"Failsafe" rigging failures in CB

Alastairdent

Alastairdent

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\"Failsafe\" rigging failures in CB

What do people think of the article in CB where the author recommends building in rigging failure? The idea being that you lose a sail or something similar, instead of the boat being driven under?

The running backstays on our barge are 10mm wire rope - BF about 10ton. But they are attached to the boat by shackles that can't be much stronger than 0.7 ton. I wonder if this arrangement is traditional? (although if a backstay went, I guess the mast might go as well.)
 
Re: \"Failsafe\" rigging failures in CB

I'd have a bigger shackle holding your backstays down. If the force on the mast is strong enough to break them then it won't last 10 seconds without backstays.

Reefing in good time is the answer. Not built in riggin failures. If you know there's a weak link in your rigging then you'll never push your boat again.
 
Re: \"Failsafe\" rigging failures in CB

I have not read the article but there is a valid point. With modern ropes such as Dyneema and vectran which have made there way into the racing and to an extent the crusing market, it is possible to be using running rigging that is in fact stonger in break load than some of the rigging!

I have seen the result of a 'modern' classic styled yacht that used a dyneema preventer line on the boom. the boom end dipped into the water surging down a wave exerting massive loads to the goosneck. the dyneema preventer did not snap but the gooseneck did. This was on a carbon rig and required a new mast to resolve the breakage.

2 lessons: make sure you can release the preventer from the cockpit and consider the break load of the rope you are using for certain jobs as strongest is not always the best!
?
 
Re: \"Failsafe\" rigging failures in CB

Mmm, when have you heard of a boat being 'driven under'????

Being over pressed normally results in being laid over, heading up, and therefore spilling wind, or broaching dramatically if on a run. surely that is the 'release point'. The last thing you want is a weak spot. All components from chainplates to mast head should be of equal strength. or you are over building and putting weight in the wrong place. Look at Classic Marines website for some cracking articles on rigging, then make your own mind up !!
 
Re: \"Failsafe\" rigging failures in CB

It's happened a couple of times with the working boats at Falmouth. Cranked over so far that they fill up with water and go down sailing. No much of a risk to any vessel with a deck.
 
Re: \"Failsafe\" rigging failures in CB

[ QUOTE ]
It's happened a couple of times with the working boats at Falmouth. Cranked over so far that they fill up with water and go down sailing. No much of a risk to any vessel with a deck.

[/ QUOTE ]

Hmmmm, well I used to own a "Tosher" One of Martin Heards FWB's, and she had a racing rig on her, she would only go over so far, no matter how much she was pressed, she would dip her lee scuppers but go no more. It didn't matter that the lee scuppers were under, as she had side decks and coamings to keep the oggin out.
 
Re: \"Failsafe\" rigging failures in CB

Haven't read this but I seem to remember at the enquiry into the loss of a sail training ship years ago, (it might have been the Marques that triggered the MCA coding requirements of such vessels but I cant remember), but one of comments made was that the vessel had been re-rigged with synthetic sails and running rigging, and that the original natrural fibre sails and rigging would have failed and probably saved her in the terrible squall that drove her down.
As for building failure in though its an odd point of view. Better to have everything as strong as possible so you can drive your ship hard with confidence, and have an axe of knife handy to cut the sheets in extremis. Sailing to the conditions as far as possible obviously makes sense but even in our climate sudden line squalls etc of immense power are becoming common.
One other point, forestays should be twinned, particularly when roller reefing is in place. If any other stay fails the rig usually falls clear of the crew in the cockpit, but if the forestay goes when pounding to windward it falls on the hapless crew, had this racing in the north sea years ago and it wasn't funny, hence all my boats have two entirely independent forestays.
 
Re: \"Failsafe\" rigging failures in CB

Read the article - having sailed under square rig, I'm not impressed. He says that as the wind gets up, the largest sails would automatically be let fly, reducing the heeling moment. Anyone who knows will tell you that it is the small sails at the top of the mast (topgallants and royals) that push a square rigger over in a squall, not the courses and topsails (larger but lower down). His proposal would leave a ship in the worst possible situation: lots of heeling moment, but very little drive. The traditional seamanlike precautions of keeping a weather eye open during day, reefing at nightfall regardless of weather, and bearing away downwind if a squall hits, will always be the correct method of keeping a traditional square rigger on her feet, not building in failure in inappropriate places.

Well that's my rant for the month: I feel much better now, thankyou!
 
Re: \"Failsafe\" rigging failures in CB

A lot more old clippers etc were lost due to rigging failures than were saved by failing rig weaknesses or sails blowing out. In twenty odd years as a rigger I only saw two total rig failures on boats I had rigged. Both were material failure in alloy masts. I suppose you could consider that as a natural weak link, but I don't think it 'saved' the vessels concerned!
 
Re: \"Failsafe\" rigging failures in CB

Apples and Oranges I suppose. Comparing keel boats to barges isn't sensible.

A square rig is also totally different from a dutch/gaff rig. We have no ballast - it is the hull shape that gives stability. Dutch barges were meant to be sailed in or out of cargo.

The huge boom (I guessing) precludes running downwind as a safety option. I 'm not exactly sure what would be the safe sailing direction in a sudden squall.
 
Re: \"Failsafe\" rigging failures in CB

I think the article is at best naive. It fails to consider that the loads on every part of a sailing boat are dynamic. Variations in wind/wave patterns put hugely and rapidly varying loads on everything. If you specify items in the rigging to have a breaking load which just about equals that required to lay the ship on her side then in some conditions those loads will be exceeded briefly without laying the ship on her side. You would at least need to be able to specify that a particular load is exceeded for a particular amount of time (smart shackles required!).

Mike
 
Re: \"Failsafe\" rigging failures in CB

Woodlouse, does that recommendation come from experience?

I just find the idea of letting a 45ft boom 'go', scary.
 
Re: \"Failsafe\" rigging failures in CB

Indeed. I know how formidable the boom of a large gaffer can be. But letting it go as you head into the wind will be less scary than being pushed over till the truck of the mast is in the water.
 
Re: \"Failsafe\" rigging failures in CB

[ QUOTE ]
Indeed. I know how formidable the boom of a large gaffer can be. But letting it go as you head into the wind will be less scary than being pushed over till the truck of the mast is in the water.

[/ QUOTE ]

Aint that the truth! /forums/images/graemlins/smile.gif
 
Re: \"Failsafe\" rigging failures in CB

Read the article in question today and all I can say is that a sharp knife would be just as effective in dire emergencies, plus you choose when to do it, instead of relying on the breaking strain of a shackle.
 
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