Do jackstays need to be tensioned?

[PhillM]

So my MAB was never designed to have jackstays. We do have fitting points and for the last two years I had a set of the Baltic adjustable jobs. I now need to change these and have bought pre-made ones.

With the high coach roof and general shape, there were two places where the old ones rubbed into the varnished wood and when you walked along. the metal clip (of your line)would hit the coachroof and cause scratching / minor damage.

My new pre-made jack stays are about 4 inches too long. This means that they cannot be tensioned. In one way, I quite like the fact that by being slacker they are not putting pressure where the old ones rubbed. However, they do look really slack and dont lie flat.

My proposal is to attach the lines using the proper sewn loops but then to double back enough material to shorten them enough to make them lie flat - then whip the two parts together. My thinking is that in general use the lines will lay flat and not damage to the boat and in emergency, if the whipping failed, the jackstay is still connected through its proper loop.

Comments, suggestions please.

 

[fireball]

laying flat on our boat means they vibrate in the wind ... can get rather irritating ... so I put a twist in them.
I still keep them reasonably taught - but not tight - they're going to deflect as you put weight on them and the difference between taught and tight is not going to alter that hugely. I suppose they could be loose - as long as you've got appropriate length lifelines.

 

[winsbury]

you could use a length of shockcord to take up the slack similar to how the toestrap is tensioned in a Laser. It would still have the give that you like but lay neatly when not in use.

 

[alant]

So my MAB was never designed to have jackstays. We do have fitting points and for the last two years I had a set of the Baltic adjustable jobs. I now need to change these and have bought pre-made ones.

With the high coach roof and general shape, there were two places where the old ones rubbed into the varnished wood and when you walked along. the metal clip (of your line)would hit the coachroof and cause scratching / minor damage.

My new pre-made jack stays are about 4 inches too long. This means that they cannot be tensioned. In one way, I quite like the fact that by being slacker they are not putting pressure where the old ones rubbed. However, they do look really slack and dont lie flat.

My proposal is to attach the lines using the proper sewn loops but then to double back enough material to shorten them enough to make them lie flat - then whip the two parts together. My thinking is that in general use the lines will lay flat and not damage to the boat and in emergency, if the whipping failed, the jackstay is still connected through its proper loop.

Comments, suggestions please.

If they are too slack, they will be useless.

 

[colind3782]

Talking of jackstays. I've been thinking that the usual layout along the side decks won't keep anyone on board so I thought about taking them from the cockpit, up to/around the mast and back down to the foredeck. That way there seems to be a reasonable chance of staying on board with a short tether.

There's nothing new in the world so I imagine it's been done. Any disadvantages apart from having to change hooks at the mast?

 

[prv]

There's nothing new in the world so I imagine it's been done. Any disadvantages apart from having to change hooks at the mast?

The main problem is, as you say, the inability to get a clear run from cockpit to foredeck without unclipping. If you have a sprayhood it can be difficult to get clipped on in the first place, though a tether can be pre-positioned on the jackstay in rough weather and the end brought round into the cockpit to be clipped onto when required.

Pete

 

[doug748]

Mine are loose, as Fireball says, they can twitter in the wind. I will try the suggestion of putting a twist in, tho it will not look so neat.

One problem with tension is the added stress it puts on the whole system. If it were to be used by a robust sailor it could well lead to failure.

 

[prv]

One problem with tension is the added stress it puts on the whole system. If it were to be used by a robust sailor it could well lead to failure.

If the small amount of tension you'd put into it with a lashing causes any trouble, then it is definitely not strong enough for 120 kilos of sailor falling at speed the full length of his tether. I've seen figures for this quoted in tonnes.

Pete

 

[MoodySabre]

I have my webbing jackstays taught. The aft end is fastened off on the side of the coaming and so, except for the foredeck, they lie against the side of the coach roof and the side decks are free.

So the lifeline clip does not drag or cause any damage I have SS rings on the webbings so you clip on the ring which then slides along easily.

 

[doug748]

If the small amount of tension you'd put into it with a lashing causes any trouble, then it is definitely not strong enough for 120 kilos of sailor falling at speed the full length of his tether. I've seen figures for this quoted in tonnes.
Pete

Yes, the tension you put in is insignificant but by linking the things rigidly you put a lot of extra tension in, should the system be used in anger. It's the Physics of the thing. Same principle as you swig up a halyard against minimal tension but an unyielding turn, around a cleat.

Anyway it is less of problem with webbing. Though a taut wire could pull a fitting through the deck.

 

[PhillM]

Interesting views

There is no way a fall would keep you onboard.

The only purpose is to keep the crew attached to the boat.

The only way to clip on and stay onboard would be a jack stay over the coach roof to the mast. I'm thinking about that but not sure how to make it work.

 

[gasdave]

The only way to clip on and stay onboard would be a jack stay over the coach roof to the mast. I'm thinking about that but not sure how to make it work.

I suppose if you use a 3-clip Y tether and have two ends clipped to the jackstay then you unclip one at a time when you move from mast to foredeck (same as the via ferrata technique). This way you are always secured to the boat. The length is a compromise between being long enough to work and short enough to stay on board in a fall. The recent articles in the press about being dragged in the water alongside a boat make avoiding this possibility look very important.

 

[jwilson]

If the small amount of tension you'd put into it with a lashing causes any trouble, then it is definitely not strong enough for 120 kilos of sailor falling at speed the full length of his tether. I've seen figures for this quoted in tonnes.

Pete

And I've seen 6mm eyebolts distorted and nearly pulled through the deck by a real pair of MOBS.
I am also a fan of cockpit-mast jackstays rather then sidedeck ones on smaller boats.

 

[prv]

And I've seen 6mm eyebolts distorted and nearly pulled through the deck by a real pair of MOBS.

Doesn't surprise me for a moment. Though I guess the "nearly" means they served their purpose

Some way down my list is fitting new jackstays on Ariam, further inboard than the current ones between toerail cleats, and I expect I'll probably use at least two M10 bolts per fitting, with decent backing plates.

Pete

 

[William_H]

Interesting views

There is no way a fall would keep you onboard.

The only purpose is to keep the crew attached to the boat.

The only way to clip on and stay onboard would be a jack stay over the coach roof to the mast. I'm thinking about that but not sure how to make it work.

I have tried being towed behind my little boat in the safety harness. Even at quite low speed it is amazing how difficult it is to survive let alone get back on board. At 3 to 4 knots (the drag slowed the little boat down a lot) when being towed from a tether middle of chest my face was being hit by the water flow. The only thing I could do was grasp the tether and try to roll onto my back. That was very difficult. It was only a test and the crew stopped the boat. But it was proof to me that it would be helpful to be attached to the boat is a falacy. The only possible way to survive being towed at any speed would be with tether to middle of your back rather than chest. This is for the case of a long tether and you clear astern. I hate to think what it would be like dragged sideways with you against the side of the boat.
You must stay on board.
The only way to do that is with a short tether and jackstays near as possible to the centre line of the boat. Or use the jackstay on the opposite side to where you are working. (and the opposite side to the side you might potentially fall over.)
Which follows then on the OP that any slack in jack stays will more likely allow you to go over the side.
olewill

 

[Daydream believer]

If they are too slack, they will be useless.

Explain please

 

[Deleted member 36384]

I have always adjusted the tension (on wire jackstays) to keep them the lightly taught, not loose. On my own yacht I have mounted them inboard on the side decks using Witchard's 8mm Water Tight U Bolt (2400/4800 kg WL/BL). Obviously one should be able to pick them up sufficiently to place a safety line on. My main criteria is to minimise the distance that an MOB will hang from the yacht below the guardrail, assuming they go over the top of the guard rail. It also helps reduce the rolling underfoot that is a risk with wire, although I do not find it a particularly noticeable risk. The stretch in tape is the main reason that I have not chosen this material for my jackstays although I appreciate why they are considered better by others. I do have marking issues at the turn of the coach roof where the wire touches which I need to deal with.

I would agree that they have to be tensioned such that there is no slack flapping about for the reasons mentioned above.

 

[Daydream believer]

I had wire originally & found that to be really dangerous as they were on the side deck & rolled under foot,
I changed to webbing but after 1 season they deteriorated so badly under UV that i now use rope.
This does not roll underfoot much as it is softer. I keep them slack so i can kick them to one side if i need to stand on the side deck.
Also being slack i can stand on the cabin top & my fairly short safety line will lift the jackstay giving me enough length
If i go over i suspect that my safety line will catch on the guardrail & slide back , bending the stanchion etc before anyone can release the top wire ( which they will not do as i normally sail SH)
I have been in the drink 3 times once not tied on & twice i slipped under the guardrail. Once when i slid on the jib which i was changing & sitting on to hold it down. The 2 layers of sailcloth acted as a slide & i lost my grip.
My boot hooked on a cleat & the lifeline held me with my head dipping below water as the bow rose & fell. i hung upside down over the side. Fortunately i was able to reach a stanchion & pull myself back. If the lifejacket had inflated or my boot not snagged i would not have got back under the wire.

 

[trapezeartist]

The idea that side-deck jackstays provide any safety benefits is largely an illusion. The skipper of the Lion was tethered to a jackstay, but it didn't do him much good. A couple of other posters have already explained the problems.

As already mentioned, the biggest difficulty with centreline jackstays is getting past the sprayhood. I am now going to try the pre-attached option as suggested.

 

[john_morris_uk]

I am anxious that there seems to be a growing groundswell of opinion that suggests its so dangerous to be dragged by the boat that its almost better not to be hooked on.

I think the reasonable assumption if you are sailing with crew is that they will stop the boat (heave to? Drop the sails? Let fly the sheets etc) and its INFINITELY better to be still in contact with the boat than bobbing around on the ocean in the dark and have them start to search for you.

The problem with Lion was that the crew (racing if I recall) didn't notice that the father had gone over the side and the lifeline had caught in an unusual way or something?

Single incidents make poor precedents for general guidelines.