Incredible "Secrets of Yacht Design" website located...

[frankofile]

Nice melt-down Frankie. You demean the word "gibberish". Time to push up the meds a bit, eh?

Re "lover"... Are you gay Frank? You know, there's nothing wrong with that. Maybe if you would admit your true sexual orientation you would escape the need to expose yourself to ridicule.

[Skippy]

Originally Posted by frankofile

Re "lover"... Are you gay Frank?

You know file, you may have discovered further evidence of a serious condition.

Originally Posted by Deep Keel

...There is definitely something Freudian here.
Maybe it is just the latent homosexual feelings you have for Jim Teeters coming out....

[water addict]

All- Please acknowledge the great one's superiority and admit your own ignorance. Down on one knee and bow to the king. Everything you learned about Nav.Arch. is wrong, and Frankie is right.

Can't you just admit it?

[water addict]

All- Please acknowledge the great one's superiority and admit your own ignorance. Down on one knee and bow to the king. Everything you learned about Nav.Arch. is wrong, and Frankie is right.

Can't you just admit it?

[Skippy]

Originally Posted by skinny boy

The THEORY of Relativity can not be tested and yet it is not a religion or philosophy.

Actually sb, relativity is well tested. The general theory (the later and more comprehensive one) was confirmed in a famous astronomical observation, during a solar eclipse in the year 1919. Astronomers have had excellent star charts for centuries, and there was one group of stars that was calculated to appear very close to the edge of the sun at the time the moon passed in front of it. Einstein predicted that the light emanating from the star would be curved around the sun by the sun's gravitational field. This meant that we would see the star appear to be farther from the sun's edge than it really was, because those light rays would curve back toward our eyes. The stars appeared right where Einstein calculated they should be, and many experiments since then have confirmed the theory further. They don't support Ballerina Science so well though.
Eclipse that Changed the Universe

btw, I just noticed the first link in the advertisements on that page. If you really do enjoy Ballerina Science, it looks like there's plenty of it in that book. Spaghetto will probly make it his new bible.

[skinny boy]

Actually there have been over 30,000 experiments to test various pieces and parts of the theory of relativity with not one providing contrary indications. While the evidence is huge it is still circumstantial. Since there has not been an experiment that has been able to test the whole theory, it remains a theory.

[mighetto]

Originally Posted by frankofile

Nice melt-down Frankie. You demean the word "gibberish". Time to push up the meds a bit, eh?

Re "lover"... Are you gay Frank? You know, there's nothing wrong with that. Maybe if you would admit your true sexual orientation you would escape the need to expose yourself to ridicule.

See first the TP52 thread. I mean Gimcrack.

http://forums.boatdesign.net/showthread.php?p=33444

"What you may not realize and what needs to be chatted about, (perhaps this week), is that in the 1930s, in the US, there was recognition that naval architects, while fully engaged in applying scientific principles to the design of power vessels, were neglecting sail boats, leaving those to "yacht designers". Designers who apparently were more interested in the interior of the vessel and looks while moored at the yacht club, than in function under sail, with no special training required to hang out a shingle.

At that time it was feared, even predicted, that foolish sailing vessels would be created, the TP52s being just the latest in a long line of them, I think, and Gimcrack being the first."

The Story of Onkabye and Gimcrack

The following information is conveyed from the History of American Sailing Ships, a book published in 1935.


This is a rather common book on the west coast of the US, in spite of its age, for folks who are studying sailboat design. The story of Onkabye and Gimcrack is found in Chapter 7 of the book.

Onkabye (or Oncabye) is thought to be the start of the evolution of American Sailing Yachts. The name means 'dancing feather'; Gimcrack in the 1840s was Yankee slang for 'useless thing'.

Onkabye, as her name implies, was a radical departure from the heavy keel-pilot schooners used for the sport of yachting in the New York and Boston areas. She was a 90 foot internally ballasted centerboarder. She was very fast, stiff, and smart, and to be used only for pleasure purposes, racing in particular.

Onkabye, didn't last long as a pleasure boat. In about 3 years the US Navy made an offer and the experiments that the owner was conducting regarding external ballast tacked onto the side of the hull and rolling in heavy seas, stopped. Rigged for war, Onkabye was a slow sailboat, very sensitive to the extra weight. She was lost 5 years later on a reef. Because of Onkabye, a very big distinction between the hull forms of a commercial Naval sailing vessel and a yacht was made by 1935.

Soon after the Navy purchased Onkabye, her owners built Gimcrack. This 52 footer had a fixed fin of between 12 and 15 feet long. Gimcrack was quickly recognized as a failed experiment.

The owners of both boats when launched were the Stevens, sons of Colonel John Stevens, the engineer so responsible for steamships. They were considered hobby sailboat designers and "apparently desired to prove that a centerboard vessel could be designed that would combine the advantages of both the keel and centerboard types and thus demonstrate the arguments of the supporters of the centerboard."

Interestingly, those supporters would later found the New York Yacht Club (NYYC) in the cabin of Gimcrack, the useless thing, on the afternoon of July 30, 1844. "Because of the shoal anchorage of the New York Yacht Club at Weehawken, later at 'the foot of Cort Street' on the Brooklyn shore and on the Jersey side from Commnipaw to Kill van Kull, the shallow centerboard yacht was most popular with NYYC boat owners.

Fast forward to today and we see American ocean sailboat yachting dominated by the deep fixed keel boat. Supporters of the deep keel were concentrated in Boston, with its deep water anchorage, back in the days of Gimcrack and Onkabye.

The bottom line is that the notion that Naval Architects do power and not sail boats and that a power boat designer is only a hobbyist if doing a sail boat is traced to day one of the evolution of the American sailing yacht. The separation between sailors and powerboaters, rag baggers and stink pots, was orchestrated right there.

I am not gay and yes I know, there's nothing wrong with that.

Good Morning Anarchists and Boat Designers.

[mighetto]

How interesting that Einstein dispensed with Newton’s absolute nature of space and time while he was working as a patent clerk in Berne, Switzerland. The most relevant scientist for sailing was Swiss. We replaced the Lethermans with Swiss Army knives on Murrelet in his honor.

In the early 1700s, the Swiss scientist Daniel Bernoulli established that changing the velocity of flow of a fluid, such as air or water, at a specific point brings about a consequent inverse change in pressure at the same point. Bernoulli's law led to its application in the venturi effect -- such as when the flow of a fluid in a tube is constricted resulting in increased velocity and decreased pressure - and the development of the curved foil. The most convincing demonstration of the venturi effect is easy to perform in the kitchen. First, run a stream of water from the faucet. Then, dangle a soup-spoon by the tip of its handle and move its convex surface slowly toward the stream. Rather than being pushed away, as your intuition might suggest, it is pulled into the stream.

- Chapman's Seamanship Under Sail 64th edition page 276

This science was explained to Mac26x owners by Roger MacGregor with the lines Most sailboats have curved bottoms. This creates downward suction as speed increases, preventing them from getting up on the top of the water and planing at high speed. Few will go more than 6 or 7 mph. The 26 (X)'s flat straight bottom allows it to skim across the top of the water with with minimim reisistance and without hurting its sailing performance. Also the boats light weight is a big factor in its ability to go fast. That science allowed X owners to recognize quickly that dealer claims for a more rounded and heavier vessel being faster under motor power than the X was likely inacurate. In the end the manufacturer stated that the M was 2 MPH slower than the X when both were mounted with identical 50 hp motors. (22 vs 24 MPH)

[mighetto]

Originally Posted by water addict

All- Please acknowledge the great one's superiority and admit your own ignorance. Down on one knee and bow to the king. Everything you learned about Nav.Arch. is wrong, and Frankie is right.

Can't you just admit it?

Since 1935 in the US there was recognition that NAs were overly focussed on power boats. The Job of sailboat design was being left to hobiests. In the 1950s British boat builders pretty much proved that small under 30 foot sailboats were safe for ocean crossing and even circumnavigation. Then in the 1970s all efforts regarding boat building seemed to turn to copying vessels in fiberglass. Perhaps the only real innovations came from the woodenboat builders and today that may still be true. I do not admit to superiority. Do not kneel or bow. I am not your king or your savior. Save yourself's and annoint yourself's Kings and Queen the next time you are in the market for a sailboat. Feed the Internet. Make us all powerful.

[mighetto]

Originally Posted by SailDesign

Well, Ignore File or not, I jus can't let these slide.

When the CG is lower than the hull (we'll assume you mean that the CG is lower than the lowest point of the canoe body), then the stability WILL be better than with the CG inside the canoe body. That is a proven fact, hydrstatically=speaking, and cannot be denied. Period.

When the CG is "below the hull", the hull integrity is not compromised any more than it may have been with the CG higher. Hull integrity and CG have nothing to do with each other, basically.

The bulb keel was around Loooong before the IMS, and will be around long after it.

You also say "I have asked for help." Well, this post is Help. Take it or go away.

Steve

I will take the help and add from another boat design thread.

Barsa;

The yacht designer who is the national IRC co-ordinator for Australia has told me that he can find no advantage in keel depth under IRC; just go for the keel depth that suits the boat best and (he say) it will be fairly rated.

I have also asked Mark Mills and John Corby about IRC "specials" and they told me that these days, a good production boat is just as competitive as the IRC specials. That means (the production boats like Beneteau 40.7s not being distorted for IRC) there mustn't be much of an advantage to shallow or deep keels.

It is likely that box rule flaws were exploited by bulb keels just as designs with small head sails and exagertated heel exploited them and there is no stability or speed advantage.

I now get to tell my Perry Story.

Bob Perry, in a presentation to my sailing society, noted that after serving as an expert witness during the OneWorld debicle and viewing the blueprints, the "Light Bulb Went On".

But was he refering to the Light bulb on ICON http://www.iconsailing.com/html/the_boat.html. This vessel has a heavy bulb and a light one that are exchanged for expected race conditions. The AC boats are going to be 1 ton lighter by 2007. There is a trend back towards "dancing feathers" in American monohull sailboat design. Which I find most encouraging.

At least consider the possibility that with IRC, the notion of a bulb of any kind on a sailboat will be questioned. The fact that they are not deployed on powerboats is a dot you can connect. The only bulb like structures are in the hull on power vessels like.



ICON might retract her bulb fin and achieve fuel efficiencies similar to those gained by such structures on powerboats, if the bulb is close enough to the hull. But I doubt it would be. Running ICON bulbless and puting the weight internal to the hull may not change the stability curves. That would have advantages. The weight could be used to improve the accomodations and the bulb would not serve as the crab pot and weed catcher it is. Of course water ballast is also a possibility.

[Skippy]

Originally Posted by Spaghetto

The most convincing demonstration of the venturi effect is easy to perform in the kitchen. First, run a stream of water from the faucet. Then, dangle a soup-spoon by the tip of its handle and move its convex surface slowly toward the stream. Rather than being pushed away, as your intuition might suggest, it is pulled into the stream.

Hey, I just tried that. It's an excellent experiment. First hold the spoon lightly a fraction of inch from the stream. Nothing. Now move it into the water. As soon as the flow attaches to the spoon, the spoon swings into the stream. Very nice. (But it still has nothing to do with the spacing of catamaran hulls.)

[D'ARTOIS]

According to the owners directory (mcgregorowners.com) neither Murrelet nor Mighetto are listed as boatname/owner.

Gimcrack is not a yankee slang word, but common English from the past centuries for a shiny and useless thing.

USS Onkahye served for a short period as a yacht, after that she was commissioned because of her speed as a pursuer of "slavers". In that, she showed very successful. She went everywhere over the Caraibic and South America. Nowhere remarks as being unseaworthy or so.

The denigrating "tone" of your remark about Einstein, that he was a clerck at the Patent Office in Zurich, shows your incapability to understanding. Shortly after, he was assistent-professor.

The notion about the ventury effect in a catamaran you have picked up from my reply to Duane's shape of floats some time ago. It has nothing to do with a curent topic and is like sand in the wind: incoherent. As the majority of your remarks.

"Since 1935 there was a recognition......" By who?

"In the 1950's British boatbuilders discovered........." Wrong. You mean Blondie Hassler's boat. That was 10 years later, in the early '60s.

Reading the current issues regarding the steering malfunctions in the 26X may shine some other light on the accident with Martin.

Why are you not listed as a McGregor owner? Neither your boat's name is entered in the registry.

[mighetto]

Originally Posted by Skippy

Hey, I just tried that. It's an excellent experiment. First hold the spoon lightly a fraction of inch from the stream. Nothing. Now move it into the water. As soon as the flow attaches to the spoon, the spoon swings into the stream. Very nice. (But it still has nothing to do with the spacing of catamaran hulls.)

Take the spoon, turn it to the other side, and note how it is pushed from the stream. Then contemplate this vessel.



She is said to be a catamaran. But if you think of her hull as an inverted spoon, the faster this vessel goes the more her hull would be lifted from the stream she would ride on. These are ocean fishing enforcement vessels and are both fast and stable. They can operate in shallow water and the one pictured is a beach landing craft.

Cathedral Hulls like these are used in the Livingston dinghies. I say they represent hollows which only recently are being allowed on monohulls such as the TP52. A common perception by multihullers is that hollows were banned from the AC because in the extreme they become catamarans. Hence banning hollows in effect banned multihulls from AC races.



The above is a mock up of a Mac26m in a Tri configuration. When the Mac26m was reviewed by Perry he did so within the context of other reviews including a vessel that was intended to be a trimaran but was sold mostly unsucessfully as a monohull. In otherwords the Amas, - outer hulls - were left off the boat. The Mac26m when it first came out listed badly to starboard when unballasted. When the boat is not in use, to prevent the ballast water from fouling over time, X owners will blow it dry. This is also a preventative measure in colder climates. If the water ballast is allowed to freeze, that can be the end of the vessel because water expands when it freezes. Anyway, I speculated that perhaps the M was a cleaver roll out of a folding trimaran. In such a configuration you might operate unballasted and you would want oneside to predictable dominate when the boat was at rest. At that time both the M and X were to be produced at the California factory, and Farriers patent on folding trimarans was expiring. I haven't given up on this but the longer it goes, the less likely MacGregor intended the M in Mac26M to stand for Middle hull of a mulihull. Roger is an innovative designer who has built transportable variable width catamarans in the past.

[Skippy]

Originally Posted by mighetto

Take the spoon, turn it to the other side, and note how it is pushed from the stream. Then contemplate this vessel.



She is said to be a catamaran. But if you think of her hull as an inverted spoon, the faster this vessel goes the more her hull would be lifted from the stream she would ride on.

Sure, all you have to do is push her sideways.

Frank, I like the trimaran idea. You should do that with the X. Just rip out the ballast tank, you won't need it. And install a rig that's about three times as big as the current one. Now that would be a nice boat.

[mighetto]

I have just updated the directory. Thanks for the URL and sorry about fading off on you all today. It has been hectic. There are many URLs involving MacGregor Yachts.

http://macgregorsailors.com/ has a link to the cruising log of the Murrelet, and it was prior to the new format of that URL when it was called MacGregor26x.com that much work and review of the cruising log was done. see http://macgregorsailors.com/links.php#pers.

The modifications section of the macgregorsailors.com URL might give you some ideas of what folks are doing with these craft. To much perhaps. The boats are sensitive to weight. Every 100 lbs is 1 MPH less top end speed according to Roger MacGregor and I suspect that applies to power under sail as well as power under motor. But then most owners have less interest in racing than I.

There is also an active group of Mac26x owners on Sailnet.net, a list service that I belong to. The archives should still contain a lot of discussion. Search for mighetto. Remember that the halt in production of the X was not known until recently to have been related to Jim Teeters. Teeters has messed with other craft that didn't suit his ideas or interests - the Barnegat Bay A Cats, for example.

Sad story that one. After Teeters, not a one new A Cat built. None of it related to science. Teeters just arbitrarily took the average weight of all the boats and recommended that future boats should match that weight at a minimum for "performance". (4800 lbs.) Best I can tell there was no research at all supporting this. It killed the development of these racers. There is an article in Sailing World on that in the February issue. This happened before 2002, and the drunken boater deaths aboard a Mac26x. The Mac26x is 3750 lbs fully ballasted. All boats can capsize, regardless of how heavy they are. Arbitrarily adding weight can do harm especially if that weight is the cause of the boat sinking after a capsize.

Be aware of www.archive.org where you can enter the url for my crusing log and get old versions of it going back to 2002. I tend to have new material entered in itallics so it is easier to spot what may still be a half baked notion.

You have demonstrated knowledge on canoes and kayaks elsewhere. Looking forward to more discussion.