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Old 15-01-2004, 13:08   #16
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Lightbulb Jeff H

I noticed you stated "the newer fin keel/ spade rudder boats lie a hull pretty nicely".
So, If I were to lower the VCG on this vessel it would have a better ride?
I have considered adding 500-1000 # bulb to the bottom sides of the keel to give more ballast and to add to it's stability, not draft, since I don't have a crew for ballast at the rails. It may create a bit more drag, but I'm willing to make the sacrafice for the stability. It might even add to my LWL a few inches. Also, I was considering creating a wing effect to the bulb, but that might add to the possibility of a knock down?

Every heavy weather advantage is a plus even lying ahull if necessary!

Whatca think?

Del..............................._/)
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Old 15-01-2004, 17:29   #17
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Keel Mod's

Check out Mars Metal "Marine" (then "Torpedo")
http://www.marsmetal.com/

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Old 15-01-2004, 19:28   #18
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Torpedo

Thanks Gord for the info and site.
If I do decide to go that route it would be good to counsel with them first. I'd have to do a little research to make sure that the existing keel bolts would except the extra weight. I'm fairly confident they would. After 23 years of use the area around the bolts looks excellent. No sign of any stress or corrosion.
I'd probably build the mold myself and have them pour unless they have some generic set that would fit the radius and length of my existing keel.

Sorry Stede, didn't mean to change the "lying ahull" subject. But this would increase the stability and chances of lying ahull for my vessel, I believe.

............................................._/)
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Old 16-01-2004, 09:05   #19
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Hi everyone,

I've really enjoyed reading the comments around this topic.IMO,there are a few items worth key-noting.

The sailboat "Satori" caught in the "Perfect Storm" - Every story always has two sides.I was impressed with the Captains credentials,which I was unaware of. The narrative given of the account,really gave me a feel of what it must of been like aboard that boat.

What is the truth concerning the incident? Who knows? It probably lies somewhere between all three accounts given. (The author,Captain, and crew.)

The boat was rolled twice, I think all accounts agree on that. The boat, a Westsail 32 (full keel, heavy displacement boat-19K.lbs+) did indeed survive the "storm of the century" in very good condition.To me, this seems to correlate with Mr. K.Adlard Coles's comments in regard to hull configuation and displacement in his book titled " Heavy Weather Sailing".It also speaks well for the construction of the Westsail 32. But of course this is only speculative on my part.

Del - No apology necessary my friend. I thought your comments on possibly modifying the keel of your boat fit in very well with the subject at hand.I am familiar with your boat,and with my basic knowledge of boat design, I would try to visualize the forces that will be present,and how the boat will behave after the modifications.Real case strategy in the making.Excellent stuff!! I always learn so much from you guys. Thanks!
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Old 17-01-2004, 08:18   #20
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I don't believe that the fact that Satori survived the 'perfect storm' proves anything at all except that the boat was pretty lucky. The book only deals with a few of the many vessels that were out there and survived that storm.

Westsails and their type offer no magic bullet. For example, one of the boats lost in 'Fastnet Disaster storm' was in fact a Westsail 32. Because this boat was not racing, it is rarely mentioned in the accounts of the Fastnet disaster. Also remember that the vessel that was lost with the largest loss of life during the Sydney-Hobart Race disaster was 'Winston Churchill', a traditional vessel very much in keeping with Coles description of a proper offshore vessel.

We know a lot more today about the factors that make a seaworthy and comfortable vessel than we did thirty something years ago when Coles wrote his seminal work. While this book is filled with all kinds of valid and useful information, it does not benefit from the twenty plus years of reseach and response to that research that has occured since the Fastnet Disaster.

We now have a much better understanding of what makes a boat that is comfortable and seaworthy in heavy going. We now know that weight distribution and buoyancy distribution, proper dampening, and a low VCG are the most critical elements in seaworthiness and motion comfort. We now know that weight in and of itself is not a good thing in heavy going. We now know that crowding a lot of weight on a short waterline is not a good thing in heavy going. We now know that a design that takes dampening into account is very critical in determining the seaworthiness and motion comfort of the boat. The Westsail 32 fails in most of these categories. While they are tough little boats there are also big variations in build quaility in these boats which make some W32's tougher and more seaworthy than others.

To me, the fact that Satori survived largely intact, says that she was probably one of the better built and maintained W32's and that she was also very lucky. It is not a universal proof that boats like these are empiricallly better offshore vessels.

Jeff
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Old 17-01-2004, 11:08   #21
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Jeff,

Easy there,big fellow...Your post comes across like your sheet is pulled in to tight and you're getting ready to blow out a sail

Many of the topics I post are in an effort to generate discussion around a subject.I appreciate views from a large group of sources,both here,through books I read,and by researching.Then,I form my own opinion,whether it be right or wrong.I know you are a very knowledgable sailor on a wide range of subjects, but the "Sailing world according to Jeff" just doesn't do it for me my friend.

I've noticed you have a tendancy to denounce opposing views to your own by many knowledgable,well respected individuals in the sailing community as "dated," or their opinions aren't held in high regard by those in your inner circle.Boats that don't meet your high standards are "poster children" for poor design,etc.,etc.etc. (Yawn....)

You have no time to welcome new members to these boards,nor generate original postings of your own because you're too busy looking to spread your infinite knowledge to us all,and correct our short comings.(scratching backside..)

Maybe we should try a different approach. The uneducated sailors like myself could make a posting, and then wait for you to tell us what's correct. That way we can avoid reading any other authors,talking to other sailors, or researching other sources for information.Just think of the time we can all save
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Old 17-01-2004, 11:40   #22
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Stede,

Dude, Don't take these discussions so personnally. You'll hurt yourself.

From my perspective it is like this, There is a whole lot of 'conventional wisdom' that is floating around that represents the best thinking of 30-40 years ago. Its not completely wrong but it is not complete and 'conventional wisdom' often contains ideas that are inaccurate.

A tremendous amount has happened in the past twenty years or so that has greatly changed or enhansed our understanding what we thought we knew about how boats behave in a seaway and what it takes to produce a seaworthy design. Designs like the Westsail 32 were as good as they got when they were developed in the 1930's (The Westsail 32 is a fiberglass adaptation of the Atkins Eric circa 1933). But with better engineering and a better understanding of the dynamics of sailing vessels there are much better suited designs out there for long range cruising and many of these are also way less expensive than the venerable W32. My comments are about providing a balance to 'conventional wisdom' and small sampling annecdotally derived conclusions.

I think that a dialogue on these topics is important. They help us all develop a better and more complete foundation for our view points. Any of us can elect to ignore the results of such comprehensive studies as the CE research that lead up to the development of the EU standards, that is our perogative, but on a forum where people with a wide range of experience and backgrounds come to discuss a topic, I think it does us all well to permit the free exchange of ideas and not try to stiffle any one person because they have ideas that are alien to our own. If we disagree with their ideas, we are somewhat obligated, in the spirit of an honest intellectual exchange, to try to make our case and counterpoint on the arguements rather than ad hominia.

And yes, Virginia, there really are boats out there that represent a 'poster child' for bad design ideas and poor construction. And yes a skilled and lucky sailor might be able to do remarkable things with one. Remember even Josh Slocum's luck changed and skills failed him and he promptly disappeared at sea. :

Respectully,
Jeff
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Old 17-01-2004, 11:57   #23
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Jeff,

Yeah, whatever...
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Old 17-01-2004, 17:08   #24
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Okay Stede,

I am not trying to start or continue a fight. Its just not my style, but I would like to understand your position. You say that you are posting these topics in an effort to generate discussion around a subject. I am only trying to discuss these topics as I understand them. You obviously disagree with my position on some of these issues and feel that my answers 'do not do it for you'. That is fine with me.

BUT sarcasm aside, what are you asking me to do here? Would you prefer if I stopped posting? Would your prefer that I ignore the information that has been gathered by leading researchers and yacht designers over the past twenty years? Surely your post must have had some kind of constructive purpose, but its purpose is not clear to me. What precisely would you like me to do differently?

Respectfully,

Jeff
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Old 17-01-2004, 20:53   #25
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Gentlemen:

If I may, I would suggest that there are many who rely on these posts for information. They understand that in some cases they are reading good data, sometimes strong opinions, sometimes anecdotes, and sometimes efforts to stimulate conversation. It is the reader's job to decide what is what, and we should leave it that way. It all still helps. (Helps me, at least)

It all provokes thought - sober second thought. It makes us doubt our opinions, maybe, and that is a good thing. Those who blow themselves up are sure. Those who fly planes into buildings are sure. Let's have more doubt in this world.

We have strong opinions on hull design, number of hulls, guns (oh my lots of them), and lots more. Many of us want to hear it all. Let's stay out from under each other's skin, even if other's writing styles are not quite what we like.

Gentlemen, go for the edit button. Otherwise, hang in. Anybody leaves, we all lose.

Sail fast, live slow. (So I'm corny!)
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Old 18-01-2004, 08:18   #26
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Jeff, my friend,

How,or why should I try to tell you how to manage yourself,when I have such difficulty properly managing me?

I had to give your question some thought before replying in an effort to arrive at the correct solution.As I stated previously,I know you are a very knowledgable sailor on a multitude of subjects.As I've visited these boards, I've witnessed you sharing your knowledge with individuals for their benefit,and many others,including myself.On several occasions,you've gone out of your way to help me, and I truly appreciate your efforts.

In an effort to improve my own knowledge base,I can't help but to have noticed that on each subject I've posted here, that you've basically told me that I'm wrong, or that the sources I've gained my information from are incorrect.With that being said, I have to question the path of learning that I've been pursuing.It's occurred to me that I'm spending too much time on these boards,rather than utilizing available time to increase my knowledge on these subjects.If the things you say are correct, than I'm even further behind than I thought I've got shelves of books that are "dated",and I need to spend more time researching topics that interest me,in order to become current, if that is ever possible

I hold no ill regard to you, or anyone here.You are all my sailing brothers,and sisters.I've enjoy our journey over the seas of topics here, but now I must set a new course.I wish you all fair winds, and may God hold you well.
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Old 18-01-2004, 09:02   #27
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Fortunately, I have never had to attempt lying-a-hull, but I have read about the technique for decades. What I do not understand is why the helm is placed slightly to leeward. Is this to achieve something similar to the motion of heaving to?
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Old 18-01-2004, 11:10   #28
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Beam on.

I have never done it either but I think the helm is put partly down so that any forward motion will drive the boat to windward. Perconaly I think doing anything that might put the boat beam on to the waves is a mistake. Bow on or stern on depending on the boat and experience would be a more sound idea from my point of view. I have been out in big waves either motoring diectly in to them in a 55 foot fishing boat, or surfing on them on a surfboard.
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Old 18-01-2004, 12:22   #29
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SJS, to answer your question first, left to its own devices under bare poles with the helm amidships, the bow of most boats will pay off to leeward and the boat accellerate downwind and in enough wind will broach. By putting the boat helm down, the boat goes through a series of small cycles as the bow of the boat will actually start to pay off and make a little way, then the helm turns the boat back up to windward again, and the force of the wind stops the boat, and the next cycle begins. It is easy to experiment with this even on a calm day. I usually use this technique to keep the boat in one place while I flake the sails when I am single-handing.


Stede:

What you say is quite reasonable and I apologize if I seemed to be overly critical of your posts or seemingly over agressive in my writing style. I also wish you well. I really do want to be helpful rather than convert people to the "world according to Jeff".

In the spirit of extending an olive branch and while I don't know if this will be helpful to you, if you don't mind, I will try steer you towards good sources of more up to date information and also provide a kind of summary of the material upon which I have been basing my opinions. Much of my most current information comes from research papers presented at the Society of Naval Architects and Marine Engineers (SNAME) Sailing Yacht Symposiums but I think I can explain the general trend in what is coming out of the research and aim you at sources as I do so.

Prior to the research and the improved engineering that began roughly 20 years ago, when you talked about light weight boats these boats were made light by reducing ballast and scantlings but without compensating in any other way. So a light weight boat was often structurally inferior and generally had a comparatively high vertical centers of gravity. Early lighter weight boats generally relied on high form stability and crew weight on the deck to stand up to their sailplans. Because that was pretty much the only light weight boats that really existed in those days, it was a safe conclusion as late as the early 1980's that light weight boats really were not suitable for offshore use.

There are a lot of very excellent books written (or revised) in the early 1980's that explain that issue very well. Probably the best of those was C.A. Marchaj's "Seaworthiness-The Forgotten Factor" which explained the physics behind seaworthiness. His explanations of the physics of seaworthiness are still extremely accurate in much the same way that Coles storm strategies are still very accurate. What is not accurate is their condemnation of lighter weight boats, which was in great part based on the typical light weight boats of that time (mostly IOR era race boats and cruisers based on the IOR rule) and not on the light weight designs that evolved after that period. They cannot be faulted for looking at the boats that existed and not predicting the changes that were to occur.

Here is what has changed. In the 1970's and into the early 1980's the laminates and resins being used in fiberglass boats changed pretty dramatically. Longer fiber fabrics and better fabric handling techniques became the norm. Less brittle and fatigue prone resins also became the norm as boat builders tried solve the resin problems associated with blistering.

Also at this time, racing began to look at the issues of flexure which was seen as slowing the boat. It was concluded that you could not effectively reduce flexure in a fiberglass boat without internal framing. This was a major departure from earlier f.g. boats desgn principles. Early fiberglass boats were purposely designed without internal framing in order to create more interior volume. The belief at time was that framing was not necessary because satifactory stiffness could be achieved by making the hulls thicker. This greater thickness was generally achieved by the use of higher proportions of non-directional fabrics (mostly mat). We now know that non-directional fabrics reduce impact resistance and increase brittleness and the likelihood of fatigue. (There are several excellent monographs on this subject that were produced in the mid-1980's and most recently an insurance industry study of insurance claims on older fiberglass vs newer boats in which included very interesting destructive testing of actual panels from older fiberglass boats. The insurance industry study was available on line. There is also a recent Naval Academy study that is very good as well.)

So in the late 1970's/ early 1980's designers began to reduce weight by adding framing in the form of glassed in tranverse and longitudinal members and later through the use of pans or grids, and by using better laminates which all permitted lighter weight without compromising strength.

At the same time, several other things happened. Research coming out of the Fastnet Disaster began to focus attention on the evils of high vertical centers of gravity and moments of inertia, extreme form stability and trying to cram too much displacement on a short waterline. (Much of this is explained in Marchaj but some of this comes from later reseach where full sized boats are instrumented and data collected)

Also the racing rule changed so that stability was no longer over penalized as it was in earlier versions of the IOR.

1983's Australia's America's Cup victory introduced the world to wing keels but more universally it brought a lot of attention to the posibility of lowering the vertical center of gravity by shifting ballast lower in the form of a bulb at the bottom of the keel. Suddenly race boats and cruisers alike began to sprout bulbs in one form or another. Most of the so-called wing keels that are on the market, really function as end plates and bulbs more than as true winglets.

If there has been a real revolution in yacht design, I would say it is in the IMS type form which is characterized by extremely low vertical centers of gravity, moderate to low form stability, fine bow sections to minimize slamming, and careful weight and buoyancy distribution to maximize dampening and minimize pitch and roll accelleration and angles.

As to sources for this, there was wonderful research done at Shiphydrodynamics Department of Delft University, Ship Science- School of Engineering Sciences and the Wolfson Unit at University of Southampton. and the Australian Maritime College, that looked at the factors that impact motion at sea, stability, wave action,etc. Some of these research result papers can be found on line. (If you can find them, two really good source papers are "An Experimental Investigation of Slamming on Ocean Racing Yachts" [mainly within the preamble] from the Ship Science- School of Engineering Sciences at University of Southampton and "The re-righting of sailing yachts in waves- a comparison of different hull forms" from the Australian Maritime College. Both can steer you to other earlier studies that were quite useful to me as well.)

Hopefully that should round out your reading list.

Best wishes,
Jeff
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Old 19-01-2004, 20:49   #30
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FYI

Here is an example of internal framing, as Jeff mentioned, that is in a Choate 40. They are hollow fiberglass forms layed along the inside of the hull through out to strenghten this cored light weight hull. They work very well. This vessel is picked with a forktruck everytime it is taken out for a weekend sail. And there has been no sign of flexing or oil canning in the hull.



This vessel is an IOR of the early 80's.
.................................................. ........................_/)

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