"Bayesian" s/y sinks in Palermo

[Lower Limit 1909]

• Tornado / Water Spout can exert higly localised extreme forces. No point in comparing the outcome of this vessel to one 100 metres away.
• 72.3 metre mast is the world's tallest according to manufacturers Perini Navi. An extraordinary amount of lateral leverage.
• All eyewitness reports indicate it went over with the mast intact. Lay flat - then sank. Once flat - sinking rapidly seems innevitable on a vessel of that design - closing doors and windows won't make the slightest bit of diference once the suprstructure gets partially submerged.
• Did it lay flat because it took on water or did it take on water because it lay flat? The MAIB will I'm sure find out, and maybe a bit of both.
• It had a lifting keel. There is no reason to believe it wasn't lowered. It will already be obvious to the diving team whether it was or wasn't so expect this info to emerge quickly as it's an obvious 'game changer' in the unlikely event it wasn't (when combined with the mast height).
• Most boats with masts are designed (properly configured) to have the ability to stay afloat when knocked down. Scaling up to have a 'motor yacht' superstructure with a mast on top (especially when rarely or ever used) may turn out to be style over function that comes with risks.
• RIP those lost. Hopefully the lessons- whetever they are - will help prevent future losses.
  

 

[Mark-1]

My guess is that lightning struck the mast in addition to the boat being tilted on it's side. The voltage blew a hole through the bottom of the boat. The boat settled o. Her bottom the puncture on her bottom cannot be seen.

This guess is based on no fact, science, or evidence.

If it was knocked flat it wouldn't need lightening to explain the sinking.

Of course, eye witnesses get it wrong all the time, so maybe it wasn't really knocked flat, but as things stand it seems it was.

Regarding the conspiracy theories there is no way this accident was an assassination. How on earth would you fake it and who would do the faking?

 

[lustyd]

Most boats with masts are designed (properly configured) to have the ability to stay afloat when knocked down. Scaling up to have a 'motor yacht' superstructure with a mast on top (especially when rarely or ever used) may turn out to be style over function that comes with risks.

The coachroof of a yacht increases AVS as long as it’s watertight. If the superstructure here had been watertight it would have helped right the boat once the wind was gone. Clearly that didn’t happen for some reason we don’t yet know.

 

[Major_Clanger]

Just left Cagliari and heading for Palermo. We had a quiet drink to those lost/missing last night.

I'm not interested in speculation, and believe perhaps the biggest lesson we can learn from this is to remember that we are all fallible and puny where nature is involved. Obviously we shouldn't court disaster, but very occasionally there's nothing sensible we can do to avoid it.

 

[onesea]

Another eye witness report here:

Sicily yacht survivor - 'for two seconds I lost my baby in the sea' - BBC News

 

[Forum Admin Team]

This thread could be removed (as a news story/current affairs), and it may well be if contributors do not stay on the strict topic of the boat and its fate, and post appropriately.

Please, no personal histories of those on board, conspiracies, speculation without known facts (unsupported), etc.

 

[chrishscorp]

All pretty horrendous with the loss of life. first mate and I are huge fans of 'below decks Mediterranean' on E4, these boats are all very grand but you can see when they hit bad weather furniture just moves around and the windows are often big picture windows and sliding patio doors and so on, how they will stand up to a knock down is something the MAIB will be able to find out. The aircon will have been on I am sure but how many had their cabin portholes open with the potential for down flooding.

Back in the 90s I saw 3 waterspouts all at the same time just off the coast of Barbati in Corfu, they were mesmerising to watch, (this was during Easter time) the staff and my building team were all on the verge of hiding in the hotels windowless basement as they got too within about 2 Km of us then veered off and headed towards Albania.

 

[RunAgroundHard]

Down flooding at extreme angles and the speed of sinking as reported, suggests huge and rapid influx of water. I wonder if relatively small cabin windows could do that. The boat has large openings at multiple levels. The garage doors at the stern or side may have been open which itself is a huge space, likely with a water tight bulkhead and doors

I know, from my line of work, that spaces like this, could be open at anchor and doors between spaces may be left open, usually to aid air flow because cool air flow can take a preferential path to the detriment of other areas. Behind the garage will be machinery spaces and while power generation will be in a contained space for firefighting, purposes, other spaces may have doors open, that would normally be closed at sea.

In my current role, keeping water tight doors closed, and fire doors closed, is a daily chore. Heat builds up fast and folks open doors to aid air flow.

We shall see what the investigation uncovers.

 

[Barnacle Bill]

Sounds like the most likely scenario was that the keel was retracted, massively reducing the righting force when heeled over - then strong wind heeled the boat over, and the weight of the mast plus the wind force got the yacht on its side. Massive water flow down the companionway(s) (almost certainly not secured - the event was not expected in calm seas at anchor) caused sudden catastrophic flooding. It will be interesting to see the accident report, but anybody with a retractable keel would be wise to note the effect of retracting it on the yacht's stability.

 

[Douglas]

Truly shocking, and my profound sympathies to the survivors and their families, and the families of those who have been lost. Those of us who have anything to do with newcomers to sailing should re-assure them that this is an incredibly rare, almost freak occurrence. Boats a fraction of this size have sailed round the world including the Southern Ocean (Chichester, Rose, Knox-Johnston, Blyth), not to mention all the amateur round the world challenges in recent years. Admittedly it's not solely down to size, but also the design and who's sailing it.

I agree with those who say that a huge yacht like this, supposedly at anchor with no sails set, would be unlikely to founder so quickly, or at all. I find myself wondering if "dangerous lightning", apparently a feature of such waterspouts, struck the very tall aluminium mast and perhaps shattered it. Depending how it was stepped, the charge might have travelled through to the hull and blown a hole in it leading to sudden catastrophic water ingress. Or, the broken pieces of the mast, which would still be attached to the yacht via rigging and so forth, may have knocked a hole in the hull.

I'd again agree with those who say that the MAIB investigation underway will be professional and thorough, and should in time yield the answer to what caused this terrible catastrophe.

Originally written before I saw Seadawg33's post

 

[flaming]

Down flooding at extreme angles and the speed of sinking as reported, suggests huge and rapid influx of water. I wonder if relatively small cabin windows could do that. The boat has large openings at multiple levels. The garage doors at the stern or side may have been open which itself is a huge space, likely with a water tight bulkhead and doors

I know, from my line of work, that spaces like this, could be open at anchor and doors between spaces may be left open, usually to aid air flow because cool air flow can take a preferential path to the detriment of other areas. Behind the garage will be machinery spaces and while power generation will be in a contained space for firefighting, purposes, other spaces may have doors open, that would normally be closed at sea.

In my current role, keeping water tight doors closed, and fire doors closed, is a daily chore. Heat builds up fast and folks open doors to aid air flow.

We shall see what the investigation uncovers.

The pic of the yacht sailing shows what looks like a forward cockpit area lower down. Any door open in that area would admit a lot of water very quickly I would think.

 

[steveeasy]

My sailboat is approx 6 tonnes. The lead keel is 30% of that and gives it a low centre of gravity and not to dissimilar to other boats of its era. More modern boats I’d assume have a slightly higher COG but offset by better designed keel shape.
The boat in question was arround 500 tonnes. HeAven knows the weight of the keel but if it was up at the time I’d wonder if this was a significant factor in it going over and not recovering from it.
I begs the question what impact the storm or waterspout would have had on a big ocean liner with such high COG.
Steveeasy

 

[capnsensible]

Your confidence in the MAIB is a little greater than mine. They will likely identify significant contributing factors - that will help interested parties know what went wrong and how it might be mitigated. However their ability to translate those into realistic recommendations/actions that actually stop future deaths is questionable. Eg, if she flooded due to open doors/hatches/windows the easy solution is obvious… but is it realistic at anchor in conditions where nobody is expecting to get knocked down? If the keel was retracted the advice is obvious, but is it realistic to restrict the range of anchorages or even safer to do so?

I suspect if any of us were told a vessel of this size was knocked down under bare poles in the med we would be a bit surprised, at anchor even more so. To be told it resulted in a total loss of the ship within seconds would be more surprising again. And to be told there was a tall ship very nearby that came through the same weather pretty much unscathed would be even more unbelievable. But I don’t recall the MAIB ever saying “this mostly seems like incredibly bad luck” OR “with hindsight these factors caused it but it’s unlikely in similar circumstances that any reasonable skipper/owner would have for seen it and acted differently”.

Do the MCA prosecute British vessels when in someone else’s physical jurisdiction? I was expecting that any wrongdoing (and there may well be nothing criminal) would be pursued by the Italians?

Perhaps you haven't read any of their reports. Their investigators are reportedly at the scene now.

The Marine Enforcement Unit will look at any incident involving Brits or Brit flagged vessels. I'm not guessing, one of their staff told me this when I was interviewed by them gathering evidence about a friend of mine. Telling them they were talking gonads did not endear me to them.

 

[E39mad]

72.3 metre mast is the world's tallest according to manufacturers Perini Navi. An extraordinary amount of lateral leverage.

Maybe when originally built but M5 has a larger mast.

 

[stu9000]

Makes no sense. Even if mast lost,.knocked down.and hatches open. There are watertight bulkheads and built in buoyancy.. Ali Hull and 56m! No.way should she have gone down like that. There is a bug piece of the.puzzle missing.

 

[Chiara’s slave]

Makes no sense. Even if mast lost,.knocked down.and hatches open. There are watertight bulkheads and built in buoyancy.. Ali Hull and 56m! No.way should she have gone down like that. There is a bug piece of the.puzzle missing.

You would very much think that. Being knocked down is an unlikely, but not impossible scenario. Just how much wind would be needed to lay a boat this size flat? And even flat, as you say, to flood enough to sink in such a short time. You’d expect watertight collision bulkheads fore and aft, and other fixed buoyancy. Enough to float her completely flooded? I don’t know.

 

[Zing]

It’s extremely improbable the keel was down. It’s not a dinghy and it’s not raised in large yachts like this to give better performance down wind. It’s lowered at all times at sea to give the yacht its required righting moment. The keel is only generally raised entering harbour. At anchor the keel would also be lowered to minimise rolling, all the more likely to be done in a deep anchorage such as where she was and where there was no risk of grounding.

I wonder what class rules require for this size of big yacht regarding stability and downflooding protection. It’s much less on large commercial yachts than on small sailing yachts because the probability of being rolled far is so much lower. I suspect the probability of this event was not built into the rules.

 

[flaming]

Makes no sense. Even if mast lost,.knocked down.and hatches open. There are watertight bulkheads and built in buoyancy.. Ali Hull and 56m! No.way should she have gone down like that. There is a bug piece of the.puzzle missing.

Watertight bulkheads have doors that are probably not secured when at anchor.

 

[flaming]

It’s extremely improbable the keel was down. It’s not a dinghy and it’s not raised in large yachts like this to give better performance down wind. It’s lowered at all times at sea to give the yacht its required righting moment. The keel is only generally raised entering harbour. At anchor the keel would also be lowered to minimise rolling, all the more likely to be done in a deep anchorage such as where she was and where there was no risk of grounding.

I wonder what class rules require for this size of big yacht regarding stability and downflooding protection. It’s much less on large commercial yachts than on small sailing yachts because the probability of being rolled far is so much lower. I suspect the probability of this event was not built into the rules.

As I understand it she'd only come out of the harbour (where she would definitely have needed the keel to be raised) that evening. If they were expecting a calm night and then to go back into the port the following day, would they bother lowering it? I doubt it's a quick procedure.

 

[Mark-1]

Makes no sense. Even if mast lost,.knocked down.and hatches open. There are watertight bulkheads and built in buoyancy.. Ali Hull and 56m! No.way should she have gone down like that. There is a bug piece of the.puzzle missing.

If everything was open the watertightness is largely irrelevant.