144,000 horsepower

[HeyBub]

A look at the current - and past - state of the U.S.S. United States.

With downloadable plans for building your own copy. Out of wood.

[Zz Yzx]

That is one SHARP bow profile. Yikes.

-Zz

[Pat Barber]

Which is how/why she could do 44kts(50mph), which is pretty much hauling ass for anything that size in the water.

Zz Yzx wrote:

[Robatoy]

Funny thing is, that she would probably do 42 kts with 50,000 HP and the next 2 knots would take 3 times as much. Such is the rule of displacement vessels. To take that one theoretical step further, if they wanted to go 46 knots, they's need 400,000 HP. 47kt 1 million. 50 kts a bezllion HP

[HeyBub]

I think 55 knots or so is the theoretical maximum a vessel can move through the water, irrespective of the power pushing it.

As the speed increases, the vessel begins to outrun its bow wave. It then has to ride over the bow wave or push through it. The faster the vessel, the bigger the bow wave.

Sort of like the increase in mass with velocity and, as the velocity approaches the speed of light, the mass becomes infinite. Only not exactly.

[Robatoy]

Not exactly indeed.

The maximum speed of a displacement vessel is determined by its length. The longer, the faster.... with the same power.

[Robert Bonomi]

Nope. not even close

Currently, unlimited power-boat races are in the 160MPH range. in years past, they got up into the 200 MPH range, but engine/fuel restrictions have brought the speeds down.

'Cigarette' boats can reach 80+knots in calm water.

Some torpedoes -- which travel entirely underwater -- have sustained speeds well over 100 knots.

[Doug Winterburn]

unlimiteds aren't displacement boats, they're hydroplanes. Cigarette boats are also on plane at speed and therefore not displacement vessels. My physicist buddy that does torpedo testing says max speed for a conventional torpedo is 55 knots, but supercavitating torpedoes are capable of much higher speeds by essentially traveling in a gas bubble and are therefore also not technically [water] displacement devices.

[Lew Hodgett]

'Cigarette' boats AKA: Bathtub toys.

I used to have to listen to there bull crap about how 'Cigarette' boats were "Blue Water" boats.

Used to piss off those guys no end when they would schedule a race then have to stay tied up at dock when a front would come thru the night before and they couldn't handle the 4-6 ft chop with 15-20 knots of wind that resulted.

I'd hang a 110 jib, tuck a reef in the main and go out and play.

Gawd did that piss them off.

I just grinned and got a cold one.

Lew

[Lew Hodgett]

The maximum speed of a displacement vessel is determined by its length. The longer, the faster.... with the same power.

-----------------------------

Theotretical limit for a displacement is = (1.4)*(square root of design waterline length in feet)

Lew

[Robert Bonomi]

I'll simply suggest that _something_ is moving the water out of the way, be it the torpedo body or the 'gas bubble'. Else an elementary fact of physics is being violated. *OR* somebody has managed to implement the tunnel diode at a macro scale.

[J. Clarke]

Your physicist buddy is playing word games. The torpedo is going so fast that flow detaches from its surface at the transition from the nose cone to the body. But it is most assuredly travelling in water.

In any case the British seem to be laboring under the misconception that their Spearfish torpedo can exceed 60 knots. Perhaps he should call them and inform them of their error.

[Robatoy]

15-20 knots and 6-ft chop wouldn't even get my old Hoby 16 airborne. I miss that thing, but I couldn't take the pounding at this age.

[Robatoy]

Zactly. Many folks also don't get it when you tell them that it takes less power to drag an equilateral triangle shape through the water by the flat end than by the pointy end. The drag is called drag for a reason. Wanna make a trailer (As in tractor/trailer van) more efficient? Put a cone on the back end... not the front.

[Larry Jaques]

On Wed, 10 Mar 2010 16:01:09 -0500, the infamous Pat Barber scrawled the following:

If you thought that was a sharp bow profile (which I feel is pretty much standard for destroyers and other navy ships) check this out:

The HSV-2 Swift, a 323-foot U.S. Navy high-speed vessel with a real knife-edge bow and outriggers.

I wonder how much wood they burn in her boilers. (lame attempt to bring it back on topic)

-- There is no such thing as limits to growth, because there are no limits to the human capacity for intelligence, imagination, and wonder. -- Ronald Reagan

[Larry Jaques]

On Wed, 10 Mar 2010 20:39:38 -0700, the infamous Doug Winterburn scrawled the following:

I can't wait to see the next hydroplaning aircraft carrier!

233mph torpedo.

-- There is no such thing as limits to growth, because there are no limits to the human capacity for intelligence, imagination, and wonder. -- Ronald Reagan

[Robatoy]

One of my all-time favourite photographs:

Raw energy at it's glorious finest

[Larry Blanchard]

I'm not a boat nut, but a friend of mine had an old wooden sailboat in Southern California. I believe it was a ketch -20 some feet long - anyway a rig he could handle by himself. Oak with a heavy lead keel. He claimed it wouldn't even get moving till the Coast Guard put out the small craft warning :-).

[Nonny]

I pitchpoled my 16 several times. It's amazing how far a body can fly from the back of a trampoline.

[chaniarts]

try a more modern cat, like a nacra or larger prindle, without a spin. you have to do something really stupid and go out of your way to pitchpole a prindle 19 or 18.2. i've never come even really close to pitchpoling my p19 and i've been out in some heavy winds. they have wave piercing hull forms, so go through rather than up and down, so it's much harder to catch the nose and trip.