yacht sunk in med

Above we see the image of a radar capturing the collapse of the water, a sum of wind and water

water that can flies horizontally

Downburst



(In fact, without these exaggerated cases in autumn in Ireland or Galicia an umbrella is of little use on a stormy day)

We should ask these questions to the professor who named the monster.

 

In any case, my proposal for a sloop that can anchor well, comfortably and safely, both in sand and in the sea is

+ the mast centered at 55% of the waterline instead of 35-40%

+ do not leave the sails furled up

+ take the rudder blades out of the water, so that the yacht does not trip when dragged backwards

if Bayesian had a 10-meter, 60-ton ballasted centerboard that went up and down... why can't 1-10 ton sailboats/yacht have rudders that can be taken out of the water to anchor bow to the wind (!)

 

Alain Gliksman ...

https://voilesetvoiliers.ouest-fran...d-mabire-6c0e3c54-8886-11ee-a92a-0b4bc05f91ae

(rest in peace)

He quotes Jean Angeli, Le calcul des carenes, and says that in practice you have to take into account 2/3 of the static calculation, which is the figure that sounded familiar to me, and which i remember having read also in a British source, perhaps Wolfson Unit, Southampton

 

@CarlosK2

This doesn't actually do much by itself. The boat will have a designed-in lead - longitudinal aero center vs longitudinal hydro center. So you must move the keel back if you move the mast back. You can increase the jib's proportion of sail area, but if that's the point, just say it that way. If you use giant headsails, the aero center bare-poles is very similar to the aero center while sailing, but there is still going to be some lead on the bare stick rig.

What you want to look at is the longitudinal aero center of the rig compared to that of the hull. You need the rig forward on the hull so that the hull's aero CP is behind the hull's hydro CP. Look at the sailboats from 100 years ago with their massive bowsprits. Those hung at anchor like ducks.

There are some rather unfortunate performance implications of this, particularly if you are designing to a sail area rule. Bow designs that endplate and augment the jib make the boat impossible to anchor because those hulls have aero centers far forward. They also make heaving-to impossible. On my old MORC flattop, an estimated 22 percent of the windward drive came from the hull aerodynamics.

If you look at the old CCA designs with their overhanging sterns, you see how the hull aero is pushed aft and the rig is slammed forward. Take the sails down and the aero lead vanishes. These boats can anchor and heave-to pretty well. And once you have an overhanging stern, you may as well stick a little sail back there, hence the yawl - which allows a smaller rudder, which moves the hydro center forward - which reduces lead - which makes the entire problem easier to solve. I love yawls.

A related issue is pushing the displacement curve and center of flotation aft as seen on modern wide-sterned designs. We always wanted the displacement pushed aft, but with modern materials, we are doing it differently and vastly reducing the wetted area.

Mainsail roach also has some very complex trade-offs when looking at it's effect on aero lead. It raises the center of effort of the sail. If built to a bridge clearance constraint, it increases the required aero lead and ballast requirements. It's essentially the opposite of a yawl in terms of the effect it has on lead, displacement, and rudder size.

 

Heave-to

It is impossible to heave-to with a modern sailboat

Note that there is no sail on the bow, not even a furled sail, and at the end of the video it is confirmed that it is across, beam to the wind and the sea.

and the inability to Heave-to caused the multi-million euro yacht Hugo Boss to capsize

 

(1 Ton WindSurf Board for an old fogey, The bowsprit is made of carbon fiber and in port it is retracted by turning towards the stern)

The solution is simple:

+ center the mast at 55% LWL

+ take the rudder blades out of the water

so the sailboat, a modern sailboat, is

1) calm anchored in sand and does not yawing

2) it is calm facing the waves anchored in the sea, and

3) it can also heave-to like a Yawl with the main sail reefed



Of course we have to move aft the Keel

The Contact Patch https://www.boatdesign.net/threads/the-contact-patch.69267/

 

(1 Ton WindSurf Board)

It's crazy to sail on the high seas with a keel on the bow



(LCF) (!)

 

Eggs of Columbus

Egg of Columbus - Wikipedia https://en.m.wikipedia.org/wiki/Egg_of_Columbus

The two eggs of Columbus of a light (D/L < 150) modern sailboat are

Reconciling the Longitudinal position of the sailboat's Centers (CF, CB, CG) with the hydroDynamic center of the Keel (HC_K)



And being able to take the rudder blades out of the water as Robert Manry did to anchor in the sea bow to the Waves

 

We reconcile the Centers

We trim (Froude => 0.5) the Hull bow up and stern down with High hydrodynamic pressures and Low hydrodynamic pressures

This way we have a Surf board with good control of Pitch and Yaw

A Surf board to Surf huge Waves

And, in addition, by taking the rudders out of the water you can safely anchor in sand or mud without the boat having a nervous behavior ...

... or in the sea with a sea anchor to avoid breakdowns and rest



And if there is no need because there are no big waves, you can leave the boat stopped with only the Mainsail reefed and it behaves as if it were a nice Yawl

 

@CarlosK2 We must be from the same generation. I read Tinkerbelle when I was about 10. And here is my version of a 40'er to compare with the YD40. Mine has much greater displacement of course. I'm not the least interested in sleds. I'm interested in manners and the ease of sailing for any level of performance.

 

LY2: the large yacht code - GOV.UK (www.gov.uk)

 

The stories that emerge from the investigation of the Termini Imerese Public Prosecutor's Office into the shipwreck of the Bayesian are dramatic. Investigators are listening to the crew members of the sailing ship that sank off the coast of Sicily on August 19 due to a sudden storm but also due to responsibility and human error, investigators speculate.

"The ship tilted and we were thrown into the water. Then we managed to get back up and tried to save the ones we could," says Matthew Griffiths, the sailor who was on guard on the bridge of the Bayesian on the night of the storm. "The boat was tilted - is the sailor's story - and we walked on the walls. We saved who we could, even Cutfield (the commander now under investigation, Ed.) saved the little girl and her mother".

The commander was asleep

"I woke up the captain when the wind was 20 knots. He gave the order to wake up everyone else. I then put away the cushions and plants, closed the windows of the forward lounge and some hatches," Griffiths recalls.

Griffiths, defended by lawyers Mario Scopesi and Corrado Bregante who also assist engineer Tim Parker Eaton, was heard as a person informed of the facts. The sailor would not have spoken of the hatches, which were not his responsibility.

 

Thanks Peter. I'm not impressed by the LY2 yacht code. It has no teeth. I gather that nothing with any teeth would ever get ratified. It basically reads here's a bunch of design guidelines that you should try to meet so that your boat doesn't sink. If you don't want to do it our way, do it your way, but try real hard to do something similar and show us your work.

Then a builder comes along and says We get it, you don't want boats to sink. But ours can't sink, so none of this really matters to us. This is how it's done in the real world. And you'll have to take our word for it because many of our methods are proprietary and we aren't sharing.

I'm glad they aren't regulating bridges or power plants.

Anyone spot any load lines on any of the PN62 hulls? I thought they were required.

The LY2 specifies a minimum Angle of Vanishing Stability of 90 degrees, which we know isn't the case here. The problem is, the rational for many of the subsequent sailboat stability criteria depends on that 90 degree assumption being true. The validity of their methods (and the usefulness of them being satisfied) is unclear when applied to a vessel that doesn't meet the 90 degree AVS criterion.

 

As I inferred previously, I wonder if "everyone" awoken was just the crew...who sealed the passengers inside by closing the windows and hatches to prevent rain ingress.