Re: [Amel Yacht Owners] Re: Rigging tune on Maramu caused damage


Patrick McAneny
 

James, I am  not a rigger , although I have installed standing rigging a few times. However I am a builder and have installed many compression posts in houses. I have always made sure that the post is absolutely plumb and straight . Once out of plumb it loses it ability to carry the loads and will more easily bend or move further out a plumb , increased loads could lead to sudden failure. It seems strange that you state that the compression post is " angled back fore and aft a lot ". I do not see how it would provide support being so far out of plumb. Perhaps someone with a Maramu could confirm that this is normal or not.  The two post angled out to the ribs would seem to be compression posts as well . Do you see any deflection in them or any deflection in the hull where they rest. Keep in mind that it looks like your mizzen mast has only moved downward very little at this point so any deflection would be slight and take close inspection to discern . Use a string pulled tightly one end placed against  each end of the posts , check it , and move around 90 degrees and check again . The string should lay flat against post , should be parallel . If you see a gap , then there is deflection . The hull eyeball it , a short straight edge maybe a foot long held on the outside of the hull horizontally where the post rest should show any hull deformation. If you find anything let the group know maybe we can come up with some suggestions .
 
Good Luck,
Pat SM Shenanigans
 
 

-----Original Message-----
From: j.lochhead@... [amelyachtowners]
To: amelyachtowners
Sent: Thu, Dec 17, 2015 4:32 pm
Subject: [Amel Yacht Owners] Re: Rigging tune on Maramu caused damage

 
Hi Patrick and Sailor,
Thanks for your responses.
The maramu is a bit different from the SM from what I can work out.  There is a small "compression" post under the seat that Then in the engine bay there are 2 posts that are angled to port and starboard onto ribs in the hull.  I will check all these again today but they look in good condition. 

Interestingly though the post under the seat is angled back a lot fore and aft, so I don't think this could possibly be taking all the load.  It has always been like this as long as we have had the boat and I don't see how it could possibly have been installed in column with the mast as the seat construction would make this impossible.  I would love to hear from other maramu owners on their setup.

Given this I think that the fibreglass seat must be acting as some sort of "beam" that is transferring the load down to the p osts in the engine bay.  What I cant work out is how this seat section is fixed in place.  I will be spending a bit more time trying to work this out today.

As far as the mast rake I have read the posts on spreader cracking and it appears that there should be a small amount of rake, at least on the SM.  Would love to know if this is the same as the maramu.

 I will loosening the forestay today and will see what this results in.

Lastly I did not say that this damage occurred at anchor.  We have not sailed the boat in the time between when I tuned the rig and noticed the damage.


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