'Largest all-composite motor yacht' in development

Tennessee!
Might have to do a post-construction check of the bilges for Moonpie wrappers and Co-cola cans.

why bother with this.. is steel just to expensive for the shipyard??

As a engineer i just shake my head at the really large fiberglass yachts... the commercial world is full of steel for a reason

oceaneer

I wonder at what point the additional amount of the weaker material required to compensate for it's lesser strength adds up to more than the weight of the conventional alternatives?
Perhaps the reduced cost of a multiple unit production boat has something to do with the decision.

the Leopard Shipyard of Rodriguez Group known for open Yachts are currently building a mold for a 56 m (183.73 ft) fast yacht powered by 3 x MTU 12V4000 M93L (3460 HP each) capable of 30 Knots. The first unit shall be ready on 2010 and is already sold

Carl,
Are they going to use some "breakthrough" materials and technology for this build? Or are they expanding on the use of current materials and technology?
Arnie

thanks for the reply.. but i think you are way off on the custom builds.. most commercial ships are series built.. this is the only way to keep costs down.

but on the strength issue you are on the money... so why do the yachts settle for a hull that is inferior in strength??? At 180+ feet this should be an ocean going ship and not a day boat.

And the fire hazards of fiberglass are much higher than a metal boat.

We will see how this works out.. but i can foresee lots of bending and flexing and a higher cost to maintain the vessel than a comparable steel or aluminum hull.

oceaneer

You mean this one... http://www.yachtforums.com/forums/14396-post1.html

Thanks Carl i do love a good debate..

on your last post on the cost.. If the vessel does bend and flex in a seaway the tabbing and bulkheads start to work and eventually fails. Also the fairing and attachment points of decks, windows, really anything that has a different bending moment or a stress concentration.
At this size the vessel will have to have some give or it will be brittle and break.

I have worked as engineer on some of the original christensens they were great boats but they did flex.. I am sure that they have come along way but i just cant see any advantage to a glass construction on a full or semi displacement motor yacht of this size.

Your comment of the fire risks is fine if you are at the dock but not if you are in the middle of the ocean. I know this much i sleep much better with a steel hull under me 1/2 way across the pond than a glass one! (in fact i just would not take the job). And boats do have fires.. just the metal ones have a far greater survival rate... so what would you feel safer on?


Thanks for the great forum
Oceaneer

I thought, from my limited experience with composite built boats, that it is the fact of less maintenance with a composite built haul, verse a steel haul, that makes it more attractive.... can any one tell me if that is correct?
Also which is more heavier of the same build, steel or composite? I have been told a glass haul wieghs more... besides those graphite composite go fast yacht situations..

Personally, a yachts a yacht whatever its built from. Great to hear of a larger Christensen in development, cant wait to see some pictures / renderings of what she will look like.
The 'debate' over build materials will never get past the various misconceptions, personal opinions and marketing hype that pulls us from one stand-point to another, from one build to the next. All materials have advantages and disadvantages compared to another...one mans fire risk is another mans hi-tech lightweight cored shell offering more internal volume, and classy finish straight from the mould without the need to spend aeons filling, fairing and painting (regularly). One mans rust bucket is another mans 'proper' yacht, built to withstand the oceans with impunity. Niether take is totally accurate, nor tells the whole story.

As a generalisation, composite is lighter than steel in most cases. The comparison between like for like builds is easier, as you can compare weights square metre for square meter. It gets a little more complicated when you take into account the various properties of a material such as impact strength, the need for filler / paint, corrosion, deflection, maximum panel spans etc etc etc. A composite cored bulkhead for example can be a fraction of the weight of an equivalent plate steel bulkhead yet offer far more rigidity with far less stiffening. A composite single-skin hull shell on the other hand, wont boast as large a weight saving against a steel plate shell due to the layup needed for optimum stiffness and minimal panel deflection.
A closer weight comparison can be made between aluminium alloy and composite construction. Like for like builds are very close in all up weight.