The perils of edgy design offshore

[Doug Lord]

The Perils of Edgy Weather in Any Boat

Oh yeah sure, they should. Why shouldn't they? The more participants to the race, the more money and visibility in the media for the show.

It won't be them anyways (the race committee members) to jump into cold and wild water and risk their own lives to save the reckless (or simply) ignorant skippers ("adventurers", as Gary Baigent calls them) when sh*t happens. No, it will be CG rescuers and crew from other boats. Too bad nobody has asked them whether they are happy or not to face the peril just because the show must go on.

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There is another possibility: maybe Gary is right?!

 

[Ad Hoc]

In a broader consideration of stability: it amazes me that this same race allows multihulls whose inverted stability is legendary and whose ability to self-right is non-existent in most cases...

So, please provide a stability, GZ Curve, of a multihull, and then over lay the result with the Kiwi35 as shown in this report.

 

[upchurchmr]

Every boat can be "improved".
Will you throw out a type of boat because one specific boat was not perfect?
Lets assume that the premise that a Naval Architect can help choose a better boat is reasonable. Nothing new here. To me this is undoubtably true.

What would be the design features making this boat "reasonable"?
Doug listed several options. What would be the suggestions of the technically qualified in this forum? Besides go get a more conventional design.

Someone mentioned skimming dishes vanishing 100 years ago due to "similar" issues. Looks like a natural evolution of trying something new, refining the design due to hard lessons, and moving on. Unless someone got excessive with the rules - I don't know the history.

 

[Doug Lord]

So, please provide a stability, GZ Curve, of a multihull, and then over lay the result with the Kiwi35 as shown in this report.

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For the purposes of this discussion what matters is that the multihull can capsize and has capsized and killed two people in a Great lakes race. While at the same time the Kiwi 35 is vilified because it can capsize and has capsized and killed two people in a Great Lakes race.

I just think there is a double standard being applied-I love multihulls but the risk is there because of the nature of the beast. I accept that when I sail one
and so do many, many others. Yet when someone suggests that a sailor ought to be able to accept the risk to sail an edgy monohull that might capsize that person is called names by at least one naval architect.
Something is just not right.

"..The crew also seemed unaware of the danger lurking in vessel’s design and how it was being used..."

Sums it up nicely too, yet here we have others reading the report and still not comprehending!

This quote from the report(not the "Findings") says it all. We are asked to believe that an experienced sailor ( who had modified the boat to increase its stability!) "seemed unaware of the danger lurking in vessel's design and how it was being used". That is just plain hogwash because in many of the writings by the owner and in the actions taken by the owner there was an obvious recognition of the edginess of the design in its particular application as a Great Lakes racing machine. I would venture to say that the skipper of WingNuts clearly understood the nature of the boat he was sailing as do those who, with the blessing of the Chi-Mac organization, sail high performance multihulls in the same conditions.
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To be clear, I think the recommendations by the report are a good thing. They don't condemn wings just boats with poor stability and good inverted stability. Monohull designs can be done that are as fast or faster than WingNuts w/o the downside and that is a good thing. But there is this nagging feeling that something ain't right here......
---

 

[troy2000]

Let me repeat myself. This is how the owner of Wingnuts himself described his own boat:

The boat is fun to sail very tender, two people out on one of the wings will put the wing in the water. You almost need a deck buddy to move around the boat. If your go port you need an equaled sized person to go starboard.
Being built of Kevlar and divinycell the boat is very light and the acceleration is amazing.

We just completed a restoration and upgrades to our Kiwi, WingNuts adding a retractable bow sprit, carbon mast and deck layout and gear.

http://forums.sailinganarchy.com/index.php?showtopic=63036

After reading that, can anyone here seriously argue that Wingnuts was designed for offshore racing? It was like taking a sports car on a Jeep trail....

What he calls 'tender,' I'd describe as downright squirrely. Lots of fun in a day race, but not something I'd take out of sight of land.

Doug, you're right when you say catamarans aren't generally self-righting, either. On the other hand, they're a lot less likely to turn bottoms-up to begin with.

 

[Gary Baigent]

All this stuff about ignorant skippers and crews being unaware of what they're getting themselves into ... is again ignorant BS; they are fully aware of what can happen when involved with overpowering elements if they're sailing an "edgy" design.
Relating back to the multihull/skimming dish mono similarity - and by the way, the skimming dish has never died, look at all the race monohulls of today, all, without exception have skimming dish-like hull shapes, in fact even more extreme than the Century old examples, anyway back on point: there were in Australia during the Crowther/Nicol early period, swathes of mouthy committee revering pundits, who absolutely denigrated to an "abysmal" degree multihulls after some at-sea losses there ... yet the multihull, through evolution has now become recognised as THE modern race yacht, hold all the records and have been developed to extreme sophistication. Who is to say that a wing-type monohull, will not do the same; say by fitting foils, blistered decks, buoyant wing rigs and so on, big foiling Moths, of which a few "adventurer" designers and sailors are working on at the moment. Some of the bigoted EG's here will of course disagree, just as they did/do about multihulls ... they will be proven wrong.

 

[MikeJohns]

..........they are fully aware of what can happen when involved with overpowering elements if they're sailing an "edgy" design.
......................Who is to say that a wing-type monohull, will not do the same; say by fitting foils, blistered decks, buoyant wing rigs and so on, .................... Some of the bigoted EG's here will of course disagree, just as they did/do about multihulls ... they will be proven wrong.

This is just religious preaching with the pre supposition that you can be nothing but right. But you have been wrong or wildly incorrect on aspects of Naval Architecture, strong opinioins don't make you an expert and you should be trying to discuss this from a technical view and learning what you can rather than retrenching into a biased viewpoint.

Again and again you continue to miss the real point, and head off on an enraged tangent tilting at imaginary windmills. They just are not there, they are in your head.

For example whether the boat has wings or not is not the issue. It's about the whole boat as a system. The same as any vessel.

Read again what I posted here:

.........If the hull has an inbuilt tripping mechanism when hit by a beam sea it had better have other factors such as good damping, roll inertia and righting moment to compensate. ...........

and here

......The real issues with a design like this should be how much higher the LPS should be above the accepted standard, to cope with the added drag from the projections in a knockdown and the enhanced overturning moment from any sideways translation........

Try and understand that if the tried tested and proven physics say it's unsafe then it is period, no matter what your opinion is.
Then only a fool argues that it's heroic advancement in the face of adversity, rather it's just a very high degree of dependence on the welfare state. And for what exactly ?

 

[Gary Baigent]

You're the preacher, MJ - with an absolute belief in old book physics, restricted book view physics - you seem incapable to think outside the box/book, yet you continue to preach your arch conservative BS. Books can go out of date, the knowledge superseded. And now, after all your earlier derogatory statements about wings, or not having wings, now the wings are unimportant, it is the whole package instead. Confusion?
Actually my strong opinions are based on historical developments, from observations about what happens, and is happening - and not the results of silly committees, or outdated books. Are you a strong committee man, MJ? I think so. I'm for the new books and the ones yet to be written about what is happening right now, modern history, something of which, it appears, you have little knowledge and have difficulty comprehending.

 

[Willallison]

You're the preacher, MJ - with an absolute belief in old book physics, restricted book view physics - you seem incapable to think outside the box/book, yet you continue to preach your arch conservative BS. Books can go out of date, the knowledge superseded. And now, after all your earlier derogatory statements about wings, or not having wings, now the wings are unimportant, it is the whole package instead. Confusion?
Actually my strong opinions are based on historical developments, from observations about what happens, and is happening - and not the results of silly committees, or outdated books. Are you a strong committee man, MJ? I think so. I'm for the new books and the ones yet to be written about what is happening right now, modern history, something of which, it appears, you have little knowledge and have difficulty comprehending.

What a load of obstinate bollocks! When you manage to produce one of these "new world" physics books, that manages to re-write the current, proven and well understood versions, then I for one would love to see it.
The REALITY is that for those who want to push the envelope, there are faster and infinitely safer boats out there to do it.

 

[MikeJohns]

You're the preacher, MJ - with an absolute belief in old book physics, restricted book view physics - you seem incapable to think outside the box/book, yet you continue to preach your arch conservative BS. Books can go out of date, the knowledge superseded. And now, after all your earlier derogatory statements about wings, or not having wings, now the wings are unimportant, it is the whole package instead. Confusion?................ it appears, you have little knowledge and have difficulty comprehending.

Ha ! You should actually stop, and consider properly whats being posted.

There is very little sensible that you've posted in this thread and you've demonstrated some very concerning ignorance about naval architecture. Your reply to this is to claim that physics has a use by date and your new physics based on nothing other than opinion is vastly superior, Therefore you are right and everyone else is wrong. That view just doesn't wash.

Anyway as to your further confusion about my view, if you cannot go back and read the link I'll post it here:

.................
The real issues with a design like this should be how much higher the LPS should be above the accepted standard, to cope with the added drag from the projections in a knockdown .....................

That's physics, it's also simple, it never goes out of date that can only happen in fantasy worlds.

All you have are opinions based on a very narrow understanding of the subject, you contribute no facts, studies, papers to contradict the professional view and you have historically shown yourself outside of this forum to be not only ignorant but to hold an extremely stilted view.

You also don't seem to comprehend that we as a professional group are not "quoting from ancient outdated books", we actually are observing from a fundamental understanding of the subject.

 

[upchurchmr]

Gentlemen,

Physics works. It is the cleaverness of the designer, engineer, builder, owner, operating within the limits of physics that provides new opportunities. Not to ignore the sailor who actually finds out how to get around the percieved limits of basic physics with technique, inovation, attention and luck.

Nothing is cut and dried. Poor boats have been sailed a long way, great boats have been wrecked thru ignorance, inattention, and bad luck.

MJ - how would you evolve this boat to be better? Second time I asked that - it is easier to yell at someone, I personally was just reminded not to do that in another forum. Guilty as charged.

What can we get out of this that is positive?

Marc

 

[Ad Hoc]

For the purposes of this discussion what matters is that the multihull can capsize...

So, since you are unable to provide as requested:-

So, please provide a stability, GZ Curve, of a multihull, and then over lay the result with the Kiwi35 as shown in this report.

...which implies you are unable to do so (thus speaking from ignorance), or do not wish to supply the data (because you know you expose yourself to more critiquing). So, here is one i made for you to understand the simple facts you are very clearly missing.



The reason why the graph looks odd, to to ensure that both stability curves are on the same scales. The GZ of Wingnuts is taken directly from the report.

So, with a strong wind heeling moment that is sufficient to knock down Wingnut, what effect does it have on a catamaran??....well, it is clear to see, the result is an angle of heel of roughly 2 degree. I shall repeat this for the hard of reading, 2 degrees! A wind heel that would capsize Wingnuts produces a heel of just 2 degrees in a typ. sailing cat.

So, you feel there is cherry picking when it comes to one boat versus another boat. With the evidence presented, please again, explain why?

 

[Ad Hoc]

Books can go out of date ....

Oh dear, someone with delusions of grandeur that is incapable of logical reasoning and theorising based upon observations to produce consistent and repeatable engineering knowledge open to any independent scrutiny.

So, the book by Issac Netwon "Philosophiæ Naturalis Principia Mathematica" published in 1687, is now out of date. Ergo F=MA is no longer valid??..hmmm interesting...tell me more

 

[Doug Lord]

Ad Hoc, I appreciate that you supplied the information that you wanted . And also the commentary to go with it. Tell, me what exactly is the "typical sailing cat"?
Most high performance cats I'm familiar with sail with the windward hull flying when racing-maybe 6- 10 degrees angle of heel. Most high performance racing cats fly the windward hull in less than 10 knots wind intentionally when racing. Yet you show the "typical sailing cat" sailing at 2 degrees in the approx. 50 knots of wind that the report says capsized WingNuts.
Whats wrong with this picture?

 

[pdwiley]

Ad Hoc, I appreciate that you supplied the information that you wanted . And also the commentary to go with it. Tell, me what exactly is the "typical sailing cat"?
Most high performance cats I'm familiar with sail with the windward hull flying when racing-maybe 6- 10 degrees angle of heel. Most high performance racing cats fly the windward hull in less than 10 knots wind intentionally when racing. Yet you show the "typical sailing cat" sailing at 2 degrees in the approx. 50 knots of wind that the report says capsized WingNuts.
Whats wrong with this picture?

From my POV, what's wrong with your argument is that you won't supply any numeric data to support your opinions, whereas Ad Hoc can & does.

So, if you don't like his choice of numbers, the solution is simple. Stop whining about what he picked and post your own.

PDW