How tight is too tight?

dwightgry · #1 (**permalink**) 05-06-2008

I have just read the thread on Tartan troubles, and have a question for the group. Didn't want to hijack thread, so here it is. There was talk about how too tight rigging split a hull. Now, I have an old Pearson 323 that I just had the rigging redone, and the old rigging was somewhat loose. But when the sails were up and full of wind, the rigging got real tight. Does too tight rigging to start with get even tighter, or what. It sems to me that loose rigging will get tight in a blow, regardless of how it is when calm.

Stillraining · #2 (**permalink**) 05-06-2008

Lots of threads here have gone over this many times..Giu has a new one that is real good...In a nut shell 10 to 15 % of cable strength to start with for stays...up to 20% for shrouds...but you have to be willing to back off theas figures on test sails..
Try to find his thread and others using search

Edit: your shrouds should slacken on the leeward side when sailing and to some degree your stays depending on weather going upwind or downwind....sailboats are dynamic not static...Racers play with there rig under sail all the time...with tentioners..running backs etc..

erps · #3 (**permalink**) 05-06-2008

Scott,
Is that slack, like just barely starting to wiggle. I sailed on one guy's boat and his leeward shrouds flopped around considerably. On my previous two boats, I would back off on leeward until they flopped and then took up the slack so they just stopped then made sure the stick was straight. I haven't messed with this boat yet.

Cruisingdad · #4 (**permalink**) 05-06-2008

moving this post to gear and maint.

- CD

dwightgry · #5 (**permalink**) 05-06-2008

Guess I missed the boat in wording my question. What I meant to ask was can you split a hull by too much tension? Can you tension a line with the buckles more than a full sail will? In the past I was worried that maybe the rig might come down if there was too much stress on the lines, but never that the hull could split. On my boat the chainplates are considerably smaller than what the hull joint is and should give first in a contest. The Tartan chainplates must be the strongest point in the whole boat.
I am not an engineer, but when I heard the company response that the rigging was too tight I had questions. Is it actually possible to pull the hull joint apart without the rigging or chainplates themselves failing first, or is the hull joint that weak in a normal boat.

beej67 · #6 (**permalink**) 05-06-2008

Quote:

What I meant to ask was can you split a hull by too much tension?

I suppose it's possible.

I own a P323 also, and I've got the extra added strangeness that 3 of my 4 lowers aren't quite the same gage as the fourth. I think my genius father (the previous boat owner) had 3 of them replaced but didn't replace the fourth when he bought the boat. Whoops.

Regardless, I just do what everyone else says to do - get out on a beam reach in 20 knot winds and tack both ways, pulling the slack almost entirely out of the lowers on each tack, making sure the mast is still centered. I've got a tension gauge, but I don't trust it to be particularly accurate.

CharlieCobra · #7 (**permalink**) 05-06-2008

bee67, that would make me nervous. Of course, I have a tendency to sail when many won't. I suppose it'd be cool for fair weather stuff.

Stillraining · #8 (**permalink**) 05-06-2008

Quote:

Originally Posted by erps

Scott,
Is that slack, like just barely starting to wiggle. I sailed on one guy's boat and his leeward shrouds flopped around considerably. On my previous two boats, I would back off on leeward until they flopped and then took up the slack so they just stopped then made sure the stick was straight. I haven't messed with this boat yet.

Ray...Yes ...not floppy slack but you should be able to easy tell the differance by pulling on the shrouds form windward to leeward that they are slacker...if not the Windward shrouds not only have to battle the pressures of the winds forces but also undo strain imparted by the leeward shrouds....So not sloppy loose but noticeably looser than at the dock that you pretensioned by your loos gauge...Your way sound good...

This does require several tacks to get right and should be rechecked a time or two if recently stepped or new standing rigging has been installed..

Stillraining · #9 (**permalink**) 05-06-2008

Quote:

Originally Posted by dwightgry

Guess I missed the boat in wording my question. What I meant to ask was can you split a hull by too much tension? Can you tension a line with the buckles more than a full sail will? In the past I was worried that maybe the rig might come down if there was too much stress on the lines, but never that the hull could split. On my boat the chainplates are considerably smaller than what the hull joint is and should give first in a contest. The Tartan chainplates must be the strongest point in the whole boat.
I am not an engineer, but when I heard the company response that the rigging was too tight I had questions. Is it actually possible to pull the hull joint apart without the rigging or chainplates themselves failing first, or is the hull joint that weak in a normal boat.

It is conceivable to do all kinds of dammage to a boat depending on configuration with to much tension....Remember this is cable pulling fiberglass...It is there for a pourpus to hold the mast straight against opposing forces....any more needed to do the job is overkill...Racers push thease limits for sail shape and performance...we need not...

Stillraining · #10 (**permalink**) 05-06-2008

I cant find the origional Video...The narrative has been overdubbed with music on this one and the fillming is not as good...If you turn it up lode you can hear some of the origional narrative under the music....

To much back stay pressure and probably a flaw in the hull or design...although the latter seems unlikely with the money , and quality control theses boats get..Didnt take long did it!!!!

YouTube - America's Cup - boat sinks and breaks