The perils of edgy design offshore

[MikeJohns]

Originally Posted by Gary Baigent

Don't know why I'm continuing to post to this ridiculous thread - but aren't you two dingalings missing something? - the most modern yacht development is the multihull........ capable of capsize .............. but according to your viewpoints, all these boats can invert, therefore they should not be allowed to sail open water. ....do you enjoy being members of the daft and backward generation of multihull bashers?

Originally Posted by Gary Baigent

........ you revert to your favourite weasel word claiming obfuscation. There is no confusion with multihulls; my above post is my first reference to them and introduced because of your biased comment about the K35, .........

You never mentioned them before? and a I have a biased view? and your not weasling (your term) away at confusing the issue ? : You aren't taking any notice of anything anyone posts here are you including yourself and you are making some foolish statements.

Originally Posted by Gary Baigent

........ These light, wide types are like multihulls. And that is accepted by crews who sail them.

Originally Posted by Gary Baigent

.The idea is to keep them on their feet, just like a multihull.

Originally Posted by Gary Baigent

However, like a multihull, in the K35's case, it didn't sink ..............

You just don't get it do you If you are interested in anything past your current opinion then consider this (again): The unsuitability for k35 offshore or the Moore 30 or any similar craft is and has been well known for many decades. The design which provides a mechanism for violent inversion in small beam seas and it's poor stability make it unsuitable for inclement weather offshore.
What part of this exactly don't you understand, or would you challenge?
Keep open 60's and multihulls out of it, just talk small light unstable winged sailboats. Then you might get somewhere towards understanding a sensible approach to assessing seaworthiness, rather than naive emotive opinions.

[magwas]

Originally Posted by Gary Baigent

MikeJohns, the basis of your dogmatic argument, resulting from your immense knowledge of naval architecture - is that the K35 is unsuited for open sea sailing because it can capsize.

I am by no means an expert, but I guess that the main point is that this cake pan can relatively easily capsize but the technical and procedural measures to make it less likely and mitigate the effects (identical or similar to those you can find about a multi) are not there.

Note that I don't have a problem with a boat which stays inverted. I have a problem with a boat which is easy to bring to that state, and even greater problems if there is no measures for when it happens.

One of my favourites is the Laser, which is easy to capsize. But it is easy to right, and I would not sail blue water with it.

[Ad Hoc]

Originally Posted by Gary Baigent

There is no confusion with multihulls;

Oh, how so:

Originally Posted by MikeJohns

So if the design is clearly unseaworthy has a higher risk of inversion and a lower chance of re-righting it makes the boat dangerous to operate offshore

Ahh…you don’t like this statement. Please explain why this statement is incorrect?

....and as you reply please refer to the graph below, which is real naval architecture, not randomly selected words to appear knowledgeable.



Now, back to the issue which you fail to grasp, simple monohulls; also for your education:



You seriously do not understand anything about stability, seaworthiness nor risks despite your endless and tiresome protestations to the contrary.

So, just that anyone reading your posts is clear, can you please answer this question before proceeding:

Are you a qualified naval architect, yes or no?

[sharpii2]

There seems to be not one but two 800 lb gorilla's in this room.

Gorilla #1:

This type of boat is potentially much faster than more conventional mono's of its length and weight. Its narrow, trimaran like hull can laugh at waterline length/speed limitations all the other mono's are more or less imprisoned by. The problem is that it would be very difficult and politically incorrect to try to rate them properly. Therefore, if it is allowed to race with more conventional mono's, even beamy ones of the same length and weight, it will soon come to dominate. Once it does, all other types will be obsolete making this the new standard type.

Now I have great sympathy for those who want to sail fast and are even willing to take a few reasonable risks to do so. I think this boat fits that bill reasonably well.

My problem is with those who are willing to force everyone else to take similar risks, if they are to have even a glimmer of a hope of winning.

Now you have taken mixed class racing and turned it into single class racing. Winged deck boats, or stay home at the dock, buddy.

I have no sympathy at all for those who claim this type of boat is as safe as a more conventional keel boat, even one of late IOR design. It is clearly not.

As presently designed, it is highly unlikely to recover from being flipped. Most late IOR boats can and did. They just took longer than a heavier, narrower keel boat would and it usually happened after a considerable amount of water had come aboard. They are generally capsized by wave action, which leads them to be righted by the same.

Most IOR boats had at least 40% or more of their total weight in ballast. With this type it may well be less than 20%. With the 14 ft Beam and the 7 ft Draft, this type has a comparable Draft/Beam ratio to a more conventional mono of the same weight and length, but likely half the ballast.

Perhaps they need a developmental class of their own. Let them race with more conventional types, but only against each other.

Gorilla #2

This boat may be safe enough to race in some off shore events (ones that have plenty of other race boats around and are not all that far from rescuers) and can even be made significantly safer without compromising its design concept significantly.

I do not see this type of boat as unreasonably dangerous as long as its flaws are well recognized. The main flaw is that it can not only capsize, but capsize with terrific force. I will not be surprised if we later learn that the two who drowned were hit by the deck when the boat went over. Helmets might have helped here. Perhaps they can be part of standard heavy weather gear on this boat type.

From what I can see in the pictures, this boat had a safety line that wrapped around its perimeter. On most boats, that are either in a type of service that they are unlikely to be flipped, or are very difficult to flip, this is a good idea. On a boat like this, in this kind of service, they may not be such a good idea.

I am a faithful user of seat belts when I drive. But if I was driving over a rickety, low bridge, I might forgo them until I got to the other side. The safety harnesses could get entangled with them in the event of a violent capsize, trapping the wearer within its perimeter, especially if he or she were injured. Without the safety line, it is very possible that the two victims could have drifted out from under the deck and floated to the surface before drowning, even if knocked unconscious.

I think that with very few design modifications and some that can even be retrofitted to existing boat, this boat could be made to be less likely to flip and maybe even to be able to recover from a flipping.

1.) The rig set up can be made to make the boat more likely to round up into the wind in a coming squall, rather than try to run before it. I would make the main roller furling to the boom and I would replace the roller furling jib with a standard jib with a down haul. In the event of a squall, the jib is quickly hauled down, leaving a bare fore stay, and the main is roller reefed to maybe one third its original height, making it a decent weather vain fin. Once rounded into the wind, the wind would have much harder time flipping the boat.

2.)The wings could be isolated from the main hull with a longitudinal bulkhead and fitted with various valves and drains. These, when put into action, would allow water to flow freely in and out of the wing deck structures, making them much less relevant when it comes to righting the boat. As the inverted boat tips to one side, the wing deck structure on the high side drains as it leaves the water. The wing deck structure on the low side stays completely filled with water, offering little or no buoyant resistance. The boat then behaves nearly as if the wing deck structures weren't there. The amount of ballast might have to be increased, floatation might need to be added to the top of the mast, and certain construction methods for the wing deck structure would have to be rejected (No buoyant cores allowed).

3.) On new designs using this concept, the Wing decks could be made more buoyant (when not flooded), making them less likely to dig in by carrying their maximum thickness closer to their ends. They would essentially have flat bottoms ending with a radius equal to half their thickness all around their outer edges.

[Gary Baigent]

Good suggestions Sharpii2, making the wings into buoyant and draining ballast tanks. Another would be to have a buoyant mast, meaning one that does not fill if immersed. This too has been something multihulls have worked on and evolved solutions from over a number of years.
AH and MJ, we've circled the same boring rock a number of times, best that you turn starboard and me port, and we'll go our different ways.
But one point before we reluctantly depart ... looking with slight interest to see if either of you have ever designed and built anything nautical.

[Willallison]

Originally Posted by Gary Baigent

But one point before we reluctantly depart ... looking with slight interest to see if either of you have ever designed and built anything nautical.

chuckle...chuckle..chuckle.... Just a few GB, Just a few.....

[Ad Hoc]

Originally Posted by Ad Hoc

So, just that anyone reading your posts is clear, can you please answer this question before proceeding:

Are you a qualified naval architect, yes or no?

And we get.....

Originally Posted by Gary Baigent

AH and MJ, we've circled the same boring rock a number of times, best that you turn starboard and me port, and we'll go our different ways..

Ahhh..that's a no then

Which very clearly explains your biased amateur emotive polemic diatribe. Thanks for the clarification

[Ad Hoc]

Originally Posted by sharpii2

… I do not see this type of boat as unreasonably dangerous as long as its flaws are well recognized…..

There in lies the crux.

Some do not see this type of design as having any flaw, quite the contrary,..ergo..what is wrong with it?

But to recognise its flaws requires only a basic understanding of stability, then mitigation is easy. You can lead a horse to water….

[MikeJohns]

Originally Posted by Gary Baigent

........AH and MJ, we've circled the same boring rock a number of times,.......

You have steadfastly sidestepped the subject with vehement denial.

Several of the more knowledgeable posters here are standing on that rock shouting “rock”, you ran straight into it and sank, now you are swimming around still saying that it’s actually perfectly safe to collide with and the subject is boring so we should agree to differ, and by the way do we design boats

[Mat-C]

I'm not one way or the other on this issue... though just looking at that boat screams unstable to me.... But, I would like to pose a question...
I would imagine that the stability curves of a winged mono and a catamaran would be about as disparate as could be up to the point where the wing touches the water. The stability would then rise dramatically - possibly to a similar level as the cat. (Feel free to correct me at any point...).
Then, as the boat goes over, both are at least as stable upside down as they are right way up.
Now, I agree, this sin't really a desirable situation! But what is it about the winged mono that makes it less suitable offshore than a cat? Is it simply that it would (I would think) take more to capsize the cat in the 1st place?

[Gary Baigent]

You mean several of your pet sycophants, don't you, MJ? Actually my designs can't sink.
East is east etc... and n'er the twain shall meet. Shall we leave it at that.
Good stuff, Mat-C - but you'll be confusing the pedants.

[Mat-C]

Originally Posted by Gary Baigent

Good stuff, Mat-C - but you'll be confusing the pedants.

Don't misinterpret my post GB.... I have an enormous amount of respect for most of the contributors you are arguing with - MJ, AH and WA in particular.
I'm simply interested ... and trying to further my knowledge... something I know they can help me with....
Ask these gentlemen a question and they'll quite happily confound you with their extensive knowledge.... debate with them by all means, using fact or physics.... but tell them they know nothing about the area of their own expertise and you are likely to get your head (politely at first) bitten off...

[DennisRB]

Not much to add, but I would rather be on a 35' multi than a 35' winged mono like Wingnuts in those conditions. 4-6 foot waves are not going to pose much threat to any well founded 35 foot multi.

[daiquiri]

Originally Posted by Mat-C

But what is it about the winged mono that makes it less suitable offshore than a cat? Is it simply that it would (I would think) take more to capsize the cat in the 1st place?

Apart that, which was summed well by the graph visible in Ad Hoc's post #123, - it's the flipping mechanism which makes the difference, or the dynamics of the flipping action. This boat's wings, if dipped in a lee wave through a combined action of strong winds and high seas, could imho act as a pivot for a catapult-like action. The force for this catapult action comes from:
- the sails' aerodynamic forces
- the heeled hull's increased windage. A hull of this form, when heeled, can be compared to a flat plate set at an angle to the wind
- the inertia force acting on the boat, once the flipping starts.
The increased buoyancy alone, due to the submerged wing's volume, is imho insufficient to counter-act these destabilizing forces - so the flipping, once triggered would be quick and violent (depending on the wind strength, of course).

While it is generally important to consider the curves of static stability, in this case it is this flipping dynamics which draws a bold line between winged monos and catamarans, and which (imho, as always) should become part of the assessment of their seaworthiness.

Sharpii has imho put it in the right perspective with few words:

Originally Posted by sharpii2

The main flaw is that it can not only capsize, but capsize with terrific force. I will not be surprised if we later learn that the two who drowned were hit by the deck when the boat went over.

Cheers

[Steve W]

After 9 pages of the edgy design subject im somewhat suprised that nobody seems aware that another boat capsized and didnt come up in i believe the same storm in a 180 mile race from Racine,WI. I think it was called the Hook race or something like that. The boat was an Ultimate 20 sportboat, apparently it capsized about 5 miles from the finish during the night, stayed down, basically sunk but not fully due to trapped air,the crew called for help on a cell phone or handheld vhf and were picked up with no injuries. This is all 3rd hand info, anyone know more?
Steve.