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#11 Sail Rock

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Posted 30 June 2017 - 06:07 PM

Cj
The solar panels shown in several of the photos you provided are just supported on single unbraced poles. I doubt they would survive in high winds or seas. For offshore, I would think fixing to the deck or a robust stainless steel frame would be required. That might make a sun tracking set up a bit more complicated.
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#12 cj!

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Posted 02 July 2017 - 06:15 PM

I used those as examples to illustrate the idea but there's definitely a need for proper mounting which shouldn't be insurmountable. 


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#13 cj!

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Posted 02 July 2017 - 06:22 PM

IT, I think it was your wording of putting a 10kg load on top of the mast being equal to 150kg on the deck, as an additional 10kg load bearing down is still only 10kg, rather than referring to it as the increased leverage as the boat heels that caused my reply. I wonder how much of a buffer designers allow for considering all of the additional things cruisers add all over their boats? 


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#14 island time

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Posted 02 July 2017 - 06:29 PM

ok, but its ALWAYS on a long lever, unless the boat is completely still - which of course it isn't.

The answer to you question is "very little"

Hence the difference between an "as designed" stability curve, and an actual or "as built" curve....


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There is nothing, absolutely nothing, half so much worth doing, as simply messing about in boats


#15 wheels

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Posted 03 July 2017 - 12:30 PM

I am just adding weight to IT's comments. He is exactly right with the comments. NEVER underestimate the difference a little extra weight can do up a Mast. the higher the object, the more influence it has. And even a small increase can have a huge negative affect. And that affect is transferred right on down to the Keel. As It said, the centre point to Boat rotates around is critical. That centre point is created by the Weight in the Keel and the Mast. Changing the weight of one influences the other and also changes the centre point. But interestingly, it can have an affect either direction of a central point in inertia. ummm, let me rephrase. You can make a Boat roll more, or roll less by increasing mass. If the Mast and Keel has been designed perfectly, the roll momentum should be perfectly dampened. If not, it will roll terribly. Heel is affected by weight up the mast as well. Some racers go to great lengths to reduce that weight aloft by even removing the covers off their Halyards.
      Then there is the concern of drilling holes in the mast to fit a bracket to mount a Radome. It happens most of the time, that Radomes get fitted at a point in the mast that tends to experience the largest amount of bending stress. Drilling holes creates the " tear across dotted line" effect.


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