Bayesian Interim Report

[flaming]

Perhaps, in your excitement at the possibility of making yourself look good by having a pop at someone, you had not noticed that I was replying to a particular point in a post by Bouba, who was wondering why a yacht's bow might not be held into the wind in a gust by its anchor chain

So may I , with all possible respect, suggest that you back off; as they say.

"Had the yacht been ketch or yawl rigged, she might have set a mizzen to help keep her head to wind."

Which yacht were you referring to, if not Bayesian? Bouba was quite clearly asking why this yacht, in particular, had not held head to wind. The first part of your reply is bang on the money, in that the bow will blow off. However, in the context of this incident, bringing a mizzen into the discussion is just weird.

 

[RunAgroundHard]

Interim report outright states it was raised (page 2, just under the diagram). Interesting that it calls it a centreboard there, keel elsewhere.

Yes, but also the report states that position of “centre board” will be “validated” upon wreck recovery. I wondered if there was any doubt over its position. Understand that validation is just, that, confirmation that it was raised.

 

[Poignard]

"Had the yacht been ketch or yawl rigged, she might have set a mizzen to help keep her head to wind."

Which yacht were you referring to, if not Bayesian? Bouba was quite clearly asking why this yacht, in particular, had not held head to wind. The first part of your reply is bang on the money, in that the bow will blow off. However, in the context of this incident, bringing a mizzen into the discussion is just weird.

What on earth are you blathering about? Are you not capable of understanding what is being said in a post, and why it is being said?

What is the matter with you? Have you nothing better to do than set out to cause trouble; and probably end up getting this thread locked?

 

[RunAgroundHard]

I get that...but 90 degrees to wind is a lot. I think the best scenario is the wind was a tornado that struck instantly at full force before the boat could move

Being knocked down at anchor in extreme winds, and turning 90 degrees can be expected. I don’t think, with or without keel down, that would be unusual in such extreme conditions and personally I have experienced such behaviour at anchor, numerous times over the years.

The high velocity of wind and force rate of increase responding to power law, centre of lateral resistance in water, all suggest that until the chain snubs tight, then bow will blow off faster than stern.

 

[flaming]

What on earth are you blathering about? Are you not capable of understanding what is being said in a post, and why it is being said?

What is the matter with you? Have you nothing better to do than set out to cause trouble; and probably end up getting this tread locked?

My dear fellow. You seem to have got rather wound up about a simple question - namely "what on earth are you talking about setting a mizzen about when the incident in question features 70 knots winds?"

It simply has absolutely zero relevance to the situation.

But hey ho.

 

[Poignard]

My dear fellow. You seem to have got rather wound up about a simple question - namely "what on earth are you talking about setting a mizzen about when the incident in question features 70 knots winds?"

It simply has absolutely zero relevance to the situation.

But hey ho.

Has the possiblity that a mizzen might be reefed, or scandalized, not occured to you?

 

[Bouba]

What on earth are you blathering about? Are you not capable of understanding what is being said in a post, and why it is being said?

What is the matter with you? Have you nothing better to do than set out to cause trouble; and probably end up getting this tread locked?

My dear fellow. You seem to have got rather wound up about a simple question - namely "what on earth are you talking about setting a mizzen about when the incident in question features 70 knots winds?"

It simply has absolutely zero relevance to the situation.

But hey ho.

Please don’t fight over me....there’s enough of me to share

 

[Poignard]

Please don’t fight over me....there’s enough of me to share

For your sake, I will try to suffer him gladly.

 

[flaming]

Has the possiblity that a mizzen might be reefed, or scandalized, not occured to you?

In 70 knot winds? No, not really. Hence my question to you "what sort of mizzen would you set in 70 knot winds?"

 

[Rappey]

"Parsifal 3" featured in "below decks". She looks very similar to Bayesian.
Parsifal 3 has a 60-63m main mast and 46m mizzen with a fixed keel. It never appeared to be happy when heeled more than 15 degrees under sail.

With possible downdraughts and water spouts affecting small areas of 50 to 100 metres could the Bayesian ever point into the wind ?
Keel down might have made no difference in what seem like extreme and rare circumstances.

 

[Poignard]

In 70 knot winds? No, not really. Hence my question to you "what sort of mizzen would you set in 70 knot winds?"

In a yawl or a ketch, as I said before, set a reefed or scandalized mizzen, or brail it in with a line passed around the leech and pulled in towards the gooseneck. Anything to increase windage aft.

In a sloop, I would do as I have done before in my Twister, hoist a storm jib up the backstay. That works well, although a V-riding sail would be better but I didn't have one.

The point is, rather than throw up my hands in despair and give up, I would do whatever I could save myself, my crew and my boat.

Now please tell us what you would do.

 

[dunedin]

In a yawl or a ketch, as I said before, set a reefed or scandalized mizzen, or brail it in with a line passed around the leech and pulled in towards the gooseneck. Anything to increase windage aft.

In a sloop, I would do as I have done before in my Twister, hoist a storm jib up the backstay. That works well, although a V-riding sail would be better but I didn't have one.

The point is, rather than throw up my hands in despair and give up, I would do whatever I could save myself, my crew and my boat.

Now please tell us what you would do.

Even if they had a mizzen mast, trying to hoist a reefed mizzen sail in the few seconds the storm hit is a complete non starter in a superyacht. Takes time and hydraulic power to unfurl and hoist huge sails. (And of the countless of superyacht ketches, never seen any at anchor with mizzen set.)

And cannot possibly "scandalise" a modern sail with in boom furling system.
These beasts are in a different world from a 30-50 footer.

PS. Once they got powered up, blasting the very powerful stern thrusters might have helped head into wind, but all happened too quickly

 

[flaming]

In a yawl or a ketch, as I said before, set a reefed or scandalized mizzen, or brail it in with a line passed around the leech and pulled in towards the gooseneck. Anything to increase windage aft.

In a sloop, I would do as I have done before in my Twister, hoist a storm jib up the backstay. That works well, although a V-riding sail would be better but I didn't have one.

The point is, rather than throw up my hands in despair and give up, I would do whatever I could save myself, my crew and my boat.

Now please tell us what you would do.

On my boat?

Nothing, wouldn't need to, it has an AVS of circa 120 degrees, and an awful lot less relative windage. It might be uncomfortable, but nobody is going to die. I certainly wouldn't mess about in hurricane force winds hanking a riding sail to the backstay. I cannot imagine for one second that this would do anything other than make the windage greater and increase the inevitable dragging of the anchor Possible in that place on that night I'd start the engine and Jettison the dragging anchor. But even then only if I thought I didn't have enough space.

On the Bayesian that night. Between 0355 when the storm was seen approaching by one of the deckhands, and 0406 when it capsized in 70 knots of wind..... Setting a riding sail would not be an option, obviously. Nor would it have occurred to the crew that it would be necessary, that there was a risk of being broadside to a wind that could capsize that boat. Lowering the keel probably also takes longer than that I would expect. As would weighing anchor. So at that point - was there anything that the crew could have done, even blessed with 20:20 hindsight? Was, in effect, the accident already inevitable once the storm hit with the keel up? The interim report certainly reads that way.

 

[doug748]

It is good that the report collates various weather forecasts that night - and there is not much to cause concern to a family crewed AWB, nevermind a 56m superyacht in sheltered waters.

There were some hysterical accusations - mainly from the builders representatives iirc - regarding crew negligence in not having all pax mustered on deck in full A/S gear due to the 'forecast storm'.

I'm glad this aspect of the matter has been put to bed.

Very true.

My money is on this coming down to limited stability, poor down flooding angles and the fact that nobody seriously considered this size of boat to be a capsize risk at anchor. I think a lot of folk would have rumbled this at the outset.

As this will lead to a lot of red faces in certain circles expect a good deal of sniping from the barricades.

.

 

[westernman]

In strong winds with the anchor starting to drag, I would run the engine to reduce the load and stop it dragging. I would not expect to need more than about 1/3 throttle.

 

[Laser310]

In strong winds with the anchor starting to drag, I would run the engine to reduce the load and stop it dragging. I would not expect to need more than about 1/3 throttle.

and that's what they were preparing to do.., but unfortunately they were just a little too late - maybe only by seconds...

 

[Rappey]

In strong winds with the anchor starting to drag, I would run the engine to reduce the load and stop it dragging

The Sir robert baden powel had engine power but still dragged anchor over 400m. I wonder is she heeled at all or avoided whatever pushed bayesian over

 

[billskip]

Yeah, that's the bit that really caught my eye, and one that surely plays into how the crew reacted to the threat.

Also, the boat never seems to have got head to wind, despite (or because?) dragging its anchor. I'd love to know what that's about. Bit rum if it couldn't sit head-to, given the danger of wind on the beam.

I thought it was a tornado.....how fast does a boat have to spin to remain head to wind?

 

[Poignard]

On my boat?

Nothing, wouldn't need to, it has an AVS of circa 120 degrees, and an awful lot less relative windage. It might be uncomfortable, but nobody is going to die. I certainly wouldn't mess about in hurricane force winds hanking a riding sail to the backstay. I cannot imagine for one second that this would do anything other than make the windage greater and increase the inevitable dragging of the anchor Possible in that place on that night I'd start the engine and Jettison the dragging anchor. But even then only if I thought I didn't have enough space.

On the Bayesian that night. Between 0355 when the storm was seen approaching by one of the deckhands, and 0406 when it capsized in 70 knots of wind..... Setting a riding sail would not be an option, obviously. Nor would it have occurred to the crew that it would be necessary, that there was a risk of being broadside to a wind that could capsize that boat. Lowering the keel probably also takes longer than that I would expect. As would weighing anchor. So at that point - was there anything that the crew could have done, even blessed with 20:20 hindsight? Was, in effect, the accident already inevitable once the storm hit with the keel up? The interim report certainly reads that way.

For the record.

Bouba wanted to know why an anchored yacht’s head could not be kept pointing into the wind if she was at anchor.

I explained the effect of windage on the bow.

I then went on to say that if, repeat if, the sunken yacht had been a yawl or mizzen then a mizzen sail set might, repeat might, have helped.

Next minute, I have some clown telling me that what I said is ‘stupid’.

A bit irritating, to say the least.

 

[bobgarrett]

An AVS of 70degrees seems very poor with the keel/centreboard up. However I recall being told an Ovni was well placed in a storm with it's centreboard up because instead of heeling more it would slip sideways. Is that right? But maybe the Bayesian would not slip sideways because of the anchor.