Are there any engineers out there who could doodle some rough numbers for me.

I'm curious about how much floatation would be required, at the mast tip to keep a Stiletto 27 from going turtle.

From my college exposure to related topics, I don't think this hard to figure... However, not having continued engineering, I just can't remember how to get that number.

So the question is: Assuming a total loaded boat weight of say, 2,500 lbs. (equally distributed in each hull), a beam width of 14 feet, a mast length of 35 feet, and assuming the bottom hull contains enough floatation to prevent it from sinking further than, say two feet of its 3 foot width.... how much “minimum” positive floatation is necessary, at the mast tip to prevent the boat from going turtle? If moved to the spreaders, how much minimum flotation would be necessary at the spreaders (or half the length of the mast) to prevent a turtle?

Thanks,

Tom

Ignoring the weight of the mast and effects of waves and wind, a float at the head of the mast would need to displace 91 lbs of water in order to support the weight of the high hull. At halfway up the mast, with the additional heal, you would need 368 lbs of displacement, again negating effects of the mast weight, waves, or wind. All of this is without any safety factor and a rather dirty calculation.

as per the old forum (and so I can post this picture), it would require around 2,000 lb of displacement at the mast tip to get the boat up from turtle (sideways).

I think Tom was asking how to PREVENT a Stiletto from turtling, and that "wheel" has already been invented, as I mentioned twice on the Old Forum. But since the engineers have started working on the concept of how to get a Stiletto back on its side IF it turtles, I am curious as to whether they have figured into their calculations the possibility that if you have something floatable at the top of your mast, it is going to create drag underwater if the boat is moving sideways at all on the surface of the water (via wind or current), and that the boat might come back up on its side all by itself? Is this another factor to possibly consider?

Personally, I do not see any reason to turtle in the first place and I would want proper masthead flotation to prevent it; but it is certainly useful to think about the options if the worst happened.

Mary,

I only put that together because they wanted to know what kind of floatation was needed to get the boat up from turtle (on the old forum)...I never figured it was a realistic scenario. That calculation also only assumes that the boat is coming up on it's side instead of a corner like they usually do from turtle.

Jake,
I know, but I thought the subject of righting a Stiletto (or similar larger cat) from turtle was worth pursuing, so I asked the additional question about it -- and I did not want to do it on the Old Forum. Winter is the time to be thinking about these things, before the boat gets set up for the sailing season.

Never mind, I'll start a new thread.