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Old 31-01-2025, 23:31   #1
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Fall arrestor on jacklines?

The idea being to prevent sliding down along the jackline if knocked off your feet by a wave etc.
There are for example progress-capture fall arrestors used in climbing like Petzl Micro Traxion. (Most tethers already have shock absorbers too)
It would have to used on static rope, not cored and nor webbing or wire cable
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Old 01-02-2025, 00:15   #2
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Re: Fall arrestor on jacklines?

Yes I am aware of Morganscloud.etc
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Old 01-02-2025, 02:51   #3
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Re: Fall arrestor on jacklines?

I think the much bigger challenge is to avoid going over the rail.


Any kind of control or arrest in whatever dimension would be a good thing, but those fall arrestor devices are not nearly as easy to clip on and off as the normal hook on a tether, and that's not a good thing. As in any given operation forward you usually have to clip on, off, back on, etc. as you work your way around shrouds, get to the mast, or whatever it is you're doing.
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Old 01-02-2025, 04:21   #4
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Re: Fall arrestor on jacklines?

Several thoughts:
It would limit your ability to return, until you took it off and switched it around, or held the cam in release mode.
It would bang up decks something horrible.
They're designed for round rope, which is avoided in jackline setups because of rolling underfoot.
They're full of dissimilar metal parts: I have other climbing gear that lasted not very long at sea.
Rather than trying to fix the bad system that is jacklines with long tethers, we should focus on the better system of adjustable tethers with lots of clip-in points midships.
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Old 01-02-2025, 06:44   #5
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Re: Fall arrestor on jacklines?

Cyrus,

Your idea is a tad of 'over-engineering'. Fall arrestors are designed to de-accelerate a falling the body before it is stopped by the limit of the tether. For example, a person is working on a platform and falls off. Without a proper fall arrestor, he would hit the limit of the tether and suddenly stop. The person would then sustain injuries from the sudden stop inside his harness. Granted, these would likely be less than the injuries from the sudden stop on the pavement, but still injuries. With a proper fall arrestor, he is de-accerated before hitting the limit.


A better system is to place the jacklines inboard. My rule was that once on deck, when clipped in, your center of mass (your a@@) should not be able to get over the rail. See also Dockhead's comments
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Old 01-02-2025, 16:53   #6
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Re: Fall arrestor on jacklines?

These progress capture devices are not the same as what roofers use

I suggest it is permanently installed on the jackline, the tether (that should already have a shock aborber) is then snapped to it (or via dyneema loop ) so there is no problem with installing and removing it from jacklines.

Indeed they require static rope, not marine line. Webbing? Jacklinea shouldn't be under feet any way but high and center board. Offshore Rules requires wire cable

Whether the jacklines are centerboard or not the force of a wave tossing you back along a jackline is significant and dangerous so stopping that sounds like a good idea?

I believe there are all alum. built devices but even if they dont arrest, you're still clipped on and no worse than without


Perm clip points along the way are of course very helpful, but just to keep you from falling back, do not unclip from jacklines

Indeed youd have to hold it while returning, which is a pain...Maybe a loose Prussick knot? People use fall arrestors already for mast climbing
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Old 01-02-2025, 22:05   #7
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Re: Fall arrestor on jacklines?

Quote:
Originally Posted by Cyrus Safdari View Post
These progress capture devices are not the same as what roofers use

I suggest it is permanently installed on the jackline, the tether (that should already have a shock aborber) is then snapped to it (or via dyneema loop ) so there is no problem with installing and removing it from jacklines.

Indeed they require static rope, not marine line. Webbing? Jacklinea shouldn't be under feet any way but high and center board. Offshore Rules requires wire cable

Whether the jacklines are centerboard or not the force of a wave tossing you back along a jackline is significant and dangerous so stopping that sounds like a good idea?

I believe there are all alum. built devices but even if they dont arrest, you're still clipped on and no worse than without


Perm clip points along the way are of course very helpful, but just to keep you from falling back, do not unclip from jacklines

Indeed youd have to hold it while returning, which is a pain...Maybe a loose Prussick knot? People use fall arrestors already for mast climbing

Try it and report back. You are introducing several new risks to a void a very minor risk. Also, a few corrections:


  • Static rope is generally cored. (Most yacht rope, for example, is static and cored. Arborist static rope is cored. Rescue static ropes are cored. progress capture devices are designed for this type of rope.) There is no requirement that they cannot be used on marine-type line. However, the roll-under-foot problem is serious anywhere on-deck. Also, it is good for jacklines to be webbing or a very different sort of rope or webbing so that they cannot be mistaken for something else at night (you don't want to clip a sheet by accident).
  • Progress capture devises can shred the cover at loads above about 1200 pounds. They are NOT rated for fall arrest. Google it.
  • There is no need for a shock absorber in a tether that is used on a jackline. The jackline stretches enough to absorb the impact (clipped to a fixed point with excessive slack can be a hard catch). I believe you will not find any modern tether failures that were in good shape.
  • Word Sailing does not require cable for jacklines. That is just one of many options, including rope and webbing. BTW, they do make progress capture devices for steel cable, but I'm not suggesting that.
You also seem unclear about progress capture devices (ascenders, which are NOT rated for fall arrest) and fall arrest devices (Petzel ASAP, Camp Goblin) whic slide freely and catch falls. But Fall arrest devices are not rated for sliding falls at low angle and may not catch. They also have a habit of catching if they are not free to hang (tether tension can lock them).


A Prusik loose enough to slide will probably just slide. Better, just hold onto the rope or something else.



Overall, I think this introduces several new problems while attempting to solve what is a relatively unimportant problem. In fact, falls while moving are rare, because the sailor is paying attention. Most are while working at a fixed point and not holding on because they are using their hands.


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Old 01-02-2025, 22:49   #8
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Re: Fall arrestor on jacklines?

It's been a long time since I was hit by a wave big enough to think about this, but this sounds like something that might be considered for a large flush deck boat maybe, where the jackline(s) goes from cockpit to bow (?) Otherwise, if the jackline is centered and the tether is fairly short, which I think is usually the case for cruisers, you're probably already holding on to something or have something to grab fairly close, no?
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Old 01-02-2025, 23:34   #9
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Re: Fall arrestor on jacklines?

Ive seen folks been knocked back a few times
One had his jacklines outside the shrouds.
Said it was to help him from sliding all the way
This is apparently a common thing
So it got me thinking

Anyway, I should have said
OSR permits not requires jacklines "Comprising stainless-steel 1 x 19 wire of minimum diameter 5 millimeters (3/16 inches)"
My point was, it is very slippery. Webbing, line etc They all are. You can't really rely on firm hand grips on jacklines to hold you, the forces are too large, the grip is slippery etc so some mechanical means is a good idea

I"d rather take the shock than be flung back
Many sailors are unsteady on their feet while stone cold sober on terra firma, what with knee problems etc so it wont take much on a boat to make to go backwards

Reinstalling the arrestor to go back while you're clipped in on a hardpoint at the bow or mast is an option
My point was to not use it on cored rope so as to not shred the cover - but honestly at 1200 lbs is that even an issue?

Youre right I don't claim much knowledge of climbing gear. My point re: mast ascenders etc is that climbing gear is already used on boats
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Old 02-02-2025, 08:39   #10
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Re: Fall arrestor on jacklines?

Quote:
Originally Posted by Cyrus Safdari View Post
Ive seen folks been knocked back a few times
One had his jacklines outside the shrouds.
Said it was to help him from sliding all the way
This is apparently a common thing
So it got me thinking

Anyway, I should have said
OSR permits not requires jacklines "Comprising stainless-steel 1 x 19 wire of minimum diameter 5 millimeters (3/16 inches)"
My point was, it is very slippery. Webbing, line etc They all are. You can't really rely on firm hand grips on jacklines to hold you, the forces are too large, the grip is slippery etc so some mechanical means is a good idea

I"d rather take the shock than be flung back
Many sailors are unsteady on their feet while stone cold sober on terra firma, what with knee problems etc so it wont take much on a boat to make to go backwards

Reinstalling the arrestor to go back while you're clipped in on a hardpoint at the bow or mast is an option
My point was to not use it on cored rope so as to not shred the cover - but honestly at 1200 lbs is that even an issue?

Youre right I don't claim much knowledge of climbing gear. My point re: mast ascenders etc is that climbing gear is already used on boats
Everyone will have to make his own judgement about these risks.

I personally, not saying it's the only way to look at it:

1. Would never have rope or cable jacklines where you can step on them. That's an accident waiting to happen. Many boats, including mine, can't do a centerline jack line, and even if I could, it would not be very useful with my 16 foot beam.

2. Would not want to be clipping on and off with a device like this -- being able to do this operation as quickly and easily as possible is key to safety in rough conditions. You do NOT, in my view, want to be futzing with something like this in rough weather when you need to move around a shroud or get to the mast or whatever (and tether should have three hooks so you can clip on the new place before unclipping the old).

3. Would worry a whole lot more about getting washed overboard by a boarding sea, which is what kills sailors regularly in real life. A friend of mine recently put netting in his lifelines, something I've always hated on principle, but after having sailed from Annapolis to Key West in December in a lot of very rough weather, see now with new appreciation.

On the last point, one terrible risk if you do go over while tethered is that you are drowned almost instantly by being dragged face-first through the water. I invested last year into a couple of the new Spinlock Vito lifejackets which allow you to release the tether so that it flips you around to be pulled back-first. Whether one would have the presence of mind to pull the ripcord, once something like that has happened, I don't know, so I think it's still worthwhile concentrating on not getting into that position.

Getting washed down the deck along the jacklines? I'm with Thinwater on this one -- not on my list of things to worry about, compared to many others.
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Old 02-02-2025, 08:58   #11
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Re: Fall arrestor on jacklines?

See nested responses.

Quote:
Originally Posted by Dockhead View Post
Everyone will have to make his own judgement about these risks.

I personally, not saying it's the only way to look at it:

1. Would never have rope or cable jacklines where you can step on them. That's an accident waiting to happen. Many boats, including mine, can't do a centerline jack line, and even if I could, it would not be very useful with my 16 foot beam.

That is why I used dyneema- 4mm has a 1300kg breaking strength. Also the doubled West Marine straps lay flat. Netiher will roll under my size 12's or even more human size feet.

2. Would not want to be clipping on and off with a device like this -- being able to do this operation as quickly and easily as possible is key to safety in rough conditions. You do NOT, in my view, want to be futzing with something like this in rough weather when you need to move around a shroud or get to the mast or whatever (and tether should have three hooks so you can clip on the new place before unclipping the old).

I have done this many, many times. Jack lines need to be reeved through or around hard points. If not they will sag under load. Using a 2-legged tether allows the user to ride the jack line to a hard point on one leg and then clip the free leg to the other side, unclip the first and move forward. If you have a tether with KONG double-action clips it is effortless. Cheap POS clips are cumbersome.

3. Would worry a whole lot more about getting washed overboard by a boarding sea, which is what kills sailors regularly in real life. A friend of mine recently put netting in his lifelines, something I've always hated on principle, but after having sailed from Annapolis to Key West in December in a lot of very rough weather, see now with new appreciation.

I do not consider netting a safety. I have taken hard falls and had my jackline keep me aboard. Two jacklines running down the middle work.

On the last point, one terrible risk if you do go over while tethered is that you are drowned almost instantly by being dragged face-first through the water. I invested last year into a couple of the new Spinlock Vito lifejackets which allow you to release the tether so that it flips you around to be pulled back-first. Whether one would have the presence of mind to pull the ripcord, once something like that has happened, I don't know, so I think it's still worthwhile concentrating on not getting into that position.

Let's start with ASA and others who rig jacklines along the edge of the deck are dead wrong. If you rig jacklines down the middle, even on a 33' boat, it is hard to get your 'center of mass' over the rail. When I had to go to the peak in truly bad seas, I would rap my free tether around the forestay. Between the jackline and forestay I was able to work using both hands confident I would stay aboard.

Getting washed down the deck along the jacklines? I'm with Thinwater on this one -- not on my list of things to worry about, compared to many others.
Agreed- getting washed DOWN along the deck is why you have jackline!
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Old 02-02-2025, 11:58   #12
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Re: Fall arrestor on jacklines?

Quote:
Originally Posted by Snore View Post
See nested responses.Everyone will have to make his own judgement about these risks.

I personally, not saying it's the only way to look at it:

1. Would never have rope or cable jacklines where you can step on them. That's an accident waiting to happen. Many boats, including mine, can't do a centerline jack line, and even if I could, it would not be very useful with my 16 foot beam.

That is why I used dyneema- 4mm has a 1300kg breaking strength. Also the doubled West Marine straps lay flat. Netiher will roll under my size 12's or even more human size feet.

2. Would not want to be clipping on and off with a device like this -- being able to do this operation as quickly and easily as possible is key to safety in rough conditions. You do NOT, in my view, want to be futzing with something like this in rough weather when you need to move around a shroud or get to the mast or whatever (and tether should have three hooks so you can clip on the new place before unclipping the old).

I have done this many, many times. Jack lines need to be reeved through or around hard points. If not they will sag under load. Using a 2-legged tether allows the user to ride the jack line to a hard point on one leg and then clip the free leg to the other side, unclip the first and move forward. If you have a tether with KONG double-action clips it is effortless. Cheap POS clips are cumbersome.

3. Would worry a whole lot more about getting washed overboard by a boarding sea, which is what kills sailors regularly in real life. A friend of mine recently put netting in his lifelines, something I've always hated on principle, but after having sailed from Annapolis to Key West in December in a lot of very rough weather, see now with new appreciation.

I do not consider netting a safety. I have taken hard falls and had my jackline keep me aboard. Two jacklines running down the middle work.

On the last point, one terrible risk if you do go over while tethered is that you are drowned almost instantly by being dragged face-first through the water. I invested last year into a couple of the new Spinlock Vito lifejackets which allow you to release the tether so that it flips you around to be pulled back-first. Whether one would have the presence of mind to pull the ripcord, once something like that has happened, I don't know, so I think it's still worthwhile concentrating on not getting into that position.

Let's start with ASA and others who rig jacklines along the edge of the deck are dead wrong. If you rig jacklines down the middle, even on a 33' boat, it is hard to get your 'center of mass' over the rail. When I had to go to the peak in truly bad seas, I would rap my free tether around the forestay. Between the jackline and forestay I was able to work using both hands confident I would stay aboard.

Getting washed down the deck along the jacklines? I'm with Thinwater on this one -- not on my list of things to worry about, compared to many others.
Agreed- getting washed DOWN along the deck is why you have jackline!

I can't remember who was talking about this recently -- was it Thinwater maybe? How you rig your jacklines, how you clip on, the rigging and also the process, is a whole science, related to the one well known to arborists and alpinists, and no less complex.


It sounds like what I do is similar to yours -- my jacklines are pulled inboard and belayed at different points, and run INSIDE the shrouds. For that reason you can't just slide the hook all the way forward -- you have to be able to unclip and reclip. But I don't settle for the jacklines -- in fact, I mostly use them just to get to wherever I need to work. I feel best and most secure with a short tether thrown around the mast. I will use the inner forestay, the forestay, dorade guards, whatever I can find. I normally have two tethers on me -- one with three hooks and two legs of varying lengths, and one short tether for tying myself right up to something.


But I'm a total coward about going forward in rough weather, and I'm a coward for my crew, too. In really bad weather I will heave to before doing any work forward. Even racing. Not only is it vastly safer, but the work will get done much faster and better.
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Old 02-02-2025, 14:33   #13
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Re: Fall arrestor on jacklines?

Quote:
Originally Posted by Dockhead View Post
I can't remember who was talking about this recently -- was it Thinwater maybe? How you rig your jacklines, how you clip on, the rigging and also the process, is a whole science, related to the one well known to arborists and alpinists, and no less complex.


It sounds like what I do is similar to yours -- my jacklines are pulled inboard and belayed at different points, and run INSIDE the shrouds. For that reason you can't just slide the hook all the way forward -- you have to be able to unclip and reclip. But I don't settle for the jacklines -- in fact, I mostly use them just to get to wherever I need to work. I feel best and most secure with a short tether thrown around the mast. I will use the inner forestay, the forestay, dorade guards, whatever I can find. I normally have two tethers on me -- one with three hooks and two legs of varying lengths, and one short tether for tying myself right up to something.


But I'm a total coward about going forward in rough weather, and I'm a coward for my crew, too. In really bad weather I will heave to before doing any work forward. Even racing. Not only is it vastly safer, but the work will get done much faster and better.
This topic gets brought up pretty regularly, and IMO it needs not only a lot more discussion, but a paradigm shift in how people approach onboard safety. There's been rapid evolution recently in auto-inflatable harness/tether design, largely because the whole system just. doesn't. work. Crotch strap, leg loops, Vito variety--it's all trying to address a situation that should never be allowed to happen.
My thought (and practice) is that when moving toward your workstation on deck, you have two hands to hang on by. Use them, without being distracted by clipping/unclipping/fumbling, etc.
At the mast or foredeck, clip in with an adjustable daisy chain (I make some for myself, and sell them on my climbing gear webstore). If you clip short below waist level, you can brace against the tether with your legs, and have a very stable stance with both hands free. I did this all through the rowdiest conditions in the Northwest Passage, as well as on several mid-Atlantic trips. It works beautifully.
Return by holding on with both hands. This gets you on deck and back a lot quicker than futzing with always trying to be clipped in every single second, and gives you a comfortable, braced stance when working at the mast or foredeck.
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Old 02-02-2025, 21:11   #14
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Re: Fall arrestor on jacklines?

Quote:
Originally Posted by Dockhead View Post


1.
Many boats, including mine, can't do a centerline jack line, and even if I could, it would not be very useful with my 16 foot beam.
.
Indeed, so how about "more inboard" than centerline

In any case this is apart from the issue of preventing yourself from being dragged down the deck


.
Quote:

2. You do NOT, in my view, want to be futzing with something like this in rough weather when
.
There's no real futzing, the arrestor is permenently installed in the jackline and you clip onto its loop just like clipping onto the jackline normally; it slides along with you.

.
Quote:

3. Would worry a whole lot more about getting washed overboard by a boarding sea, which is what kills sailors regularly in real life.

.
Certainy nobody says get rid of netting etc. Nobody says you should be any less concerned with falling overboard, the issue is to make it safer if you trip on deck in rough weather while clipped on & getting banged up along the way & this is so widely recogized as a problem "in real life" that some folks rig their jacklines outside the shrouds. Dunno if it works though.


Yes jacklines are not a perfect solution, and yes perm clipon hard points are great, using them doesnt preclude using an arrestor either, do both

But speaking of getting dragged after fall8ng overboard
:
There was a Japanese sailor who fell overboard and was dragged for days until his boat struck the east coast of Australia, if I remember right, but I cant find details onl8ne...
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Old 02-02-2025, 21:53   #15
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Re: Fall arrestor on jacklines?

Let's set aside whether we think such a device is needed, could be helpful, is a distraction, and problems. The OP asked fair question. Let's consider what the device could be. Also many of these are very rope-specific. Let's also set that aside for the moment. If not this, maybe there is an idea that will be useful in some other application.



---


The question is what triggers the locking action.



Ascender. They go one way and grab the other; going forward would be fine, but it would have to be deactivated to return. Most don't do this easily (for obvious reasons when climbing), but assuming you can get past that, it would not work for the more hazardous half of the trip. Also, some (not all) can lever off the the rope if pulled from an angle.


Fall arrest based on speed (ASAP and some others). The speed needs to be greater than a likely slide. Also, they tend to have fussy small parts inside. If it triggered at too low a speed it would catch every time the tether jerked (which is a problem with many industrial versions).



Fall arrest based on loss of weight (weightless when falling) (Camp Goblin and most industrial types). It needs to be a vertical fall. A slide will not trigger. Also prone to locking if they bump against anything, even a knee.


Fall arrest based on friction (Prusik and other possibilities). Friction decreases with speed, it does not increase. Prusik hitches grab well when snug, but can just slide if loose.


---


My boggle is that I can't figure out what "tells" the device that a fall has occurred. It's an interesting question. I have several fall arrest devices that I use regularly, from each of these categories. None of them are suitable for this.


Dockhead's comments about work station tethers are sound. Make sure you have good handholds bow-to-stern. Clip short; the 3-foot and 6-foot standards are just a starting point; you can clip shorter.
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