that there would be no safety issues with using BD Maglock(or similar) carabiners on the ends of two daisy chains or PAS's clipped into your harness with another locking carabiner. Pretty much the same system an aid climber uses for ascending a fixed rope. Plus you can clip short somewhere if need be. Same price or cheaper than a sailing specific unit.

Google ISO 12401 and you will find the standard.

One issue is corrosion; I've used mag locks climbing, but not around the boat. I don't know. But I'm guessing a lot of carabiner types are going to get a close look in the next few years.

The OSR does allow the daisy chain concept (when two lengths are required, they can be either two legs or one leg with multiple clipping points).

However, do NOT use a Dyneema daisy chain. The total lack of stretch can be dangerous. It is also certain that a Dyneema chain would fail the ISO 12401 drop test, based on UIAA drop testing of Dyneema slings. In fact, I like 8 mm climbing rope for increased shock absorption. Falling directly on daisy chains is simply brutal.