Loose shrouds

[svHyLyte]

Refer to: Hall Spars&Rigging | Resources Se also prior comments on ssca board. s/v HyLyte

[cat man do]

Originally Posted by svHyLyte

Refer to: Hall Spars&Rigging | Resources Se also prior comments on ssca board. s/v HyLyte

I found No infomation on here relating to Multihull rig's.

You really need someone who is savvy with multi's not just a mono rig tuner wanting to have a crack at tuning a multi rig.

Dave

[svHyLyte]

FYI, the only distinction in rig tuning between a multi and mono is the width of the shroud base. Shock loading rigging terminals because of oveloose shrouds has the same weakening effect (cyclic shock loading) regardless of the hull(s). Moreover, because of the relative "stiffness" of multi's--they don't heal to gusts--the loading on multi-hull rigs (and shock loading from loose rigging wire) tends to be much greater for the same (relative) size yachts. Cheers, s/v HyLyte

[44'cruisingcat]

Originally Posted by svHyLyte

FYI, the only distinction in rig tuning between a multi and mono is the width of the shroud base. Shock loading rigging terminals because of oveloose shrouds has the same weakening effect (cyclic shock loading) regardless of the hull(s). Moreover, because of the relative "stiffness" of multi's--they don't heal to gusts--the loading on multi-hull rigs (and shock loading from loose rigging wire) tends to be much greater for the same (relative) size yachts. Cheers, s/v HyLyte

Incorrect. On a mono the mast is held in column by a combination of the cap shroud tension, the upper spreaders, the intermediate shrouds, (if fitted) the lower spreaders, and the lower shrouds. You need to adjust all of these in order to hold the mast straight to Port and STBD. As well as adjusting fore and aft bend by altering backstay tension.

Modern multihull rigs are completely different. They have diamond stays, triangular spreaders and jumpers to keep the mast in column. They hold the mast straight - the shrouds (plus the forestay) just keep it standing up. It is a fact that on many cats the leeward shrouds can go quite loose - especially on a rotating mast rig.

Oh and if you are looking for another distinction - try adjusting the backstays on a cat.

[Crak]

For those interested, this is the responce I received form the manufacturer.
I guess I will be putting a few turns on each turnbuckle !!

Crak


Good morning,
We thank your for your message
There is no need at all to use a "bungee cord" if the 2 shrouds are correctly tight to not allow any loose on leeward
Best regards

Responsable Service Clients - Customer Service Manager
------------------------------------------------------------------------------------
FOUNTAINE PAJOT

Zone Industrielle – 17290 AIGREFEUILLE – France

[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,

[bill good]

Multis with a rotating mast do need the shrouds slack to allow the mast to rotate without strain. I tend to keep mine a bit tight by comparison to when it was raced. the use of a bungy is recommended. I still like not seeing the slack stay flogging & adjust to keep it just slack by taking power off the rig. Seems to sail just as fast to my limit of22kts!!

Regards Bill Goodward "GoldRush"

[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?

[cat man do]

Originally Posted by 44'cruisingcat

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?

I though I had an idea on tuning rig's as well, built a few and always tune my own.

Maybe we should crank 'em until the hull look's like this.

Dave

[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