I have also heard that number from an ex Navy man. Keep in mind the difference between a fairy tale and a sea story is how they start.
A fairy tale starts “Once upon a time”
A sea story starts “Now this is no bullshit”
Again, this is probably question that does not have a single definite answer and is a judgment call depending on circumstances.
It is like asking how much load a rope can bear. The answer is “certainly more than X and certainly not more than Y”. Between those two extremes you have to make many assumptions and qualifications. At what tension will a particular piece of rope break? It is a guess in a particular range. It depends on many things. How old is the rope? How long will the tension last? Should you use a piece of rope to lower a person away from danger when there is a certain risk that the rope might break or should you assume the risk of facing the danger which is also uncertain? All these are judgment calls.
I suppose a submarine is guaranteed up to depth X and from there the risk increases. In a crisis it is going to be a judgment call whether the risk from enemy action is greater than the risk from going to a greater depth. There are just no hard and fast numbers.
How high can an airplane fly? How much weight can it carry? How far can it go?
How much weight can a bridge bear? It is marked as safe up to X but that does not mean it cannot bear more. Should we take the risk of passing with slightly more in order to save lives? Certainly.
How fast can your wife run? Well, certainly faster than X and certainly slower than Y. then you have to take into account many circumstances. For how long does she need to run? Is she running to get a piece of cake? How hungry is she? Or is she being chased by a bear? How hungry is the bear? What have they each eaten in the last six hours?
Demanding hard figures as answers to these questions is just too simplistic.
Even questions like “how long is my penis?” do not have clear-cut answers.
You might find these two articles from the Naval Technical Board interesting, even if they are old.
Speed Thrills III - Nuclear aircraft carrier speeds
Speed Thrills IV (nuclear ships in general)
Good articles!
Is probably the closest we can get to a definite answer.
The number is easily calculated, and you can get it much more accurate than better than what was listed. A friend of mine nearly gave the Navy security people a heart attack when he was in the nuclear power program. What happened was that he showed them how to calc it, and that the information was in 300 year-old books. He also panicked them because he brought in perfectly accurate Elemental Charts from the Atomic Energy Comission. See, in the Navy, that was classified since 1943 or so. Of course, you can get them for a buck each by mail order these days.
You don’t need to be a Russian spy to get a pretty darn good knowledge of people’s capabilities. On the other hand, if you want the exact information, well, that’s not only pointlessly precise but will vary depending on a lot of factors, including how long it’s been since they cleaned it off.
That also sent up a large red flag for me. This violates what I know about carrier ops. I can’t imagine a carrier leaving its escort behind.
I know that the conventional and now retired USS Ranger (Forrestal class listed to top out at 33.6) got up to about 34 knots in the late 80s when she was already 30+ years old. I was on board for that speed run.
I find these lower number very suspect. I would guess there are unofficial, unpublished speeds significantly higher than those in the article. What exactly does design speed mean in this case?
smiling bandit, I don’t know why the people your friend talk about were shocked. There’s a lot of stuff in the Navy nuc field that is classified for people within the field, but still available in various publicly available sources. And this fact is well known to everyone I’d ever met while I was in the nuc field.
I don’t keep quiet about the numbers I know because of National Security. Like you said - most of them can be determined with a little knowledge and basic calculatons. I keep quiet because I like looking at pretty girls too much to want to spend time in Leavenworth.
Look, I know we’re most just bullshitting here but let us try to keep things at least moderately plausible. There is no way a 300 year old book has anything which can usefully be used to calculate anything reagarding the speed of a carrier. Nothing. Not even 200 year old. Even 100 year old is going to be very severely lacking.
You need to calculate the behavior of the hull and of the screws. Fluid mechanics has developed greatly in the 20th century and is still developing and even then models are used for testing. Developing screw designs is very high tech and complex and there were no screw-powered boats 300 years ago so let us not be silly here.
Not to mention thermodynamics and the power a steam turbine could yield. The assertion is just preposterous on its face.
From Wikipedia. I think this is the root of the “a CVN left her escorts behind” story. A bit of digging didn’t turn up anything conclusive either way.
Is **design speed **the same as the **maximum speed **in the usage seen in this thread and the articles linked to?
I think “design speed” is the normal cruising speed which minimises fuel consumption while maximum speed is what the boat could do, without caring about fuel consumption, if it was in a real hurry.
What Exit?, I wouldn’t think so - anymore than crush depth for a sub would be the same as its test depth or design depth.
Not being all that familiar with speed calcs (I was but a lowly Gunner’s Mate at the time), I was stationed aboard the Carl Vinson (CVN 70) back in the late 80’s. We stopped in San Diego after a WESPAC, to drop off the Air Wing. IIRC, liberty for the crew was secured around 1200 hours.
We got ourselves haze gray and underway, at which point the Skipper came on over the 1MC:
“This is the Captain speaking. We will be dropping anchor in Alameda tomorrow morning.”
And we did just that. Not sure what the top speed figured out to be; I was just impressed that a Big Gray Thing could go that fast in open water.
I think you will find the answer in slaphead’s second link
Remember that this was a casual discussion in the corner of the room, where I would have expected that your points would have been raised and discussed at length by the instructor, giving me better insight into the capabilities of our submarines. Regardless, for a certain make and model of sub, there should be a pretty good ballpark figure of how deep one can go in time of danger. I got the stonewall answer, though.
I gotta call BS on this one like the others did.
As another Nuke, I will second the statement that most of the data taught in that program is classified only because of where it is, not because the information is classified per se. For example, you might find a page in a classified book that has Ohm’s law printed on it. That doesn’t mean that there is anything secretive about Ohm’s law, just that it is shown in a military context. Sounds like a sea story.
:dubious:
I was never a BT (Boiler Technician), but this doesn’t sound right. It sounds as if the author is saying that nuke plants have instant power, while oil-fired plants don’t.
In both cases, water is being boiled by a heat source; in the former, it’s primary coolant, while in the latter it’s boiler flames. Why would boiler flames be less responsive, to the extent that one would need to gently nurse the conventional destroyer up to speed? Not that I know jack about it, but I wouldn’t mind a confirmation from someone who is familiar with oil-fired plants.
I won’t speak to tin cans, but the larger oil fired ships (carriers and battlewagons) I’ve read up on would not steam at normal cruising speed with all boilers lit. Sometimes even cruising with a full fire room/boiler room set cold. So, in some circumstances, an oil fired steam plant would take a very long time to achieve full power, because some of the boilers weren’t at full pressure/temperature. And getting from that condition to putting out steam takes time.
I don’t have a cite for this off the top of my head, but it is my impression.
ETA: Steaming with a boiler and fire room set offline was something that would be more for normal peacetime cruising, than anything that would happen in a war zone.
Fast enough to travel through time, once.
For twenty minutes.
I wouldn’t be able to tell a ships engine from an industrial laundry, but FWIW I’ve often seen rapid acceleration and general engine responsiveness quoted as one of the key reasons why navies are moving to using gas turbine engines. I’ve always had the distinct impression that getting an oil-fired steam turbine up to full output is a tricky and somewhattime-consuming task.