Loose shrouds

[44'cruisingcat]

Originally Posted by svHyLyte

Darn--

It seems that engineers here in Florida, and up at Hall Spars, and even in France, all seem to agree on this one. Too loose, you loose!

I guess this just goes to show that one good turn deserves another, eh?

Cheers,

Sounds like you are saying "I was right, You (the people who actually own and sail multi's) were all wrong".
Found those catamaran backstays yet?

[Lucky]

I crewed on a 36" plywood racing cat with three sets of stays and no diamonds. This was in Perth WA and we had at times scorching temperatures. Regardless how huch I tried to trim the stays the leward side would be all over the place on a tack! This is something you just have to live with on a cat - that's my belief. Anyway without the diamonds trimming the main was a nightmare in anything more than 2' waves! It wobbled and snaked so much you could never obtain the optimal sailshape.

Imprtant though is to set up the spar properly the stays will keep the mast onboard anyway. If you don't experience any slack in the laward stay I would worry! No catamaran should be that stiff - if it's too stiff it'll break rather than flex! If anyone can remember the so-called Liberty ships built at the end og WWII a lot of them was lost in poor weather just after the end of the war but not many paid attention to this untill loss of life became too much to not inve stigate. It all turned out that the ships was built far too stiff with both logitudinal stringers and full frames. After a surtain number of beatings of the hull they broke in half like a crisp bread!!. The fix was to cut away on the stringers to allow the hull to flex and twist. Result, no metal fatuigue.

Lots of beside the issue talk here but the main issue is that the flexing do not case failure. Use the bungee and you'll be OK. There will not be any shockloads that will causethe rig to fail in the discussed configuration. As we all know there are no backstays to consider that force is taken up by the main, which on the Athena is very solidly made.

Contact your FP dealer to get the static tension to apply when the boat is sitting in the pen and you will be fine.

Happy lead free sailin

[Viking Sailor]

While sailing on the wind, check to see if the masthead is bending to leeward by sighting up the mast. If so then your shrouds are not adjusted correctly.

I suggest that you hire a rigger to teach you how to tune your rig. This should include making adjustment while under sail.

paul

[44'cruisingcat]

SOme slack in the leeward shroud is normal. The practice of using bungee cord to restrain it is fairly commonplace. Viking, on a cat the mast is held in column by the diamond stays, not the shrouds. The shrouds hold it up, not straight.

[cat man do]

Originally Posted by 44'cruisingcat

SOme slack in the leeward shroud is normal. The practice of using bungee cord to restrain it is fairly commonplace. Viking, on a cat the mast is held in column by the diamond stays, not the shrouds. The shrouds hold it up, not straight.

Exactly right 44CC

I've sailed on cat's with 28 ft beam's that have about 1 metre of slack on a large rottating mast.

Dave

[maxingout]

Originally Posted by Crak

I own a new Fountaine Pajot Athena 38 and while sailing close hauled or close reach the leeward shroud becomes very loose and flops about and will snap tight again with a shudder if the load suddenly comes off the sail. I was told this is normal by the guy who tuned up the rig and he suggested using a bungy cord to stop the shroud flopping around on long passages. Can any one out there give me advice if this is normal on a cat, or does it sound like my shrouds are too loose?

On my privilege 39, I have never had significant slackness in the leeward cap shroud on any point of sail. I have upper and lower diamond stays to keep the mast in column, and I have cap shrouds that keeps the mast in position.

I keep my cap shrouds tight, and I have never seen them moving around on the leeward side when sailing to windward. It makes we wonder if I have kept the cap shrouds too tight.

The Privilege 39 is a very robust hull and relatively small in size. Maybe there is less flexing in the hull than in some other catamarans, and perhaps that is why the leeward cap shroud doesn't go slack.

If I was sailing offshore and saw this type of looseness in the cap shrouds I would be very concerned. Nothing good can come shock loading of a backstay.

I am wondering if there is less slackness on my cat because I have a very stiff small hull, I have double diamonds stays, and I had tight cap shrouds.

In an eleven year circumnavigation, I replaced every piece of rigging on the boat except for the cap shrouds. Interesting. Only the tight cap shrouds survived.

Regardless of what riggers say, I will continue sailing with tight cap shrouds.

Dave
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[cat man do]

I did actually see a cat several years ago in NQ, whose owner tightened her shrouds on every tack In the NQ tropical heat.

This cat ended up with severe crinkling [creep] of the glass around the chainplates.

She also had issues with the compression post area.

Poor old girl.

Some people just don't deserve nice boat's.

Dave

[maxingout]

Originally Posted by cat man do

I did actually see a cat several years ago in NQ, whose owner tightened her shrouds on every tack In the NQ tropical heat.

This cat ended up with severe crinkling [creep] of the glass around the chainplates.

She also had issues with the compression post area.

Poor old girl.

Some people just don't deserve nice boat's.

Dave

I have also seen cats with issues in the compression post area. Certainly if there were any stress cracks in the deck at the base of the mast, it would indicate that shrouds are too tight.

On my catamaran, I don't have a compression post per se, but the mast base sets on three separate bulkheads below the deck. There is a transverse bulkhead in the front of the salon, and then double bulkheads separating the two forward cabins. This seems like a fairly robust system that has stood up to the test in the past thirteen years without any problem.

I would like to have seen the catamaran with the fiberglass damage in the area of the chainplates in NQ. The heat in NQ certainly could be a factor, but you also wonder about the robustness of construction in that particular cat, and I wonder about the size of the chainplates as well.

The privilege 39 has massive chainlplates for the cap shrouds. I just walked down the dock and looked at the chainplates on a Mahe 36, and our chainplates are twice the size. In addition, we have seven large bolts holding the chainplates in place.

Every catamaran is different. They are engineered to different levels and the quality of construction varies widely. Some yachts are very robust and heavy like a privilege 39. We aren't a greyhoud, that's for sure. But we are rock solid.

Tight shrouds aren't a problem on our yacht. But some go fast boats with lighter engineering probably shouldn't have shrouds that are so tight. I don't think that slack shrouds are a problem as long as there isn't any repetitive shock loading on the rig.

Dave
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