How strong is construction of this catamaran in storm?

Here's some further exploration with a fairly proven design gp333, http://www.solarnavigator.net/transatlantic_21.htm

 

You are joking, as usual, are you?:?:

Or are you exploring well known territories which are widely unknown by you?:?:

The more you post here, the less I believe you have ever seen a boat...
Sorry Watson, you are a layman, and I do not enjoy your jokes any longer.

Regards
Richard

 

Huh ?? - Doesnt make sense to me - if they know nothing about structures or rules why would they ask about 'a known standard' ? Isnt that a set of structures and rules ?

What has 'fit for purpose' got to do with what we are talking about ? - which is structural integrity for safety in a storm, not whether it will actually work as a concept.

 

Yes - you should.

Do you think that marine insurers pull a quote out their ***...ess on a whim ? They are the reason for all the boatbuilding standards, and they wont risk a million bucks on the hull alone, and several million dollars on third party risks, unless some reputable ( and professionally insured ) names are put on the application form.

 

Q..is there a standard of any sort, to which one can design a boat…yes or no?
A..yes.
Q…has the boat been designed to meet said standard, yes or no..?
A…yes

Box ticking exercise is done.

Asking a very simple basic questions does not carry a prerequisite of knowledge, just common sense and establishing whether one has performed due diligence.

Fit for purpose = being designed to a known standard commensurate with the intended purpose.

I wish to travel the world’s oceans; do I design to a standard for inland river boats…??

See common sense goes a long way…

 

The process of getting say a million dollars of boat insurance, especially for such a different concept, is a lot more involved than 'ticking boxes'

Insurance companies are not the 'dumb paper shufflers' your post implied them to be, for that amount of money and for 'out there' projects.

Also, 'Fit for purpose' has a far wider legal meaning than the environment that the boat operates in eg http://www.qualityresearchinternational.com/glossary/fitnessforpurpose.htm

I cant remember ever seeing an insurance clause for a hull even vaguely like a 'fitness for purpose' clause. That would be a too wide and complex condition. If you have an example, I would be interested to read it.

Business Law and Practice are not based on 'Common Sense', or lawyers would starve.

 

As usual you are missing the point Mr. Watson.

Insurers do not even bother if the junk is fit for purpose, they just trust in the builders and/or classification societies responsibility and liability. We insure newbuilt vessels every other day without providing anything but the basic data and value of the boats.

And of course there is a clause of 'fitness for purpose' in every single insurance policy. If the skipper operates the insured vessel in conditions it was not designed/built for, he looses coverage.
Quotes they pull out of their ***..es (or drawers) of course. It is just the value of the boat what counts, nothing else. (the area of operation can have some influence though)

So simple is colour TV, you know?

Regards
Richard

but we are off topic on a "off topic" thread..........

 

Thats interesting Richard - could you send me a copy of the page with that clause in "Fit for Purpose" ? I would be very interested to read it.

Re "Quotes they pull out of their ***..es (or drawers) of course."
Well, the insurers in your part of the world must want to give their money away. As it happens, I was getting a quote from Club Marine yesterday on my little wooden boat project. Within two hours I had been directed to their local surveyor to arrange an inititial inspection of the building premises, and it will need a final inspection on launch day for a crappy $20k of cover.

If had rung up for a million bucks of cover, for a strange "not off the plan" design, I bet there is an awfull lot of hoops I would have to jump through besides that.

You can be as rude as you like about any boating experience I may have, but this is business - and I know how money works.

 

You should deal with pro´s.

Pantaenius..............
Hamburg

 

Claims can get quite messy if there is a claim and inadequate design is to blame.
The insurer can and often will deny cover or legal aid if the engineering report says you didn't comply with minimum accepted standards ( an acceptable current class construction rule).
There are tomes on the liability of Class societies, the insurance company’s risk assessors are well aware of just where their cover ends. The same tomes apply equally well to any designer working outside of class cover.

Insurance surveys are usually not a design check but a risk assessment based on the vessel condition. If you land in court with structural failure and a significant claim the lawyers will be challenging your design work, if it was built to class ( full procedure not just following their construction rules) then the insurance will sue the class society on your behalf, the same if a NA/ME signs off on the design.
Unless you hit something! A lot of poorly built boats claim they hit something, then whether the design is inadequate or not it’s down to the damage you’d reasonably expect from such a “collision” and that is what gets covered. Even when there’s clear evidence of poor design, materials, or fabrication.
It’s a legal world out there and a lot of people know how to play the game. If you have a moderately good case and some professional support the insurers nearly always pay out smaller claims ( a few 10’s of thousands) if you take them to court. They settle after the direction hearing but on the eve of the main hearing.

 

Looks like a bulbous bow times two which must mean it is twice as good.
The center hull is large and takes over when conditions (OMIGOD LOOK AT THAT WAVE!) submerge the relatively small Amas (pontoon thingies).
The structural loads on this vessel can get messy if the Amas are too big and break it apart. One advantage of monohulls is the water 'pushes in' everywhere, holding it all together, as many old rotten boats show that stay whole in the water but disintegrate when removed therefrom.
The thread vessel is an interesting idea and seems quite workable with the right construction.
Multihulls of any type are constantly being wrenched apart and must resist this. The traditional (relatively slow ancient Polynesian and modern Wharram Cats) do it by flexibility. Modern, very fast multis are more rigid but still very 'springy' and resilient and able to absorb large deflections (see anything by Nigel Irens) and many variations in between.
Has one of these thread vessels ever gone 'missing'? Every other hull type has.

 

Structural strength is directly related to displacement and speed.

 

Most cats don't need to be really strong , only strong enough to capsize ONCE.

FF