Sharp moments of the US Navy sonar reconnaissance at the gates of the Northern Sea Route. Deployment of the Seawolf-class ultra-low-noise submarine near the Barents Sea

Information about the arrival and deployment in the northeastern part of the Norwegian Sea (150-250 km north of the littoral zone of the Norwegian province / Finnmark county) of one of the three ultra-low-noise multipurpose nuclear submarine cruisers of the Seawolf class of the US Navy was met with a number of alarmist comments and discussions on the part of numerous domestic observers, who came to the conclusion that even a single submarine of this class taking up combat duty in the above-mentioned region of the North Atlantic can call into question the preservation of both acoustic secrecy and the combat stability of the submarine component of the Northern fleet Russian Navy in the northwestern strategic direction.

Indeed, in the light of the outbreak and inexorably gaining momentum of the "Arctic race", which consists in the incessant attempts of the United States, Canada, Denmark, Great Britain and Norway to challenge the ownership of the Lomonosov and Mendeleev ranges, which are the extremities of the East Siberian platform, as well as in the permanent demonstration of anti-submarine and tactical aviation The US and British navies and air forces of the presence directly "at the western gates" of the Northern Sea Route, the appearance of such a secretive and technically perfect uninvited underwater visitor cannot but cause a certain amount of concern either among the specialists at the headquarters of the Northern Fleet of the Russian Navy, or among ordinary observers who are aware of the tactics. -technical parameters of this submarine.

The presence of anti-submarine aircraft of the Russian Navy and the difficult hydrological situation will not play in favor of the ambitions of the submarine component of the US Navy in the Norwegian Sea

Having low-noise water-jet propellers (by orders of magnitude reducing the hydrodynamic disturbance and acoustic noise from the cavitation effect of propeller blades), the size of a modern and highly efficient "anechoic" coating, as well as multi-tiered shock-absorbing platforms on the attachment points of such elements of power plants as the main turbo-gear units (GTZA) , steam generating plants (PPU), steam turbine plants (STU) and nuclear reactors S6W, submarines of the "Seawolf" class can boast an acoustic noise level of about 50-53 dB in the "sneak" mode (at the level of the newest French MAPL of the 4th generation "Suffren" class "Barracuda SNA").

Based on technical information provided by a retired rear admiral and submarine division commander between 1984 and 1989. Vladimir Yamkov in the analytical material "The struggle of people, not ideas", it is easy to come to the conclusion that such objects can be tracked by means of nasal spherical multi-element GAS MGK-600 "Irtysh-Amphora-Ash / Borey" (included in the sonar architecture of the MAPL pr. 855 "Ash / -M" and SSBN pr. 955A / B "Borey / -B") at a distance of about 35-45 km (in the first and / or second distant zones of acoustic illumination / convergence) in normal hydrological conditions, in while the earlier MGK-540 "Skat-3" multipurpose nuclear submarines pr. 971U "Schuka-B" with less sensitive hydrophones and on-board computers with simplified algorithms for processing acoustic information are able to "probe" the "Seawolf" at a distance of 25-35 km.

Installed on the Sea Wulfs, the integrated nasal active-passive AN / BQQ-10 SACs based on spherical acoustic antenna arrays and wide-aperture onboard passive SASs based on AN / BQG-5D multielement acoustic arrays in conjunction with more efficient 70-processor on-board computers for combat information -control systems AN / BSY-2 are able to detect low-noise MAPL pr. 855 / M (do not have water-jet propellers and have a large underwater displacement, increasing the acoustic signature) at a distance of about 60-80 km, "Borei" - about 60 km and, finally , the noisier "Shchuki-B" - 100-130 km. The figures are disappointing ... Meanwhile, there is no need to dramatize.

Despite the fairly high technological parameters of the sonar complexes of the multipurpose nuclear submarines of the Seawolf and Virginia Block I / II / III classes operating in the waters of the Norwegian Sea, the hydrological situation in this region of the North Atlantic does not always favor the successful implementation of informative sonar reconnaissance. The prevailing impact of the cyclones of the Icelandic minimum quite often saturates the region with numerous and prolonged storms, significantly complicating hydrological conditions. As a result, the range of direction finding of our underwater component by means of the American SJC AN / BQQ-10 and AN / BQG-5D decreases from 60-130 to 15-35 km, respectively.

Moreover, there can be no question of the exceptional acoustic secrecy of the underwater component of the US Navy in this region of the North Atlantic and in light of the permanent patrolling of the neutral waters of the Norwegian and Barents Seas by promising Il-38N anti-submarine aircraft of the Russian Navy's naval aviation, equipped with unique airborne search and sighting complexes "Novella-P-38", capable of receiving information about the tactical underwater situation from 64 active and passive radio-hydroacoustic buoys of types RSB-41, RSB-48, densely spaced in the most unpredictable explored areas of the above seas.

Comments

[Login_Off]

As a result, the range of direction finding of our underwater component by means of the American SJC AN / BQQ-10 and AN / BQG-5D is reduced from 60-130 to 15-35 km, respectively

.
And the continuation? ... In turn, our submarine components ... can detect submarines under similar conditions at a distance ...?
Or is this distance within 5 km?

[Ilya-spb]

Could this enemy hydroacoustics ... drown out or disable?

[Vol4ara]

Quote: Ilya-spb

Could this enemy hydroacoustics ... drown out or disable?

You can, if you hit it well with a sledgehammer several times

[Ilya-spb]

Then I propose to drop a radio beacon next to each hydrophone, which will broadcast the anthem of the USSR, the song "Don't play the fool, America!" and other melodies.

[Job74]

If you watch the director's cut of the film "72 meters", there was a similar episode when the hero Krasko, Captain Janissary, caught a buoy and tried to broadcast Russian expressions to a NATO helicopter.

[Alien From]

One night, a UFO flew into our village, I was drunk with a crowbar ... how long would it take to break the car ........))))

[Rostislav]

Depth charges effectively deal with this

[Doccor18]

Seawulf turned out to be good, but it certainly did not become an omnipotent instrument of underwater warfare. The proof of this was the extremely small series of these MAPLs. Officially because of the great price. But this is the USA! They have wasted and are spending more on other projects. 3-4 yards per boat, 60 yards for 20 boats. These are clearly not the numbers that could kill the American budget. So there were more reasons ...
Therefore, panic over one is definitely not worth it.

[silver_roman]

They just understand that it makes no sense to churn out boats, which most likely will never be used, when taking into account their cost. Another thing is the military-industrial lobby, which, in fact, pushes the United States to purchase these very weapons. And MAPL is being built by General Dynamics, that of the sea wolves, that of Virginia, that of the early Los Angeles. So they are in chocolate anyway. The wolf is too expensive, and modern Virginia block 4 is an excellent nuclear submarine. in addition, they have a total series of 30 pieces.
ps before that I read about the successes of the PRC Navy, given that they were qualitatively simple and did not stand next to the US Navy, the leadership of the PRC Navy sounds too loud. Unfortunately, we are far behind.

[Revival]

Here, too, such a question arose.
Or only they are looking for us, but we don't need it by default

[Subtext]

(... far zones of acoustic illumination ...)

DZAO in the North, Barents, Kara seas - ??? Yes, in them, and the IZD subsystem has significantly modest capabilities.
And the "newest low-noise" boats from the 80s themselves.

Seawolf boasts an acoustic noise level of 50-53 dB

- and here it would be nice to indicate from which 0 (zero) we dance ...

[Johann Klassen]

Ay-Ya-Yai, dear.
Why are you asking this?

[Free wind]

And I'm not dramatizing. I watch rentals and stars. They clearly said that their boats sucked. And our wow !!!! They can even pretend to be a crocodile and quietly bite a cable at the bottom of the sea.

[rotmistr60]

Free wind
I watch rentals and stars. They clearly said that their boats sucked

And the "free wind" is clearly not blowing in your face. The very fact "in which regiment they served"? (12 chairs). Probably enough pouring constantly shit on the Russian Armed Forces and the Navy.

[dedusik]

Watch and listen to them more. The Armed Forces of all countries are actively using public misinformation

[polar bear]

The military programs of ren tv and the star are reminiscent of pre-war idiocy - we have all the best and little blood on foreign territory. And as a result, on their own and with gigantic blood. But then, at least they could boast of their numbers, some tanks were 3 times more than in the whole world.

[parusnik]

I read it, my heart relieved ... Everyone is locked up ... the enemies will not pass ...

[dedusik]

Yeah, and the key was thrown into the bushes - a joke from the 60s.

[Johann Klassen]

Good health to everyone and to the author too.
All the will of God.
Let's hope that at the right time the adversaries will go deaf and blind.
And what else remains for us if the "friends-neighbors" and "partners" seem to have lost their way.

[kepmor]

dummy article ... a set of numbers and phrases from a wiki with an Internet ...
in this topic, the author is clearly "no boom-boom" ...
the laurels and authority of Klimov and Timokhin are clearly haunted ... but not a hat ...

[Operator]

The author - propellers and impellers of water cannons have blades (and not blades like turbines)

[Operator]

The Sivulf (like all other submarines with the exception of the Russian experimental Alrosa) does not have a water cannon: this nuclear submarine has a hollow propeller in the nozzle - the so-called. impeller

Water jet impellers have a different type of blades

[Andrei from Chelyabinsk]

I answer not to the operator (this is useless) but to those whom he can mislead.
1) An impeller and a water cannon are practically the same thing. Strictly speaking, an impeller is an impeller enclosed in a ring and as such it has very different applications - for example, in pumps and turbines. The impeller is the main unit of the jet propulsion unit, in addition to which it includes other units (water conduit, etc.).
To put it simply, not every impeller is a water cannon, but every water cannon is an impeller.
2) The shape of the impellers of modern nuclear submarines is secret and what is shown in the figures and models does not correspond to reality

[dzvero]

If it is not difficult for you, can you explain the advantages of a water cannon over a "bare" propeller? I became curious why they were registered on the western submarines, but not on the Soviet / Russian ones. There are some considerations, but I'm not sure if they are correct.

[Andrei from Chelyabinsk]

Quote: dzvero

If you do not mind, can you explain the advantages of a water cannon in front of a "bare" propeller?

I dwelled on this issue in more detail here https://topwar.ru/173785-a-tak-li-perspektivna-apl-haski.html see the section "Propeller or water cannon?"
In short, the water cannon provides less noise + better protection of the propeller, but at the same time, perhaps at low and medium strokes, the efficiency of the water cannon is lower than that of the propeller. (but at high speed it can be higher)
And if I understand correctly, the propeller on our Ashes leads to the fact that the low-noise speed of their underwater course is much lower than Seawulf and Virginia

Quote: dzvero

I became curious why they were registered on the western submarines, but not on the Soviet / Russian ones.

Yes, it seems like there is something on the "Boreas" ...

[dzvero]

Thank! This article somehow eluded me ...

[Charik]

the screw on our Ashes leads to the fact that the low-noise speed of their underwater course is much lower than Seawolf and Virginia, Maybe, on the contrary, the low-noise speed is higher than that of American women

[SovAr238A]

Quote: Charik

the screw on our Ashes leads to the fact that the low-noise speed of their underwater course is much lower than Seawolf and Virginia, Maybe, on the contrary, the low-noise speed is higher than that of American women

No.
Low noise on screws up to 7-8 knots.
On water cannons - up to 20 knots ...

[Charik]

A-A-A-got it

[merkava-2bet]

Hello Andrey, thanks for the interesting articles.
I have a question, in Apalkov's book about submarines, there is an interesting point and it is not entirely clear to me. It says that the new submarines of projects 971 and 945 received a novelty, washed sand is poured into the hollow main shaft of the propeller to reduce the structural noise of the shaft itself.
But following the laws of physics, speed in various environments, I think water or oil is better, and polyurethane foam is also possible.
What do you think?

[Andrei from Chelyabinsk]

Good day, Andrey!

Quote: merkava-2bet

It says that the new submarines of projects 971 and 945 received a novelty, washed sand is poured into the hollow main shaft of the propeller to reduce the structure-borne noise of the shaft itself.

Unfortunately, I cannot say anything about this.

[meandr51]

At one time, sand was poured into the hollow metal walls of high-end Hi-Fi speakers. Oscillations are best damped at the transition of media with a maximum different modulus of elasticity.

[Operator]

You run the risk of getting an answer from the "Chelyabinsk" humanities scholar, who has a mess in his head with water cannons, impellers (supposedly the main components of water cannons), blades, paddles, Russian-Japanese shells, etc. etc.

[SovAr238A]

Quote: Operator

You run the risk of getting an answer from the "Chelyabinsk" humanities scholar, who has a mess in his head with water cannons, impellers (supposedly the main components of water cannons), blades, paddles, Russian-Japanese shells, etc. etc.

A group of comrades under the nickname Operator drank the wrong water?

[Avior]

It is often written that a distinctive feature of a water cannon is the outlet diameter - it is less than the inlet cross-section. In general, the inlet and outlet of the impeller are the same, this is a screw in the pipe.
It is difficult, however, to say whether this condition is sufficient or simply necessary.

[Operator]

For water cannons, the outlet area of ​​the flow area is smaller than the inlet area to create pressure. Propellers with a ring nozzle (impellers) have the same flow areas - the visual difference in diameters is due to the coverage of the conical end of the stern by the nozzle.

In terms of acoustic visibility, propellers are in the lead, followed by water cannons, the quietest are multi-blade low-speed propellers in a ring nozzle.

T.N. Sivulf's low-noise running at a speed of up to 20 knots is associated with its full electric propulsion - steam turbines without gearboxes drive electric generators that feed a low-speed traction motor, also connected without a gearbox to a propeller. As a result, gear noise is absent as a class.

At the same time, the low-speed traction motor weighs and is not childish. The navies of other countries are planning to implement a mode of full electric propulsion of nuclear submarines when switching to electric motors with superconducting windings, weighing two orders of magnitude less than the copper engine "Seawulf".

[Free wind]

However, the displays of waterborne combat vehicles indicate that some are equipped with water cannons, and some with propellers. At first, I also could not understand how.

[Aag]

Quote: Andrey from Chelyabinsk

I answer not to the operator (this is useless) but to those whom he can mislead.
1) An impeller and a water cannon are practically the same thing. Strictly speaking, an impeller is an impeller enclosed in a ring and as such it has very different applications - for example, in pumps and turbines. The impeller is the main unit of the jet propulsion unit, in addition to which it includes other units (water conduit, etc.).
To put it simply, not every impeller is a water cannon, but every water cannon is an impeller.
2) The shape of the impellers of modern nuclear submarines is secret and what is shown in the figures and models does not correspond to reality

As a first approximation, roughly, I agree with your presentation of the topic. By the way, to the authors, the topic for the article! According to the established tradition, unfortunately, the article is only the initiator of sometimes interesting opinions. How about a comprehensive discussion of movers in the aquatic environment? ( although some resources give the definition of an impeller as a blade machine enclosed in an annular nozzle, operating in the AIR). With regard to ships, IMHO, "an annular nozzle on a propeller, and a" water conduit "in a water cannon (with all their profiles) are different things And it's not even about the operating modes, the speed ... Although-I-I ...
Any engineering solution, -compromise. Humanity has not fully realized the potential of wheeled propellers, -suddenly (:-)), a propeller appeared. Next, - with a variable pitch. With regard to submarines, IMHO, the problem is universality. It is necessary to achieve acceptable efficiency. propeller at DIFFERENT modes, speeds. From the classics: high speed, - fewer blades, smaller pitch, propeller diameter, more revolutions. Ring nozzles, - evil. And vice versa. For example, tugs. Low speed. Maximum thrust "on mooring ". A large, multi-blade propeller, preferably in a profile ring nozzle, low-speed (exclude cavitation) ...
Noise, -separate topic (non-symmetrical arrangement of blades, profile, shape of HW blades) ...
I hope there are specialists, -popularly clarifies the topic, it would be interesting ...

[Bez 310]

In general, the sea will help us, as "General Moroz" helped us near Moscow.
And the Il-38N planes are "promising", and there is nothing here!
And about the buoys, this is - "tightly spaced on the most unpredictable
reconnaissance areas ", so generally new words in the tactics of submarines.

I'm embarrassed to ask ... The author is paid for such a note, or everyone is
pure enthusiasm, "free of charge, that is, free"?

[Region-25.rus]

in which case, in planning military actions, we will rely on the weather with reference to storms, on spiritual braces and ... we also need to set up a barrage of icons as tightly as possible! "In general - So we will win!"

[Bez 310]

Quote: Region-25.rus

rely on the weather in planning hostilities

The weather must be taken into account when planning the database,
without this it is impossible. But with the icons you came up with a good idea,
this is a new word in the drag fight.

[Charik]

In WW2, we made a flyby with some icon, I don’t remember, if something is launched into space by the main Pop

[lucul]

I'm embarrassed to ask ... The author is paid for such a note, or everyone is
pure enthusiasm, "free of charge, that is, free"?

And you measure everything in money)))
Betrayal - 30 pieces of silver and further according to the price ...
What is there to be surprised - some have their Motherland where one place is warm ...

[Bez 310]

What did you want to say?
Specify, please.

[Dedok]

I did not understand anything: and where are the planes?
bomb s in peacetime?
and how to expel them otherwise?

[Alexey RA]

Quote: Dedok

I did not understand anything: and where are the planes?
bomb s in peacetime?
and how to expel them otherwise?

In theory, the aircraft (as having the maximum size of the patrol zone) should detect the nuclear submarine, and then transfer it to the surface anti-submarine warriors. And they will try to complicate her future life as much as possible, as demonstratively watching her (they say that GAS helps from uninvited guests in an active mode).
The question is, does the Federation Council have these surface forces?

[novel66]

it seems like there are 5 BOD and 6 IPC, but here ... in what state

[Alexey RA]

Moreover, there can be no question of the exceptional acoustic secrecy of the underwater component of the US Navy in this area of ​​the North Atlantic and in light of the permanent patrolling of the neutral waters of the Norwegian and Barents Seas by promising Il-38N anti-submarine aircraft of the Russian Navy's naval aviation.

All eight available?

[Andrei from Chelyabinsk]

promising anti-submarine aircraft Il-38N

I recalled the fairy tale about the Frog Princess in the description of the gas sector:
"Here are the king, my wife!
May she be green
But there is a prospect -
There is no mother-in-law ... (well, not at all!) "

[novel66]

no, but what? every time, talking about the problems of the fleet, they come to the conclusion - they will not take out the fleet, they will take out the aviation ... but there, however, not everything is going smoothly either

[Andrei from Chelyabinsk]

Quote: novel xnumx

will not take out the fleet, will take out the aviation ... but there, however, also not everything is smooth

In short, the naval missile-carrying aviation is no longer and is not expected, the replenishment of fighters is poorly satisfactory in quality (Su-30SM) and completely unsatisfactory in quantity (a regiment of such aircraft in the fleet ... it is generally unknown when it will be), anti-submarine aviation is on its way - "Novella" would be interesting in the 80s of the last century, but now it is not at all on the cutting edge, and we have minuscule aircraft with the "short story", helicopters - old Ka-27 with minced meat God knows what year, urgently needed a new PLO helicopter, but it does not exist, there are practically no reconnaissance aircraft (AWACS never existed, and the Su-24MR remained well if a dozen) ...
In general, if all naval aviation, whatever it is, is collected into one fleet - there may be some other good, but so ...

[novel66]

well, there is a Tu-22, and 95ms is not enough, but they can ... but 142 - I don't know ...

[Bez 310]

I am wildly sorry, but how can they help in anti-submarine affairs?
Tu-22 and Tu-95? I know about Tu-142 ... In general, there is almost no hope.

[novel66]

22 and 95 are just against the fleet

[Bez 310]

And how 95 can fight against mobile
surface targets? Am I so far behind
that I don't even know about the armament of the Tu-95 anti-ship missiles?

[Alexey RA]

Quote: novel xnumx

well, there is a Tu-22

This is the Air Force. And the tasks will be assigned to them by the Air Force. And the specifics of working on naval targets for Air Force pilots are at the bottom of the priority list.

Quote: novel xnumx

and 95ms, not enough, but they can

These will not be given to the fleet for sure.
They will either "sit in the pits" or, with loaded revolvers, cut circles somewhere in high latitudes, occasionally sitting down for refueling - in anticipation of the command either to use weapons or to return to base.

[Andrei from Chelyabinsk]

Quote: novel xnumx

well, there is a Tu-22

No. They were transferred to the Aerospace Forces, so the Navy can forget about them.

[novel66]

and then the doc is still ... hopeless

[Alexey RA]

Quote: novel xnumx

no, but what? every time, talking about the problems of the fleet, they come to the conclusion - they will not take out the fleet, they will take out the aviation

Nafig-nafig. Last time, under the mantra "aviation will save us," the commander-in-chief of the Navy nailed the design of the OVR corvette and ordered the same 22160.

[Trapp1st]

often saturates the region with numerous and prolonged storms

Wait for the weather by the sea? (a phrase that makes sense, it is in vain to hope for something)

[Crabong]

There is little hope for ILs ... This Seawulf will scour the bases. The activities of the Northern Fleet will obviously become much more complicated.

[vic02]

Information on arrival and deployment in the northeastern part of the Norwegian Sea (150-250 km north of the littoral zone of the Norwegian province / Finnmark county)

Which, which zone? Recently, in publications, the language has been mocked as they want. The littoral zone in geology / oceanology is the zone of influence of tides and waves, that is, simply the coast, or coastal zone. Why is this term here? [Media = https: //shkolazhizni.ru/img/content/i171/171478_or.jpg]

[iouris]

"Revenge" is somehow postponed for a long time. "Kursk" may be repeated (also "accidentally"). So you can lose everything.

[Revival]

In general, the logic in the article touches:
So let's compare low noise and detection range.
1 approach:
And during a storm they will go blind, and we ..., but we do not care at all, we are not looking for anyone)))
2 approach:
And we will give them a brick from the plane from the corner, but in a crowd, but how will we give ... well, whose complex is better now!?)))

Here is a complete objective comparison "one to one"))

[Andrey1978]

It's no secret that enemy submarines are on combat duty off our shores, just like Russian ones. This is psychology, to scare that extra secret apparatus, on your shores, start to be afraid! I am sure there are specialists in the Federation Council who will hunt down and take for escort.

[stels_07]

If the wolf is not deza, then let's hunt with Varshavyanka

[Glebovich]

A classic water jet is a centrifugal pump immersed in a liquid, a working body in the form of a wheel with blades, the wheel can be with one disc or two. The impeller is located perpendicular to the shaft line. To reduce cavitation in front of the wheel, I install an Archimedes screw. The screw enclosed in a nozzle is an axial centrifugal pump that provides a high flow rate at a low head, in a centrifugal pump, on the contrary, the head is high, the liquid flow rate is low.

[sinoptic]

Strange, but the water cannon itself does not provide low noise. One of the main factors providing low noise of the propeller is laminar flow. Look at the stingray with its huge winged fins swims (no water cannon) and no noise.
Therefore, it is possible to have a large propeller that rotates slowly providing a laminar flow around the water, without cavitation, and will be very quiet.
So the water cannon itself does not solve anything, because if there is cavitation or vortices they will be heard.

[Aviator_]

It looks like you have never dived at sea. The squeal of the propeller from the motorboat is heard from afar, you can always determine whether it is close or far, but a jet bike with a water jet is silent, an infection, you must always be very careful when surfacing so that it does not run over. And yet - all fish swim silently, except for the marlin (swordfish), which goes at maximum speed. Then it goes in the cavitation cavity, like the "Shkval" torpedo. And the stingray swims very slowly, it is easy to overtake it with fins.

[Aag]

Quote: Aviator_

It looks like you have never dived at sea. The squeal of the propeller from the motorboat is heard from afar, you can always determine whether it is close or far, but a jet bike with a water jet is silent, an infection, you must always be very careful when surfacing so that it does not run over. And yet - all fish swim silently, except for the marlin (swordfish), which goes at maximum speed. Then it goes in the cavitation cavity, like the "Shkval" torpedo. And the stingray swims very slowly, it is easy to overtake it with fins.

"... you can always tell if it is close or far .."
It’s not even always. It’s easier in the air.
"... all the fish swim silently ..."
I won't say for everyone, but a starting crucian carp, a carp (not "at low-noise" speed :-)) is quite ... palpable. I don't know what is rattling there (scales, bones), or the outraged water forces such a "picture" ( under water, or rather in water, a person "hears" with the bones of the skull).

[Aviator_]

starting crucian carp, carp (not "at low noise" speed :-)) is quite ... palpable.

What does "feel" mean? The starting vortex, which goes in the water in the direction opposite to the movement of the fish, is quite tangible, but certainly not by the eardrums. That is, in terms of acoustics, everything is clean here.

[Aag]

That means, it feels. (When I wrote "hears", put quotation marks). Neither you, I am sure, nor I have such a sense organ as the lateral line. Nevertheless, in the water we "hear". "Established" organs hearing with "sensors" in the form of eardrums do not play a primary role there (it strongly depends on the frequency).
By the way, the aforementioned crucian carp is also "heard" on a collision course! Fluctuations of the medium, whether it be air, water, or a solid, propagate in all directions (corrected for the Doppler effect). Otherwise, you would not have heard the motorboat going in your direction.
But the density of the medium, and, as a consequence, the speed of sound propagation (increased, - if we are talking about water, compared to air) greatly complicates the positioning of the sound source both in distance (your, sorry, an unfortunate example) and in direction (azimuth ).
According to my observations, there are enough specialists in hydroacoustics, - let them forgive for intruding on their "clearing". I write on the basis of school knowledge in physics, biology; and not a lot of experience underwater hunting (in the sense of fishing))).
And again: "... not with eardrums. That is, from the acoustics point of view, everything is clean here ..."
Let a person HEAR a very narrow range of SOUND frequencies (and it narrows with age), but this does not mean that what we do not hear is not the area of ​​acoustics.
Sorry for the tediousness. I will explain it as follows. The site is full of comments with the authors of which are either uninteresting or useless, not productive to communicate. Your comments, IMHO, do not apply to them. That's why I decided to clarify ...

[Aviator_]

Come on, about boring. Rather, thoroughness, this should only be welcomed, since this is a criterion that the interlocutor wants to understand the issue. There are not many of them here. The direction to the motorboat under water is taken, of course, not as accurately as in the air to the running motor, but it is taken. Due to the higher speed of sound, a larger base between the receivers (ears) is needed. The size of our heads is optimal only for life on land. But the range is determined very accurately, at least for self-preservation this is enough. I have a very decent freediving experience, and for the last 15-20 years, due to the widespread use of aquabikes, safety problems have increased - they are practically silent because of their propeller. High frequencies are screened by the walls of the water jet channel, and there are few low frequencies. And from the free propeller there is just a squeal - the high frequencies work.

[Aag]

Quote: Aviator_

Come on, about boring. Rather, thoroughness, this should only be welcomed, since this is a criterion that the interlocutor wants to understand the issue. There are not many of them here. The direction to the motorboat under water is taken, of course, not as accurately as in the air to the running motor, but it is taken. Due to the higher speed of sound, a larger base between the receivers (ears) is needed. The size of our heads is optimal only for life on land. But the range is determined very accurately, at least for self-preservation this is enough. I have a very decent freediving experience, and for the last 15-20 years, due to the widespread use of aquabikes, safety problems have increased - they are practically silent because of their propeller. High frequencies are screened by the walls of the water jet channel, and there are few low frequencies. And from the free propeller there is just a squeal - the high frequencies work.

Thank you. Up to this phrase: "they are practically silent", etc. I agree.))) Further, subjectively, I also agree: a petrol cutter on some inflatable can be heard further than a "Beeliner" with a balanced engine, by the way, without any screens (no cavitation, quality of reducers? - if you return to the topic of the article?).
"... I have a very decent freediving experience ..." I am pleased to greet my colleague! I dived for the first time with an underwater gun ... 40 years ago. Then, neither the place, nor the conditions of service were conducive ... Now health is somewhat limited ... Anyway, I am glad that there is such a niche of existence ... You stories (more often cheerful and brainless), marriages (poachers) are categorically dissatisfied with life, and vice versa, always "hungry" ...
For hell with them, and for us!

[Aviator_]

I agree! I found my photo, in Okinawa I observed this leisurely object

I've been diving for 45 years with some interruptions.

[Aag]

I envy, kindly! Youth passed under the impression of films by Zh-I Cousteau, and similar themes. I don't remember the authors, I still have an opinion that in beauty (subjective category, IMHO), the abundance of species of flora and fauna, compete two seas, the White and the Japanese ... (I realize that Okinawa is the South China Sea, and yet)) It's nice to talk to, but, you must admit, we flood.

[Aviator_]

Come on, we communicate for our pleasure. Was in Okinawa for a conference in 2014. The general impression of Japan is that of the USSR during the heyday of stagnation, somewhere around 1980. A bureaucratic country. But there is still a samurai spirit - they don’t take tips in principle, and the taxi driver who drove our delegation to the aquarium for 100 km, made a mistake in the price and called less than he clocked up the counter - so he still took the price that he had appointed, at a loss. ... And my underwater affairs began with the book by Zh-I Cousteau "In the world of silence", 1957, publishing house "Young Guard". Favorite book of childhood.

[Aag]

"Come on, let's talk for our pleasure ..."
I agree.
"And my underwater affairs began with the book by J-I Cousteau" In the world of silence ", 1957, publishing house" Young Guard ". Favorite book of childhood."
Similarly!

[Aviator_]

And also on this trip - there was a boring paddock, fenced with a net on the side of the sea on a beach - for swimming. The boredom is terrible. And next to it is a stand: swimming outside the enclosure is prohibited. Well, this is forbidden to the Japanese, so before breakfast, from 6 to 7 o'clock, we felled this inscription, swam where it is forbidden, and then put it in place. And so all 4 days. There the stingray and filmed. Somewhere there is a photo of a sea snake, such a striped one, now I can't find it.

[Vladimir SHajkin]

It is necessary to reach the base of the "Sea Wolf / s" and hide, and when they go out on combat patrols, duck under the belly to glue and thus save energy and carry out their combat patrols, but at the same time on the paths of potential friends.

[KSVK]

Quote: Aviator_

A stingray swims very slowly, it is easy to overtake it with fins.

You tried? Try it, you will learn a lot of interesting things about "slow" floating rays.
PS Manty and eagles are also stingrays.

[Aviator_]

I did this many times, which is what I wish for you.

[ycuce234-san]

John Steinbeck, American writer, a man with life experience, in September 1960 made a psychological sketch-portrait of a typical American young submariner. It was this submariner who, adjusted for the subsequent 20 years of experience and age, showed a career growth, a well-known American underwater audacity and initiative, planned and went to the Soviet shores on the Sivulfs. Without understanding people, it is difficult to understand both the technical systems and organizational activities of US submariners. Let's get to know him better while he is young and open to the world and people:

Morning has come - clear, with reddish reflections of autumn in sunny
glare. My separation from my wife did not drag on, as we both hate
can these farewell minutes, and besides, neither I nor she wanted
stay alone after the wires. She immediately darted from her place, gave
full throttle and sped off to New York, and I, sitting Charlie next to me, took
Rocinante first to the ferry that goes to Shelter Island, then to
the next to Greenport, and from there to the third, from Cape East through
Long Island Bay straight to Connecticut to avoid getting into New York
traffic and immediately make a large haul. And I must confess that
a green melancholy immediately fell upon me.
The deck of the ferry was flooded with bright sun, it was about an hour from the mainland
paths. A slender yacht with an oblique Genoese staysail gave way to us,
like a developing scarf, the coasters dragged themselves up the
strait, or, swaying heavily on the wave, went to New York. Then in
half a mile from us a submarine rose, and the bright day immediately faded in my
eyes. A little further away, another equally dark ripped through the water, behind it -
third. Well, of course: they are based in New London, their home is here. And maybe
it turns out that with their poison they really keep the peace in the whole world. If I could
imbued with sympathy for submarines, their beauty would open to me, but
for they are supposed to destroy, and although they can explore and map
seabed, can pave new trade routes under the ice of the Arctic, all
their main purpose is to serve as a threat. And I still remember too well
how we crossed the Atlantic in a transport ship and knew that these
monsters are hiding somewhere in our path and looking out for us with their Cyclops
eyes. The light is not pleasant to me when I see them and remember the charred corpses,
which were caught in the war from the oily surface of the sea. Now on
weapons of submarines means of mass destruction is meaningless
and the only means we have to prevent mass destruction.
On the upper deck of a ferry clanking with iron, where the wind blew
there were few passengers. Young man in a sports jacket, blond
and with blue, like a delphinium, eyes, circled in red from
stubborn wind, looked at me, then showed, holding out his hand:
- It's new. It can dive for three months.
- How do you distinguish between them?
- I know. I serve myself.
- At the nuclear?
- Not yet, but I have an uncle for one. Maybe soon I will too ...
- Why are you not in shape?
“I’m walking on leave.
- And you like your service?
- You wouldn't like it! They pay well, and the prospects for ... the future are not bad.
- Is it nice like this for three months under water?
- Let's get used to it. They feed well and show movies. I wish I could be under
North Pole! AND?
- Yes, it would be nice.
- Movies are showing, and ... the prospects are not bad.
- Where are you from?
“Out of there, New London. My motherland. I have an uncle in the navy and both
cousins. We can say that the whole family is underwater.
- And I am somehow alarmed by the mere sight of them.
- This, sir, is passing. You will forget to think that the boat is diving, -
of course, if your health is in order, Claustrophobia <Pathological
fear of confined space> never suffered?
- No.
- Then you will soon get used to it. Maybe let's go downstairs and have some coffee? Time
that's enough.
- With pleasure.
It is quite possible that he is right, not me. This world belongs to him, I'm in it
is no longer the master. In the look of his blue, like a delphinium, the eyes are not felt
there is no anger, no fear and no hatred either. And maybe that's how it should be: work
as a job, it is well paid, and the prospects are not bad. Should I
impose my own memories and fears on him? Maybe nothing like that
more and will not be? But that’s his concern. The world belongs to him now. AND,
probably a lot of what he knows will simply not be available to my
understanding.
We drank coffee from paper cups and he showed me in a square
porthole dry docks and submarine skeletons under construction.
- Do you know why they are good? There was a storm at sea, but this one went under water - and
silence is complete. You sleep like a baby when up there, like all the devils with
the chains were lowered.
He told me how to get out of town, and it was one of the most
sensible explanations for my whole trip.
- Well, goodbye. Hope your hopes for ... for the future
will be justified, - I told him.
- Yes, the service is really good. Good day, sir.
And as he drove down the sparse Connecticut road, among the trees and
gardens, I felt that after talking with him, my soul felt better and
calmer.

John Steinbeck. "Traveling with Charlie in Search of America"

[mik193]

I dare to correct. Well, most likely the submarine will search not near, but in the Barents Sea itself. Back in Soviet times, 3-5 US Navy submarines were constantly grazing in the Barents Sea. About hydrology - just in autumn and winter in the northern seas (Norwegian, Greenland, Barents, Kara) it becomes optimal for searching for submarines. Winter storms will interfere with the work of anti-submarine aircraft and surface ships, especially without affecting the search capabilities of submarines. The only thing that will be limited will be the range of the GAS with GPBA, since the Barents Sea is shallow enough (up to 400 m). And in general, the submarine of this project is capable of revealing the situation in the Barents Sea, remaining unnoticed. In general, an article about complacency.

[Editor]

is there a system of noise generators-jammers?

[KSVK]

Quote: Aviator_

I did this many times, which is what I wish for you.

Explorer trimix level3 PSA, intro to cave IANTD, nice to meet you.
I think that I have already exhausted my limit of luck. Good luck.

[Vladimir SHajkin]

It is necessary to place your own GASs on the exit / entrance routes to the Seawolf port

[Paramon Pictures]

I read it like a textbook before the session: not a damn thing understood, overloaded with professionalism. You, Zheka, for whom did you write? Editor, please tell the depressed one.

[UFO]

All generals prepare for past wars, with drones leading the way. The Turks suddenly showed this clearly for the tanks. They have already made sea drones, and together with smart mines are ready to suddenly and graphically throw submarines into the dustbin of history. And in our garages 10 km of underwater locators are gathering dust.

[Lom lom]

It's a pity, but to let it go to the bottom.

[Editor]

well, all hope is for storms and hurricanes ...