I suppose I was principally replying to Luc’s thoughts concerning lowering the mast either to leeward or windward, the latter being the only acceptable choice from my perspective.  My actual preference is to telescope reef the mast.  Forces are more self-contained if this can be efficiently set up.  My interest in the hydraulic tilting mechanism arose as a means by which to: firstly, fold a large multihull and secondly right the craft in the event of a capsize - once conditions have abated somewhat.  The latter option is more practical in the trimaran configuration.  That said, it still entails significant challenges as the amas would need to be swung through virtually 90 degrees.  In the case of righting a fully overturned weight to windward proa, I have doubts that it's even possible.  The mast would have to have sufficient buoyancy, when rotated under the weather hull, to lift this hull clear of the water and through 180°.  It is not possible that such a craft would remain upside down with the mast in the vertical position to begin with. Basically, the crossbeams would have to hinge and fold inward in order to significantly reduce the re-righting moment.  Further complexity, the only consistent benefit of which would be cheaper mooring fees.

From: harryproa@yahoogroups.com.au [mailto:harryproa@yahoogroups.com.au]
Sent: Sunday, 30 November 2014 11:21 AM
To: harryproa@yahoogroups.com.au
Subject: [harryproa] Re: controlled self capsizing for cruiser

 

 

 

  You know, that's a good point.  I was only thinking about it in terms of what could go wrong with the basic mechanism in extreme conditions after the wear-and-tear of being at sea for a while.  

 

  I hadn't thought about what it would mean to try to drop that mast in 30'+ seas and 80 knots of wind, and then have the whole system work once it's down.  The forces wanting to move that mast separately from the boat would be insanely huge.  

 

  If the mast were locked in the down position, the mechanism would need to have incredible rigidity in order to avoid being buckled as the mast pokes through a wave while the boat is either climbing up or surfing down.  And if it weren't locked in place, the jarring effect on the mechanism when the mast finally reaches its limit would be even worse.

 

        - Mike

 

On Nov 19, 2014, at 2:12 PM, "lucjdekeyser@telenet.be [harryproa]" <harryproa@yahoogroups.com.au> wrote:

 

Thank you , cruisingfoiler and Mike. I'm healed ;-) if only already with the statement: " attempting this in survival conditions". Luc

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