Matrix Games

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ORIGINAL: dr.hal

One factor in favor of the CVNs is the fact that they can go at top speed (even if that is slightly less than other conventional craft) for a LONG time without refueling. When I was on the Constellation (CV 64) at full power we calculated that it used enough oil in 24 hours to power a reasonable efficient car to the sun and back. This is the sort of thing you do when keeping the world safe from democracy while cruising in the Indian Ocean.... I was also on the Bainbridge (DLGN 25 later CGN 25) for a year and while in the IO (I spent a lot of time there!) we had a medical case in the squadron with no airlift assets at hand so we took the patient aboard and did a high speed run to Diago Garcia (2000 miles or so to the south) at over 25 knots the entire time.... no other surface vessel other than the Long Beach at the time could have done that. The sailor lived by the way, no small outcome! Hal

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ORIGINAL: wdolson

I know someone who was a sailor on a Gearing class DD in Vietnam. He claims he saw the CVN Enterprise do 70 knots once, but those who know more about hydrodynamics and ship design say that's impossible. I would probably lean towards the impossible, however there have been many times "impossible" things have been done. Somewhere in the 40 knot range might be possible though.

The sailor on the DD said the carrier was putting up a rooster tail as high as the flight deck before it disappeared over the horizon.

Bill

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ORIGINAL: Dili
No. Engineering impossibilities are ...impossible. 70kt would need an outrageous amount of power plus being able to apply it to the water, an in return be able to sustain all extra vibrations and shock. It is dangerous the almost like mythology about aircraft carriers for Americans. It is just a tool.

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ORIGINAL: Justus2

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ORIGINAL: Apollo11
Hi all,




Leo "Apollo11"

Captain: WHAT!! What do you mean we forgot the coffee?? TURN AROUND!

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ORIGINAL: mike scholl 1
You really need to know under what conditions/specs the "trials" were run. A lot of ships built before WW II racked up impressive trials speeds (the Italians were notorious for it), but then proved totally incapable of reaching them under wr service conditions.

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ORIGINAL: wdolson
Propellers lose efficiency the faster they spin. You get separation of the fluid or air starting at the tips and working in as it spins faster. I know it's true for air propellers (which is why prop planes can't break the sound barrier), I believe it's true for water props too. I would suspect a ship could move faster if it had some kind of water jet propulsion.

Bill

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ORIGINAL: Apollo11

Hi all,




Leo "Apollo11"

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Are there any standard conditions for trials? Or are they "uncomparable"? I imagine the Italians used the currents in the Mediterranean to their advantages. That probably can get you a few knots more.

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ORIGINAL: janh

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ORIGINAL: mike scholl 1
You really need to know under what conditions/specs the "trials" were run. A lot of ships built before WW II racked up impressive trials speeds (the Italians were notorious for it), but then proved totally incapable of reaching them under wr service conditions.

Are there any standard conditions for trials? Or are they "uncomparable"? I imagine the Italians used the currents in the Mediterranean to their advantages. That probably can get you a few knots more.

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ORIGINAL: Shark7

I guess it depends on whether or not you consider a destroyer a capital ship. Under modern standards, I believe they are:

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If anyone is really interested in high-speed ship design and the technical truths of just how fast a ship can go, I’d invite ya’ll to Google Daniel Savitsky and check out some of his papers on this very subject.

He’s the (Stephens) Emeritus Professor at the Stephens Institute of Technology and has done much of his work for DTMB of NSWC in development of ship design. His (numerous) papers for SNAME are notable for their clarity and understandability by readers of moderate technical training but whose expertise falls outside the genre. So in response to all the apochryphal story tellers, there is hydronamics and then there is aliens. Believe what ya want.

@Wdolson, Bill, you will probably get a hit on his SNAME article on High Speed Monohulls from 2003 (defining the design parameters of a 50kt logistics ship). Important not so much for the ship params, but he details propulsion specs and talks about cavitating, transcavitating, supercavitating props, their design, advantages, disadvantages, and has a very nice section on water-jet propulsion. It’s a bit dated and doesn’t have the latest and greatest from Germany and Japan, but it’s nevertheless valid for his design regime.

He is very good at identifying the various propulsor types, by name. His analyses aren’t so much dispositive as they are pointers to further study. Just take a look at the Newton-Rader trans cavitating prop, introduced in 1961, and tweaked ever since.

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British Captains were surprised several times in WW II to find themselves overhauling Italian ships

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But with modern surface to surface naval launches missiles, a modern gunboat could sink a WW2 era Baltimore class heavy cruiser.

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ORIGINAL: janh

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ORIGINAL: Justus2

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ORIGINAL: Apollo11
Hi all,




Leo "Apollo11"

Captain: WHAT!! What do you mean we forgot the coffee?? TURN AROUND!

Jeez, must have been stunning to be onboard on that run. Awesome picture. I imagine that's how it could have looked with a torpedo alert in the waters of iceland.

They probably bolted down every coffee cup for that run? I guess stores and such are planned for that, but how would planes in the hangers take that?

And how long could a CVN sustain such a speed? How many hours or days before an extended overhaul of the whole machinery would be due?