53 foot Cat breaks in half

[FSMike]

Considering James Wharram's overall design philosophy (light weight, flexible lashed together construction, low profile, etc.) I am very surprised that he gave permission for making the boat heavier displacement with an Aero Rig.
It will be interesting to hear what he has to say about it.

In his book "The Cruising Multihull", Chris White mentions that his trimaran "Juniper", had a freestanding mast. He also mentions the difficulty involved in putting such a rig on a catamaran.

[garrobito]

..If I remember well "Elf Aquitaine", Marc Pajot big cat had multiples troubles with aerorig until capsizes...
"Fly" the first aerorig monohull still around (I think it's on sale on Europe)
The original wing sails proposed by wharram for that cat it's perfect...

[admiralslater]

Our first cat was a Wharram 27 back in 1967 when I was 4. We sailed for it a couple of years before moving on to a cat my father Alan Slater designed .There were several Wharrams around at the time and many made Atlantic crossings successfully .The only one that came to grief was a 50fter. were the owner put a large bridge structure on it . It to broke in half . Wharrams have many unusal qualities' the foremost being in disapaiting load through flexibilty. When you try and create stiff structure on a flexible platform you will have failures . We never could get forestay tension on the 27 but we also never got any jarring in rougher weather ,the boat flexed around the waves and reduced the load .As for failed lashings I would be surprised ,many of todays sport boats lash the shrouds . Modern cats are different in most ways to Wharrams designs but he was inspired but the polynesions of thousands of years ago . 15-20 years ago a boat called Gia (I beleive ) sailed from the south Pacific to B.C. maybe they saw it . I feel terrible for these people ,they obviously put their all into it. I am no great fan of Wharrams but I understand them,I just hope that he does not get blamed for this
David
Ps sorry about my spelling, typing, grammar etc

[Cheechako]

Cats: that's why they have 2 hulls... a spare for when it breaks in half....

[Paul L]

Originally Posted by mikereed100

Wharram Custom 53′ Catamaran Boats and Yachts For Sale, photos, review, specifications, price, charter

The above link states that this is a modified Wharram design with the mods approved by the designer.

I wonder what they mean by 'broke in half'. Could be anything from 'the lashings failed' (this has happened on a Wharram not built to spec) to 'the Aerorig punched through it's supporting crossbeam'. At any rate, it is a shame as it appears the owner/builders put a lot of thought and love into it, with some interesting design features.

And a quote from that link in broker talk:

Wharram Custom 53′ Catamaran is an unique boat built to last and handle everything you throw at it.

[admiralslater]

I did not spot the bit about Wharram aproving the design changes .It is so far from his style . I wonder if they went further than his revisions allowed .

[Factor]

Originally Posted by Cheechako

Cats: that's why they have 2 hulls... a spare for when it breaks in half....

Nice - really nice

[Cheechako]

Originally Posted by admiralslater

I did not spot the bit about Wharram aproving the design changes .It is so far from his style . I wonder if they went further than his revisions allowed .

Yeah, the school of marine architecture is not black and white. That's why some boats don't perform as well as the designer hoped. Some designers will honestly tell which ones of theirs have issues; have excessive weather helm etc.... etc... In the end when asked the designer may have said to himself... hmmm... why not try that?

[admiralslater]

. In the end when asked the designer may have said to himself... hmmm... why not try that?

I am not sure that designers would play fast and loose with the structure as you seem to suggest , hull shape, sail plan perhaps but things leading to catastophic failure not likely. I beleive that although there are sails on it the areo rig is structural element.
David

[shipleft]

I think you got that backward admiral, that vessel was two Haida dugout canoes lashed together, sailed by a young chap named Jordie Tocher, from what was then the Queen Charlotte Islands (Haida Gwai) to Tahiti. Forget how many days, single handed!

[downunder]

You would need a properly designed bridgedeck designed to support the freestanding rig in the center of the bridgedeck.

Dereck Kelsall has a number of cats with freestanding rigs in each hull which do not appear to have any issues.

The designer would have needed to be closely involved for the design to be strong enough.

sad case

[David M]

Naval architects spend many years in school learning all kinds of things.... far more than what we know about vessel construction. It's best to leave the major alterations to them. I had two naval architecture classes at the maritime academy and only got a little taste of what it is all about. They are worth every dime you pay them.

[Pelagic]

Disagree slightly on that one Dave.
Naval Architects are 'Idea Men'.... You pay them for their ideas but pay more to the structural engineers.

[a64pilot]

Originally Posted by Cheechako

Cats: that's why they have 2 hulls... a spare for when it breaks in half....

Oh, comon you Cats guys are supposed to respond with, "yeah, but neither half sank, monos turn turtle and lawn dart for the bottom"


Just teasing of course

[Brob2]

Originally Posted by Pelagic

Disagree slightly on that one Dave.
Naval Architects are 'Idea Men'.... You pay them for their ideas but pay more to the structural engineers.

I could be wrong, but I believe here and in the USA Naval architects and marine engineers are pretty much one and the same, unlike on land where architects and structural engineers are Spartans and Athenians?