Aircraft Carrier top speed a State secret? Why?

This is something I have wondered about for awhile.

Whenever you see shows or written reports on the capabilities of current US aircraft carriers they mention that its real top speed is a secret. Why?

Anybody who cares enough can derive an aircraft carrier’s hull speed. It might be able to push beyond that speed (given its nuclear power plant one might suppose it has the power to spare) but how much of a difference can that possibly make these days?

The former USSR managed to steal some of our country’s deepest, darkest secrets (ala the nuclear bomb) why woudl a carrier’s top speed even approach such a secret? With modern radar and satellites and not to mention that a carrier battlegroup is likely radiating all sorts of EM signals I doubt it is a hard thing to find if somebody really wants to find it. Further, torpedoes are all guided these days and almost certainly faster than a carrier. Assuming a sub got into position and fired in a carrier it is a near certainty it torpedoes will strike home. Beyond that I think it is a foregone conclusion that a carrier is faster than any other blue water ship afloat…if it is running almost not other ship will catch it and that much is known even at a low end estimate of its top speed.

Most reports I have seen peg a carrier’s speed at 32 knots or so. Some unconfirmed reports…including some people here on this board…claim speeds in excess of 40 knots. In the end who cares? Missiles, planes, torpedoes…they’ll all be able to nail a carrier if it comes to it. Unless a carrier is capable of some outrageous speed (e.g. 80 knots) I don’t see how keeping a few knots (say 10 or so) really makes a lick of difference to anyone.

To what purpose is the US government so tight lipped on this?

OK, I am not a military expert of any sort, but remember, we tend to use carriers against nations that lack satellite or sophisticated airplane surveillance. The ocean is damn big, so finding a carrier isn’t as easy as it sounds, and you may not want people to be able to find it easily. Think about this: a ship going 35 knots would be able to go in an area about 180956 nautical miles larger than one going 25 knots in one day (A=pi*r^2; r=240). I’m assuming we’re in open waters here, of course. This is also assuiming my math at this hour isn’t too bad. But that’s the gist of one possible reason.

Fair enough and I could see this being a legitimate concern in WWII. But today? A 181,000 nautical miles sounds quite large to me but how mauch ocean can be scanned by an airborn radar? Even with a coast as big as the west coast of the United States I’d bet they could scan the ocean further out than carrier aircraft could strike from with only a few dozen planes…if that many. I admit I am completely guessing on this but I feel safe in that guess. I hate to think another Pearl Harbor is possible because the capacity to scan the ocean is too expensive to do regularly.

I am not a marine propulsion engineer, but it’s also possible they do not want to give data that would allow someone to extrapolate info on the propulsion system itself, such as how the screws, shafts, turbines, etc work at certain loads, sea conditions, and so on.

I think in any military situation, you don’t want anyone to know just how good your weapon is. Though I believe carrier speed is limited to the speed of its escorts or supply ships. What good does it do to have an 80 knot carrier if the destroyers are chugging along behind?

But how many nations have decent airborne radar? I don’t know, but not all of them. And we may not be attacking just nation-states these days.

The Russians probably know how fast they can go. The Syrians may well not.

No doubt but presumably the carrier would only put the pedal-to-the-metal (so to speak) in extreme circumstances. Even in WWII the carriers were able to outpace any other major (e.g. non-planing boats) afloat. The Iowa class battleship was partly designed to be the only escort for a carrier that could keep up with a carrier at top speeds (and I think at absolute max speed the carrier still was faster but either way it was close).

Today with nuclear aircraft carriers, longer hulls (hence a higher hull speed) and the battleships in mothballs I doubt there is another escort for a carrier that can keep up if it decides to haul-ass.

Again though…so what? 30 knots? 40 knots? How does that make a difference to anyone these days? A sub will ambush a carrier so speed isn’t an issue and anything else couldn’t catch it anyway (not that it’d want to…planes and missiles will catch it if not torpedoes).

I would wager anyone (any country) that has seriously considered blasting a US nuclear aircraft carrier probably has a good idea of its top speed and even if they don’t I suggest it doesn’t matter overly much. Of course…our government sees fit to keep it a secret so I am curious what that reason is (cuz I just don’t see it).

See…that’s just it.

Why would the Syrian’s even give a crap? Anyone who has considered the possibility of facing a carrier at sea has probably inferred its performance capabilities…allow for some error and you’re good to go.

The Syrians (or anyone like them) will not threaten a carrier from the sea. If they go after one it would have to be form the air and whether the carrier moves at 30 knots or 40 knots won’t help it much.

SRVick questioned how good airborn radar is but even in WWII they could pick out the periscope of a submarine…I would guess radar sufficient to pick out an aircraft carrier is a simple matter for just about anyone these days. Don’t forget that an aircraft carrier and it battlegroup is also broadcasting a pile of EM radiation for it own purposes…not hard to pick that stuff up and triangulate on it. Considering you can buy a radar detector for your car for $50 I would think this woul be a simple matter for any military in the world today.

I think it’s beaurocratic inertia. At one time it may have been more critical to keep it a secret and now it’s easier to keep the status quo even if it’s less relavent.

Besides, we can’t let the Godless commies know which carriers are best to water ski behind.

Purely anecdotal, I know, but a friend of mine claims he was passed by a U.S. carrier in the GOM while doing 40 knots. Hmm…, I’ve got to ask him what he was drivin’.

Sure, one could probably extrapolate the true speed based upon other information. But why make it easier?

(AFAIK, the nuclear power plants reportedly have enough power that they, were they turned on full blast, would rip the hull apart.)

Easier? For someone who knows their stuff (naval architecture) they could work out the hull speed in a few minutes. With computers it woud probably only take them as long as it takes them to type in the relevant specs. The specs are publically available as are the software programs. I’d wager there are people right here on this board who could calculate the hull speed of an aircraft carrier if you gave them the relevant information.

Granted it would be easierr to simply read the answer from a web site or TV show but I think it is simple enough that anyone even contemplating an attack on an aircraft carrier would have no trouble resolving.

Sammy Hagar was imprisoned for several years after his expose on the speed of aircraft carriers, “I Can’t Drive 55 Knots.”

Another thing to think about is that a carrier’s top speed is not only tactical information (find and hunt the carrier) but also strategic.

If an enemy country knows that a carrier battle group is leaving Norfolk on a certain day, even a few knots of speed can make several days of difference as to when that battle group arrives off the enemy country’s shores.

I think most of you are missing the point. You NEVER, EVER give your opponent an advantage, especially when you aren’t sure whom you may be fighting. Make them work for every scrap of information - modern war is won by intel. Even if one enemy research team working for a few days with off-the shelf software may be enough to figure it out, forcing them to do all of those things is a good way to mess up their planning.

Plus, many nations we may be fighting simply don’t know how. There may be two or three people on this board who could calculate such things, but can Syria? Can Al-Qaeda (well, the remnants)? Make them do the work; it doesn’t cost much to not tell people things.

Maybe you should look at if from the other side of the arguement:

“Exactly how would it benefit the United States Navy to advertise the top speeds of the various types of carriers and/or carrier groups?”

It wouldn’t, but since it might introduce even the tiniest risk, it is not advisable.

It is possible that a nation tempting to invade someone would like to know the response time of American carriers. If you amass your troops on a border and know it takes “x” amount of time for the first US carrier fleet to arrive, you have worked out part of your invasion plan.

Even if you think this is unlikely, go back to my question above.

There is also a security principle: never confirm or deny what the enemy thinks he knows. Maybe the Russians know the top speed, or maybe they only think they do. It’s better to leave that uncertainty.

As for your claim that a knowledgable person could calculate the top speed of the carrier from basic design principles: if it were as simple as you say it is to do that, the relevant design info would be classified also. You could certainly make a first-order estimate of the top speed from the hull size and shape. But what other important parameters are missing, yet are still needed to make an accurate calculation?

I bet it’s because the navy is going to enter a carrier into the Americas Cup next year in an attempt to win it back from Switzerland

That would be pretty darn cool. I can see Bush doing that.

“My fellow Americans. These terrorists we call the Swiss are holding the America’s Cup. And it’s called ‘America’s Cup’, which means they’re holding it hostage. I’ve authorized the deployment of carrier battlegroups into the race to reclaim this cup for America and Americans.”