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Old 01-12-2015, 08:59   #61
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Re: Jacklines and fall protection devices?

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Originally Posted by brianlara 3 View Post
Estarzinger, the distance from my deck to the top of the rail is 650mm.

The ISAF spec is 600mm - so you slightly exceed the spec. I know there are trade-offs, and on my own boat I choose to also go about that height, but I do think from a 'safety first' perspective even higher would be a benefit. Some (quite knowledgeable and experienced) folks rig a rope 'life line' at chest height when on passage - using the shrouds to anchor it at chest height mid-ships.


The length of a vessel usually determines the number of stanchions yes?

ISAF spec is stanchion every 2,2m (maximum).

Well, on my little boat I can litterally stand on the rails.

From a strength perspective you could easily stand on a dyneema or wire life line - no problem at all.

My tubular top rail links my bow and stern rails into a very stiff cage and i think that any flexible link would allow stanchions to move independently, surely.?

A wire or dyneema life line can certainly move a little. perhaps 25mm if tight - 50mm is allowed on race boats. Certainly more than a solid tube (although even that will move some amount depending on spec). But I personally dont see this (relatively) small amount of movement to be any sort of safety issue. If you lean on a wire or dyneema life line it still holds you very firmly.

If you like the tubes, that's great. I am not at all criticising them. But I personally suspect they are more of a psychological benefit than an 'engineering' one.

I will comment that if we had had solid tube life lines on Hawk we would probably have bent them a couple times in rough docking situations.


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Old 01-12-2015, 09:39   #62
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Re: Jacklines and fall protection devices?

Although I can understand the desire for a jackline to be run down the center of the boat, I can't visualize this actually installed on my boat. The line would need to run over the center of the cockpit, in the way of everyones' heads and the main sheet (I am a center cockpit ketch). I guess could go from midline in front of dodger, but then what do I do when getting around the dodger to go forward, which seems one of the riskiest transitions while moving towards the bow. Any diagrams or photos on how centerline jackline installs have been made would be most welcomed by this sailor. Thanks.
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Old 01-12-2015, 09:51   #63
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Re: Jacklines and fall protection devices?

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Originally Posted by brianlara 3 View Post
... WHEN i get there both hands are free because I have very solid rails to use as a brace. Imagine the bracing security of a solid pulpit from bow to stern. That's what I have made.
I have handled on headsail and staysails and the pick is dropped from the cockpit.
...
Not sure I understand. You feel secure on the front deck handing sails because your lifelines are tubes instead of wire? If lifelines were all that effective in keeping people on board, I don't think this thread would exist.
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Old 01-12-2015, 10:43   #64
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Re: Jacklines and fall protection devices?

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Originally Posted by Dennis.G View Post
Although I can understand the desire for a jackline to be run down the center of the boat, I can't visualize this actually installed on my boat. The line would need to run over the center of the cockpit, in the way of everyones' heads and the main sheet (I am a center cockpit ketch). I guess could go from midline in front of dodger, but then what do I do when getting around the dodger to go forward, which seems one of the riskiest transitions while moving towards the bow. Any diagrams or photos on how centerline jackline installs have been made would be most welcomed by this sailor. Thanks.
Centerline jack lines are usually less convenient. And yes, a dodger and traveler in the way increases the inconvience. But if a centerline will keep you on board when a side deck one will not . . . Perhaps it is better to think about how to move safely around the dodger and traveler?

you can also use "inboard" ones (further inboard than side decks but not on centerline) - for instance run along the side of the top of the cabin trunk - if for you that is a better balanced between convenience and keeping you on board.

I will comment again that the vast majority of MOB are from when people are standing and working with both hands, and occasionally moving and not holding onto anything. NOT from when they are moving up the side deck while holding onto secure hand grips. So, use work station tethers when working, and kneel/sit when possible, and use hand grips when moving and watch where you place your feet, and you are pretty much good.

You watch an experienced (small boat) seaman moving and you will notice him gripping something with one hand almost all the time, just from experienced reflex. He will not even realize he is doing it.
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Old 01-12-2015, 10:50   #65
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Re: Jacklines and fall protection devices?

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Doesn't that depend on the length of the lanyard and the position of the jackline?
The problem with jacklines is that the idea is to give you a way to go right forward from right aft without having to unclip. It is essentially a dog run that can only be attached at each end. That means that if a wave grapples and boards, catching you on the foredeck, even with a very short leash to the lifeline, it can wash you aft along the line, with much to bump into on the way. Unless the jackline is bowstring taut, you'll probably be able to deflect it enough amidships to roll over the toerail. I'm talking about jacklines that actually do go from the cockpit to the foredeck here. Any sort that stop here and there and need to be clipped around defeat the purpose of the dog run.
With two daisy chains, you can very easily leave one clipped in while you find an attachment for the other one. As for operator error: if you can't figure out what or where to clip your leash to when you go forward in dirty weather, chances are you're too incompetent to put in a reef or change a headsail or whatever you went forward for. Might as well stay ashore.
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Old 01-12-2015, 11:07   #66
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Re: Jacklines and fall protection devices?

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Originally Posted by estarzinger View Post
..........
Our testing showed no jackline tether forces over about 700 pounds (a VERY worst case), so no impact injuries were predicted. The jacklines, even low stretch, stretch enough. That correlates with experience.

Interestingly, polyester jacklines typically operate at a relatively high safety factor (8:1), because they are able to stretch (compared to SS or Dyneema). Thus, in practice, there is latitude for substandard end loops and even knotted loops, though that is not good practice. That explains the good record of polyester. While I'm sure the ends failed on the SS jacklines, we should consider that VERY high stress related to no-stretch contributed. The nice thing about Dyneema is that good splices are both simple and easy to inspect. And different from lifelines, chafe is easy to see. Thus, this testing correlates with experience.

Yes, some of the tether failures were related to sewing and edges (that is why I mentioned it), but even then they were all on hard points and were likely at very high loads (the remaining stitching tested at about 2400# as I remember, and according to the military, debilitating injuries start at about 1200 pounds in a body harness). Whether long slides/stumbles in the cockpit (high impacts, softer catch) are more important than compact size (more likely to use, good for work station) is interesting. I can see using both.

---

Center jacklines. Yes, cats do have the luxury of wide bows, but the side decks are generally just as narrow. My solution is to run the jackline along the top cabin chine, right on the corner. This gets it off the deck, is still accessible from the cockpit, and it is higher and further inboard. The down sides are that dedicated hard points are probably needed and that it will need to end short of the bow (on a catamaran this is a good thing, since the primary danger at the bow is getting thrown forward--I did that once, years ago. With a tether it might even be worse than getting dragged along side.).
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Old 01-12-2015, 11:33   #67
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Re: Jacklines and fall protection devices?

Quote:
Originally Posted by Dennis.G View Post
Although I can understand the desire for a jackline to be run down the center of the boat, I can't visualize this actually installed on my boat. The line would need to run over the center of the cockpit, in the way of everyones' heads and the main sheet (I am a center cockpit ketch). I guess could go from midline in front of dodger, but then what do I do when getting around the dodger to go forward, which seems one of the riskiest transitions while moving towards the bow. Any diagrams or photos on how centerline jackline installs have been made would be most welcomed by this sailor. Thanks.
No attempt on my boat to run a single centre line from bow to stern.... one from aft of cockpit to stern...one from mast frd.
Going aft is always a 'hands and knees' job - and only required when going aft to adjust course on the S/steering- so it just lies on the deck.
As mentioned earlier from the mast frd it starts at almost shoulder height...no stooping or faffing around to clip on... and leads down to a mooring cleat by way of the capstan. Means that in most conditions I can walk to the inner forestay with a reasonable handhold the whole way.

Yes there is a lot of clip on/clip off but there are no long runs of jackline either.

My only grey area is the very short distance from cockpit to mast... I like Jon Eisberg's idea of a tether permenantly attached at the foot of the mast.
I think my comment re using the boom vang when leaving the cockpit was misconstrued... if I do that close hauled the clip immeadiately runs down to the foot of the mast ( and is in use in that manner for less than the 30 seconds it takes to get from cockpit to mast ) and there is little fear of entering a low earth orbit on a gybe

That area ( between cockpit and mast) is my only true area of concern and when I think I am at my most vunerable.
I say that having once been hove too on a night as black as the inside of a cow - back in the cockpit less than a nanosecond when the deck was swept by a sea slightly larger than the rest - goodbye solar panels, goodbye assorted other stuff down the back ... almost goodbye Ping.
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Old 02-12-2015, 04:05   #68
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Re: Jacklines and fall protection devices?

I spent quite a while last night looking at climbing gear, wondering if one of the manufacturers like petzl would consider adapting some of their designs for marine use. Some things that come to mind. An arrester that allows slow steady pull but locks when preset accelerating moment is exceeded, why not a beefed up version as a boom brake? What about ascenders and stirrups (etrier?) for climbing the mast in the climbing harness instead of bosun's chair? Very handy for the solo sailor, or one who is happier getting oneself up the mast without needing to rely on OP for winch duty.?
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Old 02-12-2015, 05:00   #69
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Re: Jacklines and fall protection devices?

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I spent quite a while last night looking at climbing gear, wondering if one of the manufacturers like petzl would consider adapting some of their designs for marine use. Some things that come to mind. An arrester that allows slow steady pull but locks when preset accelerating moment is exceeded, why not a beefed up version as a boom brake? What about ascenders and stirrups (etrier?) for climbing the mast in the climbing harness instead of bosun's chair? Very handy for the solo sailor, or one who is happier getting oneself up the mast without needing to rely on OP for winch duty.?
Much climbing and caving and arborist gear is indeed being used by sailors all over the place to get things done more efficiently. Some of the designs are drifting over to marine manufacturers (check out the Gyb'n Easy Boom Brake--basically a rappel device, or the ATN Topclimber, a modified ascender setup). One problem with using climbing gear for seafaring is that the fancier bits often have steel parts (springs and such), which require constant service to work correctly. Whenever they get designed for use at sea, the mfg. jacks up the price accordingly, and often they become heavier and larger and clumsier (witness again the Gyb'n easy boombrake. Compare the price and size of that with a regular figure 8 device).
With literally dozens of different devices each specialized for different things, it's up to the individual sailor to educate himself on their use and select accordingly to his needs. I think every sailor could benefit from a few years of rockclimbing, just as every climber should spend a few years at sea. Round things out, as it were.
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Old 02-12-2015, 11:43   #70
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Re: Jacklines and fall protection devices?

Kerry 1, thanks for the time and effort you put in, essentially trying to help others. I, for one, will benefit because I really need to fix my steaming light sans an assistant.
BenZ. How I wish I could loosen the strings (no pun intended) of your website, because frankly, I'm losing sleep. But the trade off is...'never enjoyed a better read'. What a life man, and surrounded by 4 of life's most wonderful creations.
But I digress....
Estarzinger. Try this...your Van de Start has a length to beam ratio of about 3.2 : 1 as you would be aware. My Tritons ditto is 2.63 :1
You won't agree I suspect but in any case, my deck plan is as close to a circle as yours is to a parrellogram. Can you see it? And the sides of a shoebox are somewhat floppy yes?
Factor in "rate of motion" ...double LOD.
My original post mentioned two previously shreaded shoulders and one knee (ACL) and I so I'm only ever on the foredeck when snubbing the chain or when raising sail.
What you don't know (I'd say ??), is that 900mg /day of pregabalin (Lyrica) causes imbalance. Fortunately that side effect improves per the rate of inertia. IOW, the slower I'm forced to move the more 'stumbly' I am.
My tiny horizontal ringframe is safer for me because I've virtually eliminated flexion.
Sorry, but the effect is very real & not psychological as you suggested
Hanked on head & stays'l, each with cockpit led downhaul, and a windlass rocker also in the 'pit go a long way toward keeping me off a treacherous foredeck.
IF I do need to be in no man's land with free hands I use convenientally placed eyebolts to strap me as VERTICALLY to the deck as practicality permits.
Does my peripheral neuropathy cause me to be a poor candidate as a solo sailor treading the deck of a dollar coin? Well yes, my neurologist told me to "get to hell off of there". (5,100 nm & C. 5 years ago).
You see, tubes help defy inertia.
No??
Mr estarzinger, weariness and self esteem are the sole reasons why I take leave of this thread. Possibly any other threads too...time will tell..I hope I once again attempt to contribute.
Clearly, the higher the rate of motion the more unsatisfactory are flexible rails IWHT
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Old 02-12-2015, 13:53   #71
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Re: Jacklines and fall protection devices?

I have 1 modern climbing ascender to help getting up the mast. The teeth are super aggressive so you wouldn't use it on your boat lines. You end up needing a complete rig with dedicated rope to use one of these ascenders. I use a 3:1 set-up so that's quite a chunk of rope.
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Old 02-12-2015, 14:53   #72
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Re: Jacklines and fall protection devices?

Thanks Guy. I need to go up the mast for numerous reasons and never having climbed anything which didn't have branches I'm interested in what you mentioned. I'd only need a hundred feet of rope along with the stuff you mentioned but after googling "ascenders" and then going to images what I found was not enough to make a purchase.
I'd be grateful if you'd describe in more detail your kit. Would save me having to take the mast down because I suspect I can then renew my stays one at a time using Stalok terminals X 14. Do you use your legs and secondly, can I use my 'never been used' bosuns chair?
Really grateful. cheers brian
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Old 02-12-2015, 14:57   #73
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Re: Jacklines and fall protection devices?

Guy...I forgot to mention, I have bad shoulders so only my legs would give me lift. Do I need arms to do what you do?
Thanks.
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Old 02-12-2015, 15:09   #74
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Re: Jacklines and fall protection devices?

^^ details on mast climbing using rock equipment . . . http://www.bethandevans.com/pdf/mastclimbingpics.pdf

there are a number of ways to do it . . .but the two I found easiest are described in some detail.
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Old 02-12-2015, 15:15   #75
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Re: Jacklines and fall protection devices?

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Guy...I forgot to mention, I have bad shoulders so only my legs would give me lift. Do I need arms to do what you do?
Thanks.
I use just 1 arm ascender while sitting in a chair. You can get a foot ascender that straps to your shoe but then you might need some sort of descender too if your shoulders are weak.
ATN Topclimber looks like a leg lift system. I see the guy at boat shows, he makes it look easy.
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