Multihull Capsize Prevention <split>

Indeed.
Now he appears to have gone because it became clear the Emperor has no clothes, I don't feel "smug" pointing out his hypocrisies, typical of self appointed and claimed experts:

He claimed to be such an expert and offer his services here:
http://www.boatdesign.net/forums/fi...courses-central-florida-42498.html#post543215

Yet was constantly asking basic fundamental questions of his "expertise":
http://www.boatdesign.net/forums/boat-building/what-joint-use-bulkheads-38333.html
http://www.boatdesign.net/forums/boat-building/easiest-way-lay-up-glass-one-person-37058.html
http://www.boatdesign.net/forums/boat-building/getting-ready-place-core-questions-36183.html

This is the problem when trying to have a serious debate, self proclaimed experts do not like to be questioned and rant and scurry off into the shadows, from their self imposed limelight, when exposed!

Back to the thread.

HASYB,

There are two points you raise.

1) The experience of the Capt./Master/Crew in their seamanship.
In terms of should they have known in advance not to have gone into such a "situation" to begin with?
From setting off to read the warning signs from the weather charts and even the simple meteorological signs that surround them at the time.

2) The design, per se.

The design, not matter how it is perceived to be "fail-safe" IE not able to be capsized, must always have a risk mitigation built in to enhance the inherent "natural" safety features. In this case, as you point out, the EPRIB.

However, there is a difference between the "cruising" type of vessel to the racing type. In terms of the acceptable levels of safety that are 'designed' into the vessel as a whole.

So, as MJ attempted way back, we really need to set limits and definitions of said limits to ensure we are all talking about the same thing and recognising where an event is either controllable or not, and the ramifications of risk mitigation based upon the hazard.

In the commercial world, which I am in, this is a HAZOPS study. I am not in the leisure market, so I am unaware of how much attention is paid (if any at all) to such rigorous studies of the design and its max-min design limits based upon the SOR and 'area of operation' and intended use.

Perhaps others who are in the leisure market design field can comment directly on such studies, if any.

Ahh..just as I posted:

In my field, it is a requirement to produce operating manuals, aimed at the design, which is more often than not based upon a rigorous HAZOPS study.

 

See he has come back and now says: "Location: With Apex1"

Well Sean, Richard would have hammered some sense into you . . .

Cheers,
Angel

P.S. - Meant Richard is the same as CatBuilder was referring to as Apex1, which is another one as Woods.

 

Angelique, may be the problem is you can hammer common sense into some people. As well the ones that do know know better than to try (Aka Richard)

How ever I agree with you Angelique in that I would like to hear Richards point of view, as I under stand he is involved in setting safety standards.

 

Weird and unpleasant to encounter people who throw a fit when not everyone agrees with their opinion. Some people always have to be right.
Too bad this CatBuilder wasn't capable of putting aside ego for a reasonable dialog with MikeJohns and Ad Hoc.

 

I think that in life you gotta cut people a bit of slack, every one gets a bit "burred up" now & then- if you don't get pi$$ed off etc or whatever occasionally maybe your just being tooo nice! Consider the great value that Catbuilder has brought to this forum, in that being very forthright in the trails etc in his timber build & the flow of info supported by a great range of questions he's raised in regards to construction, propulsion & systems of great interest to many. It's a shame he's bailed, of course there's a major construction that needs plenty of attention that's a long way from loved ones etc. All the best from Jeff.

 

Ad Hominem fallacies in lieu of logical discussion is poor behavior from anyone.

http://www.nizkor.org/features/fallacies/ad-hominem.html

There is no excuse for personal attacks. Aggression is required to be tempered by self control in society it should be much easier on an internet forum. It’s easy enough to leave the response and come back to it later with some intelligence and dignity.
But reading his responses they are not hot heated, they are calculated even if illogical and he steadfastly and carefully avoided discussion.

I think if you want to understand Catbuilder (and others) look up Psychology and Defence Mechanisms. Denial, Rationalization etc

 

I agree with you to some degree Jeff but as multihull sailors we should be careful not to go down the path of saying our boats are invulnerable to capsize or other problems. Understanding risks and how to best address them makes us better sailors and more likely to make the right decisions in a dangerous situation not denial that anything bad could happen. It's part of the reason in my view why multihulls had a bad reputation to start with early skippers taking unnecessary and unreasonable risks to "prove" seaworthiness. It's important we temper our faith in our boats with a bit of reason and common sense it's always proved the best approach.

 

Would it be a case of under standing the boats limitations eg: center boards or mini keels could influence your options.

It would be good to see some solutions put forward as well.

My personal observation has been, that it started out as wave only capsize, then to include wind assistance and now the human error into the capsize.

 

This is where it becomes a problem, and as Corley pointed out, spills over into the "invincible" aspect of their design/perception of any problem.

One can only propose to put forward solutions, if one recognises that a problem exists in the first place. There shall be many, as Corley noted, that take the approach, "if it ain't broke, why fix it"..based upon their own bias towards a subject/experience.

Thus if there are those that refuse to accept that ANY issue is a potential hazard, they shall also refuse to accept any solution.

As I noted earlier, one must first separate the issues from controllable...ie design...to uncontrollable, ie weather. This is what MJ was attempting in defining the limits and definitions being used by many posters.

Once we have a common set of definitions and understanding of what can or may or does occur, this forms the platform for a pro-active discussion and to explore where it may lead. Since one must look at every aspect and not begin with a predefined opinion/outcome based upon an assumption. No matter how small the possibility, it must be explored, and then and only then discounted based upon XX or YY or ZZ reasons, where possible. The final solution has its "probability" of occurrence, and the risk/hazard is based upon that probability.

Every airplane in the sky has a certain probability of falling out of the sky, but where such events that lead to it are minimised (from a very very rigorous study of such events, no matter how "irrelevant" to others it may be) to the point of being almost insignificant can the system be determined to be "safe". The probability exists, but everything that could be done has been done to mitigate it.

This is what is required in such a debate. Thus ego's and emotions has no place. Just sound engineering,science and practical experience and knowledge of what can occur to explore all aspects of such an event.

 

Corley said:- "as multihull sailors we should be careful not to go down the path of saying our boats are invulnerable to capsize or other problems.'

I have been sailing both monohulls and multihulls since 1958. I have never experienced a "Rogue wave", nor an "Air burst". Nor have I experienced a capsize or pitchpole in any boat over 16 ft.
Perhaps I am just lucky, but I have had some frightening experiences on Lake Ontario, the Bermuda Triangle, Bass Straight and even Lake Simcoe in Ontario, Canada.
One particularly wicked night, in the Annual Sommerville Race on Lake Ontario, three monos lost their rudders, two lost their masts and a very nice home designed, home built, 40 ft Catamaran broke up and sank. We were sailing a 28 ft trimaran, which attained some remarkable attitudes, and took on a considerable amount of water thru the leaking float hatches, (supposedly watertight), but otherwise held us safe.
As a result of these experiences I would NEVER say that a multihull, of any configuration, is invulnerable to capsize or other problems.

 

Well thats just the point isn't it Oldsailor I've never experienced a capsize on a large multi (wind or wave) either and hope to never have one. It's just good not to be blinkered and say that it could never happen. Accidents drive improvements as long as we can learn from them and this is one area where the aircraft industy is really good they document all failures (no matter how minor) and discuss them both the human and mechanical aspects. I'm not losing the (multi) faith or anything mate . Trimarans and catamarans have proved through usage to be very safe and it's not heresy to suggest they could be designed to be safer or that certain approaches to seamanship would not improve your chances of survival in the worst conditions.

 

I agree with Old Sailor and Corley in their comments, you can only pass on what you know.

What I meant by solutions was lessons that can be passed on to provide more options to reduce the chance of a capsize or pass on lessons learnt, which I have noticed in magazines article when there is an article.

I would like to be productive rather than just knocking any comments.
As the heading mentions prevention as well as capsizes.

 

I would have preferred that the thread title had remained just multihull capsize since there is are cause and effect issues. For example capsize in heavy weather also render the upturned hull dangerous as a survival platform. I'd really like to see designers to take this more seriously.

Perhaps it's important to understanding the designers limitations or the compromises they choose as well ! Performance is seductive in a world where designers can be judged on how fast the design performs rather than how safe they can be made.

Perhaps a good assessment of a designers consideration of safety especially for performance designs is to look at what they have considered for inverted floatation and access.

A big problem I see with multihulls is that they appeal not exclusively to good skilled seamen but also particularly to people who have very little skill in seamanship. They are attractive to some primarily as as floating condo's, and sailboats second. The choice of design based on marketing and performance. But performance means light weight, fine bows and large sail areas, the very vessels that needs more experience and skill in their safe operation. Consequently and inevitably less knowledgeable operators are mislead with a popular culture of misleading information. They are the operators more likely to suffer casualties.

Less experienced people would arguably be much better off in a monohull when the conditions deteriorate simply for the obvious warnings the type of craft provides.
This is borne out by looking at insurance claims in the charter fleets. Claims for cats are surprisingly high and are far less for monohulls pro rata. There's also apparently a surprisingly high rate of loss of catamarans (pro rata) that have been purchased ex-charter in the Caribbean and are being sailed back to the US mainland in the Atlantic by their new owners.

In Australia we don't see so many claims because the routes are coastal with good shelter along the coast and the cat is so admirably suited for the Australian East coast .

But be aware that ‘designers’ and marketers are not immune from pop culture either. I was told by a salesman at a boat show recently that he had it verbatim form the designer that a 50 foot cat could not be capsized at all by anything! No wonder people get confused.

Then there’s this sort of misinformed prejudice in marketing material:

The most stable position for a catamaran is indeed upside down on the top of the ocean. But the most stable position for a monohull is at the bottom of the ocean. A well built and properly designed catamaran is very hard to sink….

…which is not Naval Architecture, it’s just hype. This isn’t about monohull vs multihull and I don’t have a bias, but when it comes to boats, a well built and properly designed monohull is a much safer vessel overall and will be not only very hard to capsize but completely immune from sinking from a capsize if it happens. And admirably able to effect self rescue.
This is a good illustration of pop culture subverting fact since it gets dished up by people even 'designers' who should know better.

 

Well I have Gavin Le'Sueur's Multihull Seamanship on my bookshelf which details some practical approaches to multihull safety such as towing drogues and sea anchor usage plus a number of steps towards inverted safety should the worst happen it's a pretty good read.

There is also John Shuttleworth's article on considerations for seaworthiness (cats and tris) that is a good read and details capsize mechanisms and some suggestions on how best to address them while sailing multihulls. It is an older article now but the points are still pertinent.

http://www.john-shuttleworth.com/Articles/NESTalk.html

 

Thanks Corley I also have a copy of Gavins book and now he can add capsizing to his experiences albeit in a racing situation. Gavin also passed on what he learnt from it in his article in the multihull word article issue 112. Boat ex top gun.