Custom Tether Design: Absorption & Reflectivity Questions

[tarian]

https://www.sail-world.com/news/2009...actor-in-death
https://www.gov.uk/maib-reports/safe...sailing-yachts

https://eoceanic.com/sailing/tips/32...er_conditions/
read the article and see that 15 sailors lost their lifes mainly due to harness failure or tether points

your life your risk

[NPHiker]

Thanks very much to everyone for the contributions.


Has anyone ever added photoluminescent material onto webbing? If anyone has done so, did you choose to use thread, or did you add tape or patches of material?


Any thoughts are appreciated. Many thanks.

[thinwater]

In fact, the Gibb/Spinlock clip has been demonstrated to unlock. This was also in the report.




https://youtu.be/CbyhyC7ua8g

[Marathon1150]

Originally Posted by requiem

As someone who also has some climbing background, this is a test you don't want to put your own body through. For perspective, such drops can break Dyneema slings (rated to ~22 kN). Humans are a bit squishier, however, and can absorb a bit more energy by flopping around and squeezing or breaking things (e.g. sacrifice the spleen to protect the sling), but once forces rise above 10 kN you're risking internal injuries.

This is why in climbing one should never climb above an anchor when tethered with a sling, and avoid positions that accumulate too much slack in the tether. On a boat of course you're less likely to encounter such a directly vertical fall.



I'd be very curious to learn more about this setup; any chance you have it tidily documented somewhere?

Here are some pics of our attempts to keep the jackline in the centre of the boat.

The first pic shows the jackline leading from the front of the boat, over the lashed down dinghy (a bad idea for several reasons) and back to the liferaft cradle to which it is anchored.



The next pic shows how we routed a second jackline around each side of the dodger. We would move from the cockpit to the side deck on either side using the short tether. We were still clipped to the wire jackline running along the sole of the cockpit or one of the padeyes at the companionway entrance with the long tether.



In the first photo above you might be able to see a line of double braid running between the two solar panels on the dodger. We tried using that as a jackline initially but getting the tethers around the solar panels was too difficult so we implemented the "around the dodger" approach. It worked well, was reasonably easy to use and would keep us inboard in most imaginable circumstances other than something seriously extreme like a knock down.

Once around the dodger we would clip the long tether to the jackline running midship to the bow and unclip the short tether. This approach requires a lot of clipping and unclipping but we think that it is safer.

We also have a rule that everybody wears a lifejacket whenever outside of the cabin. This was ok until this year when we started getting closer to the equator and warm, humid air that exists there. We eventually agreed that the person on watch had to wear a life jacket but others could wear just a harness. The tether rule was always enforced.

The following pics show the excellent Spinlock lifejacket that is loaded with super features but are a bit warm in the tropics, the companionway padeye (one on each side) and the Plastimo harness.





On our boat, other than the hassle of multiple clipping and unclipping events to deal with reefing, changing headsails etc (but there is always one tether arm attached to something substantial), the centre jackline runs over one of the two hatches. We could probably get the hatch open in an emergency if we could not exit the boat through the companionway. However, the lashed down dinghy is over the other hatch and it would be impossible to open it in an emergency. I'm not sure what we will do about this.

The photos are not showing up in the preview (I have never previously embedded photos in a post), so I may post them elsewhere if they don't show up in the real thing.

[thinwater]

Yes, you have to link to them, which means posting them somewhere accessible. In my case, I often use my blog.


(On multihulls, centerline jacklines really aren't needed. Rope can often be used instead of webbing, which is nice, because it lasts longer in the sun.)

[jmh2002]

Originally Posted by tarian

https://www.sail-world.com/news/2009...actor-in-death
https://www.gov.uk/maib-reports/safe...sailing-yachts

https://eoceanic.com/sailing/tips/32...er_conditions/
read the article and see that 15 sailors lost their lifes mainly due to harness failure or tether points

your life your risk

Thanks, I was about to add links to this subject. Practical sailor also did extensive articles and testing in relation to the Simon Speirs / 2017-08 Clipper Round the World Race incident, and it makes sobering reading regarding the possible failure modes of equipment.

Safety Tethers Under Scrutiny
https://www.practical-sailor.com/iss...y_12371-1.html

Originally Posted by PracticalSailor

Conclusions
...In our view, World Sailing should tighten its standards so that safety tether snap hooks meet UIAA-121 Type K tests, including all labeling requirements for test strength. The stronger Type K snap hooks are no more expensive than the flat plate stainless steel clips sailors are using now. Raising the standard will increase the general ruggedness and decrease vulnerability to bad clipping geometry...

...Which clip do we like? In the end, it was a very close decision between the Kong Tango and the Wichard Proline. The Tango is faster to clip and stronger, and the Proline lighter, more resistant to accidental unclipping, and based on our initial look seems better armed against corrosion. Both are easy to use in the dark with gloves and strong enough to handle minor clipping errors. Either would be a reliable component in your safety tether....

Building a Custom Safety Tether
https://www.practical-sailor.com/iss...r_12322-1.html

Originally Posted by thinwater

In fact, the Gibb/Spinlock clip has been demonstrated to unlock. This was also in the report.

https://youtu.be/CbyhyC7ua8g

Here is another related video:

https://www.youtube.com/watch?v=C76OYOjYRr0

And a good video example from Wichard showing a lot the features built into their Proline Safety Hook and Tethers:

- ErgoLockSystem (patented): automatically closes and locks the snap hook
- Locking indicator
- Retro-reflective webbing, visible at night
- Overload indicator (as per ISAF offshore special regulations)
- Removable snap hook lets you increase the lifespan of the product by replacing the webbing only

https://www.youtube.com/watch?v=wXTzi8Hn0_I

[Marathon1150]

The Wichard hook/tethers shown in the preceding video look very well thought out and designed. A big improvement over the version that I abandoned about 10 years ago. Presumably many people complained about how difficult it was to open the clip. Too bad they show the jacklines running up the side deck.

[Marathon1150]

Originally Posted by Marathon1150

Here are some pics of our attempts to keep the jackline in the centre of the boat.

The first pic shows the jackline leading from the front of the boat, over the lashed down dinghy (a bad idea for several reasons) and back to the liferaft cradle to which it is anchored.



The next pic shows how we routed a second jackline around each side of the dodger. We would move from the cockpit to the side deck on either side using the short tether. We were still clipped to the wire jackline running along the sole of the cockpit or one of the padeyes at the companionway entrance with the long tether.



In the first photo above you might be able to see a line of double braid running between the two solar panels on the dodger. We tried using that as a jackline initially but getting the tethers around the solar panels was too difficult so we implemented the "around the dodger" approach. It worked well, was reasonably easy to use and would keep us inboard in most imaginable circumstances other than something seriously extreme like a knock down.

Once around the dodger we would clip the long tether to the jackline running midship to the bow and unclip the short tether. This approach requires a lot of clipping and unclipping but we think that it is safer.

We also have a rule that everybody wears a lifejacket whenever outside of the cabin. This was ok until this year when we started getting closer to the equator and warm, humid air that exists there. We eventually agreed that the person on watch had to wear a life jacket but others could wear just a harness. The tether rule was always enforced.

The following pics show the excellent Spinlock lifejacket that is loaded with super features but are a bit warm in the tropics, the companionway padeye (one on each side) and the Plastimo harness.





On our boat, other than the hassle of multiple clipping and unclipping events to deal with reefing, changing headsails etc (but there is always one tether arm attached to something substantial), the centre jackline runs over one of the two hatches. We could probably get the hatch open in an emergency if we could not exit the boat through the companionway. However, the lashed down dinghy is over the other hatch and it would be impossible to open it in an emergency. I'm not sure what we will do about this.

The photos are not showing up in the preview (I have never previously embedded photos in a post), so I may post them elsewhere if they don't show up in the real thing.

Here are links to the jackline photos. I've also created a gallery with these photos and others of our tethers, harnesses and life jackets.

https://photos.app.goo.gl/ZdGW3ytFZ5ZZEz947

https://photos.app.goo.gl/H9JPgjfc2pEyTSK28

[thinwater]

Originally Posted by Marathon1150

The Wichard hook/tethers shown in the preceding video look very well thought out and designed. A big improvement over the version that I abandoned about 10 years ago. Presumably many people complained about how difficult it was to open the clip. Too bad they show the jacklines running up the side deck.

I talked the engnieers, and yeah, that's about it. They also changed the locking mechanism from via ferrata clips; it is different, but I got used to it an a few weeks. The pic of the tether on the F-24 trimaran and the one around my waist are Wichard Proline. I have several different tethers, but I use that one most. It's a little more user friendly.

[stimpsonjcat]

Originally Posted by Marathon1150

Here are links to the jackline photos. I've also created a gallery with these photos and others of our tethers, harnesses and life jackets.

https://photos.app.goo.gl/ZdGW3ytFZ5ZZEz947

https://photos.app.goo.gl/H9JPgjfc2pEyTSK28

Are the port covers for rain or UV? Do they leak? Not sure I have seen that before.

I see duck tape!!!

[andrzej0nl1ne]

I'm trying a slightly different approach. I used about 5ft of ~8mm dynamic climbing rope (shortest length that reaches my foredeck) with a climbing fall arrestor at the harness end. This allows me to use a single tether and adjust it to the shortest length possible by pulling in or letting out line through the fall arrestor.

My Jack line is dynema loop stretched tight on either side of the cabin top. I've never tested this in anger, but I have fallen when climbing so aware of the issues.

I use a kong on the far end and a screw carabiner on the harness. I'm not a fan of the unvoluntary quick release snap shackle. I prefer the theory that I can release the line through the fall arrestor, even under tension, if that's the need.

Curious about your thoughts on this setup.

[Marathon1150]

Originally Posted by stimpsonjcat

Are the port covers for rain or UV? Do they leak? Not sure I have seen that before.

I see duck tape!!!

The covers over the opening portlights keep rain out while the portlight is open. They work quite well - when it is 30 degrees C and warmer outside and raining it is really helpful to keep air circulating through the boat.

The manufacturer are super to deal with (Seaworthy Goods).

So far, no duct tape! Fingers crossed

[thinwater]

Originally Posted by andrzej0nl1ne

I'm trying a slightly different approach. I used about 5ft of ~8mm dynamic climbing rope (shortest length that reaches my foredeck) with a climbing fall arrestor at the harness end. This allows me to use a single tether and adjust it to the shortest length possible by pulling in or letting out line through the fall arrestor.

My Jack line is dynema loop stretched tight on either side of the cabin top. I've never tested this in anger, but I have fallen when climbing so aware of the issues.

I use a kong on the far end and a screw carabiner on the harness. I'm not a fan of the unvoluntary quick release snap shackle. I prefer the theory that I can release the line through the fall arrestor, even under tension, if that's the need.

Curious about your thoughts on this setup.

Define "fall arrestor." Gri-gri? Connect Adjust? I think the idea is interesting. Personally, if I need a shorter tether I double it around something.


I've used 8mm for tether lines on my last boat. Makes a lot of sense. Gives a nice soft catch.



(And that would be involuntary, which seems potentially more descriptive than accidental. In fact, the ISO and World Sailing standards do NOT require quick release, because there are differences of opinion. Personally, I rather like a Kong-type carabiner at the harness end, because I can get that off pretty quickly, under some load.)

[requiem]

Originally Posted by Marathon1150

Here are links to the jackline photos. I've also created a gallery with these photos and others of our tethers, harnesses and life jackets.

Thanks for this!

Originally Posted by andrzej0nl1ne

I'm trying a slightly different approach. I used about 5ft of ~8mm dynamic climbing rope (shortest length that reaches my foredeck) with a climbing fall arrestor at the harness end. This allows me to use a single tether and adjust it to the shortest length possible by pulling in or letting out line through the fall arrestor.

What's the fall arrestor? AFAIK different models behave differently, e.g. a GRIGRI can be released under load, but can let out rope if unattended or "bouncy".

I've had the quick-release shackle come open unintentionally once or twice, so have mixed thoughts on those. I suppose clipping the other arm to my harness eliminates that problem, but has the downside of extending the tether length.

[andrzej0nl1ne]

Google ce rope grab rock. Something in this $25 category. The grigri is too big.