Jackstays

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Graham_Wright

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www.mastaclimba.com
If you go over the side whilst attached by your safety line to a jackstay running along the deck, by the time your harness runs out of length, the shock on it and the jackstay can be considerable. For jackstay strength, (tape), I have seen a figure of 3 tonnes breaking force recommended. I prefer to use a SS wire rope (it is positioned out of "tread" area).

What is the best way to secure the ends? A standard rigging termination (Sta-Lok or similar) conceals its strength inside the body. Would 2 or 3 buldog grips be better?

I am concious that the through-deck would have to be a comfortable termination.
 
If the stays have little slack in them, then the aft securing point will take all the force when the life line slides back and strikes it. By that logic doen't matter too much what the stay itself is made of.

Maybe some sort of arrest system say 0.5 - 1m from the aft end would help. I mean a big bead sort of thing that one clips (the life line) on in front of, that will slip under a high force, thus absorbing a lot of the energy.

3 tonnes of force jerking on your harness is going to do some pretty serious damage to the person envolved tho. Do ou know what speed that is quoted for? I struggle to imagine it would be quite that high for a cruiser's hull speed, but may well be wrong!
 
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If the stays have little slack in them, then the aft securing point will take all the force when the life line slides back and strikes it. By that logic doen't matter too much what the stay itself is made of.

Maybe some sort of arrest system say 0.5 - 1m from the aft end would help. I mean a big bead sort of thing that one clips (the life line) on in front of, that will slip under a high force, thus absorbing a lot of the energy.

3 tonnes of force jerking on your harness is going to do some pretty serious damage to the person envolved tho. Do ou know what speed that is quoted for? I struggle to imagine it would be quite that high for a cruiser's hull speed, but may well be wrong!

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<span style="color:red">Good point but if you are working inside the shrouds as I would be, you could exit before them which would mean the force would be about midway along the length of the stay. </span>
 
Webbing strops if they are stitched as climbing strops will quite easily take the load of a person falling over the side, as a climber I've seen a webbing sling smaller than my jackstays take an 80kg person with climbing kit falling 2-3m. It's good to have it strong but I believe that using something that has some give in it will always be better for the fixings and the person. A wire with no stretch will give a much greater shock load to fittings and the person attached to it.

We would also take them off, wash them and check the stitching regularly, (get the stitching done in a different colour thread to the webbing) Many people tend to leave wire ones in place, in many ways it's more difficult to check the condition of the terminations where salt and corrossion can build up.

I also think most of the time you will fall through the guard wires rather than over them, if its rough you're on your knees and a wave can wash you along the deck and under the guard wires. It would be difficult to slide back along most jackstays as there are usually winches, stays, clutches cleats in the way even if you did go over the top of the wires.

I have in the past found wire strops on deck or coach roof less than helpful if you put your foot on one. Even when they are sited out of tread area, when its rough you end up using any bit of the boat to stand on, from windows to the side of the mast. In my experience every bit of the coach roof is used as deck at some time.
 
Wire Jackstays

2 reasons for not having wire jackstays:

Can roll under foot and may actually contribute to someone falling/slipping

If you are clipped on and moving about on deck, they can be annoyingly noisy to someone who is off watch below trying to sleep.
 
Would you prefer your mast to be held up by bulldog clips?
They are for bodging!
I would go for webbing. It's fairly tried and tested.
 
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Would you prefer your mast to be held up by bulldog clips?
They are for bodging!
I would go for webbing. It's fairly tried and tested.

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The point in favour of buldog grips is that you can see the attachment and it is easy to introduce redundancy by using more than one.

But the points made for elasticity and the noise considerations are ones I had not considered.

So. the question changes to "how do you attach webbing to the cabin top strong points"? I don't like the idea of U-bolts and would prefer a through-post well backed up.
 
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3 tonnes of force jerking on your harness is going to do some pretty serious damage to the person envolved tho.

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3 tonnes load on the jackstay does not translate to the load at the harness. The tighter the jackstay the higher the load on it. Trouble is if the jackstay is slack the crew is in the water which rather defeats the object. There's no simple solution - there have been loads of threads on this in the past....
 
What I plan to do is to make up some wire jackstays with 25 or 40 mm D rings on each end to all attachment to M10 U bolts through bolted to my deck (deck is steel in my case so very strong).

I will then sew 25 or 38 mm webbing each side of the wire with the webbing wrapped around the D rings and sewed to the webbing in between the rings to cover the ring to wire attachment.

The jackstays D rings will be attached to the U bolts with stainless bolt shackies

This IMHO gives you the best of both worlds.
 
Definitely use webbing jackstays and as suggested have them sewn with contrasting thread. Wire is a pain as it will roll under your foot, wherever it's placed. I also fit a snap shackle at each end so they can be removed after every trip and stowed below to prevent UV degradation. Also marked 'P' and 'S' as they are slightly different lengths!
 
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