Re: [Amel] Super Maramu mast vibration

amelliahona <no_reply@...>

Hi all:
Interesting discussion and good to know that others have experienced this. In my case I isolated this to vibration of the spare balooner halyard also described as a spinaker halyard (an optional exrernal halyard fitted just to stbd at the main mast head. It is stowed at the toerail to stbd and taken on the stbd lower main mast winch). Depending on how tight it is it will thrum at various frequencies at various wind speeds. I have found that a bungee cord around it to the boomerang will stop the vibration. Besides this the mast will pump at times (by this I mean a very low frequency 1-2 cycle per sec vibration) in certain loading conditions.

Just a couple of more thoughts as to possible causes.

Gar Silver
s/v Liahona. Amel SM2000. # 335
St John USVI

--- In amelyachtowners@..., "Joel F Potter" wrote:

This is a peculiarity common primarily to the Super Maramu although I have
experienced it on the Santorin. If the rig is tuned tight and proper, try
completely easing the jib halyard when the boat is not going to be sailed.

You will note a diminution if not the complete elimination of this
resonance which can be quite annoying but doesn't actually hurt anything. I
know, this seems strange.try it.

Be absolutely sure to crank up the halyard tension when returning to sailing
mode as you will bend/collapse the stainless steel support triangle under
the jib furling motor/gearbox assembly if you do not. When re-rigging Super
Maramu's I always encourage the owners to strengthen this component part as
I have seen many bent and in progressive failure. A similar material
doubler on the front side of the support triangle seems to do the trick.

As a matter of curiosity, is the rigging on your SM 53 original?

All the best,

Joel F. Potter

Joel F. Potter - Cruising Yacht Specialist, LLC

Amel's Sole Associate for the Americas

Mailing Address: 401 East Las Olas Boulevard #130-126

Fort Lauderdale, Florida 33301

Phone: (954) 462-5869 Cell: (954) 812-2485

Email: jfpottercys@...

From: amelyachtowners@...
[mailto:amelyachtowners@...] On Behalf Of islandbwoy4434
Sent: Sunday, January 06, 2013 11:22 AM
To: amelyachtowners@...
Subject: [Amel] Super Maramu mast vibration

Having owned Libby (SM197) for a year now and about 2000 miles of Pacific
under her keel we have one phenomena that we need guidance on.

While tied up at the dock we consistently notice the main Matt will start to
pulsate with a mild wind. We can hear the furled main sail rattle inside the
mast. We can feel this right throughout the boat. It is not violent motion
but noticeable.

My thoughts are that the upper and lower shrouds may need adjusting.
Has anyone else experienced this?

Is there a specification and procedure for the shroud tension?

Any other thoughts?

Thanks in advance.

Terry&Dena Singh
SV Libby

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