Submarine cloak

[asparagin]

Some recent advances in the development of anti-sonar cloaks.

[Pilotasso]

These days sonar is hardly the sensor you use to locate a sub. Its done passively for the most part, and in this area they are all stealth but the oldest ones still navigating. Detection is done by listening to engines and props. Using the sonar gives away your position and intention much like a full blown STT lock on fighters.

 

The Submarine are like F-22's of the sea.

 

There are only 2 kinds of ships: Submarines and targets. ;)

Edited January 26, 2011 by Pilotasso

[asparagin]

These days sonar is hardly the sensor you use to locate a sub. Its done passively for the most part, and in this area they are all stealth but the oldest ones still navigating.

 

The Submarine is like having F-22's at sea.

 

There are only 2 kinds of ships: Submarines and targets. ;)

 

You are talking about sub vs. sub.

Sub hunters (surface) don't care about stealth, there's no need for them to use passive arrays. The sooner they locate the target the better, and active arrays are the fastest.

[raynor]

SONAR is how you listen to the sounds in the ocean. Their are two "modes" active and passive, by simply listening using a SONAR array you are not broadcasting your position. Using passive SONAR does not give away your position.

 

Anything you can do to keep sound from being passed through your hull to the ocean helps in avoiding detection.

[Pilotasso]

You are talking about sub vs. sub.

Sub hunters (surface) don't care about stealth, there's no need for them to use passive arrays. The sooner they locate the target the better, and active arrays are the fastest.

 

Using the sonar is like lighting up a big lighthouse. You can see it much further away than it sees you. These days you can shoot a torpedo from 50km homing on those sounds.

 

Make no mistake, a modern sub will always enjoy a big advantage over surface ships even in great numeric deficit.

[Pilotasso]

SONAR is how you listen to the sounds in the ocean. Their are two "modes" active and passive, by simply listening using a SONAR array you are not broadcasting your position. Using passive SONAR does not give away your position.

 

Anything you can do to keep sound from being passed through your hull to the ocean helps in avoiding detection.

 

The article is clearly talking about active sonar as in suppressing the pulses at the hull from being reflected back. You cannot suppress the subs own noise like this, the approach to achieve stealth from own noise is by having a super silent engine and a well designed propeller. This is a completely different ball game and its the championship every submarine maker is at right now.

Edited January 26, 2011 by Pilotasso

[Maximus_G]

These days sonar is hardly the sensor you use to locate a sub.

Using active sonars is a common practice these days. They are used widely in sub hunting. Google "active sonar buoys" or "DICASS" for example.

[raynor]

The article is clearly talking about active sonar as in suppressing the pulses at the hull from being reflected back. You cannot suppress the subs own noise like this, the approach to achieve stealth from own noise is by having a super silent engine and a well designed propeller. This is a completely different ball game and its the championship every submarine maker is at right now.

 

With that sort of technology you would be effectively creating a buffer between your hull and their so yes it would in fact be possible to limit the ability for other ships to hear what is going on inside your hull more than current technology.

 

US submarines have already countered the noise fight with nuclear reactors but you still have a lot more going on a submarine that is loud and can give away your position.

 

If it didn't help deter passive sonar they would not pursue it (because that is how a submarine finds another submarine/surface vessel in the first place).

[asparagin]

Using the sonar is like lighting up a big lighthouse. You can see it much further away than it sees you.

 

This isn't everything in naval combat.

1. Even if you get an active sonar emitting platform with your sensors, you don't have immediately an accurate firing solution.

2. The only advantage of the passive sonar is not giving away information. Active sonar is superior in every other aspect: range, and the fact that it delivers you instant location of the target.

 

These days you can shoot a torpedo from 50km homing on those sounds.

 

For an effective shot you need a good or fairly good solution. Firing without it, is like a shot in the blue, even if the torpedo has homing. Torpedo homing is restricted due to it's size.

 

Make no mistake, a modern sub will always enjoy a big advantage over surface ships even in great numeric deficit.

 

Saying that subs are superior to everything is a bit naive IMO. As always it's the question, what they're up against. Subs are not top of the food chain. Sonar is not deployed only by ships but also planes and choppers.

Edited January 27, 2011 by asparagin

[Groove]

Pilotasso, don't mess up between passive and active sonar. :)

[shaggy]

Nothing will ever beat our swedish subs http://en.wikipedia.org/wiki/Gotland_class_submarine

 

In 2004, the Swedish government received a request from the United States of America to lease HMS Gotland – Swedish-flagged, commanded and manned, for a duration of one year for use in anti-submarine warfare exercises. The Swedish government granted this request in October 2004, with both navies signing a memorandum of understanding on March 21, 2005. The lease was extended for another 12 months in 2006. In July 2007, HMS Gotland departed San Diego for Sweden.

HMS Gotland managed to snap several pictures of the USS Ronald Reagan during a wargaming exercise in the Pacific Ocean, effectively "sinking" the aircraft carrier. The exercise was conducted to evaluate the effectiveness of the US Fleet against diesel-electric submarines, which some have noted as severely lacking.

 

 

I dont know much about subs, but we had an instructor when i did my service that had been an sonar operator in the Gotland Class submarine, and he always said. if you have an silent enough engine no one will be able to catch you, not depending on what equipment they use to home in on you. The new submarines are so friggin good that they can clearly tell a small shipping vessel with maybe 2 engines and 3 props, to a bigger one with 2 engines and 5 prop blades. everything is about listening and analyzing the data.

[Groove]

You need nuke torpedos to sink an american CVN :D

 

But i like your attitude about swedish subs :)

[asparagin]

I dont know much about subs, but we had an instructor when i did my service that had been an sonar operator in the Gotland Class submarine, and he always said. if you have an silent enough engine no one will be able to catch you, not depending on what equipment they use to home in on you.

 

Silence is a factor only against passive sonars. From active sonar you can only hide (with range, depth and using the layer).

 

The new submarines are so friggin good that they can clearly tell a small shipping vessel with maybe 2 engines and 3 props, to a bigger one with 2 engines and 5 prop blades. everything is about listening and analyzing the data.

 

Correct, but that is not enough to give you a firing solution, you will further need location, bearing and speed. This equation can be solved when only using passive sonar (you only have bearing and maybe range) if you have enough data.

 

I myself am a fan of subs, and think the modern capabilities are extraordinary, but ASW is not to be neglected, it can be carried out pretty effective these days also.

[Pilotasso]

Using active sonars is a common practice these days. They are used widely in sub hunting. Google "active sonar buoys" or "DICASS" for example.

 

 

this is COMPLETELY different from using a ship based sonar. Sono-buoys are expendable and doesnt necessarilly betray the location of the ship, but it also requires you to already know the Submarine is inbound. Either the sub commander screwed up, or its a really old submarine, or a surface ship of your fleet has already been attacked.

 

For an effective shot you need a good or fairly good solution. Firing without it, is like a shot in the blue, even if the torpedo has homing. Torpedo homing is restricted due to it's size.

 

Modern subs and torpedoes dont require a lock on previous to launch. They can be shot once a surface ship has been identified by the submarines sensors (there are severel methods of doing this without using active sonar) and then the torpedoes can be guided via optical cable untill they come within range of their own sensors, similarlly like an AMRAAM (including multi shot capability).

 

Surface ship VS Submarine, the sub should hold the advantage in the vast majority of scenarios.

Edited January 27, 2011 by Pilotasso

[Pilotasso]

Nothing will ever beat our swedish subs http://en.wikipedia.org/wiki/Gotland_class_submarine

 

 

 

 

I dont know much about subs, but we had an instructor when i did my service that had been an sonar operator in the Gotland Class submarine, and he always said. if you have an silent enough engine no one will be able to catch you, not depending on what equipment they use to home in on you. The new submarines are so friggin good that they can clearly tell a small shipping vessel with maybe 2 engines and 3 props, to a bigger one with 2 engines and 5 prop blades. everything is about listening and analyzing the data.

 

 

Heard of that story as well. Nowadays AIP submarines can dive deeper and sail longer without snorkel.

 

The latest models are U-212/214 vessels. They are even stealthier and longer ranged than the Gotland. The 212 is limited to shallower dive depths but its magnetic signature is next to nill (amagnetic steel). 214 ships can dive MUCH deeper, but use different ways to nullify the magnetic signature.

[Maximus_G]

These days sonar is hardly the sensor you use to locate a sub.

this is COMPLETELY different from using a ship based sonar.

What exactly is "COMPLETELY different" there?

 

Modern subs and torpedoes dont require a lock on previous to launch

:D

[asparagin]

..and then the torpedoes can be guided via optical cable..

 

Guided where?

 

From passive sonar you get only the bearing to the ship, classification and (if you are Seawolf) an approximation of range. You don't know the course of the ship. Without this you can send your torpedo in a completely different direction.

 

With enough info (and time) you can get a good approximation of the ships position and vector, when using passive sonar. (as I already said in the previously post) It is important to know when your solution is good enough to make the shot, because you have also to consider that by firing you give away your element of surprise.

[bumfire]

Supposedly, and I dont know if this is true, but the new Vanguard class subs from the UK can detect a vessel leaving port on the east coast of america, when the sub is lurking underwater beside the west coast of ireland, all done passively.

 

If true, thats a range of roughly 3000 miles that it can detect a surface based ship. That is pure nuts.

 

As for the Gottland class sub finding the US carrier, I wouldnt say thats a great achievement, especially when a noisy ass collins class sub from Australia did the same thing :) Its a good achievement, just not as great as the collins attempt, simply because the collins is known for its shitness.

 

The collins class subs are as quiet as throwing out time at the local nightclubs and, it slipped away from an american seahawk sonar dipping helo that had been pinging it for 12 hours solid and it got right in amongst a US battlegroup undetected and took pictures of some carrier, I forget the name and it was classed as a kill.

 

^ that is an achievment, getting away from sonar dipping helos and practise torpedos isnt easy, yet an underwater jukebox did it :)

Edited January 27, 2011 by bumfire

[VTJS17_Fire]

German subs 4tw. :D

http://www.abendblatt.de/politik/ausland/article483581/Das-Zielfoto-das-einen-US-Admiral-wuetend-machte.html

(Sorry, it's not englisch. But google helps ...)

 

U-24 observed USS "Enterprise".

 

 

Während eines Manövers in der Karibik durchbrach ein deutsches Diesel-U-Boot (U24) den angeblich undurchdringlichen Abwehrring um den US-Atom-Flugzeugträger "Enterprise", feuerte aus günstigem Schusswinkel einen simulierten Torpedofächer ab, fotografierte den 75 000-Tonner durch das Angriffssehrohr und tauchte dann ohne Vorwarnung unmittelbar neben dem Riesenziel auf.

 

Ein anderes U-Boot des Typs 206 A (500 ts) passierte in der Karibik ein auf es angesetztes US-Jagd-U-Boot der Los-Angeles-Klasse (7100 ts, Atomantrieb) in geringer Distanz mehrmals, ohne dass die US-Crew den nahen "Feind" erkannt hätte. Amerikanische U-Boot-Offiziere an Bord des deutschen Bootes verfolgten das Duell nach Zeugenaussagen "mit Schweißtropfen auf der Stirn".

 

 

kind regards,

Fire

[Pilotasso]

What exactly is "COMPLETELY different" there?

 

 

:D

 

Sono buoys are used on helicopters. Ships have their own embeded ones. While these last usaually are more powerfull, sonobuoys avoid betraying the ships exact location, though coverage, and time on station is limited.

 

Torpedoes can be guided by cable before their own sensors can achieve a lock on, whats so funny about it??

 

http://translate.google.pt/translate?u=http%3A%2F%2Fwww.defesanet.com.br%2Ffrance%2Fdcns_torpedo.htm&sl=pt&tl=en&hl=&ie=UTF-8

Edited January 27, 2011 by Pilotasso

[bumfire]

All this sub talk and Silent Hunter 5 sucked sooo much balls, it makes me sad :(

 

Dangerous Waters/SH3/SH4 :punk:

[EtherealN]

I've never really studied this aspect, but I don't see why you couldn't get course and range with passive sonar. You listen to the track, identify it, and once identified it's basically a standard candle which gives you the range, and subsequent changes in bearing and range give you course and speed.

 

You don't do this in the blink of an eye, but I don't see why it would be technically problematic to achieve it.

 

Similarly, on cable-guiding a torpedo - even if you only have bearing and rough range, send the torpedo over there while processing data, and update as you go or the torpedo finds the target with it's own sensors. Obviously though, launching a torpedo early might give you away and help them find your location...

 

Bumfire, agreed. SH5 was such a dissapointment. Narrowly escaped that bullet and is very happy I read a few reviews before buying it.

[Pilotasso]

Precisely etherean, though some sub types have a new technology that allows silent deep watter launches making their detection rather hard.

 

No one, but no one sailing at surface wants to face a sub without their own Sub escort. Even then theres no garauntee that any of the Subs will even see each other.

 

If you dont want to shoot aircraft, carry amphibious assault vehicles or aircraft, the sub is the best possible choice you can possibly have in fending off enemy fleets, and even land targets. They also take less personel and manitenance costs to keep them sailing.

Edited January 27, 2011 by Pilotasso

[asparagin]

Supposedly, and I dont know if this is true, but the new Vanguard class subs from the UK can detect a vessel leaving port on the east coast of america, when the sub is lurking underwater beside the west coast of ireland, all done passively.

 

:D Sry, I don't buy it.

 

I've never really studied this aspect, but I don't see why you couldn't get course and range with passive sonar. You listen to the track, identify it, and once identified it's basically a standard candle which gives you the range, and subsequent changes in bearing and range give you course and speed.

 

You don't do this in the blink of an eye, but I don't see why it would be technically problematic to achieve it.

 

Range is not normally given by listening. In simple geometry, you don't know when the sound left the target, only when it reaches you, so you can't have the range. AFAIK the Seawolf can do an estimation on range, must be something like signal strength, don't know exactly.

You can also determine the course even if you don't have range, but you have to know the speed. (which you can get from the propeller sounds).

Of course you can get the solution, but you don't get it as soon as when using active sonar, and second, if the target makes changes in course, you have to start from the beginning with your calculation.

[Pilotasso]

Estimation of range by signal strength is more than enough to send a torpedo on a path where it will aquire the target by its own sensors. You can do this for multiple sources as well. And there are other means to locate and ID ships. However information on what exactly they are is skethcy and kept classified.