Sinking superyacht

[CarpeDiem 510]

10 minutes ago, Black Panther said:

45 degrees?

It would seem that way. 

 

[Black Panther 1,691]

Got to admit I'm gobsmacked by that. Can't count the times I've been past 45 degrees. 

[aardvarkash10 1,065]

bloody hell.  Or heel.

We've had SO beyond 45 degrees from time to time.  Don't even get wet in the cockpit.  Well, not from seawater.

[Psyche 726]

55 minutes ago, Black Panther said:

45 degrees?

its not a yacht as we know them, 200 tons of lead ballast!

 

Quote

How the vessel came to be taken outside her operation limits is what the investigators will need to determine, which I’m sure they will.

any idea what this means?

[funlovincriminal 189]

32 minutes ago, aardvarkash10 said:

bloody hell.  Or heel.

We've had SO beyond 45 degrees from time to time.  Don't even get wet in the cockpit.  Well, not from seawater.

Had my Ross 830 at over 90 degrees with me in a bosuns chair at the top of the rig, and the retractable bulb keel up against the hull. Mast tip hit the water, had a cordless drill, phone, car keys etc on cockpit seat and didn't get one drop of water over the coamings. I remember hanging out in the river strapped to top of the mast, looking at the boat and thinking "So that's why it's that shape" 

[K4309 353]

6 minutes ago, Psyche said:

 

any idea what this means?

I think this is going to be key to the skipper not being charged / getting off.

From that article posted above by the previous skipper, it sounds like they have a stability manual for all scenario's, like exactly what sails to have up in what wind strength. I assume much like how most of us know when we need to reef the main, and that we can use the number 1 jib up to X knots, the blade jib up to Y knots, and that you can't (or at least shouldn't) put the A2 up if its blowing dogs of chains, etc.

Being a 460 tonne yacht, instead of just letting the crew see what she can handle, the document all of this using the design data and possibly dynamic modelling, CFD analysis, or at least the sailmaker software for sail design, healing forces and structural function of the rig.

I'll bet a good bottle of whiskey though that all the analysis and the stability / operating manual did not consider what happens in the freak event of a violent downburst or waterspout.

In short, the crew have a manual / standard operating procedure and probably aren't allowed to make the boat heel more than X degrees while sailing. IF they did, that would be taking outside the operating limits.

Given they were an anchor, I can't see how they could have taken her outside of the operating limits.

In this way, the designers / builders can make a boat with a very low AVS and an even lower downflooding angle. To make that safe, they write a manual that says the crew can't lean the boat over more than a little bit. In normal operation the crew can meet those requirements. In violent downdraft / water spout, everything is completely beyond the crew's control, boat capsizes and sinks.

[Bad Kitty 284]

15 hours ago, K4309 said:

I think the stability requirements are the classification society requirements, not the requirements as per the laws of physics to keep it afloat.

I know it is only a song, but it does remind me of the esteemed and highly regarded data by one Mr Frederick Dagg, that the boat met the minimum crewing requirements, of one, and had very stringent design and materials requirements. No cardboard. No cardboard derivatives...

 

Jokes aside, the only plausible explanation I can think of for a boat like that sinking in a water spout is that it was laid flat, exceeded it's AVS and capsized. We do know (without reference to FB or MSM experts) that it had the tallest mast in the world, the mast was alloy (so not carbon, and comparatively heavy), and that of the 12 or 15 sister ships, the rest are all ketches, and therefore have lower C of G of the rig.

We know it is entirely plausible a water spout or down burst can lay a yacht like that over flat, cause we've seen it on CCTV from Westhaven.

The AVS data appears to come from the Chairman of Italian Sea Group. So it all adds up. The only inconguity in all of that is that the Chairman of Italian Sea Group seems to think an AVS of 73 degs is good, where as it couldn't even get Cat 5 in NZ, hence why the yacht his company built is 50m under water and we are all talking about it.

 

Superyachts use a different system for calculating stability, the boat would have had a full stability book, like any ship. It’s not a clear comparison to say “it wouldn’t meet Cat 3”

[Psyche 726]

1 hour ago, funlovincriminal said:

Had my Ross 830 at over 90 degrees with me in a bosuns chair at the top of the rig, and the retractable bulb keel up against the hull. Mast tip hit the water, had a cordless drill, phone, car keys etc on cockpit seat and didn't get one drop of water over the coamings. I remember hanging out in the river strapped to top of the mast, looking at the boat and thinking "So that's why it's that shape" 

lol! I'm imagining the boat righting and sending you into low orbit

[Addem 120]

44 minutes ago, Psyche said:

lol! I'm imagining the boat righting and sending you into low orbit

exactly what I was thinking. "Don't dare touch that halyard!

[K4309 353]

2 hours ago, Bad Kitty said:

Superyachts use a different system for calculating stability, the boat would have had a full stability book, like any ship. It’s not a clear comparison to say “it wouldn’t meet Cat 3”

No, it's not a clear comparison, you are correct.

BUT, this Superyacht (with the tallest mast in the world) couldn't dip it's mast head in the water and recover, where as any boat in NZ that meets Cat 5 (and Cat 3) can.

It appears that the result of that is the boat is 50m under water, its wealthy owner and his daughter are dead, along with several others. Noting of course that what I am saying is completely uneducated assumptions on the interweb.

I guess you could say its just like any cruise ship, or other large commercial ship. They can't roll to 90 degs and recover either. The only difference being no other commercial type of ship has a 75m tall lever that can easily make that vessel roll to 90 degrees. (which, as an aside, would appear to be why every vessel that does have a lever on top has enough lead underneath so it can roll to 90 degrees and recover).

[waikiore 444]

You have to take these internet talk show people with a grain of salt, that yacht report guy last week showed the security footage from our Westhaven event and said that there was someone inside the cat the flew backwards over the Marina !

 

[B00B00 317]

Just to clarify its no where near the tallest mast in the world.  It's the second tallest alloy mast in the world. There are many masts that are much taller. Maybe when it was launched it was close but not these days. 

The yacht A for example has 3 masts with one of them being 100m which is 28m taller that Bayesian. 

Aquijo has 2 90m masts

M5 89m

Bayesian 72m. Tall mast but way off the tallest and in fact she's not a huge boat in the superyacht world. 

I'm no stranger to these big boats, have delivered and raced them all round the world but I am truly staggered at the low AVS on this boat. But I guess it's pretty standard on these big boats? 

[funlovincriminal 189]

4 hours ago, Psyche said:

lol! I'm imagining the boat righting and sending you into low orbit

Funnily enough the first thing I did was start to unclip the chair from the halyard, but I came to my senses.

A slow letting out of the halyard was duly undertaken - after a delay from my mate to snap a few incriminating photos. 😁

When it happened I felt the boat stiffen as it got to the edge of its hull stability, then the downward arc of myself and the top of the mast seemed to accelerate once past the point of no return. 

[waikiore 444]

Yes I thought M5 was taller , by another Kiwi naval architect. 

[waikiore 444]

Sorry I mean the same Architect, they definitely have a stability book that they live by.

[Cheap Transport 74]

On 28/08/2024 at 3:48 PM, funlovincriminal said:

Funnily enough the first thing I did was start to unclip the chair from the halyard, but I came to my senses.

A slow letting out of the halyard was duly undertaken - after a delay from my mate to snap a few incriminating photos. 😁

When it happened I felt the boat stiffen as it got to the edge of its hull stability, then the downward arc of myself and the top of the mast seemed to accelerate once past the point of no return. 

This is one of my favourite memories on Shapey... and yes, it was 100% worth getting photos😆

I still remember thinking, or maybe even saying out loud "every man for himself! " as she started going over and I scurried over the lifelines onto the side of the hull... not a drop of water on me....

Good times 🤣🤣🤣

[raz88 97]

On 28/08/2024 at 2:57 PM, B00B00 said:

Just to clarify its no where near the tallest mast in the world.  It's the second tallest alloy mast in the world. There are many masts that are much taller. Maybe when it was launched it was close but not these days. 

The yacht A for example has 3 masts with one of them being 100m which is 28m taller that Bayesian. 

Aquijo has 2 90m masts

M5 89m

Bayesian 72m. Tall mast but way off the tallest and in fact she's not a huge boat in the superyacht world. 

 Weight difference of the massive tin rig is surely like strapping a Rouge to the top of one of those carbon ones? Same as Nigels situation above but with no halyard to ease out...