Published
From the report:
The Met Office study of satellite imagery indicated that the mesocyclonic storm front was demonstrating the properties of a significant supercell with associated downdrafts and possible near-surface winds in excess of 100 miles per hour (87kts). The study concluded that a mesocyclonic storm was highly likely with an associated supercell being probable. It also concluded that tornadic waterspouts and downdrafts were possible where local winds could reach extreme hurricane force well in excess of 64kts. Such tornadic waterspout features could be of very limited horizontal extent (50m to 100m wide)
The investigation has also established that, in the assumed loss condition, wind speeds in excess of 63.4kts on the beam were sufficient to knock Bayesian over. It is possible that Bayesian was similarly vulnerable to winds of less than 63.4kts.
These vulnerabilities (when in the motoring condition with sails lowered, the centreboard raised and 10% consumables on board) were not identified in the stability information book carried on board. Consequently, these vulnerabilities were also unknown to either the owner or the crew of Bayesian.
The Met Office study and local observations indicated the probable transient presence of hurricane force winds well in excess of 64kts at the time of the accident. These winds were sufficient to knock Bayesian beyond its angle of vanishing stability
2 Likes
Actions to evacuate (guest & crew) still a bit patchy, awaiting “new evidence may become available”.
" …instruction for the rest of the crew to be woken" but any(?) instruction to guests simply not mentioned, nor any “general alarm muster”.
“C/O had found the owner and pushed them through the cascading water up to the skipper on the flying bridge” is stated, but no mention of the other guests (who died) or of owner returning to cabin.
G1-4 will have only told their part, obviously.
This is probably where the Italian process will focus -
The part I was hoping to find was a general explanation of where the water was flooding in from. What doors etc. I guess we’ll have to wait for that.
2 Likes
A knockdown would have put the vents for the engine room under.
From the report:
At around 0400, DH2 ran below and woke the skipper. Together they returned to the flying bridge. At about the same time, the chief engineer (C/E) woke up. Having experienced bad weather at anchor before, the C/E got up and walked to the engine control room to prepare the vessel for manoeuvring. After making sure that all three generators were running, the C/E went to the wheelhouse to start the steering pumps and hydraulic pumps for the controllable pitch propeller.
1 Like
1 Like
This explanation of the disaster describes the cause of the sinking as pretty simple: doors were left open on deck (video minutes 10:29 and 11:25). The vessel heeled 90 degrees and the downflooding came through the doors.
Of course, that doesn’t mean that addtional flooding didn’t happen elsewhere, such as ER vents.
Doors, it seems, are the Achilles heel of any yacht.
4 Likes
Yes, you’re right. I missed this in the report:
There was no indication of flooding inside Bayesian until water came in over the starboard rails and, within seconds, entered the internal spaces down the stairwells.
I wonder how many vessels, at 90° on their side, would not downflood once you need to open doors to get out?
1 Like
After the disaster we saw several videos of other sailboats knocked down by wind gusts yet righting themselves. Big sail boats are designed to survive knockdowns. They are a common occurrence in racing especially. Nothing unusual.
From the first I wondered why a big sailboat like this couldn’t survive a simple knockdown. I think the answer is simple but still puzzling.
To survive a knockdown you need all the hatches closed. SOP at sea on a racing sailboat in heavy weather.
But it seems this one had several open. Not strange given she was at anchor. The puzzling part to me was why she would have hatches open in summer when the a/c was presumably on. Maybe that’s normal for the system.
After this incident I would hope that professional yacht crews of vessels like this keep it in mind, and make sure a minimum of hatches are kept open while at anchor , or drill so that if the wind suddenly rises the first thing to do would be to quickly secure all topside hatches, then tell passengers not to panic and open them.
2 Likes
At the time the C/O had instructed the bos’n and DH1 to go on deck to secure loose items and the Captain and chief were preparing to maneuver so as to deal with dragging anchor. Seems unlikely at that point they would have expected a knockdown.
The yacht starting dragging at 0357, captain was called at around 0400. Six minutes later:
As the skipper prepared to manoeuvre Bayesian up into the wind from their position on the flying bridge, the wind suddenly increased to more than 70kts. The awning over the flying bridge ripped from port to starboard. At 0406, Bayesian violently heeled over to 90° to starboard, taking less than 15 seconds to do so
2 Likes
Surely the engine air intake(?s), vulnerable at (?) 40-50° heel, played a role as they were presumably open if the generators were running to power Aircon etc?
As was pointed out earlier, almost certainly air intakes were flooding by the time they got towards 90°.
"From the liferaft, the CS saw the bows of Bayesian rise" and Baden Powell “skipper briefly saw a dark triangular shape descending” suggest going down by the stern - i.e. machinery spaces aft.
This is a screenshot from Super Yacht News: Bayesian Captain Gets Lawyer, Refuses to Talk to Prosecutors - Shows the location of the E/R air vent:
The photo also shows the recess in the deck for the entryway into the main cabin.
From the same video:
2 Likes
The vessel went down to stb
yes the vent but its mca stability book says 2 watertight compartments flooded and it floats.
Need to see where the water came in when it was at 90 degrees at a huge rate.
Looking at the drawings no stb stairs on the deck and its buoyancy on its ear still had the centreline well about the water line as the last photos at night show the mast above the waterline when at 90 degrees.
I was ( on a megaycht ) not far from a 90’ yacht in similar condition but middle of the day, top of mast in the water so boat past 90, was there for a while but popped back up, clearly watertight at that angle and centreline well out of the water hence the main doors.
Not making any point or claim about the flooding, just posting screenshots that show the location of the vents. Given what’s in the report it’s likely not all that relevant in this case.
There was no indication of flooding inside Bayesian until water came in over the starboard rails and, within seconds, entered the internal spaces down the stairwells.
Relevant to the overall design philosophy of the vessel.
2 Likes
Perhaps the Captain should of taken it out past the environment to avoid any wind?
All yachts are still waterproof with the rail in the water as the drawing shows.
Is the yacht still the design thats was in its stability book?