Bayesian Interim Report

Why did the Bayesian sink and Sir Robert Baden Powell remain largely unaffected .... this is footage of a relatively small waterspout (common in the Med, I've seen a few) hitting an anchored AWB and laying it on its side. It is very localised and the nearby boats don't get touched. This one pops up again with just canvass damage - still would not want to be on board though.

 
Baggywrinkle said:
Why did the Bayesian sink and Sir Robert Baden Powell remain largely unaffected .... this is footage of a relatively small waterspout (common in the Med, I've seen a few) hitting an anchored AWB and laying it on its side. It is very localised and the nearby boats don't get touched. This one pops up again with just canvass damage - still would not want to be on board though.
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I remain convinced that the main (only?) problem is likely to have been the catastrophic entry of masses of water through the openings on the deck, i.e. here:bayesian.jpg
 
capnsensible said:
Isn't there some little ditty about assuming making you look an ass, or something?
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Often spouted by the same sort of people who claim there's "no 'I' in 'team'" and then take credit for all your work.

For some reason they're rarely amused when you point out there's plenty of four-letter words with 'u' in them...
 
Bouba said:
For a superyacht that is not a lot of openings
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Anything near the waterline can be sealed in normal use, no doubt the engine and air con vents are well out of danger. I'll bet the downflood angle of that vessel is over 40 degrees and it isn't even intended to heel in normal use.

The class of motor superyachts with limited sailing ability seem to have vulnerabilities that don't exist in true sailing boats and don't exist in true motor yachts. We've seen a plastic AWB in the video above shrug off a massive downdraft, equaly the vessel in the photo doesn't have a massive mast for the wind to lever.
 
First of all, I don’t think down flooding is a primary issue here, it is simply that the vessel was knocked down beyond its (according to the approved certificate) AVS. In a relatively calm sea, the chance of her returning to an even keel was not an (static) engineering possibility. At this point (90 degrees in LESS than 15s) any large vessel is susceptible to water entering the hull, simply because centre line only openings are not practical and don’t on their own provide suitable escape routes in the event of sinking/fire

The question of downflooding was only mentioned in passing in the report, presumably due to a lack of confirmed evidence. Lots of claims regarding the angle of down flooding, rate of flooding etc. Where have these claims come from?. we do know the DH on watch went to secure hatches due to the rain etc. Therefore there can be no effective discussion on DF until further evidence comes to light. Moreover, once a vessel gets to situation where pax and crew start to abandon ship, hatches that were closed might have subsequently be opened. No amount of safety brief is going to prevent people doing unwise things unless it is backed up practical training
 
boomerangben said:
At this point (90 degrees in LESS than 15s) any large vessel is susceptible to water entering the hull
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Most large vessels are Mobos and not likely to a) Heel close to 40 in normal use. b) Have a massive pole on top with huge leverage.

This vessel seems to have suffered a knockdown at anchor. There's a least one video of a vessel of this "genre" knocked down in a Marina. You just don't see Cruise Ships doing that, so they can get away with openings off the centre line and because they have more space they probably find it easier to fit intakes on the centreline. These semi-sailing vessels have the double whammy that their intakes can't easily go on the centre line and are also far more like to submerge in normal use.
 
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billskip said:
I think years ago they designed a submarine aircraft carrier.....
I think it sunk because the watertight doors were a problem....
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British_Submarine_HMS_M2,_2.jpg

Not very successful and from a submariners point of view, lethal. Post WW2 and prior to Polaris, the Americans had a small class of submarines with a missile hanger. Results missiles with instant sunshine warheads. Always looked a bit iffy to me.
 
Mark-1 said:
Most large vessels are Mobos and not likely to a) Heel close to 40 in normal use. b) Have a massive pole on top with huge leverage.

This vessel seems to have suffered a knockdown at anchor. There's a least one video of a vessel of this "genre" knocked down in a Marina. You just don't see Cruise Ships doing that, so they can get away with openings off the centre line and because they have more space they probably find it easier to fit intakes on the centreline. These semi-sailing vessels have the double whammy that their intakes can't easily go on the centre line and are also far more like to submerge in normal use.
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I’ve missed something here, where do you get 40deg from for the angle of down flooding?
 
boomerangben said:
I’ve missed something here, where do you get 40deg from for the angle of down flooding?
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Exclusive: Loose Cannon Obtains Official Bayesian Stability Document

Former Bayesian captain offers insight

According to Captain Stephen Edwards, who posted his analysis on LinkedIn.
“The Downflooding Angle is much more important though in the scenario we are talking about.”
“This is the angle of heel at which water will start to enter the vessel (usually through engine room or accommodation ventilation ducts)... once this starts the vessels is in serious trouble as stability is quickly reduced or lost due to the flooding.”
“The downflooding angle for Bayesian was around 40-45 degrees... much less than the AVS. So, unless the vent dampers are closed (which with HVAC systems and generator running they would NOT be as they need to be open for that), the vessel will start to flood rapidly
 
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