MultiHull Motor Yachts over 100 feet.

[PsychicWarrior]

There seems to be so many advanatges to these ( Much faster, fuel efficiency, seaworthiness, ability to handle rough seeas at speed etc) yet I am suprised that there are so few designs.

www.newzealandyachts.com & http://www.cld.co.nz/ seem to be the only ones doing it proficiently.

Who can tell the rest of use why such a seemingly advanatgeous design isnt being used more?

Aside from the folks who just like convention, I must be missing something?

[Alik]

We have done 75' and 120' catamaran yacht designs...

[PsychicWarrior]

Have any links/details?

Were they ever built?

[Alik]

I can't post the pictures/links here; yes two boats are in construction.

[PsychicWarrior]

Well feel free to PM me with any details you can provide. I am most interested.

[Doug Lord]

Here's more: http://www.gizmag.com/ship-design-au...picture/89239/

Originally Posted by PsychicWarrior

There seems to be so many advanatges to these ( Much faster, fuel efficiency, seaworthiness, ability to handle rough seeas at speed etc) yet I am suprised that there are so few designs.


Who can tell the rest of use why such a seemingly advanatgeous design isnt being used more?

Because the statement is wrong! Only "seemingly" was right, and "faster" to some extend.

Regards
Richard

[PsychicWarrior]

Well I beg to differ based on the high number of Naval Architects etc who have adopted the design and now the US Navy is adopting multi-hulls as well and you know they do a Billion$ of research before doing anything.

The heavy roll, pitch in high seas and fuel consumption in any sea ..nevertheless the relatively slow speed for the full displacement hulls says there is a better way.

I am assuming convention is the main reason which isn't good enough for me.

Originally Posted by PsychicWarrior

Well I beg to differ based on the high number of Naval Architects etc who have adopted the design and now the US Navy is adopting multi-hulls as well and you know they do a Billion$ of research before doing anything.

The heavy roll, pitch in high seas and fuel consumption in any sea ..nevertheless the relatively slow speed for the full displacement hulls says there is a better way.

I am assuming convention is the main reason which isn't good enough for me.

Navies build very different vessel for the different tasks, and by far the minority are multis.

The "better ability in rough seas" for example, is wrong. The opposite is the case.
The better speed in all conditions is wrong. Only in light weather there is a better speed achievable.
And so on.....

Not to start a completely senseless debate about mono vs. multi, we had that more than enough. But just throwing a few false statements in the ring, and assuming we go ahead from that point, brings you nowhere.
The industry does very well know about all the pro´s and con´s of any possible design, and we have a lot of "out of the box" designs afloat. From SWATH, through Proa, to Cat and Tri, you can find everything in the megayacht world. Just that YOU don´t know about them, does not mean they are not there. They are.............
Assuming convention is the main reason, the industry does not build more of them is bold. We are far less conventional than you expect, just the advantages you would like to see, are not there.

So, what would you like to know?

Regards
Richard

[peter radclyffe]

they cant handle rough seas at speedhttp://www.youtube.com/watch?v=w8K2B1nRRyA

[CatBuilder]

I'm a catamaran guy and looking at that video Peter put up, I can safely say going into those seas with a catamaran would probably not work out. You could maybe... just maybe sail at 45deg to the weather/seas and hope for the best, but all you could probably do is run with those conditions (using drogues) or throw out a sea anchor. That's "no go" territory for a catamaran.

The confusion of those seas is ridiculous. I can't believe that lighthouse is still standing. Great video.

When you watched the youtube video, search for "Aries Lord" on the tube, I was on board when this clip was made (by mobile phone from the oil rig).

As Cat builder says, a no go area for cats. But that was not too bad weather in the North Sea! Just force ten, nothing to fear. And the pump was delivered!!!

Regards
Richard

[jehardiman]

I concur with Richard here, there are many reasons to chose a hull form, and cats excell at some and not at others.

The big reason I think that you don't see more of them as yachts and warships is that they are more costly to build, maintain, and operate than a similiar tonnage monohull. Also for a warship, they have less usable tonnage and are more affected by damage. More than governments, owners of yachts are hard-nosed about money, and do not waste money on unneeded capability. Additionally, owners do not usually accompany thier yachts on repositioning transits. If they want real speed, there are "toy" boats for that, while the main yacht sits in the harbour.

As for the LCS's, 3 words, overweight, overbudget, and behind schedule, ...and you should read the seakeeping requirements before holding that up as a point for cats. Go look up the specs of a WWII Gearing Class. For 15% more power in the LCSs you get far less armarment, less cruise speed, less cruise range, and only 5 knots more speed in flat water. Replace the DD's M-type boilers with modern ones and it would be no contest.

[PsychicWarrior]

To deal with this intelligently one must compare apples to apples. Sure that tug is impressive..http://www.youtube.com/watch?v=AwgaLSF03gk yet earthrace would leave it in the dust in that weather and much worse... but of course its not a tug.

A ship that is a monohull with a similar design on a dual hull per the links I showed above will handle inclement weather much better as well as be faster/more efficient as well as more space etc. It's simply the physics of it all. Yes its more expensive to produce and only recently has the material strength been high enough to do it well. Thats really the reason.

In the US NAVY's own words "multihulls give higher speed, more efficiency, and can carry heavier loads in any weather.".

[Man Overboard]

My son is a US Marine - Recon, The military shuttles their unit with a large 3 deck SWATH; I asked how ruff the cat (SWATH) was during heavy weather, his response was "We don't go out in bad weather, we wait for a calmer day. The purpose of the SWATH is to shuttle us and all our gear quickly."