Ultimate Multihull - a Trimaran

[Pat Ross]

If you have not seen this boat I think you will be pleased to take a moment and appreciate where multihulls are favored

http://www.multihulldynamics.com/new...?articleID=200

Pat Ross

[david@boatsmith]

That'sway cool. David

[DaveJ]

Hmmmmm manufactured by Austal, makes me proud to be an Aussie.

Looks to be a stealthy ship aswell (so those pesky priates can see it on their radar) by the slanted hulls.

[troy2000]

I think it's interesting that we're finally getting around to ships purpose-built for coastal waters again, to go along with our blue-water Navy. About damn time, I'd say. I gives us a lot more flexibility.

[joefaber]

Sweet!
It looks like some of the Navy's rigid sidewall research from the sixties and seventies is finally being put to use.
And she looks like she'd handle blue water pretty well.

[Chris Ostlind]

Originally Posted by troy2000

I think it's interesting that we're finally getting around to ships purpose-built for coastal waters again, to go along with our blue-water Navy. About damn time, I'd say. I gives us a lot more flexibility.

I totally agree with you, Troy... and I wasn't even a Navy guy in the military. Boats like this one are the answer to the monster fleet thing from our Cold War days of solving the world's issues with a huge fist.

With the future looking like it'll be more and more small theater conflicts, the need to have vessels that can deal with those conditions and proximity are important. A smaller, faster fist that can do its job and not require a major mobilization to get it done.

[sailsocal]

"She's aerodynamically designed"

That's an absurd statement, the upper deck structure is about as aerodynamic as a brick wall. Like most new military ships, everything above the water line is designed first and foremost to minimize radar reflections (i.e., no curved surfaces).

[kach22i]

It looks cool, no wonder the Navy could not say NO to her.

[joefaber]

sails,

aerodynamic isn't always curves.
and curved surfaces can minimize radar reflection.

[sailsocal]

Originally Posted by joefaber

sails,

aerodynamic isn't always curves.

Yes, it is. You can't get laminar flow around planar surfaces joined by sharp edges.

[Boston]

If I remember this rightly the limiting factor of this type of hull is the wave height
once the waves basically start beating the daylights out of the connecting structures then its time to slow down
although Ive often wondered if some relief holes might not help that some
that and some creative forms to direct the wave pressure to release through the holes

this thing is probably fast enough to avoid the ugly stuff but still if I remember wave height is a key element

[joefaber]

Boston,
The limiting factor you speak of may be true for boats.
the USS Independence, however, is a ship.
the following gives you a better idea.

General characteristics
Class and type: Independence-class littoral combat ship
Displacement: 2,176 tons light, 2,784 tons full, 608 tons deadweight
Length: 127.4 m (418 ft)
Beam: 31.6 m (104 ft)
Draft: 13 ft (3.96 m)[
Propulsion: 2× gas turbines, 2× MTU Friedrichshafen GmbH 8000 Series diesel engines, 4× waterjets, retractable Azimuth thruster, 4× diesel generators
Speed: 44 knots (51 mph; 81 km/h)
Range: 4,300 nm at 20+ knots
Capacity: 210 metric tons (206 long tons, 231 short tons)

and this video shows her at sea.
http://www.navy.mil/navydata/featurePlay.asp?id=62

[Boston]

ya I'd still love to see it hit in a 10 meter wave
what they show of her is in a glass sea state and Im betting once the wave peaks make contact with the underside of her connecting tissues its time to slow that thing down to a crawl.

time will tell and eventually there will be shots of her in heavy weather

cheers and thanks for the flicker
that boat is really pretty slick

B

[Asleep Helmsman]

Originally Posted by sailsocal

Yes, it is. You can't get laminar flow around planar surfaces joined by sharp edges.

At forty or sixty knots, wind resistance is not going to be that critical. Remember air is one thousandth of the density of water.
The small amount of turbulence generated by the angles on that ship will be negligible. Even with its highly angular shape the F117 Stealth Fighter can approach the sound barrier. Its stealthy shape (F117) makes it harder to control, but a ship gets its control from the sea, not by redirecting airflow.

[Boston]

there are several threads in here concerning this very issue and its been pretty clearly shown that wind resistance is an important factor in determining the resistance and energy required to propel a vessel.

they dont call it the wobblin goblin for nothing
all those shifting vorticies make it dam near impossible for even a computer to control