C&N managed yacht sinks off Sicily, 7 missing

[desodave]

Originally Posted by Tupaia

Assume the fore mast (in front) of the CB is increased in size and weight the vessel will sit bow down. Remove the aft mast less weight aft of the CB will increase the bow down stance. From a purely engineering point of view adding balance weights as far aft of the CB as possible, longer lever arm will reduce the amount of weight that is needed.

The article notes that but also says;

"But where this ballast was placed was curious, maritime experts said. Rather than spreading the ballast evenly across the bottom of the boat — which would have guaranteed the best stability — the builders stacked it toward the rear of the ship’s hull.
“When I first saw this, I couldn’t believe it,” said Mr. Roberts, the naval architect. “It made no sense to me.”
The ballast seems to have been pushed toward the rear of the boat to offset the single, heavy mast closer toward the front, Mr. Roberts concluded. He said he had never seen the main ballast used in such a design tactic before."

[Don C L]

Originally Posted by desodave

The article notes that but also says;

"But where this ballast was placed was curious, maritime experts said. Rather than spreading the ballast evenly across the bottom of the boat — which would have guaranteed the best stability — the builders stacked it toward the rear of the ship’s hull.
“When I first saw this, I couldn’t believe it,” said Mr. Roberts, the naval architect. “It made no sense to me.”
The ballast seems to have been pushed toward the rear of the boat to offset the single, heavy mast closer toward the front, Mr. Roberts concluded. He said he had never seen the main ballast used in such a design tactic before."

Sounds like the hull was not designed to be a sloop.

[Lee Jerry]

Originally Posted by lestersails

Big article today in the NY Times, which seems quite thoroughly investigated. They talked to a good number of naval architects. They lean quite clearly on the theory that switching from double masted to single and adding ballast to the stern (to balance her fore and aft) lowered her in the water. Coupled with the vents, the design led her to have lower stability and make it easier to flood upon heeling. They pretty clearly also lean toward fault lying with Perini Navi, and not the captain. They are also quite generous in describing Karsten Borner, who rescued the survivors.
All in all, it seems like a pretty solid piece of reporting, especially for a general publication.
Apologies it is behind a paywall, but I think you can sign up for a free account for access to a limited number of articles. Interested to know what others think of the article.
https://www.nytimes.com/interactive/...ing-italy.html

Thanks for the heads up and link. That was indeed a pretty good article. Would love to see all of the extra information they and their sources have seen (like the full stability reports for both Bayesian and a sister).

The first, biggest thing I noticed is that the article talks about Rod Holland Design doing the initial ketch design, but does NOT mention him/them when talking about the modification to the sloop. Makes it sound like it was all done in-house at PN (or maybe that was an oversight by the authors).

And then there was this familiar line: "All the attention this tragedy has received could result in a closer look at yachting regulations."

Originally Posted by JPA Cate

For a major media article, hat's off to the reporter, too -- got a whole lot right.

ReporterS - seven-person byline, plus three more listed at the end that "contributed."

Agree, they got a lot right, but not everything. As good as any others I've seen.

Originally Posted by desodave

The article notes that but also says;

"But where this ballast was placed was curious, maritime experts said. Rather than spreading the ballast evenly across the bottom of the boat — which would have guaranteed the best stability — the builders stacked it toward the rear of the ship’s hull.
“When I first saw this, I couldn’t believe it,” said Mr. Roberts, the naval architect. “It made no sense to me.”
The ballast seems to have been pushed toward the rear of the boat to offset the single, heavy mast closer toward the front, Mr. Roberts concluded. He said he had never seen the main ballast used in such a design tactic before."

I'm not sure if they took TR out of context or what, but surely he's seen trimming ballast before and knows that the "main ballast" is the ~200 ton in the fixed keel and ~50 tons in the lifitng keel?

There were a few other questionable things, too, but generally not bad.

[Lee Jerry]

Originally Posted by lestersails

Yes, that is exactly what the article said. They also said something that really blew my mind - "Beyond being exceptionally tall — more than 40 feet higher than the original foremast — it was also very heavy, at least 24 tons of aluminum, possibly more."
Does that number sound plausible to the naval architect types? Of course, one would have to subtract the weight of the original forward mast, but that is a lot of weight to add to a boat, even if it is 184 feet long.

We can do a sanity check fairly easily.

Assume 243 ft (74m) length of keel stepped mast, 5 ft long by 2 ft wide.

Assume elliptical shape, and using the "simple formula" for the circumference:
C = 2 pi sqrt((a^2+b^2)/2) = 2 pi sqrt((2.5^2 + 1^2)/2) = 11.96 ft = 143.6 in.

Assume 1 in. wall thickness.

Therefore, the volume of aluminum is:
V = C*t*L = 143.6 * 1 * 243*12 = 418,740 in^3

The weight is aluminum is ~0.10 lb/in^3, so the weight of the "mast" is:
W = V*w = 418740 * 0.1 = 41,874 lb = 20.9 ston = 18.7 Lton = 19.0 tonne

So it looks like that is in the ballpark of "24 ton."

I am not sure how reasonable the assumptions are (ellipse, 5ft length, 2 ft width, 1 in. wall), but you can adjust as you feel appropriate. For example, if you think the wall thickness is 3/4 in., then the weight becomes 15.7 ston.

And of course this does not include the weight of rigging, spreaders or sails, which I expect are not light either.


(N.B. - you'd have to subtract the weight of BOTH masts.)

[dannc]

Originally Posted by Lee Jerry

...
The first, biggest thing I noticed is that the article talks about Rod Holland Design doing the initial ketch design, but does NOT mention him/them when talking about the modification to the sloop. Makes it sound like it was all done in-house at PN (or maybe that was an oversight by the authors)....

DUH! I did not think of the builder doing the design themselves but that would explain the builders blaming the crew.

I wonder if they original designer was consulted and said no. That would be interesting.

[CaptTom]

Originally Posted by lestersails

...The apparent desperation and vitriolic nature of the backlash from Navi Perini will harm them in the long run...

I can't help but wonder who the real audience for that attack was.

On the one hand, yes, it might be an effort to deflect legal responsibility. But it seems to me it was also a statement to their customers. Something along the lines of "Blame it on the help." I imagine that's exactly the kind of sentiment which sits well with their clientele.

[dannc]

Originally Posted by CaptTom

I can't help but wonder who the real audience for that attack was.

On the one hand, yes, it might be an effort to deflect legal responsibility. But it seems to me it was also a statement to their customers. Something along the lines of "Blame it on the help." I imagine that's exactly the kind of sentiment which sits well with their clientele.

Not long after the sinking, I saw a report that the builder already had six orders canceled. I don't think attacking the crew helped the builder at all.

[CaptTom]

Originally Posted by dannc

Not long after the sinking, I saw a report that the builder already had six orders canceled...

I saw that. What I didn't get was whether that was before or after the builder accused the crew. I like to think that people who buy yachts in that class are smart enough to see through the attempt to deflect blame. But based on the news stories I see lately, I'm not so sure any more.

We might have great respect for experienced seafarers, but I wonder if, to the billionaires, they're just "hired help" in the same category as servants and other employees. Handy scapegoats when the big-shot's decisions turn out poorly.

[GordMay]

Originally Posted by CaptTom

I saw that. What I didn't get was whether that was before or after the builder accused the crew. I like to think that people who buy yachts in that class are smart enough to see through the attempt to deflect blame. But based on the news stories I see lately, I'm not so sure any more.

We might have great respect for experienced seafarers, but I wonder if, to the billionaires, they're just "hired help" in the same category as servants and other employees. Handy scapegoats when the big-shot's decisions turn out poorly.

Most billionaires are, really, just rounded up millionaires.
The haves, and the have yachts.

[Don C L]

Originally Posted by CaptTom

We might have great respect for experienced seafarers, but I wonder if, to the billionaires, they're just "hired help" in the same category as servants and other employees. Handy scapegoats when the big-shot's decisions turn out poorly.

Could be, I've served folks like that, but the one experience I had crewing for a billionaire, he was very respectful and appreciative. However he was also a sailor himself so that explains it; he was a great guy.

[barnakiel]

Interesting.


Would the mast wall be truly one inch? Man. That's quite a thick wall.


The boatyards attitude very rude. Hard to guess who is in charge there but probably not the right person. Bad PR that's sure.



b.