Naval Architect Discusses Bayesian Yacht Sinking
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- Опубликовано: 15 сен 2024
- Yacht Designer and Naval Architect Bill Prince helps to set some of the record straight on a yacht sinking that has captured the world’s attention.
The sinking of the 184-foot Perini Navi Bayesian has taken the world by storm and that makes sense, the story seems to have it all: Tragedy, a superyacht, a billionaire, a freak weather event, conspiracy theories, intrigue. What stood out to us as we read the reporting on this yacht sinking was just how many apparent falsehoods were being reported and how misunderstood the yacht industry is. While there is still so much unknown about the Bayesian sinking we knew that some of these falsehoods needed to be addressed, which brings us to today’s guest, world renowned yacht designer and naval architect, Bill Prince who also happens to be a friend and an exceptionally popular Power & Motoryacht columnist. He helps us to separate fact from fiction.
Sponsored by Volvo Penta.
Several days past the event and finally get someone who knows what he's talking about. Thank you for this.
We probably should have gotten on this sooner, we were trying to ensure we didn't fuel any misconceptions. Thanks for watching!
@@PowerMotoryacht My comment was no shot at you but more frustration with the online environment overall. Thanks again.
@@PowerMotoryachtand you didn’t!
Great stuff. Thanks so much. 🕊🥳🧚♀️
Take a look at eSysman, he’s highly experienced.
THIS is the kind of discussion I’ve been waiting to see/hear. Not that the others I’ve seen didn’t have good information, but to have an actual skilled naval designer/architect provide critical information is really good. For someone who knows little to nothing about sailing vessels and large boats this stuff is golden. Thank you very much.
Pity the sound volume was so pathetically bad
@@james5796 only the left one, put subtiles on then its okay to understand
'Naval Architect' is the correct term and most important sign of knowledge in this respect
I'm not a marine architect but I know what a retracted mechanical keel combined with excessive sail area leads to. This ship was designed to list to 90 in a breeze. The only storm it was designed to handle was one of controversy.
@@marclawson2536 Another channel said the keel only added about 10degrees.
I was a submarine sailor aboard USS Ohio. Our air intake for both the diesel backup and ventilation fans, when at periscope depth, was from a snorkel mast which was raised up hydraulically from the sail. Inside the boat, we had a seawater separation sump that could deal with a few hundred gallons per minute of intrusion from waves. If it got overwhemed, there was a giant flotation-style valve that would shut as automatically if too much water entered and could not be pumoed out fast enough. It would slam shut to prevent flooding. We posted a watchnan on sound-powered teleohones to watch the sump through a lighted porthole into the separation sump. If the flotation valve failed, we were the manual backup to rapidly shut that valve hydraulically. I stood that watch several tines. The sump and viewing port was just forward of the Trash Disposal Unit space just outside the scullery.
It seems to me that a multimillion dollar sailboat should have HVAC intakes protected by a sump and float valve at minimum. 45 degree downfloading angle is just massive design oversight incompetence, in my opinion. I can design MUCH safer boats than these idiots. Hire me for your multimillion dollar yacht design.
That is not a bad idea to have a valve that can shut in such an event.
Thank you for providing context to this tragedy,your insight and no nonsense analysis are appreciated.
Thanks for watching and the note!
www.youtube.com/@YachtReport this is the best source for solid complete information on events like this. Esysman lives this world as a chief engineer on superyachts.
Thank you for your explanation. I find it shocking to hear that on the one side, Superyachts are super well designed and documented and certified, whilst on the other, the expert finds it normal the yacht should be considered a ‘sail supported motor vessels’ which should make it okay for the tipping point to be somewhere between 75 and 90 degrees, where regular large sailing yachts have tipping points at around 120, 130 degrees. Safety at sea doesn’t care about our classification schemes and definitions. It was a sailing vessel with a very tall mast. It should have had sufficient resilience against tipping over. It didn’t. So my conclusions is that its design was one of the factors contributing to the disaster.
And even worse. A flooding angle of 44°!
I've read the angle of vanishing stability, according to the yacht manufacturers, was 88 degrees with the keel down, without such it was reduced to 77 degrees. It would be interesting to know if those figures would hold with that super tall mast she had. There's video on the internet of a 50ft catamaran being lifted right of the water surface and flipped completely over by a water spout in Westhaven, and nearby cameras showed the Bayesian pushed almost certainly beyond her AVS. But crucially, the down flooding angle of the Bayesian was just 45 degrees. The main entry to the inside were two huge glass pocket sliding doors which needed locking pins to prevent it from sliding open under its own weight. Naturally, these would not be locked while the boat was anchored. In all probability, Mother Nature got the better of EVERYBODY, and all will learn much from this event.
A classic example of why it is not a good idea to build a luxury motorboat with the sailing qualities of a racing yacht. Hybrids don't work at sea. Designers often forget Murphy's general rule. Difficult to say "no" to ambition. So the boundary is always being pushed. Important question for the owners of such boats: what does comfort really mean when sailing? I would like to take the responsibility of captain on such a "maverick". In that sense I understand his strategic silence during the interrogations. I would also keep my lips closed at first.
wouldn't like...
If foul weather is foercasted.
If you can see land and have a visitor visa, go stay in a italian hotel.
If you are referring to the video of the downspout that ripped the cat and then knocked the sailboat down about 90º that was a fixed keel boat this popped right back up, not the Bayesian. This is how keelboats are traditionally built. The rest of the comment is likely correct.
Do these angles assume things are static? If the boat is actively swinging down with some momentum behind it, that'll change things. There's more to it than a single angle, this is a dynamic situation. Think of the moment of inertia (that is, the second moment of mass) of that big mast. Static analysis misses that. Moment of inertia is proportional to length squared, while static analysis only looks at the first moment of mass.
I'll never understand why air intakes need to be within a few feet of the waterline when they could easily be piped to a higher point on the vessel. Especially when we're talking about sailing vessels which by their design are going to heel over when sailing. If a jeep can run though a pond with the engine completely submerged, why can't ships safely draw intake air?
On any sailing vessel heeling over 20-25 degrees, IMO no opening in the hull below toe rail level should ever be allowed. These engine and HVAC openings below toe rail level are flawed and invite disaster. The need for launching water toys should be accomplished from the superstructure and not from any openings in the hull sides or stern. I have seen these anomalies for a decade now and have always wondered at the logic and safety of the design engineer.
Having worked on many ships and sail boats in my life, having the air intakes where they were is bad. They were only there probably because of ascetic's and noise issues in the areas where crew and passengers hang out. I'd say they contributed to the down flooding. That combined with a freak weather event, the faulty massive saloon doors, as with airline disasters, it's usually never just one thing.
Excellent Question!
Agreed.
On a yacht, in a harbour. Calm sea, and it's 03:00. All the guests and crew are asleep, weather warning comes across. There is no apparent danger implied. Maybe an Amber warning, but it's a good boat.
And the the waterspout developed, minutes away. Wake the captain, sound the alarm?
Two minutes later the spout is 50m away, the boat is tipping, and the spout comes over you.
I think that a review of tornado damage on land is a necessity. Strips of land 50m wide totally destroyed, rooves, automates, flipped up and left some distance away.
The mast went over with the wind.
Upspout, downspout, the eye centred on the boat with the mast not vertical.
The rapid change in air pressure within the centre of the spout destabilised the buoyancy of the hull.
The boat tips 90deg. And this won't be minutes, it will be seconds.
If they'd anchored 60m North they'd be sailing to Capri today.
This is life. Shit happens. Whatever you do to design it away.
I've watched this three times now. Probably the best conversation out there right now on this tragic topic. Thank for sharing your expertise and calm, measured analysis. Much needed in this time.
We actually don’t know that Baysian was hit by a downburst or a water spout, it’s a theory. We also don’t know how strong the wind was. It’s also speculative to say it didn’t hit the other yacht nearby with the same strength. Just because the other boat didn’t sink doesn’t mean it wasn’t subject to the same forces. I would expect a naval architect be open to the possibility that there was something inadequate with the design of Baysian, especially considering that extreme weather events are becoming more common. Blaming the weather (or crew) without knowing the facts is essentially the industry trying to wash its hands. Boats like the Baysian are designed with a lot of hubris, wanting maximum space, max comfort, wanting the highest mast etc. You can’t with a straight face tell people that the Baysian was designed with safety as the main priority, it’s obviously not. The hull side engine vents are proof of that point, they don’t need to be hull side.
The nearby rescue boat was 400 yards away - so that captain thought it was safe to be there-
In 2019 there was a similar storm hit Auckland New Zealand where a 60ft catamaran went flying and a 145ft yacht got knocked down just in a matter of seconds that boat didn't sink. In my mind the Bayesian must have a design flaw.
Not design flaw. A design regulation flaw.
The design passed the regulators sea worthy check
the catamaran didn’t have a design flaw, but didn’t survive. not surviving a tornado isn’t a design flaw.
The 145 foot sailboat may have been a real sailing vessel as opposed to a large motor cruiser with a crazy tall mast. The architect's description of ultimate stability would explain why the 145 foot sailboat survived and the Bayesian didn't.
Accidents are not always caused by design flaws. While shortcomings designed into a boat because special circumstances were not considered in the initial design can certainly be a factor, it also takes unique circumstances like a freak downdraft of ferocious winds to exceed the design criteria of any manmade object. We did not foresee, for example, how a fully fueled jet airliner purposely flown into a skyscraper could achieve the objective that a truck fully ladened with explosives detonated in the basement could not. Not until 9/11/2001. That which is previously thought to be impossible, once proved to be possible is what leads to design enhancements invented to deal with such unforeseen situations.
@@richardvivian3665 It's both, actually. The regulations are there in the first place to catch and eliminate design flaws from sea worthy vessels. In this case the regulations and checks failed to catch those flaws. But often anything is possible when enough money changes hands.
World's tallest mast + 45 degree downflooding angle. Certify that all you like, I'm not going aboard.
Best comment. And unlike this long winded video, straight to the point 👍
As if you're going to figure all that out before going aboard.
@@riccileggio Fairly nonsensical comment in my opinion.
The results were the same for the Bayesian passengers as the Titan.
Yep that looks like a disaster waiting to happen 😢
Great discussion. First, Ron Holland has designed this boat with many compromises likely from owner requirements such as I want to get into Monaco, St. Tropez etc. I want the tallest mast, I want sunken lounge areas fore and aft etc. Holland has designed some of the most iconic sailboats in the world during my 50 years of racing. Second, to say the captain and crew should have expected a water spout or micro burst is absurd. I’m sure they have sailed and motored through many severe storms without issue. Last, I know the captain and 1st. Mate are in the crosshairs of the prosecutor but did this rise to gross negligence based on what we know now? I would argue no but certainly that could change. They did save 15 lives which is important to remember. This should be a wake up call to owners, designers, builders that there are irrational requirements for design, people should say no to them, walk away from the project. As a crew member and passenger, safety must be the culture and absolute. There can be no compromise.
Mr. Lynch who lost his life in unimaginably desperate conditions was not the original buyer. He probably asked a broker to find him a nice sailing vessel and bought this one. Of course it looks wonderful and it is. I very much doubt the possibility of sinking would have been high on his list. 'I want a nice, safe yacht please', voila here's this one.
Only a throughout investigation, bringing into light the design issues or the decisions that caused this event, will enable us to understand what went wrong and learn from it.
"As a crew member and passenger, safety must be the culture and absolute. There can be no compromise." Exactly this is human error and teh captain failed here - sadly! They should have prepared the boat and have the right personnel that night! Afterall they are responsible for the life of the guests and they must consider the worst case scenario and check radar regularly but they DID NOT! this needs to be investigated.
@@johnair1 sometimes Nature overwhelms any sort of preparations. It may feel satisfying to go after the captain and crew because "someone has to pay", but stuff happens even when people do everything the correct way.
No charges on crew because of a freak storm. Charge the boats designer for bad layout and bad recommendation to Only put raised keel down when under sail. Also for making the ship super sinkable with those water scoop stairways leading under the main deck height of the ship and No remote closure for any doors from bridge or engineering. But then Mfgr knew of these flaws or they wouldn't be pointing fingers at everyone else on day 1 and trying to deflect blame, they know they are guilty.
eSysman SuperYachts has done a lot of good reporting on this. In the following video (starting at 7:30) the downflooding angle is reported to be 40 to 45 degrees. He also said the designer stated the angle of vanishing stability was 77 deg keel-up, and 88 deg keel-down. Do these angles seem appropriate for a vessel with the amount of windage that the large mast has?
ruclips.net/video/mGULtQjJrvQ/видео.html
yeah, he is my main source of information on this subject.
By far the most balanced and informative.
Once again, the techie, in this case naval architect, refuses to believe that there could be a design flaw with this vessel. Over and over he says how many engineers worked on this vessel. The London regulatory body. Blah, blah, blah.
Blinded by his gospel of science, he then stumbles to the conclusion that the huge glass cabin doors, which fly open when the boat heels 20 degrees, likely contributed to the down flooding.
THIS IS A DESIGN FLAW SON!
Thanks for watching and the feedback. We wanted to point out the rigorous regulations these yachts go through to debunk the many mainstream stories that suggest large yacht by nature are unsafe and unregulated.
Anyone looking at that mast would think it is way too tall and could contributed to the accident.
If no power to change anything no electricity if water was in there ? Idk but this is so bizarre an so sad . Another mentioned plumbing an such if the pumps didn't work ? I'ma novice as we see
If the huge glass doors flew open at a 20 degree angle then that is not a design flaw. That is human operator error. These doors have locking pins to fix them shut when open. Either that was not done or maintenance was needed on the mechanisms. If I don't service my car brakes and I crash due to brake failure that is not a design flaw.
@@marviwilson1853 Was there another escape route for the guests?, would deadlocking these door have locked the guests in and condemned them to certain doom if the water got in through other hull openings ie. the engine room/HVAC system openings. We know too little to make a blanket statement.
I have been following this tragedy. I want to thank you for the presentation. I am glad that someone finally said that this was in the middle of most peoples sleep time, they were not even thinking about something like this happening. and certainly disoriented. There may have been some wrong decisions, but everyone was stressed to the max and just overwhelmed. I live in tornado alley on land, and the ones we have are extremely unpredictable and can destroy things you could not imagine that they could and yet not touch a building next to one that was destroyed. I agree that it was a combination of things. May the families find peace with such a horrific way to lose your loved one. Thank you gentlemen.
When people live and work on the Ocean they have to be the best and be prepared for anything, storms , underwater earthquake, etc. That is why they are called Marine Professionals, in the Merchant Navy they are subject to the Merchant Shipping Act, as was this yacht registered in UK, designed by New Zealand yacht architect, most recent work carried out by UK Shipyard. The yacht should have used both anchors if fitted with sufficient chain or warp, 5 times the depth , using the procedure for Northern hemisphere, first Port anchor and then Starboard anchor, the opposite to Southern hemisphere, first Starboard anchor and then Port. This ensures the anchor chains or warp does foul anchors. All hatches and vents closed to prepare to weather storm. The investigation will examine all aspects, required by International Regulations for preventing Collision at Sea and Sea Survival. It may also include the possibility of underwater object, IE submarine that have many times collided with vessels .
Correction, Does not foul anchors.
I’m not a sailor or boat owner yet I am obsessed with this story, just like I was with the Titan submarine. And now it’s got me obsessed with Below Deck Sailing Yacht since the Parsifal III is apparently a sister to Bayesian.
I respect that loads of thought and calc's go into the engineered design of vessels. But, the angle of down flooding seems very low for a S/Y. With steps leading down from main deck level to aft and forward cockpits located very close to the gunnel (which are at the same level to the saloon and sliding door access), it is easy to see how mass water ingress to this whole area could happen very quickly. Sure, there are cockpit drains. But they may not be able to drain at all until the vessel righted and may have been restricted by items washed during flooding. In addition, the companion ways are not small with raised openings... they are more like open stairwells allowing saloon flooding to flow below.
They are
Those stairs dipping below main deck just inches from hull are a water scoop that leads down to those lounge doors like a badly laidout death trap waiting to sink under the right conditions which in this case it took a freak storm downburst, plus no remote closure on bridge or engineering, so yeah there are design flaws.
On almost every yacht you go down from the deck into the vessel. No one knows exactly the cause at this point other than it took on a lot of water quickly.
@@JoeLinux2000sure, but the problem is the access down being right next to the side of the boat. If on he center line, the water may never have entered.
5 watertight compartments, 2 could be fully flooded and it would still float. The steps lead to a lounge and that is one of those watertight compartments. The doors were left open, there was flooding before it went over, the power went out up to 15 mins before it went over. How?
On another video I saw it was said that as the storm approached the crew was called on deck to gather up the cushions etc to prepare the boat for a rain storm. When the unexpected downburst hit, the boat heeled dramatically that’s when most of the crew was thrown into the water. If true, that would have left few if any on board to address flooding or assist the passengers. Might not of made a difference but then again maybe it could have.
The question should then be why the crew was dealing with cushions as the storm approached instead of waking up all passengers and made them go on deck?
@@aldosinisgalli8490 Would you call the guests up on deck for a regular thunderstorm at anchor? This wasn't a regular thunderstorm and the microburst was a surprise. With 2020 hindsight it sounds like a good idea, but no one has 2020 foresight and this sort of event can't be predicted in any reasonable fashion.
@@US15522 The microburst is just a hypothesis at present.
@@AndreaGG-i8t the Italian Air Force stated that there was a microburst.
@@US15522 You are right. I just read it too.
Excellent expert info and commentary! Thanks for painting a clearer picture of what may have contributed to this tragedy. The most eye-opening & horrifying comment to me was about the boat being at 90 degrees and guests being unfamiliar & disoriented with the interior layout at 90 degrees, while water was rushing in in the dark, and how the cabin door may have been at the top and unreachable to get out of the cabin. I can only imagine what the victims went through in their final moments. Extremely sad, and my heart goes out to everyone affected by this tragedy. I wish everyone strength, comfort and healing to get through this.
I heard all the people were found all together? I could be wrong IDK but yea how awful either way a horrible way 2 go
Visualize a 24 story building. That's how long the Bayesian mast is. Visualize 13 feet, or two men heights. That's its depth. That's 13' of draft trying to hold up 244 feet of mast, about 240 to 1. A 35 sloop yacht has a ratio of about 7.5 to one, that is mast height versus depth. The Bayesian was a really scary, dangerous design. The manufacturer built a dangerous yacht, which is why they are trying to use the crew for a scapegoat. They are a 300 million Euro Italian company and can bribe a lot of politicians. Don't trust the Italian government's investigation. The yacht's former captain said the swing keel was 60 tons, and the fixed ballast 200 tons, about. It floods at 45 degrees of heel, also very scary.
I think you mean 24 to 1. Still a scary ratio.
Great explanation thanx. Scary. there's alot of strangeness going on
i’m dumber having read this. floors aren’t 10 feet tall. 244 divided by 13 isn’t 240. righting moment is not simply a ratio of height vs draft.
@@swerne01 Yes, I wasn't describing a ratio. Your ratio is correct. I'm trying t
@@russ254 I didn't say any of the things you claim I said. I actually know how to calculate righting moments. You need information not publicly available to do so. I looked up the height of some actual 24 story buildings. However, Archimedes said,
"Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."
Thanks so much for this. It was extremely informative. Like all offshore racers I have been in yachts that have lain flat with a spinnaker full of water and bounced back as soon as the load was taken off. So I just assumed all ballast keel sailboats behave like this. But the reported AVS values of 75 to 85 degrees with keel up or down for this yacht seem marginal to me, particularly with such a huge rig. But the value that really hit me was a reported downflooding angle of 44 degrees with engine/generator and HVAC vents open (at anchor). Surely engineering could increase this value? Was there a degree of complacency because of the vessel's sheer size and opelence?
The only safe answer to this terribly low downflooding angle which makes the vanishing angle of heel irrelevant largely is automatic shut off valves on such openings as with big ships.
A downflooding angle that low seems entirely inappropriate to a sailing yacht whilst entirely apt for a large ship.
Thank you for watching and the feedback. Impossible for us to report on possible complacency but it certainly seems plausible, especially when taken by surprise.
Unforgivably lax.
The rules aren’t good enough.
I’d say the problem is that these luxury yachts are more about creating the ambience of a floating luxury lounge room than worrying too much about the sink angle.
Is there a degree of regulator capture at the luxury end of the market?
This event has put paid to the notion that being at anchor is safer than being at sea. Storms can get you anywhere.
Yacht designer waffles and minimises potential role of yacht design in yacht tragedy. Meanwhile, it is very clear that the yacht's design is strongy implicated.
The sea is an unforgiving master and when you are making design compromises so that you can incorporate the features of a luxury villa, a sailing yacht and a motor yacht into one vessel then you must also compromise seaworthiness, and so it is here.
Really? It was a yacht capable of racing. It had been raced under it's French flag. Hard to do that with a compromised seaworthiness surely.
I didn't think he waffled at all. I found his input very helpful.
1. You can't build an unisnkable vessel.
2. This means what is an acceptable range and risk of sinking, how far are you pushing the safety.
3. Industry standards, this goes for ships, planes, ... , are mostly made around accidents that have happened before as in an accident/tragedy happens, respective bodies go over what happen and look into if it could have been avoided and how and as such implement changes to regulations if necessary and if they are actually beneficial; for example if having self sealing doros acrosss the ship could lead to the saving of the ship, at the same time a possible malfuncion or similar could mean that people could get trapped and die because of it.
4. Freak accidents happen, plenty of passanger planes have crashed due to downbursts, this doesn't mean that the planes are badly designed and/or that now civil passager planes neeed to be equiped with booster rockets to fly them out of those downbursts.
Stupidly high mast, there are much lower masts running more sail
Lawsuit
What doomed this vessel is its inability to sustain a full knock down. The boats manuals document this design flaw. That is the primary cause. Susceptibility to rapid down flooding was likely the second design flaw. All the other factors that contributed to sinking would not have been an issue if the vessel righted itself within a few minutes.
Luckily I have never been in a tornado but we did live about an hour away from where a F 5 tornado hit in Plainfield IL. There was no tornado warning issued. It hit during the day, 29 people died and 350 people were injured. If the crew and passengers had no warning that this was coming, especially at the time the down draft hit, there was not a lot the crew could do. The winds are so powerful and it happens so quickly.
You are correct, I live on an island where every year we have hurricanes. Some are very bad, but when they come at night it is worse as you can’t see anything. Sometimes there are tornados in these storms but you have no way of telling until it is on top of you. When daylight comes or when you can go out after a storm like that you will see where a tornado hit your neighbor and not you and their house is badly damaged. Wonder how many tornados occur in that r3gion and did the crew even have any experience with such extreme weather.
This boat was in the wrong place at the wrong time.
A beast like that had to deal with extreme wind speed. Wind speed almost not imaginable.
Greetings from France
Boats should be designed for the wrong places
@@jcBurton2094Tell that to the Titanic
The Titanic is the simply the original example of the truth of that statement.
My bet is downflooding from the cockpit when the large glass door slid open. Ie. a design fault and not the crew. Would it be unfair to criticize Italian design as very cool but dangerous? Maybe.
Was it Italian designed or were the builders not designers Italian.
I think this is the consequence of bad design that fundamentally undervalues seakeeping for pretensions. This ship was designed with a deck crew of 3 NOT 10. There was a cook and three stewardesses (none of whom are deck hands) an engineer, 1st Mate and Captain all of whom have specialized _and essential_ duties keeping them from the deck. Weighing anchor at night with the attendant noise and movement (offending the billionaire passengers) in weather, with no substantially safer anchorage immediately at hand AND short-handed presents a dire alternative to the captain.
All critical incidents many small events combine and lead to the eventual critical event.
As someone who has lived aboard for a few years, there are many small questionable events apparent in the tragic sinking of the Bayesian. Remember no other boats were sunk.
I've followed some yachting channels over the past few to several years and the Italians have a _reputation_ for being the best looking, but the worst in real-world safety.
The glass doors would be locked in a storm so that is not valid point .
Captain knows this that's why he is the captain .
The fact that it suddenly when down so quick suggests that hatched were left open to flooding .
Air vents don't let that amount of water that quickly .
We saw the stability book online posted by the previous captain .
This guy is forgetting the torque factor of the 90,000 pounds on the end of the 10 meter keel .
X that by a multiple
Crew is going to get railroaded by Italian police to hold somebody responsible- and they probably don't like to go after the Italian builder. It's just going to add more victims to this tragedy.
You don't know what you are talking about
The problem is regulators.
The boat was built to legal specs and was deemed sea worthy and insured.
It’s not a design problem. Designers will stretch the regulations as far as they can as long as they stay on the side of legal.
@@richardvivian3665 Which is what the customers want - the best boat at the lowest price extremely logical and appropriate.
@@richardvivian3665 Nothing that humans can build (at least for now) can be designed to withstand everything that the environment can throw at us. Regulation is always a balance between cost-effectiveness and risk, and _no_ regulator will tell you that their rules are sufficient to ensure absolute safety because _no such thing is possible_ . This looks like classic Force Majeur to me.
@@fernandodemartino2821 Isn't this the legal system that convicted a bunch of university geologists for not correctly predicting an _earthquake_ ? Admittedly those convictions were overturned 2 years later, but those were an extremely rough 2 years for those geologists, and that incident provides ample evidence that the Italian legal system is "blame-intensive".
IMO a tornado or downburst pushing a yacht beyond any anticipated heel angle is a classic instance of "force majeur" - The Earth's environment showed us something we (and this boat's designers) never expected to see, and humans died as a consequence. As both the manufacturer and the boat's previous skipper have confirmed, the boat could not self-right when inclined beyond ~75 degrees in its docked configuration. Once that happened, the Bayesian was doomed, and there was very little the crew could have done to save those guests. Have _you_ever tried to rescue an obese 59-year-old from a belowdecks cabin in a ship that has tipped 90 degrees and has no lighting/power? That simply wasn't going to happen.
The Italian prosecutors should be ashamed of themselves. What they are doing is a travesty.
The crew started stowing away stuff off the deck when they should've been battening down the hatches and lowering the keel...
Ive grown up on the ocean and lifes are more important than anything on the deck
They should have alert the passengers and get them in their life vest before they get into the life boat . When your sunken deck is flooded and your water tight doors are broken. 😢
This ship has sailed around the world since 2008 without any issues. I think that the Mediterranean is becoming more tricky every year because the water temperature is every year higher.
10 days ago a friend of mine, sent me a picture from Puglia with three waterspouts raging the sea at the same time. I think simply the boat was tilted over his Angle of Vanishing Stability (77 with lifted keel) and sank...
The waterspout or downburst was a tempest inside another one. The first took the crew on the bridge to fix and close everything, the second flipped the boat throwing this people in the sea and injuring them. With the crew in the water, nobody could close the watertight doors and save the boat, with the remaining people inside.
The next time someone builds one of these sailing yachts:
Make the retractable keel silent when down, so there is no noise issue necessitating raising it at anchor so passengers can sleep.
They should make every watertight door to the engine room automatic closing, the engine room always needs to be the last compartment to flood.
They should shorten the mast, it was clearly too long, as they wanted speed over safety. The mast should be limited based on the next point, the righting angle.
The righting angle should be closer to 100 degrees as a rule, 75 degrees as stated means when this boat goes on it's side, it will 100% sink.
Forward cockpits are just stupid designs for a sail boat. They hold water...period. They need channels on the sides for fastest water drainage, like between waves fast, or just eliminate them.
They should add LED emergency light strips that turn on when the lights go out or when there is an emergency alarm, showing the route to the nearest exit, like they do in Airplanes.
Lastly, but not least, there are sub $200 mini scuba tanks that hold 5-10 minutes of air, the size of a bicycle tire pump. You can place these in every bedroom hanging on the wall by the door, and in corridors around the ship. Those alone would likely have saved all the people onboard. They had 15 minutes to get out, but couldn't go through the flooded compartments.
And if they do all these things the next time, it means they made mistakes this time.
Such great analysis on this tragic event, appreciate the expert opinion and knowledge.
Thank you for watching this and the nice compliment, we were lucky to have Bill's expertise for this.
The time span for the vessel to go from upright and stable to knocked down past the point of no return would be no more than 1 or 2 seconds. I cannot see how any crew actions (or inactions) could have either caused it to happen or prevent it from happening.
They could prevent it from happening first by being aware that a thunderstorm was coming. Everybody in Porticello saw it coming, no fisherman went out to fish. They said one could see the lightinings already at midnight. Only the crew of Bayesian didn't see it (their word). When a thunderstorn is on sight every serius skipper will prepare the ship to face it in security: close every aperture (especially the lazarette), lower the centreboard (not the rectractile keel as said in this video) and start the engine to keep the bow to the wind and so avoid tilting. From the AIS tracks we now know that the foul weather hit the ship at 3 am. One can see she was zizzagging first at anchor and then when the anchor was dragging. Nothing of that was done in the hour that passed before the boat started to take in water and sank. Of course when she was full of water and heeled of 90° nothing could be done.
@@lungarottacorrect every one knew in that area as this storm comes every year in august and was predicted and tracked. Every one should have been prepared especially the crew of a super yacht with valuable guests on board. But in this case ?? So strange
@@lungarottathey never said they did not see the storm coming. Ofcourse they were aware and prepared for the weather - the same way they always would. Centreboard lowered only when sails are up, as instructed by the manufacturer. However, they did not see the DOWNBURST coming. If hatches/doors were open, blew open or were opened from the inside by someone trying to get out, is not yet known🤷🏼♀️
@@karinhedman6903 No, the skipper said to the investigators that he didn't see the storm coming. This is the key to understand all that follwed. IF they left the lazarette open that means they were not prepared for the bad weather. Hatches were closed because they had air conditioning, as stated in this video and anyway the water which might have come in through the hatches or any other small opening couild not be sufficient to sink the boat. A huge amount of water must have entered in a relatively short time and that, according to the builder, could only enter through the lanzarette (where the dinghy is stored and from where it can be put into sea). Also the fact that they didn't lowered the centreboard shows that they were not prepared to face a thunderstorm, which as every sailor knows, can produce very strong and nasty gusts. You don't need to have a downburst or a tornado o whatever it was, to lock the boat and to lower the centeboard.
@lungarotta it also sounds like the Captain decided to go to bed for the storm and leave an unqualified hand as watch that night. The first storm for quite a while I believe and the Captain decided it was not important to stay awake for
Best explanation of this freak incident that i have seen online!
Thank you for watching this and taking the time to comment.
This was an exceptional breakdown on yacht building in a thumbnail sketch. Thank you.
Thanks for watching it!
SORRY TO STRONGLY DISAGREE with both your general conduction of your video, but especially the justifications claimed by your guest, a Naval Architect, no less (!)...
This video is mostly directed to portray the Yatch Industry as "very safe", very throughly "engineered and designed" and blah blah blah...
The FACTS are:
-The Bayesian sank.
-It sank in a very fast manner.
-It claimed lives.
But both your video and your distinguished guest (which credentials are commendable), seem to follow a very logical INDUSTRY's attitude that follows exactly the interests of the business: To PRESERVE "the good name" of the yatch designers, their design decisions and the image of "engineering excellence" of the industry..."
NONSENSE !
Bill Price appears to sympathize with the ltalian shipbuilder designers, probably because he is also a Naval Architect and immediately jumps on the message that "thousands of Engineering Manhours went and currently go into the 'superior' design of yatchs...
ALLOW ME TO DISAGREE: Take a Boeing B737MAX, that had MANY more thousands of "expert" engineering manhours than ANY luxury yatch has ever had or will ever have!... but TWO of those airplanes crashed due to poor engineering, Period!
And those planes had even more "Approval" and Certification papers than ANY yatch design will ever receive!
I am not a Naval Engineer or Architect (my late father was), but as a P.E. Engineer with 42+ years of experience, I can tell you both, that all those "Certifications,
"Approvals",
"Classifications" etc etc are NO GUARANTEE that a certain design IS INDEED, free from design vulnerabilities (some can for shure be called "design errors")... and no amount of papers, are going to impede that, under some circumstances, the design is VULNERABLE and Prone to Failure... and will irremediably FAIL.
Take for example the recent very sad and hard to believe Airplane Crash in Brasil, where 62 persons perished on an ATR-72-500, a COMPLETELY CERTIFICATED, APPROVED AND VERY POPULAR TURBOPROP AIRLINER, Approved to fly IN ALL the countries of the world!... But that has proved, sadly, to be ESPECIALLY VULNERABLE to Flying under ICING CONDITIONS...
Now, ask yourselves, Is tge ATR-72 a "dangerous" airplane?... Should it be banned from flying ???, Should it be grounded after SEVERAL VERY SIMILAR ACCIDENTS HAPPENING ???
CERTAINLY NOT... BUT
Its Design has a few factors that aligned under the proper circumstances, are TRULY UNFAVOURABLE... like having a 'Hi Performance Wing Profile (that happens to provide great lift, but a terrible Stall...), a T-Tail That is quite common with other Turboprop designs like the Dash-8... tgat happens to make the aircraft vulnerable to go into a condition called "Super Stall" at high angles of attack... A pair of heavy engines placed on the wings, together with a Baggage and Cargo bay located far in front of tge wing, together with a longer fuselage, "stretched" from the original ATR-42 shorter design, and that placing the masses of tge engines, baggage and lenghtened fuselage farther out from the CG, all contribuye to favilitating a completely irrecuperable "Flat-Spin" following a Stall caused by flying under Icing conditions, that are NOT corrected or sufficiently reduced by the quite LIMITED Deicing and Antiicing systems... the "recipe" for a disaster, seededbfrom the very initial Design stage... And even when the first icing accident of tge type happened in 1994 (30 full years ago!), and even with SOME "redesign" of the airframe took place... at least another FOUR MORE SIMILAR ACCIDRNTS HAVE OCCURRED... SO MUCH FOR A "EXPERTLY" CERTIFIED AND FULLY APPROVED DESIGN...
One thing the ATR 72 tragedy has in common with the Bayesian tragedy, is that BOTH CRAFT were fully "certified", both were designed by highly competent groups of expert engineers, both were fully approved by their respective industries and governmental authorities... and BOTH resulted being VULNERABLE and FATALLY misbehaved under specific sets of circumstances...
My message for your guest, (and take it as going from an Engineer (older in fact) to another Engineer), is a humble advice, on not to fall into the mousetrap of the mountain of impressive certifications of high prestige Naval Classification Societies and diverse Autorities... a certain hull (or airframe) design will not "self correct" or "protect" by itself from design vulnerabilities firmy planted from the design stage, and no amount of paper Certificates will allow it to automatically correct Design Vulnerabilities that can escape from the many layers of inspection, rating, evaluation and approval of experts... Both the Naval, the Aeronautical, the Automotive, the Chemical and Petroleum industries; and even the more strict Nuclear industries are FULL of "accidents" that, in one way or other, can have been initiated by DESIGN ERRORS or "occult" vulnerabilities that went UNDETECTED until the unfortunate set of conditions made those designs fail miserably, taking lives and causing a lot of pain and material damages.
SO, as a designer of watercraft, don't ever assume that the abundant Engineering Manhours by the thousands, automatically mean that a design "must be safe"... that is not true, neither constitutes a magical way to guarantee or just "assure" it is not vulnerable.
Well said and illustrated. Like the old saying,The best plans are good until they meet the enemy( in what ever that form takes). If all these highly designed structures were foolproof, then why have safety devices such as life jackets, lifeboats, flares, fire extinguishers. The Titanic was claimed unsinkable and she sank on her maiden voyage, she was classed and certificated. Design is a compromise at best, with 'What if's' . How much of these approvals are just rubber stamped and somebody has their fingers crossed, hoping their name is not on the certification , but stamped by Corporate as the Royal We, not by one person. In the days of paper drawings, you had a column on the right, Designed, Drawn, Approved, for in house, then it goes out to Classification and Regulatory body approval. Each has a stack of drawings a foot high, the shipyard is pushing for approval to continue the design or production. With all the will in the world some are going to be rubber stamped without checking. Its human nature against the unpredictable forces of nature.
Take the Concordia Gulf cruise ship disaster. Even Military ships have similar disasters and the Bridges on those are top heavy with people all doing a little bit, unlike a Merchant ship when there is only one Officer on the bridge and a seaman during the dark hours as an extra pair of eyes.
I hate to break it to you but you can't engineer a vessel to not be vulnerable to a freak weather event.
So, how would you design a boat to withstand any type of storm or weather event or natural disaster. You can't, it's impossible, how would you design a boat to survive a say tsunami or whatever, you can't.
So, please let the investigation be completed and then we can comment.
The moment you compare a plane that flies at thousands of feet above the earth to a boat that’s floating on water and sinks I am sorry but not at all valid or helpful .
I watched this and don’t understand your comment. They mostly dispelled erroneous rumors about why this tragedy occurred and discussed the vulnerabilities the vessel did have. All of the great information they provided only added to the incredible freak nature of this event and added enormously to understanding the horrifying situation the people aboard faced. “These are extraordinarily designed boats and it takes an enormous act of God” for this to happen and the fact that the circumstances it faced were unlikely and unpredictable.
This discussion is one of the most reasonable I have listened to among many. Thank you.
If you want a safe sailing boat :
90-110° stability
90-110° downflooding
It's not that hard, you just have to put proper ratio mast/keel and keep hatch & opening in the middle of the boat like on almost all sailboat in the world
yes you will lose performance in light wind, yes you will lose some aesthetics
The issue is ower of those superyacht want them good at everything, well this come at a price
Exactly
I agree 100%
This is the crux of the issue.
Sounds like a rehashing of esysman's comments.
Great podcast thanks. Follows a lot of my thought process. The CEO of the ISG group really needs to resign his position based on the interview he did shortly after the accident. He must be held accountable for his comments.
After this there will be a lot of rich owners thinking about safety for the very first time.
This was giant for a sloop. 236' mast. It must have enormous healing moment
Several Design errors 45 degree maxium down flooding angle on a sail yacht. Automatic opening sliding doors on a sunken deck. The Mast was way too much they had to add enough weight to lower the vessel 10 inches to get acceptable righting momentum. Clearly they negelcted the watertight doors.
The automatic opening can be turned on/off. Another report from a previous captain has stated the doors, even when closed, had a nasty habit of opening on their own when at certain angles because they were so heavy. Without putting physical locks (dog locks? Pin locks? I don't recall the proper term) in them, the doors would open on their own. The sunken cockpit would be a bane in this situation (great on sunny days) and I definitely agree on the mast.
The lady who survived holding her baby up stated they heard glass shattering before everything went chaotic. It's possible that could have been glass on the starboard side and then when the ship rocked, you have the windows that shattered taking in water, plus the cockpit, plus the vents. That's my guess on why she sank so quickly.
Delivered as ordered by the owner 🤷🏼♂️
Was there any heros? Besides the woman who saved her child. That woman is awesome.
Supposedly in the media the captain saved the child
One observation about the low hull opening in the stern section, which may or may have not been open: it's been said that the ship was healing to starboard, therefore the opening, on the other side, would have been further away from the surface. Correct, but this also implies that the wind and the waves were impacting the port side of the hull of the ship, and if that opening was actually open, well, it could have just been the starting factor of the chain of events that led to the sinking.
Another thing: from what I understand, a guest (the owner's wife) was woken up by the wind and the listing of the ship while the captain remained sound asleep and had to be woken up by the guy on watch.
No other boat in the path of this 'weather event' sank.
Nobody talks about what a tornado does to the water at the touch down point. It can suck a thirty foot hole in the water or put so much air in the water that a boat either falls into the hole or just sinks into aireated water and is just swamped. Tornado is not known as a freak storm for no reason.
The downflooding angle (vents etc) was only 40 to 45 degrees. The angle of vanishing stability was 77 degrees keel up and 88 degrees keel down. Clearly the keel would be up as when the vessel is at anchor there is a regular low frequency sound not unlike a drum as the keel moves athwartships. This mast is a roller furling mast quoted a bit longer than wide … maybe a ratio of 2.5 to 1 from photos I have seen so pure speculation on my part would be if it filled with water, is that taken into account when calculating the AVS ? One thing is for certain… the company rep who stated the vessel was unsinkable in those conditions is a fool. I would refer him to the statement made in the movie Titanic from the vessels naval architect to Bruce Ismay the owner:
“Ismay: "But the ship can't sink."
Andrews: "She's made of iron sir. I assure you she can, and she will."
Thank you gentlemen, I was waiting for this one because the speculations of the armchair warriors drove me crazy
Thanks for watching this and the compliment, we agree with the armchair experts!
@@PowerMotoryacht being in law for 31 years, one quickly realize which channels to watch & which to ignore. This was an excellent podcast buddy👍
I think Bill said that the sinking "seems pretty quick, it seems very quick", without further elaborating. Then he quickly moves on describing why 6 out of the 12 passengers died, while 9 out of 10 crew members surveyed.
But key to this tragedy is to understand how possibly could the Bayesian sink "very quickly". Can the aircon and the engine room vents combined cause a flooding that sinks a vessel like this in (maximum) 15-16 minutes, drowning 50% of its passenger with it?
Was it a design issue (Ron Holland), a construction issue (Perini Navi), a human mistake made by the crew, a mix of the aforementioned?
Or shall we really accept the idea that, in the 21st century, a ship of this size may sink in 15 minutes, while at anchor in a bay, simply because of the weather?
I understand I shouldn't let this tragic event color my perception that this might happen to me. But I would like to be reassured that the airconditioning and the engine room vents alone cannot cause a vessel like this to sink like a rock, no matter the weather.
@user
Exactly.
The fact that sinking of super yachts are extremely rare is a testament to the engineering involved in the design, what makes most sense about this sinking is the extraordinary length of the mast and the accoutrements on its cross bars ie way too top heavy and unable to correct itself once it listed beyond 45 degrees due to the forces on the yacht from the sudden extreme weather.
Perhaps super yacht designers will not be pressured into pushing the envelope with design to meet the billionaire aesthetic demands.
All super yachts that accommodate multiple guests should be mandated to have guests do emergency evacuation drill before leaving harbor, the crew have to do drills weekly I believe, there’s nothing crew can do for the guests if the guests don’t know what to expect or do in an emergency.
There are reports that within minutes the crew were thrown into the water while trying to secure the deck furniture when the storm first hit them.
The story is despite advances yachting technology the unpredictability of natural forces will always cause disaster.
Let it “..tune up your safety and self awareness.” Perfectly said
Also as a cruise line captain ( retired) might I ask some thought be given in advance as to how to rescue the passengers following a collision between 2 ships each holding 5 thousand souls . It’s night time and bad weather conditions…in crowded Caribbean waters . Most passengers being elderly … Time to think about it is now ! Not following the event . Andrea and Stockholm event should have taught us something about this potential eventuality.
@@mastercommander4535
As a captain, you should have a clear understanding of what went wrong to allow your example incident to have the outcome that it did. As far as a modern cruise ship (a barge with a top heavy hotel stuck on it) having a significant incident, it would seem more likely that it would not be a collision with another ship but something more along the lines of Costa Concordia or the failure of the Azipods clutches during a storm (like what nearly happened on ANTHEM OF THE SEAS) or the failure on the Viking Sky while being blown onto a coast. These solitary events are what I find more likely to end with a large loss of life.
@@Mentaculus42 What needs to be understood is that now there are far more cruise ships travelling in the same sea lanes than in my days. There is a limited number of attractive destinations such that the congestion in Caribbean hot spots is a common occurrence with some ports having to deal with as many as three cruise ships at the same time ( and incurring the wrath of the locals that live there ) .Thus I think my concern as to the potential of an offshore incident becomes more plausible.
Wow. I'm a sailor and Bill got exactly at my major question. 77 degree angle of vanishing stability with the keel up. Now I understand why. Huh. I'm used to 40 ft raceboats that go to 130.
Hello, anyone home? THINK, please think.
The woman who was out on the deck at 4AM (who survived) with her infant child was NOT outside with her baby during a storm. She was out on the deck because it was nice and calm outside at that time. It was a freak weather event that no one saw coming and that no one expected or had any reason to expect. There was zero time to react. There was absolutely nothing that could have been done to prevent this outcome because the design specifications for this yacht stated that at just 40 to 45 degrees of heeling this yacht would take on a significant amount of water and it had heeled over far more than 40 to 45 degrees.
Ship was not prepared for the night, normally you take measures of safety because you can't see the sky at night which can change quicly like everybody knows who is in boating. It was the size of the ship which gave a false safety feeding.
Storms were forecast. Strange weather phenomenon were talked about amongst captains. Thunderstorms were happening at 3 o clock in Palermo. Fishermen didn't go out. But they didn't even put the cushions away?
In the discussion of the time it took for the Bayesian to sink, the point I find interesting is the story of Mr. Lynch's wife who was below in a cabin and got on deck and was rescued. She may have been the only passenger below deck who lived because the family of 3 with the little girl was already on deck when the storm hit. Her story as I saw it reported was that the storm somehow woke her and her husband up and she went up on deck and was thrown into the water. She might have some idea of how long that all took and whether the boat was already listing or knocked down when she woke up. Did any other passengers who were below deck at the time the storm hit survive?
No, no other guests survived. Tragically, guests are disturbed as a last resort at all times. The mum of the little baby was on deck because she was nauseous, Mrs. Lynch went on deck to find out what was going on. Everyone would have been thrown in the water when the boat heeled over which is why they survived. The life raft if it had not already been deployed would have had its' hydrostatic line released as its supposed to which is why they managed to get into it. It's not that easy to get into if you are in the water but crews train to be able to do it, albeit in flat calm often in a swimming pool, rather than in pitch black in a raging storm. I suspect that out of this tragedy, if you are a guest on a superyacht you will immediately be aware if you have the slightest misgiving, to get yourself on deck. A bit like the Tsunamic disaster of 2004 and the Japanese disaster. If you see the sea disappearing, you now know to run as fast as you can to highest ground you can find. Ex crew.
@@andyblyth4519 The crew and the wife lived in the s/y and were used to it. The wife might have gone to the deck and left some of the doors open. The chef might have been in the kitchen.
In addition to the mother, her baby, the husband, and Lynch's wife who had been on deck, wasn't there two other guests who survived? Not sure if they were on deck or not. (Ref: 9 of 10 crew survived; total of 15 people survived therefore of those 15, 6 would be non crew)
@@janb200 Exactly. That's my math too.
@@janb200 Further research showed that the two other guests who survived were Ayla Ronald, a lawyer whose firm was associated with Mr. Lynch, and her partner, Matthew Fletcher. I was unable to find out whether they were below and came up or if they were already on deck when the boat began to go down.
I would think that the same design characteristics that automatically releases and inflates life rafts should be incorporated into the vents/ingress points. When the boat tips X% and the life raft is wet it releases and inflates. If water ingresses a vent it should close.
Genius
To my thinking the key differences with this boat to make it vulnerable to a disaster like this were its oversized mast, but more importantly the sales were roller reefed into the mast. This second point means that if the mast entered the water it would fill with water and with a 75 meter moment arm the hold down force would be significant enough to delay the righting time sufficient to allow the boat to flood. That the boat flooded quickly is the second issue. The Saloon central double doors seem to be an issue in that they can be forced to slide open when sailing on a heel. This is so easily prevented with a rack on each door with a central pinion gear to balance the weight of each door against the other. This kind of arrangement is also more compact and easier to design in relative to standard belt drive arrangements typical in malls. Self sealing bifold outward opening doors are another good mechanism to keep openings closed at all times. A/C vents are the most likely culprits where there might have been design compromises. The possibility that the boat could go dark is an other issue. No where in our world goes dark with so many emergency exit battery operated devices available.
The other thing that hasn’t raised a mention is that the boat dragged anchor to the spot where it sank. There is a far less expensive boat in our marina here which has a self docking feature (for the comfort of the boat owner’s wife) and this system has a “Hold” button. Press the button and the boat’s motors and engines hold the boat in that precise spot. I’m amazed that a boat of this safistication can be allowed to drag anchor the distance that it did without power assist cutting in to hold position. Even us lowly yachties use engine assist in difficult anchorages and bad weather. Most of us have and use anchor alarms. But you cannot causally connect these two events.
I don't think you know the boat very well, the mainsail was furled the boom, not the mast, huge difference.
@@RichardFKeith I heard that the wrong way. Correct big difference.
@@RichardFKeith
Good catch, as that is very significant.
The "downburst" or microburst factor here is huge, as the designers seem to indicate. Its hard to imagine unless you have experienced one on a sailboat. Ive , unfortunately , experienced 2. They are VERY specific local . like 20 to 40 yards of actual hitting area , with strong horizontal wall winds around and following immediately after the downburst. No one on my boats were injured, the 2nd incident attested to the designers explanation of flooding angle, It was a 5500lb keeled 30' racing boat with a 50' mast.. (bare poles) which went UNDER water and ripped off the masthead instruments, but the boat stood back up like a cork! Great piece and discussion here by very good marine architects!
There were weather warnings and the storm was very visible from the harbour and the ships nearby. With a storm coming and being visible why was nothing done,why were the passengers not warned, why did the boat sunk from the stern?
Agreed. The Captain of the boat that actually ended up rescuing the people in the raft said he kept watch on Bayesian while he was running his engine and making sure his boat was in the correct position for the storm, while making sure his boat didn't get to close to it. He said he looked out and wondered why the Bayesian wasn't doing any sort of preparation. It was also confirmed that the boat had been notified during the daylight hours of the approaching storm. The boat never got back with the person onshore who had tried to contact them about the upcoming storm.
Finally, a grown up and informed discussion of this disaster.
I've been getting incredibly angry trying to fight/counter the conspiracy theories and ignorance online using 90% of these very points. The hole in my argument being failing to consider/mention the static ballast element of the design. I feel silly for over looking it. But in my defence, I was typically typing angry at the idiocy others were insisting on sharing.
So glad I found this discussion because I was starting to feel like the only sane person in the room.
Great knowledge, maturity and appropriate caution on display here. Seriously, thank you.
Thank you for the nice compliment; we know exactly how you feel!
My sincerest condolences to the families of the loved-ones lost.
And thank you for the various explanations. Very helpful insight re.: the yacht being designed for motor-sailing rather than pure sailboat. Seems the mast height, retractable keel, low righting angle, air vents, and side stairwell design combination together is the flaw. So stated otherwise, it really was not a well engineered sailing ship, despite all the certifications and sign-offs by authorities. Add to this a seeming designer's disregard for how a yacht this size actually operates with crew and guests vs. what the "manual" states regarding how it should be operated, i.e perhaps not having the water-tight bulkhead doors closed. Designer Ron Holland has not commented yet and far as I have seen.
Good analysis, terrible way to go, might have been prolonged. There’s a video of the Maltese Falcon heeled with the rail in under sail; the main saloon opening is not far from the water on deck. I imagine that aft cockpit well would’ve been similar. Seems like a gross weak point not to isolate the interior better. The main saloon doors on Bayesian, as you say, had to be locked shut, which would trap the guests in. These Med super yachts owners need to demand more seaworthy, less stylish designs for their own piece of mind. Insisting on a ridiculous rig is a contributing factor.
ruclips.net/user/shortsDIBLRjvWFVM?si=Rzv_eUtbgXUa3tDM. As a super yacht heels over. The keel will weigh down the yacht to a point water will flood into the cabin. Imagine the “Falcon” in this video heeling over an extra 10 degrees till the sea enters the cabin…
The yachts stability booklet states that the keel must be down only when sailing or when over 60nm from shore neither of which it was doing
When in anchored outside the port .
Anyone who has experienced the sudden ferocity of a downdraft can attest to how unexpectedly catastrophic it can be.
I understand that every RUclipsr wants a piece of the pie when it comes to explaining why the sailing yacht Bayesian sank. However, it’s unfortunate that those who should be providing expert commentary don’t take the time to read the publicly available documents and instead resort to speculation.
There are already published statements from former captain Stephen Edwards of the Bayesian yacht, who explained that all yachts like Bayesian are delivered with a "Stability Information Book" approved by the yacht's flag state, which defines loading and operational limits. One section relates to the use of the movable keel and specifies when it must be lowered. In the case of this vessel, it was required to be lowered when using sails and/or when over 60 nautical miles offshore (regardless of whether sailing or only using engines). At all other times, it could remain in the raised position.
The stability book contains data regarding righting angles and the watertight integrity of the hull. Two important numbers are mentioned here: the Angle of Vanishing Stability (AVS) and the Downflooding Angle.
The Angle of Vanishing Stability is the angle of heel at which the vessel's righting moment reaches zero, meaning the vessel will not return to an upright position. The figures are 77 degrees with the keel raised and 88 degrees with the keel lowered.
However, the Downflooding Angle is much more critical in the scenario we're discussing. This is the angle of heel at which water will begin to enter the vessel (usually through engine room or accommodation ventilation ducts). Once this starts, the vessel is in serious trouble, as stability is quickly reduced or lost due to the flooding. The Downflooding Angle for the Bayesian was around 40-45 degrees.
Water spouts not rare in the Med this summer. The temp of the water 3 degrees above normal
nor are they dangerous.
Disappointing that you get a yacht designer buddy on and then don't focus on just the design issues.
Boats sink from taking on water not by heeling over, unless that heeling over results and it taking on water.
It should become obvious that the 45° angle for water ingress is the significant factor here, not the 75 to 80 something degree angle of vanishing stability. So the main thing your design a friend should be focusing on is how it would sink if a broadside on wind from the downdraft had the yacht healing from 45 to 70°. The obvious thing to focus on then is the cutaway side deck with the stairs and walkway down into the aft saloon. From their water can easily flow straight into the main saloon, and the entire insides as well unless the bulkhead doors are closed. Neither of you gave more than a fleeting acknowledgement of that sort of scenario. I would have expected your designer friend to have highlighted this. The closest he got was in talking about the vents down into the engine room. While that is valid, I would think that those vents would admit far less water down threw them compared to what would dump straight in via the aft saloon and the saloon doors. It's only a question of how much would go through via that pathway at different angles of heel.
Correct. Not only was the key aspect only fleetingly addressed but they took FOREVER to say very little.
The potential danger represented by the engine/ac openings is minuscule compared to the rear cockpit.
Agree.
@David
Agree.
Einstein, why don't you just post your viewpoint, and not disparage the other information gained here?
A very balanced assessment of a tragic event by a knowledgeable expert.Thank You!!
Our office (floor to ceiling windows) overlooked the port. One day at lunch time I was idling at the stenographer's desk and happened to look out. I saw a double waterspout. I called the few people still there to look out and see. And someone telephoned colleagues on other floors for them to look out too. Regretfully, this was pre-cellphone cameras. So no footage. I worked in that building for about 10 years. That was the first and last time I ever saw such a thing in real life.
thanks for explaining the function of the keel and also the ballast that the ship had. As far as the down draft. The question is what kind of radar that the weather services in the area had. A thunderstorm that strong didn't just form at that point. It moved into the area. A doppler weather radar could have at least provided some warning of about an hour or maybe less that such a storm was heading that way. It sounds like no boat could be designed to withstand such a down draft. So all that can be done is to get to safety when you know that such a severe thunderstorm in the area. If they had proper warning, they could have taken a boat tender to shore.
I worked on roro ferries for 20 years, and never saw a watertight door shut.
This was a great commentry. It does come back to the horrible way to die. I also appreciate that this was a freak event and significant weather evernt but there's plenty examples of technology "designing out" problems and yes I appreciate that having a yacht be knocked down is unlikely in any situation but particularly in that case and just as before titanic it was considered unnecessary to equip ships with enough lifeboats and post it we got SOLAS, in this case this yacht may have been "well designed" but it's pure hubris to assume that it was built as well as it could have been and that it wasn't possilbe to design out the factors that led to her sinking. My personal opinion is that a 56m yacht that's knocked down should be able to self right and recover itself wihout down flooding - if it flooded thorugh the HVAC - why isn't there a valve or baffle that prevents significant water flooding down what is an airvent. Why don't the watertight compartment doors autoclose and secure themsleves if they're left open for a period of time? Expecting a crew to follow protocols 100% is a clear failure point and aviation has appreciated that for decades. We will need to wait and see what comes out of the investigation but one thing is clear - whatever effort went into building and crewing this yacth it failled and the passengers and a member of crew died in a horrible way.
(Also wrt. yachts above a certain size having to be "sail assisted" - clearly not true - go and look at any museum of ship models - or any tallship race - there are sailing vessels that are far bigger than this yacht)
The boat was built to stay afloat with 2 of the 4 water tight compartments flooded. Apparently the water tight bulkhead doors were not closed... and no boat is designed to stay afloat when flooded, except a Boston Whaler.
2 of 6, not 2 of 4
This sailboat was an extreme design not built to maximize safety. Hubris is at play and now the yacht industry wants to play the blame game. "ITS TOO BAD"
I believe the former captain said that the down flooding angle was only40-45 degrees. That’s shocking for an ocean going vessel.
I've been in a downburst before. The unleashed power is off the scales.
These two commenters stated that the the storm had not been predicted but that is not what other videos state. The probability of severe weather was announced well in advance.
Absolutely it was. They knew. They were warned. Granted, they probably didn't know about the downburst situation, but they should have prepared the boat better.
I am very sad for the people who perished in this horrible event. Unimaginable tragedy.
This was probably a case of static analysis not accounting for dynamic factors. That mast will have swung down fast with a lot of angular momentum behind it. This is a question of "moment of inertia" that is second moment of mass. Proportional to length squared. Contrast with static analysis which only cares about the first moment of mass (proportional to length). I wonder to what extent the designers considered these sorts of dynamic scenarios.
I haven't heard anyone talk about the amount of actual water that's associated with a down burst / micro burst.... If it is hundreds of thousands(!) of gallons of water coming straight down in the center of the microburst, and the yacht just happened to be right there, the yacht would have literally been forced down underwater in a very short time.
I've seen it described as an enormous water balloon popped above you in a thunderstorm cloud. That's not just heavy rain.
If I was a billionaire I would have the hull filled with foam to make it virtually unsinkable. I would also make the boat as light as possible (carbon fiber) so as little as possible foam is needed (to not waste internal space). The boat should be survivable even if it is capsized with all the windows shattered in the middle of a winter storm.
He was wealthy enough to have had his own yacht built as such. Don't know why he bought that older boat. It wasn't even the best one in the series ( sister yachts).
THis guy is very detailed about the construction of the vessel and says that side ports/windows WERE NOT open; and the flooding of the vessel was due to A/C vents and other vents in the boat. THe information given previous to this analysis was social media buzz. This guy is an absolute genius!!!
It is also crucial to point out that a boat at anchor normally points towards the wind and would therefore not heel even if the wind is very strong. What causes this accident is not so much the wind force as such, but the unforeseeable sudden change of wind direction which lead to that the boat was hit by strong wind from the side even though it was at anchor.
I wonder if the owner had allowed or required any safety drills for passengers. The crew is required by regulation to drill. On private yachts, passenger drills are up to the owner. RIP passengers and crew who lost their lives.
I think that alcohol played a great role here, as with all sailing boats. I know of a cargo ship that went aground because everybody was drunk. This is quite common.
OMG, finally someone who knows what they are talking about. This architect Bill Prince is spot on compared to so many armchair experts on this terrible tragedy. The only other is esystem now Super Yacht News, gives good expert comments without putting blame on anyone.
I'm sure Bayesian will be raised then maybe able to do some testing to be able to find out why it sunk so quickly.
Thanks for watching and for the nice compliment.
Very interesting. OK the boat was a motor-sailor, but it had a fixed mast. To have an AVS of < 90 degrees and be considered seaworthy, seems astonishing to me.
and worse a downflooding- angle of 44°. Scandalous regulations .You define this yacht with its record- high mast a motorsailer and can undermine all principles of a good seamanship- ie. a seaworthy design.
The sliding doors could have had a double sided latch so that they could be opened from either side (like my garden gate!) which would have stopped them sliding open as the yacht tilted.
Excellent video. Much appreciate your effort and time.
Millions of Dollars for a yacht that raddles🥴Doors that open on their own🥴Tell us this boat was built sooo well it had to be the captains fault🥴
The Angle of Vanishing Stability for the Bayesian is reported to have been 77 degrees. If the wind knocked down the boat beyond that, then it would have sunk regardless. Without its sails up, a 77-degree list is highly unlikely.
The down-flooding angle was about 40 degrees. Crew statements indicate that the vessel reached at least this angle. Inflow through the engineering and HVAC vents would contribute to the flooding, but much more water could enter through the cockpit via the sliding doors. This is the failure point of the boat’s design.
The key takeaway, in my opinion, is that boats are only “unsinkable” in particularly ideal circumstances. Down flooding changes the circumstance enough that any vessel can sink in the worst conditions. Another is that not all sailing vessels are the same. Bayesian is or was a motor sailing vessel and not a typical sail powered boat. Which means that even when under sail, the engines are typical used. Like the sailboats most of us sailers operate, sailing while the motor is running is a way to increase cruising speed. Especially in light wind conditions. Where the sails “assist” in powering the boat. With a motor sailer, the opposite is typically the case. Where the sails are ancillary to the motors which do most of the work of moving the boat.
Most interesting is that Bayesian weighed over a million pounds, hundreds of thousands of pounds of ballast strategically positioned to create stability and improve its righting force. Countering the healing force of the sails is one thing. But, creating enough stability to counter such a huge mast to prevent a blowdown in high wind conditions is another requirement. Which should call to question the degree of stability of any sailing boat. The taller the mast, the more vulnerable the boat is to the potential of blowdown. Again, a concern for any sailing vessel.
As someone who went down to the sea in ships -- as a Naval Officer & occasional sailor, during my mis-spent youth -- I waited w/ baited breath through the entire video for a detailed analysis of/commentary on the size of the "upright penis" [w/ apologies to "The North Atlantic Squadron"]....
I don't recall it being addressed except in fleeting passing, if that !!!
I then waded through a couple hundred of the comments -- sorted in top order, below -- to see if anyone, armchair sailor & expert alike, picked up on the curious Italian regulatory 'permission' concerning operations w/i 60 nm from shore....
I was shocked to find that NONE did, before I gave up....
WTF does stability/safety of an ocean-going vessel have to do w/ distance offshore ???
Have none of them/you sailed w/i ~60 nm from shore, say in the notoriously shallow North Sea, or on a shallowing continental shelf, as in a passage parallel to the West Coast of North America, w/ a beam wind, sea & especially swell, coming all the way from the remnants of a Typhoon in Japan ???
And have none of them/you read 'the ancient Pilots' about recommended distance from shore when passage planning in such 'prevailing' circumstances ???
The Italian regulators obviously have not !!!
But in fairness, they might have been nostalgically thinking of "Mare Nostrum"....
If so, they should have limited the yacht's operation to the Med. -- not by some arbitrary & illogical 60 nm.
Thus endeth the sermon: 'Dominus Vobiscum'.
Your view is very thoughtful, I was wondering about furniture moving forcefully from one side to the other could cause damage to the windows (heavy item's made of metal) after all it was what 60 ft wide?
Another channel talked about how they don’t usually run safety drills with the passengers.
Thank you for explaining the reality of the cell phone as it relates the idea that a natural weather event seems now ubiquitous.
crew was NOT prepared
Eveyone should listen to Bill before jimping to all sorts of crazy conclusions. Thank you Bill ~ for sharing your knowledge and wise words. Axxx
It was 35 minutes not secpnds as first claimed .
You cant seal the internal water doors woth passengers below .
That why everyone should be on the top level .
It dragged anchor for 250 meters over 30 minutes
ON THE BOTTOM on its SIDE. How can this yacht - with its keel intact, and with a 75 meter mast - be sitting on a smooth bottom ON ITS SIDE in 50 meters of water? Even if it was blown beyond its ‘keel-up’ 90-degree departure angle on the surface, it would have come to rest on the bottom mast-up. Certainly not lying at 90 degrees on a smooth bottom. I know it’s a stretch, but is it possible that the trauma of being hit with catastrophic winds, somehow ‘broke’ the keel clean off the boat? With virtually no more ballast - certainly not when expressed as a significant percentage of the total boat weight - the boat COULD be lying at rest on its side. Please share your thoughts on how this vessel could come to rest ON ITS SIDE with its keel intact. Thank you.
The boat can’t sit on its bottom. It would naturally lean over when it hit the bottom
Apparently the microburst layed her on her starboard side. Anything not screwed down would have slid to that side making her heavier on that side.
Rescue divers said the mast was intact. If someone recovered this vessel, one could stand the mast up and it would be out of the water while the hull rests on the sea bed. This enormous mast will make the recovery of this vessel difficult unless the mast were 1st removed underwater.
Calculating conversation at last, this is superb.