Texas Size KILL ZONE
 

From some boat guys:

http://www.boatdesign.net/forums/showthread.php?t=9354

I know that it will make you and your cronies very happy when the day comes when Red China or Iran puts a sub somewhere in an ocean around us and lobs several nukes over and takes care of America for good. The fishes will have been saved from a terrible death by the dreaded American military.

Then all the fishes in the sea will be caught by the country who wins and be eaten. Thats a lot better than a few possibly being killed by a weapon that might protect the country.

Thanks for the article, makes me remember that I have not had any good fish lately. Time for some swordfish tonight!

JoeA

(Member of PETA, aka people eating tasty animals)

Spotted Owls.

Thanks for being so open minded.:rolleyes:

From Snopes :

http://www.snopes.com/critters/crusader/sonar.htm

From 2001................Status: Undetermined.

I suggest you at least read it, and make up your own mind.

Whenever environmentalists have a movement or petition or lawsuit to "ban" something, there's a simple test to determine if they are yahoos or not: Just ask them how many whales/spotted owls/little furry kittens/monkeys in cages it's acceptable to kill given various other benefits to society.

If they say "none" then say "thanks for coming" and move on, since you're dealing with a wacko fringe group. If they've actually done an analysis and their argument is that a proposed action will impose an excessive burden on an ecosystem, species, etc, then--just maybe--you're dealing with reponsible, thoughful scientists who have a valid point.

I'm affraid it will take some digging or diving on this one to determine the facts. It's been five years since first reported, if this program is not on Rumsfeld's wish list I don't think we have much to worry about.

The problem then becomes that no one knows just what constitutes an 'excessive' impact to the ecosystem. For all we know, that fringe group who says that losing one more blue whale will upset the balance could be right. We just might not be able to recognize that for a hundred years or so. Greenies tend to err on the cautious side.

How does an ever expanding circle/sphere not lower it's energy? Or is it directional? The description does not work with classical laws of physics.

Water is a lot more dense than air (100 times). I think in air it's the square of the distance the db level goes down.

I have read that the very low frequency of whale singing can travel very far - Artic Circle to Antarctic Circle.

EDIT: got rid of my post. I'm clueless too. Time for more research when workload permits.

Part of my job in the Navy has been to hunt submarines from the air. There are two ways to track a sub, passively (you try and listen for tell-tale sounds with sensors in the water) or you use active methods, basically emit energy in the water and hope for a return echo from the submarine (in very simple terms, it is like radar in the water.)

As submarines have become increasingly more quiet (US subs are amazingly quiet) active sonar tecnologies have been improved, usually by increasing the power out of the sensor (more power increases range of detection) or moving to low frequency spectrums, which travel farther in water than higher frequencies.

The impact of these sensors on marine mammals and fish has been an issue for years...when I was doing flight test, we had to get specific environmental clearances to test our airborne, low-frequency sonars we were developing for the H-60. In addition, employment of the sensors are often very restricted.

There are some sub guys on the board who are no doubt experts, but this has been, and will continue to be an important issue.

I'm wondering if the Navy took into account the temperature of the water and how that affects it's natural resonate frequency, found a way to ride this and bent a few rules along the way.

Maybe they just used UFO's.:D

I did not read all the papers linked to, will have to do this later.;)

Trust me, the various acoustic environments in the world's oceans and seas and the effects of temperature, salinity, depth, etc. is taken into account. Again, the sub guys live there and are better qualified...all I can say is that the chess match played out above, on and below the water is a facinating 3-D game and the sub bubbas rule it.

One last thing: I have listened to whales sing on my passive sensors, very beautiful and eerie.

With a statement like that, it's not the water that is dense. The inverse square rule applies no matter what. Unless it's focused like a laser. In that case, it is a tight beam, and then it's not indescriminate.

So, you can't have it both ways.

Here's a better approach:

http://en.wikipedia.org/math/a/e/5/a...149909f046.png

where p is sound pressure (N/m^2), ρ is medium density, c is speed of sound in medium and ξ is particle displacement. I suspect particle displacement as a lot to do with the strength of the initial sound. So lets plug in some numbers while keeping ξ = 1; ω = 314 rad/s or 50 hertz; ρ(air) = 1; ρ(water) = 800; c(air) = 331; c(water) = 1450.

In air,
p = (1)(331)(314)(1) = 103934 N/m^2

In water,
p = (800)(1450)(314)(1) = 364240000 N/m^2

In water, the sound pressure exerted (force per units squared) will be about 3500 times greater than in the air. Of course it will take a lot more energy to create this sound in the water than in the air...

Now lets look at the pressure/distance relationship which is actually 1/r. Since it's simply an inverse relationship, the pain (or in this case, death) threshold will be 3500 times further away in the water than in the air.

Someone please check my math and my assumptions. I am not an acousitcal engineer. :)

Yes, but it would take 3500 times the energy. So what? And the inverse square rule still applies.

This all "sounds" like junk science to me.

Not necessarily 3500 times the energy to create it, and it's an inverse, not an inverse-square relationship. That's beside the point anyway. Because sound travels further and faster underwater, we need to be careful that the things we put in the ocean. We already know that there are sound pressures that will burst the human eardrum. A whale's lungs act as a tympanic membrane when enough pressure is exerted - and those can be burst too - with more lethal consequence for the whale than the human concert-goer with the burst eardrum.

IT IS AN INVERSE SQUARE. Has to be. That is how it works. You are talking about a "wave" which is focused, like the laser. When things "radiate" they follow the inverse square rule. You can have one, or the other, but not both.

I read a few of the articles linked, seems to me that no one knows exactly what this does. That being the case, it would appear that more research is needed before deployment

How many species do we really need, anyway?

Ok, I'll admit to being a submariner. Let me clear some things up:
1 - Inverse square law applies to sound in water, too, just like common sense (and science) dictates it should. Further, there are also propogation losses due to interaction with surface and bottom as well as with suspended particles or other material in the water. Inverse square prop loss is really an unrealistic best case. Even in a carefully directed ping, the signal is attenuated pretty quick -- the logic that "focusing" a beam somehow makes it go farther works well for lasers because they're completely different than transducers.
2 - LF Active has some theoretical advantages, namely the range. However, there are other disadvantages that make it nearly useless, really.
3 - Submariners detest active. It gives away our position like nothing else. We detest all self-noise. Active sonar is the sort of thing that we use only in extremis, and only to the minimum extent absolutely required by the tactical situation.
4 - Worse even than a simple ping is a super-loud ping. Nobody fires a ping at max intensity. Not only is it unnecessary, it's tactically idiotic.
5 - Worse even than a really loud ping is an omni-directional ping. You may or may not find the guy you're looking for, but not only does he know where you are, so do his 6 buddies floating nearby.


Your Friendly Local Submariner, now leaving communications depth...

See, I told these guys rule. I hope all is well djmcmath...do well in the fleet.

Thanks, Seahawk. Never underestimate the power of a (cued) airborne search, though. ;)

Probably unrelated, but interesting.

Scores of Fish Beach Themselves in N.C.
http://news.yahoo.com/s/ap/20060226/ap_on_sc/fish_jubilee
Camp Lejeune = Marine Corps' New River air base?

http://en.wikipedia.org/wiki/Marine_Corps_Base_Camp_Lejeune
http://en.wikipedia.org/wiki/Marine_Corps_Air_Station_New_River
http://www.globalsecurity.org/military/agency/usmc/ii-mef.htm
http://en.wikipedia.org/wiki/Mobile_Bay_jubilee
Man or nature - you decide.:)

The Jubilee at Mobile Bay has been going on since recorded history of the area, so one could hardly say it's influenced by man.
The bay here is very shallow for the most and can easily be influenced by by bad weather and extended periods of sunlight, which would certainly change the water's ability to retain O2. Other theories have to do with algea content and blooms which would of course be likewise influenced by the CO2 content.

Natural.

Mmmmm...Spotted Owls...taste like chicken.

That's what I was thinking. Else, guys like Seahawk would only have to follow the path of dead floating fish. ;)

http://img.photobucket.com/albums/v6...0-V2132-09.jpg

Just a gratuitous picture of a great man...no reason really.

The prime consideration in this argument is the answer to the question, Does the US Navy need this system? The answer to that is a profound no.

The cold war is over and has been since 1989. This is why the US government military needs a serious reining in, they're still operating as if 2006 is 1956.

Submarines are not relics of the Cold War, Pat. We are a maritime nation...the proliferation of relatively cheap, diesel subs is subject you might want to explore.

I'm aware that more nations are buying these military toys; a very foolish expenditure of capital, but then these are the naval equivalent of privately owned cigarette boats.

So, just how would another nation successfully attack America with one of these subs? Answer, none will because there is no known method.

What will another nation do with these subs? Sink American warships sitting off their coasts deploying agents or intimidating their shipping lanes.

Our government is spending the same as the next 27 countries added together; other nations rightly perceive that as a deadly threat, and the threat has been made real by the Iraq attack, invasion, and partial conquest; and the saber rattling and more against Syria and Iran.

So, again, I state that the US Navy profoundly does not need this equipment.

:rolleyes:

that's it? . . that's all you've got? "no method"

I'm aware that more nations are buying these military toys; a very foolish expenditure of capital, but then these are the naval equivalent of privately owned cigarette boats.

Nope. You confuse cigarette boats with warships. I don't have that option.

just how would another nation successfully attack America with one of these subs? Answer, none will because there is no known method.

Your lack of insight into the weapons carried on these vessels voids your statement.

Our government is spending the same as the next 27 countries added together; other nations rightly perceive that as a deadly threat, and the threat has been made real by the Iraq attack, invasion, and partial conquest; and the saber rattling and more against Syria and Iran.

Doesn't apply...you know better.

So, again, I state that the US Navy profoundly does not need this equipment.

Active sonar is the only way to defeat these vessels. I profoundly think that the small investment is needed.

Er no, it was a relative comparison between military buying fun toys and private individuals buying fun toys. There was no confusion on my part.

Quote:

just how would another nation successfully attack America with one of these subs? Answer, none will because there is no known method. Your lack of insight into the weapons carried on these vessels voids your statement.

In order to successfully attack America, a nation would have to have the capability to attack with thousands of weapons simultaneously, of the few that might approach having this capability none has any reason to do so. No reason for such an attack is expected to develop at any point in the future unless the US government stages yet another cluster fornication against yet another country.

Quote:

Our government is spending the same as the next 27 countries added together; other nations rightly perceive that as a deadly threat, and the threat has been made real by the Iraq attack, invasion, and partial conquest; and the saber rattling and more against Syria and Iran. Doesn't apply...you know better. So, again, I state that the US Navy profoundly does not need this equipment. Active sonar is the only way to defeat these vessels. I profoundly think that the small investment is needed.

I don't agree. Passive detection is significantly better, is less dangerous, and is less an offensive threat.

Now, you want to discuss permanent locations for these devices, and yes I realize the weaknesses of that, then perhaps. But in no case should the US government be issued yet another weapon to deploy outside American waters.

Yeah, Like on 9/11.

What a failure those attacks were.:rolleyes:

Terrorist attacks are not attacks on all of America by submarine. While I'd think that's obvious to almost anyone, perhaps it's obscure.

Further, the attacks of which you speak were directly caused by the most colossal failure of the US government in the history of it's existence.

***** is getting deep in this thread too. I think Red UFO is back.

Some interesting points being made here, and a lot of confusion. Fastpat, I think that your confusion about submarine employment (both by US and ROW forces) is an interesting point in itself. The Submarine Force on the whole is a very quiet bunch by nature. It's the Silent Service, except that we're so silent, nobody knows what we're up to. It's a bit of a quandary facing the Sub Force...

Some unclassified things that may be of interest ... the new diesel boats are very impressive platforms. Some of them are incredibly quiet, and carry extremely modern weaponry -- on par even with the US torpedoes. Like Seahawk says, active sonar is an excellent way to geolocate such a platform. Extremely low frequency active, as I noted above, and which is the original topic of this thread, is pretty silly, however. Even higher freqency active is becoming a less preferred method with the advent of some useful tools to counter it. Currently, the best way to find any submarine is to listen for it -- classic passive sonar. (Well, not quite "classic" passive sonar -- we've come a long ways since WWII...) A lot comes down to the training and experience of the crew, which is generally a reflection of the force as a whole. For example, it is well known that submarines from a certain country routinely make loud noises caused by crewmembers doing stupid things -- we'll say dropping hammers, leaving bits of metal in free-flood areas so they rattle when the boat moves, that sort of thing. Such a submarine is easy to find -- but it takes little more than crew training and attention to detail to transform such a boat from "impossible to miss" to "impossible to find."

Diesel boats present an interesting threat. Such a platform is more than capable of carrying and delivering an arbitrary weapon of choice to anywhere they'd like. While many of the older boats are very limited in speed and range, the newer boats are far more capable. A submarine threat capable of delivering a warhead of choice to anywhere in Europe or Asia has been a longtime reality. Submarines capable of (and interested in) delivering to the US are becoming an increasing likelihood.

The question for you, Pat -- how many nuclear warheads landing on US soil would it take to constitute an "attack?"

Terrorist attacks are one threat. National attacks are another. Remarkably, both of those very disparate defenses are handled by submarines these days.

You clearly don't know what you are "agreeing" with. And for the love of ASW, active sonar is not a weapon.

SOSUS is a joke, BTW, yesterdays news...