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By: - 4th January 2016 at 12:53 Permalink - Edited 1st January 1970 at 01:00
Ok I'm not sure of the point that is being aimed at here, but, some questions to hopefully show you why creating 'absolutes' as you seem to be trying to establish here is quite impossible:
You state dB values that I am assuming are supposed to be radiated noise?.
- Are your radiated noise readings at source or at a measured distance?. Is that distance uniform?
- What power setting is that radiated noise reading achieved at. Is it uniform across all hulls?.
- What point in a boats deployment cycle is the radiated noise reading taken. Boats come home from a patrol noisier than they go out. Is the noise value recorded at identical phases of an operational patrol?.
- At what time interval from last refit were the noise readings taken at. Boats straight out of a major refit, post-shakedown, will be quieter than ones that have been in commission for 8 months etc. Were all radiated noise readings taken at the same period in the submarines commission?
When you understand the operational impact on acoustic signature hopefully you'll see why any attempt at a list such as this is utterly meaningless. That the signatures themselves are highly classified, and would never genuinely be public domain information, doesnt even become relevent!.
By: - 3rd February 2017 at 11:07 Permalink - Edited 1st January 1970 at 01:00
Revealed: Russian-Built Kilo Submarine 'Kills' American Nuclear Sub
The Indian media is claiming that one of New Delhi’s Russian-built Kilo-class diesel-electric attack submarines managed to “sink” a nuclear-powered U.S. Navy Los Angeles-class attack submarine during exercises in October.
The Indian submarine INS Sindhudhvaj (S56) allegedly “killed” USS City of Corpus Christi (SSN 705) during an exercise called Malabar that is held annually between India, Japan and the United States. According to the Indians, the submarines were assigned to track each other down in the Bay of Bengal. “The way it happens is that the Sindhudhvaj recorded the Hydrophonic Effect (HE) - simply put, underwater noise - of the nuclear powered submarine and managed to positively identify it before locking on to it. Being an exercise what did not happen was the firing,” an Indian naval officer told India Today. The Indian vessel then “sank” USS City of Corpus Christi using 533mm torpedoes.
If the Indian description of the events is correct, it would be a bright spot in an otherwise dismal record for New Delhi’s undersea force. In recent years, the woefully neglected Indian submarine fleet has suffered numerous calamities. Submarines have run aground, caught fire and even sunk due to a combination of underinvestment, negligence and corruption. Perhaps the worst incident was when INS Sindhurakshak sank when at harbor in Mumbai after a series of explosions in the forward torpedo bay, killing eighteen sailors.
Nonetheless, it’s not a huge surprise that a Russian-built Kilo would be able to defeat a Los Angeles-class attack boat. The Los Angeles-class is a dated design that is slowly being replaced by the newer and exponentially quieter Virginia-class submarine. However, it must be noted that we do not know the rules of engagement or parameters that the sides had agreed to. Furthermore, it must be noted there is the possibility of exaggeration.
But the basic facts are that the Kilo is an extremely quiet and very capable submarine owing to its diesel-electric propulsion system. Running on electrical power while submerged, diesel-electric boats have been described as “a hole in the water” and are a vexing problem for the U.S. Navy. Developing ways to counter such vessels is a high-priority for Washington as many potential adversaries like China and Iran operate such submarines.
While diesel-electric boats are generally quieter than nuclear submarines, the U.S. Navy prefers atomic powered vessels because of their range, speed and endurance. The U.S. Navy’s global mission essentially mandates a vessel that can operate independently far from home waters for extended periods. Navies with a more localized mission can afford to operate short-range diesel-electric boats.
While the Indian report may or may not be correct, this incident highlights the need to completely replace the Los Angeles-class with Virginia-class boats as soon as possible. The Virginia-class is orders of magnitude quieter and offers far better sensors and carries more weapons. The newer vessels are far more effective against threats like the Kilo than their Los Angeles-class predecessors. Buying as many Virginias as possible becomes especially important as more and more potential adversaries procure advanced diesel-electric boats like the Kilo or the even more capable Russian-built Amur.
Posts: 194
By: blackadam - 2nd January 2016 at 13:01
Virginia class nuclear submarines
Noise level: near the 95 dB
Armament: 4 × 533 mm torpedo tubes (Mk-48 torpedo)
Los Angeles class nuclear submarines
Noise level: 110 dB
Armament: 4× 21 in (533 mm) torpedo tubes, 37x Mk 48 torpedo
Seawolf class nuclear submarines
Noise level: 95 dB
Armament: 8 × 660 mm torpedo tubes Mark 48 torpedo
vs
Kilo 636M
Noise level: 105 dB (And will fall further as it is the data published from the 1990s)
Armament: 6 x 533 mm (21 in) torpedo tubes 18 torpedoes
Lada class AIP submarines
Noise level: not public (but surely it at about 100-110 dB)
Armament:
6 × 533-millimetre (21 in) torpedo tubes
18 torpedoes SSM
RPK-6/SS-N-16 Vodopad/Stallion
Type 214 AIP submarines
Noise level: not public (but surely it similar Lada)
Armament: (8) 533 mm torpedo tubes, (4) subharpoon-capable
Each time, submarine technology development and reduces noise down 1dB. Seawolf's sonar systems may be superior, but ability sonar submarine detection very difficult, the scope of the submarine ASW together only about 10km or less. The submarine has run a quiet mode, nuclear submarines will run in this mode rather noisy than diesel-electric and AIP submarines, by nuclear reactor cooled machine alway running, it emits a larger noise of submarine batteries diesel and AIP, because without a cooling system reactor. Weakness of diesel submarines and AIP is always need to charge the battery