What sank there unsinkable Bayesian?

[Big Rig]

British tycoon Mike Lynch is among the five bodies that have so far been recovered from the wreck.
Raising doomed £30m superyacht to surface 'not on the agenda' (msn.com)/
There is a theory that a water spout called a "black swan" dumped enormous amounts of water into the boat

Giovanni Costantino, founder and CEO of The Italian Sea Group, which built the Bayesian, blamed human error for the disaster.

'The passengers reported something absurd, that the storm came unexpectedly, suddenly. That is not true. Everything was predictable.'

The Italian Sea Group has also dismissed speculation the enormous 264ft mast was to blame and says only a massive entry of water could have caused it to sink.

 

[danmand]

Hmmm, these boats are designed to be unsinkable.

 

[Zoot Allures]

Look at that huge mast in relation to the size of the boat!
Seems like that mast is all about show. Did it throw off the boats stability during the storm?

The Italian Sea Group, which built the Bayesian, blaming human error before the facts are in sounds like a very defensive position as their stock drops

 

[Mr Deeds]

Very rear for a boat like that to sink, something would have had to put a large hole in the bottom for that one happen. Even then the occupants whole have time to escape. I think there's more to this.

 

[Zoot Allures]

Very rare for a boat like that to sink, something would have had to put a large hole in the bottom for that one happen. Even then the occupants whole have time to escape. I think there's more to this.

Sounds like a perfect storm of events.

My scenario is made up but here it is


With a mast that huge they did not try to outrun a storm but weighed anchor instead

Then a very rare black swan water spout dumped masses of water into boat which boat had not been prepared for IE keel retracted, deck holes still open , not everyone had vests on

But I am not a sailor so I am guessing

Boat is only 150 feet down and with survivors they should be able to figure it out

 

[Robert Mugabe]

Sounds like a perfect storm of events.

My scenario is made up but here it is


With a mast that huge they did not try to outrun a storm but weighed anchor instead

Then a very rare black swan water spout dumped masses of water into boat which boat had not been prepared for IE keel retracted, deck holes still open , not everyone had vests on

But I am not a sailor so I am guessing

Boat is only 150 feet down and with survivors they should be able to figure it out

That's what I heard some guy say over there. On Global News. No boat could survive the type of storm that ran over that boat, according to him

 

[SchlongConery]

So this yacht had an extraordinarily tall mast capable of carrying big sails in high winds.

To counteract that force of the sail and mast trying to tip the boat over when sailing, it required a very long and heavy keel. Problem is that the keel needed to be so long that the boat would need 35 feet depth. That really limits where you can go in terms of marinas, channels and anchorages. So the designers used what is called a retractible keel with a 20 tonne ballast bulb at the end.

This allowed the keel to be retracted so the yacht only needed 12' of depth when it was at anchor or going into shallower areas.

The problem here is that even without a sail up, the mast itself, the boom, and the rigging (guy wires) the radar and satellite domes etc (so called 'bare poles') still have a lot of 'windage' surface area that the wind can blow against. Imagine how a tornado can snap bare hydro poles off like toothpicks!.

If the keel is retracted at anchor, roll stability is reduced and enough wind was hitting broadside it could blow the boat right over.

So in this case, a "water spout" which is just another name for a tornado on water struck the boat broadside and blew the boat over far enough that water started coming over the deck and filled up the cockpits, main deck salon etc as the hatches and doors were apparently not closed. Once it listed that far over past the center of gravity, the boat became unstable and the inrush of water made it worse and it basically swamped itself and filled up with water and sunk.

Anyone downstairs in their cabins would have to fight their way through hallways on their side and through furniture etc.

Literally a freak accident.

 

[SchlongConery]

Just listened to a segment on eSysman SuperYachts. a daily superyacht news programme. He is a really credible, knowledgable and experienced Superyacht crew member.

Sort of what I said above but there is some more details, different thoughts and generally good commentary.

 

[massman]

So this yacht had an extraordinarily tall mast capable of carrying big sails in high winds.

To counteract that force of the sail and mast trying to tip the boat over when sailing, it required a very long and heavy keel. Problem is that the keel needed to be so long that the boat would need 35 feet depth. That really limits where you can go in terms of marinas, channels and anchorages. So the designers used what is called a retractible keel with a 20 tonne ballast bulb at the end.

This allowed the keel to be retracted so the yacht only needed 12' of depth when it was at anchor or going into shallower areas.

The problem here is that even without a sail up, the mast itself, the boom, and the rigging (guy wires) the radar and satellite domes etc (so called 'bare poles') still have a lot of 'windage' surface area that the wind can blow against. Imagine how a tornado can snap bare hydro poles off like toothpicks!.

If the keel is retracted at anchor, roll stability is reduced and enough wind was hitting broadside it could blow the boat right over.

So in this case, a "water spout" which is just another name for a tornado on water struck the boat broadside and blew the boat over far enough that water started coming over the deck and filled up the cockpits, main deck salon etc as the hatches and doors were apparently not closed. Once it listed that far over past the center of gravity, the boat became unstable and the inrush of water made it worse and it basically swamped itself and filled up with water and sunk.

Anyone downstairs in their cabins would have to fight their way through hallways on their side and through furniture etc.

Literally a freak accident.

Reasonable explanation, but the boat sank in 150 ft of water, why would the keel need to be retracted?

 

[JohnHenry]

Reasonable explanation, but the boat sank in 150 ft of water, why would the keel need to be retracted?

Probably gets better knotage with the keel up.

 

[Robert Mugabe]

Probably gets better knotage with the keel up.

While parked, in dock, like this one was?

 

[versitile1]

Apologies if this has been asked already but do yachts and ships have a "black box" like on airplanes, that would have recorded critical data, wind speed, pitch/yaw, wave height, which hatches were open, etc.?

 

[SchlongConery]

Reasonable explanation, but the boat sank in 150 ft of water, why would the keel need to be retracted?

I don't know exactly about this specific situation that night and in the eSysman video, the builder says it should have been fine with the keep fully retracted.

However, in two yachts I have sailed on with a retractible keel, it tended to clank in the keel box when it was fully deployed at anchor in rolly, cosswind swells When there was tension on the lifting mechanism, the clanking pretty much went away.

In this case, other YouTube channels there was mention that this yacht in particular only filly deployed the keel when under sail, and with significant wind. When it was under power,(not sail) the keel was retracted so as to reduce drag and reduce the chance of hittiing random stuff and picking up seaweed etc.

One thing for sure is that was one fuck of a wind!

 

[SchlongConery]

Apologies if this has been asked already but do yachts and ships have a "black box" like on airplanes, that would have recorded critical data, wind speed, pitch/yaw, wave height, which hatches were open, etc.?

Not AFAIK. But maybe because who knows how extravagant these super yachts are equipped. My knowledge of that size of yacht is observatory.

There is a collision avoidance device called an AIS that transmits and receive vessel's names, type, position and direction speed and status (underway, anchor etc).

And maybe (probably) the weather sensors, ship pitch and roll angle which report to the Navigation system through the NMEA 2000 Network. So depending on the equipment on the vessel, I guess it could be recorded on some sort of non-volotile memory.

And now that I think about it, I've seen sophisticated security systems at the Miami, Fort Lauderdale, Annapolis and Dusseldorf trade shows that give real time updates on open doors etc.

With living witnesses, including crew, an accessible wreckage and recoverable instruments I've got confidence that the mystery will be conclusively solved. Especially since it was a British flagged vessel because then the British will be involved in the investigation. There will be lawsuits and the insurance will certainly cover the salvage/recovery of the wreckage.

Time will tell...

{EDIT: These yachts DO have expansive CCTV systems that must at least record to a DVR, if not live streamed to an off-site server. The DVR HDD's woudl certainly have the videos of whatever happened. And even despite being immersed in seawater, they can be saved and the data recovered. )

 

[versitile1]

Not AFAIK. But maybe because who knows how extravagant these super yachts are equipped. My knowledge of that size of yacht is observatory.

There is a collision avoidance device called an AIS that transmits and receive vessel's names, type, position and direction speed and status (underway, anchor etc).

And maybe (probably) the weather sensors, ship pitch and roll angle which report to the Navigation system through the NMEA 2000 Network. So depending on the equipment on the vessel, I guess it could be recorded on some sort of non-volotile memory.

And now that I think about it, I've seen sophisticated security systems at the Miami, Fort Lauderdale, Annapolis and Dusseldorf trade shows that give real time updates on open doors etc.

With living witnesses, including crew, an accessible wreckage and recoverable instruments I've got confidence that the mystery will be conclusively solved. Especially since it was a British flagged vessel because then the British will be involved in the investigation. There will be lawsuits and the insurance will certainly cover the salvage/recovery of the wreckage.

Time will tell...

I saw on my newsfeed that there may be manslaughter charges coming.

 

[massman]

Being reported that keel was actually up.

 

[Robert Mugabe]

Apologies if this has been asked already but do yachts and ships have a "black box" like on airplanes, that would have recorded critical data, wind speed, pitch/yaw, wave height, which hatches were open, etc.?

 

[Zoot Allures]

So this yacht had an extraordinarily tall mast capable of carrying big sails in high winds.

To counteract that force of the sail and mast trying to tip the boat over when sailing, it required a very long and heavy keel. Problem is that the keel needed to be so long that the boat would need 35 feet depth. That really limits where you can go in terms of marinas, channels and anchorages. So the designers used what is called a retractible keel with a 20 tonne ballast bulb at the end.

This allowed the keel to be retracted so the yacht only needed 12' of depth when it was at anchor or going into shallower areas.

The problem here is that even without a sail up, the mast itself, the boom, and the rigging (guy wires) the radar and satellite domes etc (so called 'bare poles') still have a lot of 'windage' surface area that the wind can blow against. Imagine how a tornado can snap bare hydro poles off like toothpicks!.

If the keel is retracted at anchor, roll stability is reduced and enough wind was hitting broadside it could blow the boat right over.

So in this case, a "water spout" which is just another name for a tornado on water struck the boat broadside and blew the boat over far enough that water started coming over the deck and filled up the cockpits, main deck salon etc as the hatches and doors were apparently not closed. Once it listed that far over past the center of gravity, the boat became unstable and the inrush of water made it worse and it basically swamped itself and filled up with water and sunk.

Anyone downstairs in their cabins would have to fight their way through hallways on their side and through furniture etc.

Literally a freak accident.

If you are correct, and that seems the likely scenario, then it was the Skippers fault not to recognize such a scenario and prepare for the worse IE he was not consulting weather forecasts as the conditions for water spouts must have been forecasted in this day and age

Boats are only unsinkable if the captain behaves

Don't boats talk to each other and give warnings? How could the captain not be aware?

The vessel that came to the rescue was nearby and undamaged lending credence to the water tornado. I wonder if he had prepared properly and gave Bayesian warning?

I know you will find this interesting: (I shall try to be articulate)

Concerning the keel, it behaves like an airplane wing forcing a plane up or down by creating high and low air pressure systems upon itself
( Bernoulli’s Principle ).


The keel creates these same forces with water upon itself .

The keel is forced to the low pressure side by the high pressure side of the keel.

In the case of a airplane analogy, the high pressue is on the bottom of the wing with the low pressure on the top forcing the plane to rise during take off . (The belief that the plane rises because the air has a longer path over the top of the wing than the bottom is false) This is why a plane will not fly if it was put on a treadmill driven by the planes speed and going at 100 MPH as only the wheels will turn at 100 MPH but there are no pressure systems being formed on the wings as the plane is not moving even though the propellers are turning

This water force, created by the keel upon itself , is opposite to the air force created by the sail upon itself so it is actually is the keel that tells the boat where to go, not the sail. The sail gives the boat speed, not direction.

Always fun talking to you

 

[Zoot Allures]

Being reported that keel was actually up.

Does that mean keel was deployed or retracted ?

 

[SchlongConery]

Does that mean keel was deployed or retracted ?

Retracted is up.

Here is a retractible keel deployed in the down position for sailing. In the sunk ship, the lead bulb at the end is being reported as being 200 tons of lead! I may be wrong but find that hard to believe. Maybe 20 tonnes of lead. Either way, imagine the leverage and center fo gravity with that much lead at the end of a 10-15' long fin?

You seem quite interested in the subject so here is a good article from Boat International magazine that discussed keell selection on a 65m sailing yacht. Slightloy longer than the one that got blown.

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