ASW technologies and techniques

[Firn]

A fine production by Arte (German):

The "Alberich" - named after the dwarf in the Nibelungen in possession of cap capable to make him invisible proved to mask the German U 480 almost completely against the acoustic band used by almost all ASDIC devices. Special coatings and mats are now on every modern submarine.

ASW-ships with ASDIC were unable to detect U 480 from as close as 100m in calm sea. It is interesting to see that a good deal of the tactical elements is still valid today.


[ame="http://www.youtube.com/watch?v=mkZFXNbkz2w&feature=related"]U 480 1/5[/ame]

[ame="http://www.youtube.com/watch?v=5GCQ8Ava16M&feature=related"]U 480 2/5[/ame]

[ame="http://www.youtube.com/watch?v=zarO5W1nR3M&feature=related"]U 480 3/5[/ame]

[ame="http://www.youtube.com/watch?v=etKvM-mgae4&feature=related"]U 480 4/5[/ame]

[ame="http://www.youtube.com/watch?v=OwuclvdJlkw&feature=related"]U 480 5/5[/ame]

Perhaps the biggest enemy of the modern VLO submarine sank the U 480 - a mine.

A battle of wits, technology and ressources

 

[Firn]

Docu of the National Geographic (German):


While there are a fair share of shortcomings and easily desputable elements I rather enjoyed it, especially because the filming and material are sometimes excellent. Overall a good docu.

[ame="http://www.youtube.com/watch?v=VNJSNpjxtqQ"]1/5[/ame]


[ame="http://www.youtube.com/watch?v=LCpqdU_5S40&feature=related"]2/5[/ame]


[ame="http://www.youtube.com/watch?v=LxXejZ13WYs&feature=related"]3/5[/ame]


[ame="http://www.youtube.com/watch?v=6IHq0WG88WY&feature=related"]4/5[/ame]


[ame="http://www.youtube.com/watch?v=Rt7hlK48mvI&feature=related"]5/5[/ame]

MCM and ISR UUV(s) will be soon standard on every submarine...

 

[Firn]

Good video material, even if sometimes the commentator gets it plainly wrong. I wonder how he came to the conclusion that the psychological pressure eased when the submarine surfaced...

[ame="http://www.youtube.com/watch?v=y-TSly9zdio"]Italian submarines WWII[/ame]

Take also a close look at the mastarrays. While the forms changed a lot, the important functions were all already there...

 

[Falstaff]

A fine production by Arte (German):

The "Alberich" - named after the dwarf in the Nibelungen in possession of cap capable to make him invisible proved to mask the German U 480 almost completely against the acoustic band used by almost all ASDIC devices. Special coatings and mats are now on every modern submarine.

ASW-ships with ASDIC were unable to detect U 480 from as close as 100m in calm sea. It is interesting to see that a good deal of the tactical elements is still valid today.

Interesting to watch. Don't know why I missed this documentary in the first place.
Although I do not wish WW2 had taken another turn I guess that Alberich is one of those "too little too late" items that could have had tremendous influence on the war. Together with the RCS reduction efforts regarding the sail it coould have made ASDIC and RADAR almost useless, at least for some weeks or even months. And here we're talking about a class VIIc sub, imagine what the combination of class XXI, Alberich and (later model) Zaunkönig would have done if provided in sufficient numbers.

 

[Firn]

Interesting to watch. Don't know why I missed this documentary in the first place.
Although I do not wish WW2 had taken another turn I guess that Alberich is one of those "too little too late" items that could have had tremendous influence on the war. Together with the RCS reduction efforts regarding the sail it coould have made ASDIC and RADAR almost useless, at least for some weeks or even months. And here we're talking about a class VIIc sub, imagine what the combination of class XXI, Alberich and (later model) Zaunkönig would have done if provided in sufficient numbers.

Some aspects of the tactics used in conjuncture with ASDIC. Anyway an XXI with Alberich (very high sonar/sound absorbation), Tarnmatte (great RCS absorbation coat), FuMB10 Borkum (Radar detection system) Niebelung (improved passive and active sonar) and Zaunkoenig (acoustiv homing-in) already contains practically all the elements of a modern SSK with long endurance. It would have been the terror of the sea lanes and would have put the bar very high indeed for the ASW teams on the other side.

[ame="http://www.youtube.com/watch?v=5CIJVaNPyKk&feature=related"]XXI[/ame]

A supreme design in terrible times.

Further informations

 

[Firn]

After having studied the Battle of the Atlantic I can appreciate the complex nature of the myriad factors influencing warfare on the sea.

I still wonder if the discussions about modern ASW - at least here - don't focus too much on the - very important - technical and strictly military issues, giving little attention on the commercial aspects.

 

[Firn]

For those who are not too much into reading:


The first videos of two great series. The first one contains some factual errors but is a great docu nevertheless, the second is a co-production and it shows, sadly it is just available in German. It is interesting just see how much Roosevelt (rightly) pushed for war and how murky the "neutrality" of the USA was already in 1940.

[ame="http://www.youtube.com/watch?v=s6JV9_Kn2F4"]Battlefield Atlantic [/ame]

[ame="http://www.youtube.com/watch?v=M5dnT-QebmA&feature=related"]War in the Atlantic: The Hunters (German)[/ame]

BTW:


[ame="http://www.youtube.com/watch?v=El6SU9sgq6U"]The Sinking of the Lusitania[/ame]

An excellent series which portrays what according to the best of the current knowledge happened back there. It puts Churchill not in a good light, this should be said beforehand. Like the second docu about the War in the Atlantic it also shows the plight of the poor hands and souls lost in the cold grim sea.


Here we see just how many factors, often first of all political ones influenced ASW and will influence it.

 

[Firn]

Some thougths

I actually have increasing doubts about the utility of the an martime patrol aircraft like the new P-8 Poseidon in specific parts of the ASW. Don't get me wrong it still has unparalleled capabilities which will prove priceless. The excellent maritime surveillance radar combined with the qualities of the aircraft will provide an excellent overview and SA. The sonobuoys will prove priceless in quickly covering sealanes with a net of interlocking acoustic sensor. All in all such an aircraft provides an essential C4Isr node.

However IDAS is a gamechanger when it comes to the aggressive hunting part. When searching for a submarine MAD, ARPDD and the sonobuoys are the key assets of the MPA. A key problem for any MPA is on the other hand the strong (acoustic) signature. Even in complex batthythermy every air asset should be spotted (heard) before it can detect a "silent" submarine (take a look on the links I posted). This is a consequence of the laws of physics and only very quit aircraft could evade the sensitives ears in the ocean. IDAS now puts almost every aircraft in an position capable of detecting the submarine in very grave danger.

This is also why I rate well laid intelligent mines, UUV (plus USV and UAV) and sensor nets (sonobuoys, SOSUS-alike) very highly as elements of the overall strategy

 

[Salty Dog]

Some thougths

I actually have increasing doubts about the utility of the an martime patrol aircraft like the new P-8 Poseidon in specific parts of the ASW. Don't get me wrong it still has unparalleled capabilities which will prove priceless. The excellent maritime surveillance radar combined with the qualities of the aircraft will provide an excellent overview and SA. The sonobuoys will prove priceless in quickly covering sealanes with a net of interlocking acoustic sensor. All in all such an aircraft provides an essential C4Isr node.

However IDAS is a gamechanger when it comes to the aggressive hunting part. When searching for a submarine MAD, ARPDD and the sonobuoys are the key assets of the MPA. A key problem for any MPA is on the other hand the strong (acoustic) signature. Even in complex batthythermy every air asset should be spotted (heard) before it can detect a "silent" submarine (take a look on the links I posted). This is a consequence of the laws of physics and only very quit aircraft could evade the sensitives ears in the ocean. IDAS now puts almost every aircraft in an position capable of detecting the submarine in very grave danger.

This is also why I rate well laid intelligent mines, UUV (plus USV and UAV) and sensor nets (sonobuoys, SOSUS-alike) very highly as elements of the overall strategy

I have no doubt about a subs ability to hear low flying aircraft, as the current ASW/MPA aircraft are rotary wing or prop, their audible frequencies are lower than those of the turbo fans found in the P-8 which should be magnitudes quieter (to the sub). It would be interesting to compare underwater acoustic data between a helo, the P-3, and S-3 aircraft.

AFAIK IDAS is mainly used against rotary wing targets and smaller surface craft which makes it somewhat altitude limited. How effective is it against higher and faster flying MPAs?

 

[localhost127]

sorry if this has been addressed,

but how difficult would it be to launch drone/UAV aircraft from a sub when ASW aircraft are above and patrolling?

i would think that ASW patrols would be fairly easy to target and take down - from an air-combat point of view...i guess the question would be, how would you control the UAV/drone from below the surface?

can anyone detail what defenses a sub may have (existing or in the works) against ASW aircraft/helo patrols from below the surface?

thanks-

 

[Firn]

I have no doubt about a subs ability to hear low flying aircraft, as the current ASW/MPA aircraft are rotary wing or prop, their audible frequencies are lower than those of the turbo fans found in the P-8 which should be magnitudes quieter (to the sub). It would be interesting to compare underwater acoustic data between a helo, the P-3, and S-3 aircraft.

Yes it would be. Again the absolute signatures depend a lot on the specific bathythermy and many other specific factors but it would be very interesting to see how the dB and frequencies of different platforms compare...

AFAIK IDAS is mainly used against rotary wing targets and smaller surface craft which makes it somewhat altitude limited. How effective is it against higher and faster flying MPAs?

Given the context in which it was imagined and than developed I think that ASW helos were the primary target, with relative low flying "killer" MPAs a secundary one. It is all in all a point defense SSAM. A high and fast flying MPA searching wide areas for periscopes and other targets should be safe as long as it doesn't threaten the submarine directly. Usually too much of an kinetic advantage and too much reaction time.

Perhaps we will see one day an long-range SSAM in the class of the Aster 30 on SSG or SSGN used in conjuncture with other assets.

P.S: If a surfaced submarine receives a radar warning with an bearing indicating an MPA is (too) close by I imagine that an IDAS into it's path would help the escape a lot.

 

[Firn]

As I have written before too often people focus on (interesting) questions like "AIP submarines vs. CSGs" and forget about the other roles of the submarine. This is especially true for the guerre de course and/or the military and economic, direct and indirect impact of submarines. The following links show just how terribly effective and efficient submarines have been in this regards. Especially the indirect factors are usually not even considered..

Results of the German and American submarine campaigns in WWII

Conclusion and Implications

We can draw several important lessons on the effectiveness of submarines attacking sea lines of communication based on our study of the two World War II historical cases. First, both these campaigns were directed against vulnerable opponents who required the use of the sea both to import raw materials and to project military forces far from the homeland. A submarine attack on seagoing logistical lines of communication would obviously not be effective against an insular, continental power. Second, both campaigns, including the "failed" German effort, incurred disproportionate costs on the side conducting Anti-Submarine Warfare (ASW). Third, the indirect and second order effects of these campaigns were virtually as important as the direct costs. In fact, the continuing indirect and second order effects played a key role in logistically constraining the Allies in the Atlantic after the allied defeat of the U-boat threat. Finally, in both campaigns, the effects of submarine warfare on an opponent resulted in a substantial reduction of the opponent's strategic choice and had significant effects on his industrial policy.

In the case of the Atlantic campaign, the Allies modified industrial priorities and reduced production of amphibious lift. Lack of logistical and amphibious lift resulted in constrained allied strategic choice for most of the war including a delayed ability to open a second front in France. In the case of Japan, the U.S. submarine campaign substantially reduced Japanese war production, and, ultimately, significantly reduced the Japanese ability to implement their preferred defensive strategy. As a result, the submarine campaign proved itself as an efficient way to wage war against a competitor that must supply its forces over long distances by sea.

It is interesting to contemplate to what degree the United States is vulnerable today to a campaign by a committed regional power or peer competitor against our sea lines of communications. Within the U.S. Navy today, one hears some discussion on the possible impact of submarine attacks against our battle groups, but few consider the impact a campaign against our vulnerable sealift train might have. Since America remains dependent today on sealift to project military power, an opponent might well assess this vulnerability worth exploiting.

The analysis conducted above leads one to question the need for more careful and extensive study of issues relating to economic warfare and statecraft. This avenue of national security studies remains understudied and misunderstood, but it should not remain so. The submarine campaigns of World War II demonstrate that the ability to sever or attack industrial output or prevent supply to deployed forces can markedly change the conduct of a war.

Conclusion:

The Allies total investment was $26.4 billion compared to the German investment of $2.76 billion. The Allies spent at least 9.6 times the German investment.

 

[Firn]

sorry if this has been addressed,

but how difficult would it be to launch drone/UAV aircraft from a sub when ASW aircraft are above and patrolling?

i would think that ASW patrols would be fairly easy to target and take down - from an air-combat point of view...i guess the question would be, how would you control the UAV/drone from below the surface?

can anyone detail what defenses a sub may have (existing or in the works) against ASW aircraft/helo patrols from below the surface?

thanks-

First of all you should look for "IDAS" here on in google to find this SSAM capable to deal among others with airborne threats.

There has been already at least one launch of an from an submarine, I expect quite some development in this area. There are some plans and ideas to equip the U 212A with a special "drone" mast. Radar warning and detection system on buoys, masts and in the future UUV enable an submarine to get a look. The tactical situation than dictates if UAV get launched or not. An MPA scanning the area will usually mean no launch.


Personally I think that ISR and SIGINT UAV can be priceless assets in many situations. Of course the intrinsic nature of submarines and the current layout of them allows only for small UAV with limited endurance, payload and range.



Some nice links:


Sources about IDAS


How does one control an UAV from a submarine?


"Waisted" UAV launched while submerged


Aladin - a mast launched UAV?


Navy Sub launched UAV



All in all I think that intelligent use and a well planned flight pattern could greatly help to mask the location of the submarine both during lauch and the data download. Think SIGINT from the submarine and it's assets, intial sea-skimming (5-15min) flight, SIGINT or ISR phase in higher altitudes, descent and 5-15min seaskimming for the download, perhaps to an UUV controlled by the submarine. For many very interesting missions such care is of course not needed.

 

[Firn]

The US PAC campaign in WWII:



The impact of the US submarine campaign evaluated


Retreat and Retrenchment


Winning through


Here we can see just how devastating submarines can be as part of the overall campaign against a far flung insular power with little ressources when the strong tries to strangle the weak. Even if the US submarines had a dismal start through a combination of poor doctrine, different strategic priorities, partly very long approaches, over-cautious officers and perhaps most of all very bad torpedos they ended being the scourge of the Japanese shipping. It is perhaps an excellent case for just how submarines supported by greatly superior ressources and technology perform against strategically very vulnerable opponents which suffer from ever decreasing ressources, very poor ASW and which lag behind in key technologies.

 

[gf0012-aust]

dot points.

• subs can hear aircraft (and did so regularly in the cold war)
• the italians developed acoustic tracking in WW2, the technology has changed and influenced other developments such as sniper detection systems and being able to hear torpedo tube gates opening
• subs have launched Reaper sized UAV's in recent trials
• subs in the past have carried manpad for AA, but there are any number of programs underway where SLAA is being developed

there are a few generalisations in here....

having attended a few sub and UDT conferences over the last few years, I can say that the next generation of subs is very different from what we see today.

there are vast changes happening in how weapons will be carried and delivered.

there are vast changes happening in the way that subs can sense "red threats" - but correspondingly, that capability will also migrate to aviation platforms.

water is a denser medium to air - but the sound travels almost 4 times the distance further...

eg I have a recording of a "sounding charge" being picked up at 1500k's distance.

 

[Grand Danois]

The French sent a Rubis class SSN to look for the data and cockpit voice recorders from flight 447. That's an interesting quest...

 

[gf0012-aust]

The French sent a Rubis class SSN to look for the data and cockpit voice recorders from flight 447. That's an interesting quest...

It will be interesting to see what ends up in Signal, Ocean News and Technology and/or Sea Technology within the next 12 months time....

The sub by itself will not be too interesting, it's the ROV that will be ..

 

[Grand Danois]

It will be interesting to see what ends up in Signal, Ocean News and Technology and/or Sea Technology within the next 12 months time....

The sub by itself will not be too interesting, it's the ROV that will be ..

Don't think any of the two ROVs en route have suitable acoustic sensors (at least not the Victor 6K). Woods Hole perhaps?

Oh, and would the sensors on an ssn really be tuned for this kind of work? :devil

 

[gf0012-aust]

Don't think any of the two ROVs en route have suitable acoustic sensors (at least not the Victor 6K). Woods Hole perhaps?

They won't be using acoustic sensors, more likely to be synthetic aperture sweeps - and thats an ROV's job. The sub needs to detect the emitter to narrow it down, but its the ROV's that will do the work...

Oh, and would the sensors on an ssn really be tuned for this kind of work? :devil

Only because its the fastest truck they can get into the area, and because it can carry the ROV's quicker than anything else they have in their fleet.

Otherwise you could throw the capability off the back of a prawn trawler.... (which funnily enough the soviets and chinese had AGI's for during the cold war - although the chinese are still using AGI's disguised as trawlers whenever the US has fleet manouvres in areas of mutual interest...

 

[Grand Danois]

They won't be using acoustic sensors, more likely to be synthetic aperture sweeps - and thats an ROV's job. The sub needs to detect the emitter to narrow it down, but its the ROV's that will do the work...

Well a SAR sweep would also be done by an acoustic sensor. Nitpicking here.

Only because its the fastest truck they can get into the area, and because it can carry the ROV's quicker than anything else they have in their fleet.

You see, this is the obvious part, which I missed.