Dutch couple found dead, their sailboat found upturned

[estarzinger]

Originally Posted by Snowpetrel

I do think the displacement to be floated by the foam might well be less than the 14 t or so that you have used.

Yes, agreed, you need to use the average density of the displacement to do this properly and that could vary quite a bit - for instance we used a very light low density foam cored interior while this boat I guess used a much higher density traditional solid wood interior . . . but we were so far off that I think we both agree it would probably not float.

The plans called for 1" of foam, and most of the boats were built with that, but we used 3" in our boat, and most of the people who talked to us about details before building theirs put in 2" - which was the plan ring frame depth - we increased our ring frames to 3"). So there is a factor of 3x here we could be off, but I think it most likely this boat had the plan 1".

A further issue - the type of foam - most (but not all - a dutch Royal Huisman I worked on had open battening insulation) aluminum boats use closed cell and the calculations I did are roughly right, but quite a number of steel boats use open cell type insulation and it would fill with water and not provide much floatation at all.

So like everything , there are complications and we have to make some assumptions, but I think most likely to not have enough to float without the keel.

I always assumed that Hawk would sink but that the 'watertight' compartments and foam would give us a bit of time to try to plug hole or to properly abandon ship.

[s/v Jedi]

Originally Posted by LakeSuperior

Thank you for your largeness in gently correcting my typo and the fine geography lesson. You are indeed a generous individual.

Furthermore, technically I did not quantify risk off either coast I just pointed out that risk is increased off both coasts in my (and others BTW) frame of reference.

What you were doing is implying that the deceased should have sailed somewhere else. You could have waited until at least their funeral service is behind us before bringing it down to that level. This may just be an Internet forum, but these people were real and me, as well as other members here, were very good friends with them and don't need to hear your wisdom about sailing where it is safe.

[Polux]

Originally Posted by sy_gilana

....

4 IMHO the Dutch are some of the finest builders and designers in the world. Ahem..I also own a Van De Stadt, in Corten A steel, and I feel safe. The Dutch invented the yacht. The Dutch have a reputation of fair and thorough investigations (Komsomolets, Kursk, the Malaysian Airlines plane etc)
.....
6 You cannot compare this Van de Stad's construction to the mission critical racing boat design, once described to me by a naval architect friend as, a keel supporting a sailplan with adequate flotation to support them both. John Martin's "Allied Bank" lost its keel in a round the world race. It was a bulb, some 12 ' down a machined High tensile blade, and the bulb was filled with depleted Uranium. (the IAEA was really upset at the loss off Chile)
...

Yes not all boats being them Steel or fiberglass are built alike but the fact is that Vand de Stadt steel boat, designed and built in Holland lost the keel and the hull don't show signs of the boat being rammed hard against the rocks while some fiberglass "racing" boats have been rammed hard against rocks for a considerable period of time and kept their keel in place, even if probably sustain structural damage.

It is convenient not generalize about this.

[Polux]

Originally Posted by Lizzy Belle

..
From what their son said, there was no contact with the couple after March 25th -- which was unusual, as they would normally send their location every 24 hrs or so. The last contact was a simple "we're underway" message on the 25th.

So it seems something went wrong within the first 24 hrs or so after they left Colón ... But even that is just guessing, based on them normally contacting home and missing all usual check-ins after leaving Panama. But not being able to contact home can have many reasons. So we really don't know anything as of yet

So the odds are that the loss of the keel had been the accident cause and that would have happened at open sea. For what I have understood the bodies were found far away from the local where the boat went aground and that is also consistent with that.

[Brob2]

Originally Posted by sy_gilana

A few points.
The Dutch have a reputation of fair and thorough investigations (Komsomolets, Kursk, the Malaysian Airlines plane etc)

None of those investigations involved noteworthy Dutch economic interests. Their parallel Teneriefe airport runway crash investigation was an abject failure precisely because it did involve significant Dutch national interests.

Are semi submerged containers an issue in that area? I find this a particularly sad story for some reason, perhaps because members here know them. Accomplished sailors and very decent people it seems.

[LakeSuperior]

Originally Posted by s/v Jedi

What you were doing is implying that the deceased should have sailed somewhere else. You could have waited until at least their funeral service is behind us before bringing it down to that level. This may just be an Internet forum, but these people were real and me, as well as other members here, were very good friends with them and don't need to hear your wisdom about sailing where it is safe.

You are putting words in my mouth. In fact, I was speculating on the possibility that they could have come to a bad end at the hands of others in those waters. The yacht would then have drifted unattended onto the reef. In no way was I passing judgment on their decision to passage in that area. I believe that folks should take whatever risk level they can tolerate.

Many thanks again for your fine lectures. You make a wonderful teacher.

[estarzinger]

BTW . . . . My guess about the keel has been confirmed (by people who knew the boat) . . . It was a bolt on.

[Snowpetrel]

^^ Thanks for the update Evans. That answers a few questions

Sent from my SM-G930F using Cruisers Sailing Forum mobile app

[estarzinger]

^^ further . . . . And the boat had been hard aground twice, hard enough to cause some amount of "leaking", without the keel bolts being replaced, (at least to the knowledge of the two immediate boat yards involved.

[Lizzy Belle]

Originally Posted by estarzinger

at least to the knowledge of the two immediate boat yards involved.

You have personally talked to local boat yards representatives that have seen actual damage?

[estarzinger]

Originally Posted by Lizzy Belle

You have personally talked to local boat yards representatives that have seen actual damage?

Yes, I talked to two people involved in the repairs.
The boat was leaking after the second incident.
They both said they did NOT see damage to the bolts, they said if they had they would have replaced them. However they did not do any NDT - I am not sure if there IS any good NDT to determine this.

[robert sailor]

Originally Posted by estarzinger

^^ further . . . . And the boat had been hard aground twice, hard enough to cause some amount of "leaking", without the keel bolts being replaced, (at least to the knowledge of the two immediate boat yards involved.

Years ago when FG boats were built with substantial keel stubs and lead keels our club boats would bounce off rocks and hit bottom on a semi regular basis sailing on Lake of the Woods, a lake full of high rocks. For the most part a bit of bondo in the keel ding was all that was required. The vessel Cheeky Refiki lost her keel at sea and it was reported that the boat had been grounded earlier. I know little about metal boats but my question to you is, Do metal boats put more load on the keel bolts in a grounding than a fiberglass boat?

[estarzinger]

^^ interesting question.

I would strongly guess that boats with steel envelopes around the lead put more stress on bolts than those with the lead "exposed" . . . . Because the exposed lead will deform more easily thus absorbing initial shock loading.

[olaf hart]

This is a repair to a steel encased fin that hit a rock at 7 knots, I didn't get a pic of the original ding.

The fin was 1/2" stainless, deformed over an inch, so you get some idea of the loading

[Polux]

Originally Posted by robert sailor

.. Do metal boats put more load on the keel bolts in a grounding than a fiberglass boat?

Probably there is another way to look at it: the load on the keel on case of a collision will have to do with the mass of the boat. A steel boat is proportionally heavier than a GRP boat so the mass will be comparatively substantially higher as well as the loads on a grounding.

The steel boat, since it is heavier will need more ballast and the boat structure will be prepared for the additional weight and consequent stress forces but it does not seem to me that on the case of a grounding the increase of loading will be proportional to the boat needed keel reinforcement structure due to normal operating conditions.