ASW technologies and techniques

Firn

Active Member
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.
Given the way the change in the speed of sound in the medium water influences refraction and reflection it is not surprising that a sounding charge can be picked up from over 1000 nm away. SOSUS wasn't an integral part of the ASW strategy in the Cold War for nothing.. :)



Submarines will also have and retain the lead when it comes to detecting "red threats" - their very nature is all about being silent. The assets trying to find them are increasingly forced to go "active" or "red".
 
Last edited:

Salty Dog

Defense Professional
Verified Defense Pro
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
The US Navy is sending two towed pinger locators (TLP) that are capable of detecting emergency beacons to depths of 20,000 ft. The request originated from France so most likely the TLPs will be employed by French naval vessels. By the way, (4) of the AF 447 pax were friends of mine, two Americans and two Swedes, may their souls rest in peace.
 

Firn

Active Member
The US Navy is sending two towed pinger locators (TLP) that are capable of detecting emergency beacons to depths of 20,000 ft. The request originated from France so most likely the TLPs will be employed by French naval vessels. By the way, (4) of the AF 447 pax were friends of mine, two Americans and two Swedes, may their souls rest in peace.
Tragic indeed, may they rest peacefully.
 

Firn

Active Member
An good docu about the US submarines in the Pacific. The supreme value of the COMINT, the (unopposed) search radars, the interaction with aircraft and a good deal of other facts are nothing new. However the TDC struck me among other things as remarkable, a brilliant innovation at that time.

It also shows how dangerous the "German" strategic and tactical approaches were and how much easier things were in the Pacific for the submarines. It is certainly ironic that the condemned "underhand" unrestricted submarine warfare was initiated 6 hours after Pearl Habour. Equally ironic is that the US submarines increasingly operated in a way the German had long mastered but were forced to limit. Running long distances surfaced at night .(or even day) with a radar scanning would have meant a short live in the Atlantic.

[ame="http://www.youtube.com/watch?v=uSjKT8JPQAc&feature=related"]Silent Service 1[/ame]
 

Firn

Active Member
The search of the Japanese submarine bomber carrier:

[ame="http://www.youtube.com/watch?v=wHoD3ok2_To&feature=related"]Ghost Fleet - I 400[/ame]


Submarine aircraft carriers

All in all it would rather easy to build (modify) a sub capable to launch and retrieve a large number of TUAVs (Scaneagle/Integrator to mention one). The questions here is if it makes sense. Perhaps it could.
 

Firn

Active Member
How vulnerable would the modern sea traffic be to a guerre de course by modern AIP submarines compared to the one in WWII? For the sake of simplicity let us say the one to and from Japan.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
How vulnerable would the modern sea traffic be to a guerre de course by modern AIP submarines compared to the one in WWII? For the sake of simplicity let us say the one to and from Japan.
against a modern sub (and AIP is not the be all and end all) - they're dead.

btw, the americans are giving allegorical commentary that the Italian 212's are more difficult to find than the Gotland
 

Firn

Active Member
against a modern sub (and AIP is not the be all and end all) - they're dead.

btw, the americans are giving allegorical commentary that the Italian 212's are more difficult to find than the Gotland
I meant how much easier or more difficult would it be today to protect the traffic on the sea lanes to a country like Japan? History shows just how efficient and effective instruments of war submarines were, at least according to the studies I linked.

For example nowadays the ships are huge compared to the ones used during WWII and the shipping and handling at the harbour have become much faster and efficient. This creates a new set of advantages and disadvantages. On the other hand the ability of the hunter to detect and attack the prey has been greatly increased. It is hard to estimate how the odds between ASW and submarines are since WWII, but I would argue that they have shifted more toward the submarine.

That the U212A seems to be according to your sources harder to find than the Gotland fits well my expectations after more than a hard view on the relevant laws of physics. Thanks for that take on the issue.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
On the other hand the ability of the hunter to detect and attack the prey has been greatly increased. It is hard to estimate how the odds between ASW and submarines are since WWII, but I would argue that they have shifted more toward the submarine.

It's almost universally acknowledged that the skill sets for ASW hunting and detection declined across all "involved" militaries after the collapse of the Soviet Union and WARPAC - the skillsets needed to constantly track and monitor the largest submarine force ever fielded just peeled away. As such ASW aviation migrated to new roles, and basically that included greater ground target movement detection, as well as a higher emphasis on monitoring surface assets

In effect, ASW skills slackened off as the threat diminished amongst the larger players.

However, I have attended a number of UDT conferences over the last 10 years and it has been self evident over the last 5 years that there is a greater emphasis (initially by western countries) to get back into the capability. The USN started making it very public 5 years ago that the sub threat was on the rise and that the shift would ne to make their largest fleet the one in the PACRIM rather than the Atlantic. This has effectively already happened. In addition, there have been any number of indicators from entities such as the US Naval Submarine League about the ratio of "allied red" subs to "allied blue" - and that ASW needs to be far more focussed

Subs require disproportionate levels of effort to be tracked - and if tracked it more or less needs to be constant. eg The USN had the luxury and capability to track WARPAC/Sov SLBM assets on a one for one basis as well as a high level of confidence to go for the ship killers in real time.

20 years on, the numbers are down, the technology is under redevelopment and the threat matrix and threat capabilites have changed.

It's a challenging battlespace - the advantage still lies with subs - hence the growth and increase in submarine purchases by various countries in the PACRIM
 

Firn

Active Member
It's almost universally acknowledged that the skill sets for ASW hunting and detection declined across all "involved" militaries after the collapse of the Soviet Union and WARPAC - the skillsets needed to constantly track and monitor the largest submarine force ever fielded just peeled away. As such ASW aviation migrated to new roles, and basically that included greater ground target movement detection, as well as a higher emphasis on monitoring surface assets

Subs require disproportionate levels of effort to be tracked - and if tracked it more or less needs to be constant. eg The USN had the luxury and capability to track WARPAC/Sov SLBM assets on a one for one basis as well as a high level of confidence to go for the ship killers in real time.

20 years on, the numbers are down, the technology is under redevelopment and the threat matrix and threat capabilites have changed.

It's a challenging battlespace - the advantage still lies with subs - hence the growth and increase in submarine purchases by various countries in the PACRIM
I had looked recently on the acitivity levels of the P-3 Orion - I will try to find the link again - and one could see just how much the ASW-related activites dropped after the Cold War.

The third battle offers and very interesting perspective on the issue of ASW and submarine warfare in general. The latest phase clearly shows just how more difficult the job of the USN has become because, among other very important factors the noise level of the Soviet submarines dropped greatly. The geographical change in the "hot zones" due to the increased range of the SLBMA also posed huge challanges for the US Navy.

A very "exciting" topic indeed and one which has came, as you said once again into the focus on many navies.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
The latest phase clearly shows just how more difficult the job of the USN has become because, among other very important factors the noise level of the Soviet submarines dropped greatly. The geographical change in the "hot zones" due to the increased range of the SLBMA also posed huge challanges for the US Navy.
and unfort no thanks to a Japanese national at Toshiba who sold signature modified propellor tech to the Russians
 
Last edited:

Firn

Active Member
and unfort no thanks to a Japanese national at Toshiba who sold signature modified propellor tech to the Russians
True enough. From "The Third Battle"

This in turn indicates that rafting and other, more advanced quieting techniques first adopted by Thresher in the United States were probably adopted by the Soviets only with Victor III. It also demonstrates the significance of the Toshiba, nine axis milling machinery obtained by the Soviet Union which gave them the ability to make the kind of skew back propellers that reduce blade rate tonals.(84) This technology, combined on Akula with the quieting technologies already demonstrated on Victor III, gave the Soviets by the mid 1980s a nuclear submarine that could elude SOSUS and frustrate efforts by tactical ASW platforms using passive sonar to establish and maintain contact with it.(85) At long ranges its narrow band, low frequency tonals had been reduced below the source level of its continuous broadband signature, and the source level of that broadband signature was close or equal to that of American Sturgeons and early 688s.(86) Absent a strong narrowband tonal structure, and with low broadband source levels, passive acoustic detection, classification, and localization of submarines becomes quite difficult at long range, and counter-detection becomes more likely at shorter ranges.
 
Top