jack stays

ChattingLil

ChattingLil

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I have no intention of scrimping on safety equipment, but... can anyone tell me what the difference is between a jack stay that costs £30 in the chandlery and luggage strapping that says it can take 550 kgs in B&Q on sale for £3.99??
 
about 3 times the length, and propper stitching. 'marine' stuff will be rated for a much higher peak load too,

Chap in my marina got his from a hot air baloon specialist, reckoned they were cheaper, but can't remember how much he said. maybe worth investigating...
 
Be VERY careful!

Proper jackstays, on which your life can, quite literally, hang, should be made out of polyester webbing. This can withstand the effects of UV, unlike the polypropylene that is normally used for cheap straps. Polyprop degrades quite rapidly in sunlight.

If you want to save money, buy proper polyester webbing, preferably orange in colour (more easily seen), and sew the loops by hand over a length of at least 12". Make many rows and go over the stitching three times in both directions, using polyester whipping twine and a darning needle if you don't have sailmakers' needles. It is not difficult to do.

Do not go narrower than 30 mm; heavy duty webbing would be some 2.5 - 3mm thick.

Your life could depend on it!
 
thanks, that's what I wondered. I knew there had to be something materially important and hadn't thought about it before I saw these things today. I have already have the 'proper' ones anyway, I was curious.
 
Can I recommend TP retail as a supplier of strong, well made jackstays, I am pleased with mine, worth a look.
tpretail.co.uk
 
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The one I happened upon in B&Q today was 8 metres (long enough for me)!

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B&Q cheap steel fittings barely up to the task. Thin polypropylene straps with zero safety margin on the materials, fittings or construction methodology.

its your life but you might fnd it difficult to find crew /forums/images/graemlins/smile.gif
 
The difference is £26.01. Duno bout the difference in spec, i bet it's minimal - there agin...550kg applied ...how?

However, it sounds quite lot, and if replaced (cos it gets weaker in UV) i bet it'll be fine. But who knows? So, test it...

You could actually test it (eventually quite violently) by loading your whole weight on it, by rigging it up a halyard and you in a harness. This would likely be more testing than most have ever done on their jackstays ("tick").

Incidentally, they are "jackstays" not jack stays.
 
How much do you/anyone else hooked on weigh? What dynamic load factor (eg. you are thrown by a wave) do you want to allow for? What safety factor do you want to add on (allowing for UV degradation; chafe etc etc?)

I (big guy) would want to see at least a 2t SWL

Sad epitaph - "He saved £50 on his jacklines but...."
 
The advantage of using a coloured polyester webbing is that you can see as it fades in the sunlight - and as soon as that has happened it would be prudent to consider replacing them.
 
I replaced the webbing jackstays on my previous boat as when I got it it was faded and obviously had been permanently rigged for many years. I replaced it with 2 tonne polyester webbing with snapshackles on each end so they can be easily removed at the end of each trip. I stlll have the original jackstays and now used when the boat is laid up tied around the cradle legs to tie the tarpaulin ropes to. The webbing very soon began to disintegrate so I probably replaced it in time!
 
Not so. Imagine he is hooked on at the centre of an 8m length, and goes overboard. The jackstay which was fairly straight along the deck is now pulled taut with its centre about half a metre away from the straight line between the attachment points. I have forgotten the formula for calculating the end pull on the webbing in such circumstances, but it is a considerable multiplier on the weight hanging at the centre. I very much doubt that 550Kg is anywhere near enough for a 20 stone man in such circumstances, and the suggestion of a minimum 2 ton breaking strain being correct for jackstays looks about right to me, provided they are set up in the first place with a little bit of slack in them.
 
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2tonnes? Jeez. That's 20g on quite a big 100kg guy.

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As an instant snatch load, that would not be out of court. I reckon you could generate 5g quite regularly.
Now imagine if your webbing is subject to a point load, like being caught on a stanchion or similar. The 2 tonnes SWL could easily be reduced to 1 tonne or less as all the load impinges on half the webbing width, without even considering angular loads.
Then we will add the gradual UV degradation, and in a couple of years, your safety margin is reduced further. Add a bit of chafe or thread squash in the ends where the shackles are, or maybe some general chafing, you have even less.

Lastly of course, you should use an approved pattern of stitiching such as used on aircraft load webbing nets, which is tested. PS don't use Kevlar thread, because its weaker not stronger, when forced into radii you will make it go when you stitch it.
 
Rock climbing equipment it genrally rated with 2.5 tonne breaking strain and would want to see at least a 2 tonne rating on a boat. i went for plastic coated rigging wire that way you don't have the uv problems.
 
Forget the B&Q webbing ... it's not good enough. 550Kg is nowhere near enough for snatch load if you fall.

Best is to find a truckers emporium and buy webbing for load tie downs. Replacement webbing for their ratchet strapping. SWL 2000 kgs is advised.

Stitching the eyes in - look at a car safety belt and see how it zig-zags and crosses over the stitching. That's what you should aim for as minimum. Another has suggested 12" run of stitching ... not necessary. 4 - 5" is enough .... 3 - 4" if really done well with good seaman waxed twine.
 
Talking of replacing Jackstays:
What do others give the expected life as, mine have been fitted for two years.
Also does washing them reduce quality? as they sure do clean up better with hot soap and water.(or washing machine)
Mike
 
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