Rigging advice please

[William_H]

Rigging wire failure

I have a little training in fatigue and metalurgy however my experience with 7X19 rigging wire failure does not seem to relate to theory at all. I was involved with maintenance of 10 tiny training boats with 1/8 inch wire used about 15 times per year for 2 hours. All the rest of the time the masts and rigging were stowed indoors. The stays started to fail at about 15 years old in this case seen as individual strands breaking.
I ended up replacing all the wires all with strand failure. 30 examples.

Then 4 different boats in our club had rigging wire fail. In each case the rigging wire was original and about 25 years old. the fist to fail was a 21fter which had hardly been sailed at all for most of its life and then was raced. the side stay let go without warning on the bottom swage. It would have been easily noticed if a strand had failed and unravelled as they do first.
this example was followed in quick succession by 3 others the last being a 26ft mast head rig with quite heavy wire. (7/32 inch dia ). In each case the mast was ruined.

From that experience and completely contrary to theory the history and use of the boat makes no difference just time. Inspection of the wire is of no real value or substitute for replacement.
Now solid SS fittings bolts etc that is definitely a different matter and should be inspected. olewill

 

[vyv_cox]

On the two shrouds I've had part, both have gone at the upper T-bar swage. Neither parted completely and were an inner, after 18 years and a secondary, after 12 years.

One of my lowers had failed at the same place when I bought my boat. The rigger at Dickies of Bangor advised me that the design of older T-ball fittings was not ideal in that unfair loads were placed on the wire as it entered the swage. He replaced the socket fittings on the mast and supplied new lowers with the later design. These are still working well.

 

[doug748]

To a rigging virgin like me, how does one assess what "reasonable" tension is? I know there are various gauges out there which claim to measure tension but are these really necessary for your average cruiser?

By the way, the link to Dixieland marine by cimo is helpful - thanks!

I have always found it easy and I doubt the cheaper shroud tension meters would help much. There is a lot of printed info on what to do.
As a rough guide, get the thing in position upright with a little tension on each part. Wind up each shroud by a equal number of turns till it feels twangy (done with small hand tools you would find it difficult to overtension). Check the mast is still upright fore/aft port/sta. After a bit of sailing re-tension a turn or two and re-apply the twang test. Note it is quite usual to have the leeward shrouds looking rather loose when on the wind. (unless you have a racing boat of the more expensive sort)

 

[Chris_Robb]

FWIW I've found riggers to be amongst the more honest tradesmen in the marine industry - ask a professional to take a look and they'll PROBABLY give you an unbiased report, albeit with a few caveats to cover themselves in case it all falls down tomorrow.

But if you hear the sucking of teeth at the start of the conversation - run!

 

[PeterGibbs]

Firstly may I say how impressed I am at the wealth of knowledge out there! I am new to yacht ownership and very much at the learning stage, so appreciate all useful advice.
1. The standing rigging on my newly acquired Sadler 26 is 10 years old and I have read that this is a reasonable safe lifespan. Consequently I am considering replacing it this winter - what do you think?
2. The backstay is a split one with a block and tackle adjuster to either side of the transom. Should I keep this arrangement or could I live without a backstay adjuster on this boat? I will not be racing.
3. Should screws be replaced with the rigging?
Thanks in anticipation!

A suggestion: is your rig one where the forestay is critical to the trig remaining standing, and where other shrouds can compensate for one another if one shroud parts? It's like that on my boat so I had the forestay replaced at 10 seasons. I'll consider the other shrouds in due course but not to any particular time forumla. It also happens that the forestay is largely hidden in the Furlex - another reason to take pre-emptive action.

The rigger will tell you if the screws need replacing - it all depends how much they have galled ie become unusable. On mine, I just replaced the pins.

I take a contrarian view now on "resting the rigging" for winter. I have kept my rig in place without removal since launching new in 1998. Dropping and retensioning (except for replacing the forestay) serves no purpose. Like steel on a bridge, it's best kept in tension.

PWG

 

[oldharry]

You have probably gathered by now that this is one of those 'long as a piece of string' questions! The problem is that some rigs have failed in less than 10 years, while others (my own boat included) had the original rigging (1972) when I bought her. Not any longer.... although I could find nothing wrong with the old stuff after I had taken it all off. Did it need it? Probably not - but I feel more comfortable in bad weather knowing it is all new.

The main factors in rigging failures depend a great deal on the way a boat has been used: crashing round the buoys every weekend regardless of the weather with as much sail up as she can carry (too much?) will obviously stress the rigging a great deal more than that of a cruising boat which will reef down much sooner (mustn't spill the tea/ upset the cook!), even though the two boats may spend similar amounts of time at sea.

Cyclical stress loading is known to be a major fatigue factor, of the kind a boat on an exposed swinging mooring will have regularly been subjected to as she bounces around, while a marina based counterpart or one on a nice sheltered mooring will not have suffered in this way. Has the rig been taken down and inspected regularly? Not only the wires, but the fittings. The only time I experienced rig failure was when the masthead forestay fitting failed on my Eventide - fortunately being on a downwind run the mast stayed up, but we had a fine time sorting it all out!

At the end of the day, with an unknown history, 'expert' opinion is probably little more than re-assurance that nothing is obviously wrong at present. Stainless steel is notorious for its unpredictability when fatigue is present. The only way to be certain is to start again - and at a price!

 

[Bosun Higgs]

I take a contrarian view now on "resting the rigging" for winter. I have kept my rig in place without removal since launching new in 1998. Dropping and retensioning (except for replacing the forestay) serves no purpose. Like steel on a bridge, it's best kept in tension.

PWG

Dont forget you are resting the hull too. Moodies once told me that GRP can creep ie under tendion the chainplate fixings inside the boat will slowly move.FWIW

 

[Crabman]

Rule of thumb turnbuckles should not be passed half way closed ,if they are its time to replace .

 

[gasdave]

You have probably gathered by now that this is one of those 'long as a piece of string' questions!

Thankyou all for a wealth of helpful advice. I guess a lot of it comes down eventually to one's attitude to risk, combined with a useful dollop of knowledge and experience!

At my stage I think I will end up erring on the side of caution, given that my experience is really just beginning and I have no sound knowledge of the prior stresses exerted on this particular rig as the boat is new to me. The last thing I would want (as would anyone!) is a failure under use. There is some comfort from knowing that one is starting out with a fresh rig, although I also take note of comments regarding potential problems in the first year - proper setting up is clearly crucial. However I have found this a very useful thread.

 

[abbott013]

my surveyor quoted me 12 years for standing rigging

 

[liverpool]

Rigging - ndt

A visual inspection is almost always sufficient, although the NDT people will be delighted to tell you different.[/QUOTE]

Interested in further thoughts on NDT. I got an NDT report when I bought my boat 3 years ago as it was then 5 seasons old. I have recently had a further report and the yard suggests results are concerning, apparently based on expected figures from the "Maidsure Register" and increase in the resistance readings between the two dates.

Should I replace riggings based solely on NDT results?

Welcome thoughts.
Thanks
Liverpool.

 

[gardenshed]

the only failure that I've had was an aft lower that failed less than 3 months after it was fitted. My view is that either it was insufficiently tensioned and the cyclical loading beating the length of the med and up the portugese coast against the wind, is what did the damage.

alignment: the wire must pull straight from the terminals. Go up the rig to check each terminal in-situ
tension: tighter is better than looser
and
always lubricate the rigging screws before you make and adjustment or you risk stripping the threads.

 

[saltwater_gypsy]

The NDT electrical rigging test was given a lot of publicity a few years ago and is still available at
http://www.rigcheck.co.uk/7.html
Has anybody had experience of this technique and does it keep insurance companies happy?

 

[liverpool]

Rigging - ndt

Saltwater Gypsy - thanks for ref. My concern re insurance is that if rig fails after yard has recommended replacing rigging and have NDT results indicating some concern, then.....Also, how would I feel if someone hurt. So feel I have no choice but to replace. Liverpool.

 

[rob2]

Whilst you're considering rigging wires, check over the guardwires too. I took mine off and ripped my hands open whilst coiling them - so new were needed. i don't want to fall against the rails and find out they have failed!

Rob.

 

[Dan the man]

If you fit new stuff you know where you are.

re backstay tensioner, they are more applicable to a fractional rig where its main purpose is to bend the tip and alter draft etc in mainsail. You masthead rig should be set up almost in column, all you would be doing is tensioning and de tensioning the forestay, I cant see that it would alter the bend in the mas much. it is good to release the banana effect in the hull though!!!

Mast manufacturers have done me good deals on rigging before, like z-spar, or selden. bronze screws coated are good.

I hope this doesnt re-itterate.

its daft to try and squeeze maximum out of structural items, much cheaped than a new mast, and as we know you wouldnt get a lot of help from insurance if you had to buy a new rig.

get it down, replace, and service everything. check lights work, vhf aerial wire, and sheaves and ropes. then you shouldnt need to lower it for maintenance for a few years.

tension, sounds crude, but I pluck a shroud and when the mast stays still and doesnt wobble aboutI think it is ok (please dont shoot me for this). If not sure get a rigger to go over it with you, its experience. The shock commen is important to bear in mind....

I hope you enjoy your new boat, very pretty craft.

Have fun