Thanks for all that cool info, BigGiantHead!
The part about the warhead being used to void the water was particulary interesting. A question though: what is there instead of water during the explosion? The gasses from the explosion? Vacuum? Gasses coming out of solution from the sea water?
Brilliant – I never would have thought of that. Have you ever done the “break a bottle with your bare hands” trick? (Bear with me – this relates.) Take an empty bottle, preferably a thin walled one, and fill it almost to the top with water. Strike it quickly and strongly, and I mean strongly, straight down with the heel of your hand, and the bottom pops out. How? If you hit it fast and hard enough, the bottle accelerates downward faster than the water, leaving a small vacuum filled void between the bottom of the bottle and water. For that instant, 14.7 psi of air pressure is forcing the water downward, so it rushes down towards the bottom of the bottle, filling the void. When the water reaches the bottom, the water is traveling significantly faster than the bottle itself, so it slams into the bottom with a lot of momentum, but water will not compress, and glass will not stretch, so something has to give, and the bottom pops out.
You have to hit the bottle really hard. I have bruised my hand many times trying, but it does work. It is most impressive after you have finished off a bunch of cold ones with your friends. Of course, do this over a trash can.
I wonder if the torpedo action is similar – the explosion creates a huge void in the water beneath the sub. The water rushes back in, with a heck of a lot more than 14.7 psi to accelerate it. (I assume we are at several hundred feet here, so if my memory is correct and there is about 3 atmospheres for each 100 feet, we should be talking 200+ psi.) The impact under the sub would be significant.
Question: do torpedos used against surface ships use the same technique, or do they go for direct impact? If so, it might imply my idea is correct, since the hulls of surface ships routinely span long distances between crests of swells in heavy seas.
Hmm. We seem to be digressing slightly from original “whispering” thread…
It does sound funny, but it also makes absolutely sure nobody f#@%s up.
1000+ lb high explosive fish warhead would get pretty hot…prolly explosion gases + steam.
Actually, parkerea, I answered with a hit against a surface ship in mind. I suppose the difference with regards to weather crests-and-waves must come from the suddenness and shockwave factor. But presumably, your explanation also plays into both surfaced and submerged hits. And, yes, 3 atm./100 feet is about right (we use 44 lbs).
And you’re right about losing the thread.
'slinger is also right about gases/steam.
We’re all right! Isn’t that great?
Re: BigGiantHead’s discussion of modern torpedo theory:
This effect is, of course, what the notoriously defective magnetic exploders of early WWII US and German torpedoes were intended to achieve.
The Royal Australian Navy website has a rather spectacular set of photos and diagrams illustrating the principle, in the context of a live fire test last year in which the new diesel-electric sub HMAS Farncomb sank a decommissioned Destroyer Escort.
And another one for all current submariners:
those new closed-cycle diesl-electric subs 9that the French and Swedes have)-how quiet are these? (I assume with their diesls shut down, they make less noise than a nuclear sub). Also, becasue they carry liquid oxygen, they can stay submerged for several weeks. Are these a threat to our subs?
Ok so let’s pretend that I am an ex-navy sonar operator. Now I might know a thing or two about the U.S.'s or even Russia’s modern day sonar capability. But considering how some of this information may be considered…uh, sensitive, I’m sure you’ll get the idea when I say I’m gonna make up a story.
How sensitive are modern hydrophones?
Well there was this fairy tale about some happy little bubbleheads hopping into their submarine and pulling out of thier port on the extreme northeast portion of their country (i.e. Alaska area). Well these little fellows had no idea that Big bad Mr. Sonalyst was listenning to them…from hydrophones off the coast of California. You see boys and girls, water conditions change, and on clear days you can actually hear sounds thousands of miles away. Not only did Mr. Sonalyst hear them, but by detecting harmonics caused by machinery and propeller imperfections, he was able to determine exactly which sub our friends were in - right down to the name of the boat.
Ok so this was a stationary hydrophone not attached to a ship or sub, but sitting on the sea floor. It is true that own ship movement affects your ability to detect underwater contacts. Basically the faster you are going, the less chance you have of hearing the bad guys. This applies to hull mounted hydrophones as well as arrays (hydrophones towed behind the vessel).
One of the biggest indicators in locating modern subs because they’re so quiet, is listenning for machinery harmonics or transient noises, the latter of which includes all the weird sounds a submerged metal tube full of people might make. Mostly this entails bow planes, rudders, and normal stuff like that. But I’ve heard of subs actually being found because somebody heard a noise that didnt belong out in the open ocean (wrenches dont clink when they sink usually).
Russia has good subs, but ours are better…right?
Sorry folks. They’ve got us on that one. The country may be broke, but they still have a fleet of faster, quieter, deeper running, more advanced subs. I heard somebody mention that the Alpha class can withstand mutiple torpedo hits due to its titanium hull. Well you’re almost right. The Alpha is a hunter/killer, or fast attack sub. It’s the quietest, fastest, and deepest running sub in the world. But it isn’t designed to withstand multiple torpedo hits. Actually your thinking of the Typhoon (sub featured in The Hunt For Red October). The Typhoon is your baby killer, a ballistic missile boat. This bad boy has 2 hulls whose sole purpose is to allow the boat to withstand several direct torpedo hits while it continues to fire off its nuclear missiles. As you can imagine, this boat is huge, completely dwarfing our ballistic missile boats.
Where can I get me one of those Typhoons?
Try under the polar cap. SSBN’s (ballistic missile submarines) don’t like to be found by anyone. They [Russian and American] usually hide out under the polar ice and wait for word to fire their nukes off. The Typhoon even comes equiped with shrouds around its twin propellers to help break through the ice. On word from command, they prepare the nukes, surface the ship, and launch enough firepower to wipe out most major U.S. cities - and thats just with one boat. And you thought the cold war was over.
Bad Russians! Let’s get em!
Actually Russia isn’t much of a threat. Its an understood agreement between us and them that neither one of us would win in a nuclear war. The real threat lies in Russia’s technology and poor economy. When you’re a country and you’re hurting for cash, you start looking around for stuff to export. Well Russia had a whole fleet of old subs that were just rusting away, so why not sell them to the highest bidder? Enter Iranian officials, purchase sub, send crew (comprised of political officials sons) to Russia for included training, and watch as the sub takes off on its maiden voyage under new management. It’s just a pity that those darn Iranians forgot to close the hatch when they submerged - chalk one up for ditsy driving. Enter mourning Iranian officials, purchase 2nd sub, send 2nd crew, and recieve word from Russia that the crew is a bunch of morons and the sub will be delivered on land (got some great satellite footage of that one).
Old subs=noisy and primitive=no threat to us…right?
Let’s compare our old diesel engine powered sub to our new, high tech nuclear powered sub. The nuke can go down and stay down for as long as the food supply lasts. It’s fast too, and runs deep, and most of all it’s quiet - very hard to detect. Ok so now here’s our diesel engine powered sub. It runs near the surface will it uses its diesel engine to power its batteries - loud as hell! Then, batteries full, it shuts off its diesel, dives down, and runs off of battery power. Sure it can’t go very fast or very deep, but guess what? You can’t hear the damn thing!!! An old boat running on battery is quieter by far than a modern day Alpha class. Case in point: Cuba is out cruisin in their new diesel boat, makin a ton of racket, then they dissapear. Three days later they’re picked up returning from the coast of Florida (who needs rafts?). Always a bad sign when you lose a sub your tracking.
Ok that message was entirely too long and my ass is now swollen. I’m off to go make up stories in real time. Remember, everything you’ve read here was made up, or was it? I can never remember.
-m
What Typhoons? You mean the ones that are all out of service?
Per your missive, how is Russian submarine technology so advanced and better than ours if their electronics and technological infra-structure is a generation or two behind our own. Or is this more capitalist lies?
BTW I have a MK XII-3 torpedo gyro from WWII (I think) Marvelous piece of metal engineering. Still spins seemingly forever on just a little push.
Wallrat’s assertion about the Typhoon’s damage resistance doesn’t really have much to do with the technological advancement of Russian subs relative to our own. A Typhoon would have a better shot at withstanding damage by virtue of its sheer mass and double hull. This has been the cliche Russian/Soviet design philosophy for most of recorded history: Build everything like a tank – aircraft, shoes, whatever. It certainly has its advantages in a setting where quality control is marginal, maintainance questionable, and training almost non-existant. However it has costs in terms of effectiveness and versatility.
Certainly the Soviets/Russians expended a lot of effort in the '80s and early '90s in trying to catch up with the US in the quality of their submarine technology. By means of espionage and questionable purchases of technology from countries like Norway and Japan, they quieted their subs considerably. The latest Akula and Sierra model SSNs are widely rumored to rival US subs in terms of stealth, and the Kilo class diesel subs actively sought by countries like China and Iran are no doubt that much more formidable because of those efforts.
That said, I haven’t heard much about the state of Russian detection technologies, weapons, and other submarine systems, probably because they are harder for outside observers to evaluate. While I’m sure that advances in off-the-shelf computer and electronic technologies have helped them, it’s difficult to say how agressively or effectively the Russians have pursued these fields. The use of liquid-fueled rocket-propelled torpedoes which came to light in the context of the Kursk sinking indicates to me that the Soviets/Russians were willing to pursue radical concepts in the hope of achieving an edge. This may not always have been the best use of their resources, however, and may have caused more problems than it solved.
The woeful state of Russian industry today can’t be helping the quality of their subs. It remains to be seen whether the Kursk sinking was the fault of crew or equipment, but I’m sure that relatively casual attitudes toward safety in both contexts contributed. Foreign purchasers of such equipment do so at their peril, and with the further handicap of reduced familiarity with systems.
You’re quite right about some of russia’s technology being inferior to ours. Very little is known about their actual capabilities for obvious reasons. We only know what we can pick up on our own, hence why we know that their subs are damn quiet! From what intelligence we do have, it appears that russian sonar systems aren’t very sensitive compared to ours. Thats pretty much the best thing we have goin for us. As far as all the typhoons being laid up and not in use: well it costs lots of money to have a fleet of subs in working order and out in the sea. So rather than keeping all of em goin, you retire a few when they break down. Don’t worry though, there’s still enough nuclear firepower under the ice caps to keep America glowing for a few thousand years.
The thing that I never understood, is why you would build a huge, bulky, indestructible sub and then skimp on the reactor core shielding. Maybe it’s part of a population control thing - keep your submariners sterile. Ask your local russian embassador about the logic behind that one.
-M
I would like to ask the submariners on this thread some questions about the extent to which the US Navy has mapped the bottom of the oceans.
Do submarines travel deep enough to do magnetic maps of the ocean floor? From a bit of searching it seems average depth of ocean is around 4000m.
Are there sections of the ocean that are just a flat plane of mud on which a big chunk of iron meteorite would be easily detected?
Being married to a submariner for 22 years, I always heard him say yes. But sssshhhh “SS” really means silent spouse…
Part of the reason for needing such extreme quiet is to enable the subs own listening abilities to remain effective.
Wallrat… I don;t know which subs you served on but the ones I’m familiar with are much quieter than anything the russians have.
As far as the titanium hulled alpha class,has anybody here ever heard of the adcap MK-48 Torpedo?
This message is for Dipen.
I think anyone can register to this column and type a response. I’m not denying any fact written over here, I just can’t validate the same since even I can write anything that I want to.
Random facts by Aakash Parekh:
Dude, really? 17 years ago and you have to waken a zombie to say that?
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Welcome to the SDMB, aakashdrake.7scp.
In the General Questions forum, we ask that you only revive old threads like this if you have something new or significant factually to add to the discussion. Since this contains no new factual information, I am going to close this thread.
Thread closed.