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Polux · 11-04-2014, 18:10

Quote:

Originally Posted by s/v Jedi

So explain why my narrow boat doesn't heel much at all?! The view of wider equals less heel is simplistic and only valid for the average design. There are enough exceptions to that mid stream design to make it flawed. The effect of hull-shape moving through water at speed is completely left out for example. Still, it is what provides our bow the lift and why it doesn't bury in every wave. Also, my boat is a planing design as are many that are discussed in this thread. Planing is a different playing field. Multi-hulls do not plane but also escape the rules of displacement hulls.
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A planing sailboat!! Do you have a race boat? Most of what some call planing boats are semi-planing designs. Anyway even raceboats don't plan close upwind and that's where sailboats heel more. If you have a narrow boat that does not heel a lot upwind or you are beating physic laws or you are not pushing the boat.

Any decent amount of initial stability comes from beam, the beamier the more initial stability you get, to the point of an Open60 to be able to sail for thousands of miles after losing its keel. On a narrow boat there is only one way to get enough RM to sail and that is with a considerable heel. There is nothing wrong with that. That's just how it works.

**s/v Jedi** · 11-04-2014, 18:23

Quote:

Originally Posted by Polux

A planing sailboat!! Do you have a race boat? Most of what some call planing boats are semi-planing designs. Anyway even raceboats don't plan close upwind and that's where sailboats heel more. If you have a narrow boat that does not heel a lot upwind or you are beating physic laws or you are not pushing the boat.

Any decent amount of initial stability comes from beam, the beamier the more initial stability you get, to the point of an Open60 to be able to sail for thousands of miles after losing its keel. On a narrow boat there is only one way to get enough RM to sail and that is with a considerable heel. There is nothing wrong with that. That's just how it works.

Your post just shows you know little to nothing about the Dashew designs. Of-course you don't plane close upwind, why are you saying that?

A Sundeer 64 has a 64' waterline. The 24h record on tape is 384nm. That averages to a constant plane. In reality 20+ knot speeds are normal and thus there are periods of regular speeds at or below hull speed. However, only planing boats put those 24h numbers down.

Tell me how the boat can be pushed harder?!

Here's a vid of Beowulf which is the generation after Sundeer:

https://www.youtube.com/watch?v=J4zg5vD_jvI

leftbrainstuff · 11-04-2014, 18:31

Interesting question. Heeling is purely a function of forces and moments. I guess the sailboat that doesn't heel much is the one sitting on the hard.

Polux · 11-04-2014, 18:58

Quote:

Originally Posted by s/v Jedi

Your post just shows you know little to nothing about the Dashew designs. Of-course you don't plane close upwind, why are you saying that?

A Sundeer 64 has a 64' waterline. The 24h record on tape is 384nm. That averages to a constant plane. In reality 20+ knot speeds are normal and thus there are periods of regular speeds at or below hull speed. However, only planing boats put those 24h numbers down.

Tell me how the boat can be pushed harder?!

Here's a vid of Beowulf which is the generation after Sundeer:

https://www.youtube.com/watch?v=J4zg5vD_jvI

Instead of asking me how a boat can be pushed harder you would better read properly what I said:

"If you have a narrow boat that does not heel a lot upwind or you are beating physic laws or you are not pushing the boat."

Because it is upwind that a narrow boat heels much more than a beamier one, not downwind (as the one you posted).

Regarding Sundeer it was a fast boat but there is a reason for today's offshore race boats to be a lot beamier, specially the ones that are solo sailed: They sail faster and are more easily driven, specially on autopilot

Maybe if the Dashews sailed a modern boat based on modern solo racers they would not have turned so soon to motorboating. Modern Solo racers have done several times over 500 NM in 24 hours.

Here you have a modern cruiser based on Open racers and one capable of going at those speeds on autopilot:

https://www.youtube.com/watch?v=CXj1G5NUmHE

But I don't understand what all you say has to do with narrow boats sailing with a lot more heel then beamier boats, specially the ones that have all beam brought back. That's a fact, not some disputable thing.

**s/v Jedi** · 11-04-2014, 19:12

You don't get it, do you? The Dashew designs are not racers. You are green to all this and it shows

eyschulman · 11-04-2014, 22:10

Why all the fuss about heeling its part of sailing. If you don't like heel don't sail. Get a motor boat then you can rock and roll in multiple directions at the same time. A heeled boat properly trimmed is a joy and can be relatively stable particularly compared to a motor boat in a seaway. If you have a motor boat that is over active one of the cures is a SAIL. A heavy multi hull that is conservatively sailed will not heel but it will still bounce around and some find that quick motion worse than on a conventional sail boat. The middle ears of some are such that boating is torture sometime amenable by drugs and sometimes tennis or golf is a better choice.

Stumble · 12-04-2014, 00:33

Pollux,

While I am a big fan of Dashew and his boats, the idea that he switched to powerboats because he didn't know about modern high performance designs is ludicrous. He designs boats to be easily driven (modern offshore racers aren't) simple (same), and incredibly durable (again they aren't). His boats are monsters at long distance cruising. Not as fast as a modern offshore racer, but much easier to sail.

Dashew's boats achieve huge speeds by being very long and narrow allowing them to break traditional displacement speeds regularly. They also have a very high ballast ratio carried low on deep keels. I would question that the boats have ever planned, but they certainly are known for how easily they can surf which can provide speeds similar to planning speeds.

**weavis** · 12-04-2014, 02:03

Why a sailboat heels.

the sideways components of wind and water on the boat make the boat heel (tilt) away from the wind.
These two horizontal components have equal size but opposite direction: as forces they cancel, but they make a torque tending to rotate the boat clockwise.
This is cancelled by another pair of forces. The buoyancy and the weight are also equal and opposite, and they make a torque in the opposite direction.
As the boat heels to starboard, the lead on the bottom of the keel, which has a substantial fraction of the weight, moves to port and exerts an anticlockwise torque.
These two torques cancel.

Its Newtons law of physics. Designers use it to implement a characteristic and peculiar (to that vessel) balance for weight and pivotal release from the known elements of counter balance and by tweaking release points. (Mast height, sail spill, etc)

Gary. High school. Mr Pilkingtons class of '72.

Polux · 12-04-2014, 06:02

Quote:

Originally Posted by Stumble

Pollux,

While I am a big fan of Dashew and his boats, the idea that he switched to powerboats because he didn't know about modern high performance designs is ludicrous. He designs boats to be easily driven (modern offshore racers aren't) simple (same), and incredibly durable (again they aren't). His boats are monsters at long distance cruising. Not as fast as a modern offshore racer, but much easier to sail.

Stumble, let's stay with facts. Fact is that Dashew changed to motorboats because sailing a sailboat fast (their designed sailboat) has too much for an aging sailor.

Fact is that in what regards solo sailing racing the easy handle of huge sail power is a determinant factor to performance and those boats have been developed for decades by the best designers to perform the best possible way winning races. It is with what they have learned in solo racing that the designers improve their cruising designs, not only in what regards speed but easiness of use.

It is obvious that if the Dashew type of hulls had advantages in what regards speed and easy of use over the beamier type hulls that are used on solo sail racing they would be used for that. Several NA have tried and it was proven in the race field that a boat designed that way was more difficult to manage and in the end was not faster. Particularly an American NA, Sponberg went that way and designed an Open 60 that was never competitive. Other (French) also have tried the narrower boat approach in what regards Open 60 solo racing and the concept never proved to be competitive.

With all this knowledge it is obvious that even if a narrower boat has some advantages, particularly in what concerns going fast upwind, in what regards solo/short crew sailing it was proved that a beamier boat was the better way to go fast with an easy sailed boat, a boat that can go fast sailing on autopilot.

The Dashews left sailing for motorboating because his boat was an handful to sail fast, regarding their diminished abilities (with age). In their time they were great sailors, much above the average cruiser. what I said was that if his boat was easier to sail and could go fast on autopilot, probably they would not have felt the need to change to motorboating so soon and yes, experience had proved that modern solo boats are easier to sail fast with a short crew than the older designed Dashew narrower type of boats. That does not by any means to say that those where not great boats.

We are going to see on the next big Transat a well known 75 old sailor racing solo an Open 60. He is not going to cruise, he is going to race. That is only possible because those boats are very easy to sail. Off course a cruising design based on those boats, like the one that I posted before, is even more easy since the sail area is reduced.

It seems to me that the Dashwes passed to motorboating well before 75 years of age

Rohan · 12-04-2014, 11:52

Quote:

Originally Posted by s/v Jedi

Then there's catamarans. Not just waves but also wind can capsize these

Most modern catamarans will not capsize from wind, they would instead lose their mast before that happened. If you believe the manufacturers that is.

As far as monohulls go, what about chines? Once again, according to the manufacturers, the hard chines you see along the hull on the new Beneteaus and other sailboats are supposed to reduce heeling and give a smoother ride as well. Here is an example:

Polux · 12-04-2014, 12:07

Quote:

Originally Posted by Rohan

Most modern catamarans will not capsize from wind, they would instead lose their mast before that happened. If you believe the manufacturers that is.

As far as monohulls go, what about chines? Once again, according to the manufacturers, the hard chines you see along the hull on the new Beneteaus and other sailboats are supposed to reduce heeling and give a smoother ride as well....

I would not say a smoother rider but an easier ride since the chine does not only increase hull form stability, at that particular heel angle, as most of all will help to maintain the boat on the right grove, the one where it sails more efficiently.

Regarding cats not capsizing with big winds because they would break the mast first, that is a lot of bull ;-) Who is the shipyard or designer that come with that?

Stumble · 12-04-2014, 12:44

Pollux,

Just so much wrong... No place to start...

The opens, turbo sleds, maxi racers, even the mini's are not easy to sail, they are not comfortable, and they will brutalize the unwary. I have thousands of miles on them, and while I love sailing these beats, they are always almost out of control.

The Dashew's boats, while I have never sailed one, are long, lean, and easily driven. Capable of huge turns of speed because of their design. But that design is so different and intentionally so than an Open.

Polux · 12-04-2014, 13:48

Quote:

Originally Posted by Stumble

Pollux,

Just so much wrong... No place to start...

The opens, turbo sleds, maxi racers, even the mini's are not easy to sail, they are not comfortable, and they will brutalize the unwary. I have thousands of miles on them, and while I love sailing these beats, they are always almost out of control.

The Dashew's boats, while I have never sailed one, are long, lean, and easily driven. Capable of huge turns of speed because of their design. But that design is so different and intentionally so than an Open.

I am not talking about turbo sleds or Maxi racers that need a large crew to be controlled. I am talking about solo IMOCA boats, vulgarly called Open 60's that are designed to be sailed by a single sailor. They race day and night and the boat is most of the time under auto pilot, even in extreme conditions. I am talking about the type of boat that is going to be raced across the Atlantic by a 75 year old man. How can they be out of control most of the time if most of the time they are on autopilot?

As I have said the type of boat you are talking about was tried in what regards solo racing and it was just too dificult to handle and in the end it was less fast on account of that. But I agree that narrower boats, even if more difficult to control can be sailed faster by a crew. That's why a VOR 65 or 70 is less beamier than a IMOCA boat, and also faster....but not with a solo sailor only. It needs a crew.