Rig Tuning


n33077@...
 

I think I just found it:
o understand why the rig tension on an Amel is so very different than
on other fiberglass boats, we must first consider and understand the
structural differences that Amel boats have compared to more ordinary
boats from other builders.



Amel boats are true monocoque structures. An egg is a perfect
monocoque structure, as an illustration. If you take an egg and place
it in the palm of your hand, wrap your fingers around it evenly, and
then squeeze as hard as you possibly can, it will not break. Go ahead,
off to the fridge you go...I'll wait.



See what I mean? Only if you "point load"/unequally squeeze the egg
will it crush. Great party trick by the way...



Recall the recent story about Eric Freedman and being inside his Amel
offshore in hurricane wind and seas; not a sound inside. No creaking
or groaning. No oil canning. No panel deflection... Amel boats are one
piece, no conventional hull to deck joint, they are very strong and
uncommonly rigid. They are a genuine monocoque.



On most fiberglass boats, the rig is tuned tight but when sailing, the
leeward shrouds flop around like al dente spaghetti while the windward
shrouds are tight as a drum. This is due primarily because of hull
flex. Even the better known "premium brands", you know who they are,
have this flexing in the hull.



THIS IS NOT GOOD. Fiberglass, just like metal, gets weaker and weaker
every time it is bent or flexed. Just as when one takes a paperclip
and bends it back and forth a few times and it breaks in two, a flexed
fiberglass hull gets weaker with use. Amel boats are designed not to
flex for good reason; they stay stronger and last longer that way. The
rigging needs to be exceptionally tight as well for reasons I'll
relate shortly.



Riggers will never believe this as it is contrary to what they know to
be usual and correct. Unless a rigger unfamiliar with and not
accepting of Amel idiosyncrasies can put his hands on an Amel that has
been tuned by Amel, they will never believe and will refuse to tune an
Amel to the tension that is required.



An Amel should be tuned so that the mast is absolutely straight and
perpendicular to the mast step/90 degrees. The shrouds should never be
loose on the leeward side even under the press of strong breeze. Just
a tad slack, but not loose and certainly not able to be moved back and
forth. The headstay should only have a very modest bend even in a good
breeze. I have tuned many Amel rigs and I can do it but it is hard to
tell you how tight is "tight". I don't use a strain gauge, I just do
it. I was a rigger in an earlier life so I know the sequence to follow
to get the right outcome but it is difficult to impart to you how
tight. REAL tight. Tight as you dare then a tad more. Ringing bronze
tight...ahh, what's the use......



Try to find an Amel that is owned by someone we (Amel and or me) sold
a boat to. We impress upon our new clients and my second hand boat
clients to take note of how tight the rig is and to keep it this way.
They usually do. Second only perhaps to mechanics who call all flaming
irate to tell me that the Amel drive system will never work (once or
twice a month sometimes) are the riggers who call to say the rig is
way too tight or to insist they won't tighten it up the way we tell
them too. It is the "not invented here syndrome" all over again. Ain't
what I am familiar with so there-fore it can't possibly
work...Sometimes they say uncharitable things about my ancestors...



What's the risk? Plenty. If the rig is loose, it can move around.
Combine wave action and puffy breeze and the rig can pump and move
around inches with tremendously quick acceleration and sudden
deceleration of all the rigging mass. This can more than double the
ultimate load placed on the rig and all the components. It will loosen
the boat up real quick. As mentioned before, that is not good for the
structure. Just imagine accelerated pulling/jolting on all the rig
points with wire connections; kinda like squeezing that egg unevenly,
no? Hmmmm...



Show this to your rigger. Have him call me if he says fiddlesticks.
Better yet have him call Amel. They may be a bit more, uh, forceful
than me (if that's possible...) but from the horses' mouth the truth
shall flow. Maybe they will believe the builder as they seldom think I
have it right. Best is to let them see a properly tuned Amel rig.



After new rigging is installed, Amel tuned tight, and sailed in heavy
breeze and seas, it will stretch as much as 8% and even more dependent
on the wire quality. Tune it tight again, then put the little bolts
and nuts back in the wire ends inside the turnbuckles (bet you
wondered why Amel does that..) and smile. You will only need to very
occasionally retune rig components as once it is right, it doesn't
move, it NEVER pumps, and it stays as it was meant to by God, Captain
Amel, and the entire Amel team. Me too.



Trust me on this or put your hands on a well kept Amel.



Have fun with your Maramu. They are very sweet sea boats.



All the best,

Joel



Joel F. Potter - Cruising Yacht Specialist, LLC

Amel's Sole Associate for the Americas

401 East Las Olas Boulevard, #130-126

Fort Lauderdale, Florida 33301

Phone: (954) 462-5869

Email: jfpottercys@...

<http://www.yachtworld.com/jfpottercys>
Joel F. Potter - Cruising Yacht Specialist, LLC (Fort Lauderdale, FL)

 


n33077@...
 

I just got my electric motors rebuilt.  Riggers got the forestay back up.  Now comes the question of tuning. I searched the site for Joel Potters   Rig Tuning           but did not find anything.


From the other posts I found that the rid is to be tight.  How tight?  My traidic is lose, and I am having the riggers come back and re-tune the rig (moving mast forward.)  Since the boat is a Sharki, I think I can use most of the info tailored to the Sharki.


I also posted this on the new site too..

Thanks


Aras

Sharki #163