Re: [Amel Yacht Owners] Collapsing mizzen mast support on a 1986 Maramu


James Alton
 

Jacob,
   I own a 1987 Maramu.  The mast box has not seperated from the cabin at all but I have seen this on other Maramu's.   The issue seems to be caused from the mizzen mast box compressing at the cut out for the engine hatch at the base.  The driving force in my opinion is caused by high static rigging tension. In other words the compression column has a notch in it on the front face which is needed for design reasons but makes that forward face less able to resist compression loads.  The actual mast step based on my personal inspections and observations is sufficiently strong to handle any normal sailing  including extremely high momentary  loads and is well designed. But constant high rigging tension combined with heat and time allows the glass to creep/change shape slightly resulting in some compression and it does not take much to create the gap you are seeing.  You can see this same glass creep in the boat stands that are set up too tight.  Intitially the hull deflection is slight but if the pressure is high and left in place for a long period the deflection increases. As the mizzen mast step compresses on the front face at the notch, the load is transferred to the connection to the forward face of the aft cabin which causes it to bulge out slightly and the whole step to rock forward thereby opening the joint at the mizzen mast step/cabin interface.  I doubt that a 1/4" gap is a structural concern but if the mizzen rigging seems to be tight I would ease off the tension and see if the gap closes.   Maramus are wonderful boats IMO. 
 Best of luck. 
James Alton
SV Sueno Maramu #220
Sardinia, Italy


Sent from my Galaxy S®III


-------- Original message --------
From: "jacob.champness@... [amelyachtowners]"
Date:03/09/2017 7:51 AM (GMT-05:00)
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Collapsing mizzen mast support on a 1986 Maramu

 

Hi all.  I'm looking at a 1986 Maramu where the box supporting the mizzen mast has separated by about a quarter inch from the aft bulkhead in the cockpit, and the box itself has begun to buckle slightly.  Has anyone else seen a case like this and addressed it?  How well did it go?


Thanks, Jacob

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