Usn Asw

USN ASW exercises

It looks like the US Navy is beginning to neutralize the diesel sub threat. Here's a link:



Some highlights:

Steindl said his sailors found ways to track the Gotland during their exercises, though he declined to say how. He said the training prepared his crew well.


Gotland, a Swedish submarine that is among the world's quietest and hardest to detect diesel submarines.

"If we can go against her, we can go against anyone," he said.

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The Navy also has been training with other nations that have diesel subs in their fleets. Last fall, U.S. ships held separate exercises with the Australian, Indian, and Japanese navies.

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These diesel submarines aren't challenging the U.S. Navy's undisputed supremacy at sea. They can't go fast enough for long enough distances for that.

Just over half of China's diesel submarines are outdated Romeo-class subs, but Beijing moved to upgrade its fleet by acquiring four advanced Russian-made Kilo-class submarines in the 1990s and ordering eight more in 2002.

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This report surely makes things more interesting due to the Swedish reports that states that HMS Gotland has evaded being tracked by USN. The question is of course who you should trust. I assume that the truth will only come out the day that war is upon us and SSN subs encounters a carrier group.

Mazepa said:

This report surely makes things more interesting due to the Swedish reports that states that HMS Gotland has evaded being tracked by USN. The question is of course who you should trust. I assume that the truth will only come out the day that war is upon us and SSN subs encounters a carrier group.

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Great report for the USN. But I want to know both sides of the story. Mazepa if you find anything about this operation in the Swedish press please post it. Thanks.

I'm sure that the HMS Gotland in previous operations eluded the USN forces. I sure would like to know what were the parimiters of these excersises. That way we cna better understand what each force had to deal with.

Mazepa said:

This report surely makes things more interesting due to the Swedish reports that states that HMS Gotland has evaded being tracked by USN. The question is of course who you should trust. I assume that the truth will only come out the day that war is upon us and SSN subs encounters a carrier group.

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I'm sure it's a combination of both really. I'm willing to bet that the Gotland did find ways (ocean environment)to penetrate inside of the ASW defenses. But in the same vein, it looks like the USN has found new ways to make it more easy to localize them. I hope Gotland continues to make life rough for the USN....so they can continue to refine their ASW diesel tactics. Good to see that they are making significant progress. Looks like the diesel sub isn't going to be as hard to find as in the past.

But anyway you slice it, diesel subs aren't going to be of any utility against a CSG. They are too slow, they lack endurance, are noisy at higher running speed (even on batteries), and lack the overall firepower to be of any real threat. Diesel subs are most effective in the littorals, where you get the bottom bounce effects and towed sonar arrays aren't as deployable. That's where these diesels are dangerous. On the open ocean, they are much less effective...and much more vulnerable.

That leaves a question...if diesels are only good for littorals, then what does the u.s navy have to fear from them? Nothing, provided they dont go snooping around in foreign waters.

then again, that might be too much to ask...

also, the sucess at finding a SINGLE sub does not ensure that an entire wolf pack of them can be found. Thee sailors at least know what they are looking for. in the ocean, anythign can pop out of anywere(why japanese maru need to watch out for u.s subs!!)

AIP offers another weapon against CSGs, cause it signifigantly increses the range of a diesel.

MIGleader said:

AIP offers another weapon against CSGs, cause it signifigantly increses the range of a diesel.

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But if it moves more than 5 knots it makes noise, if it makes noise it's dead. If a US Nuke can make 10 knots and stay below detection of a PRC diesel's passive sonar (who has the better sonar?? and how significantly better??) and/or the diesel needs to make a lot more noise than it wants to to track and challenge the nuke. The big thing is who is going to who. If the Nuke is going into the path of a still and silent SSK on battery and the SSK does not need to manuvoure, the SSK has the edge. But when you put any kind of motion limitations on the SSK - such as it needs to track a Nuke or a CBG or SAG, and the SSK needs to move, it makes noise, and it loses it's edge. That SSK is best in a spot where targets need to go to it. It does not go roaming around in search of targets...

Seacraft said:

But if it moves more than 5 knots it makes noise, if it makes noise it's dead. If a US Nuke can make 10 knots and stay below detection of a PRC diesel's passive sonar (who has the better sonar?? and how significantly better??) and/or the diesel needs to make a lot more noise than it wants to to track and challenge the nuke. The big thing is who is going to who. If the Nuke is going into the path of a still and silent SSK on battery and the SSK does not need to manuvoure, the SSK has the edge. But when you put any kind of motion limitations on the SSK - such as it needs to track a Nuke or a CBG or SAG, and the SSK needs to move, it makes noise, and it loses it's edge. That SSK is best in a spot where targets need to go to it. It does not go roaming around in search of targets...

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Precisely, Seacraft. That's why diesels are not too large a threat to USN carriers. They may be more dangerous to transiting SAG's or logistics ships. Carriers roam out in the open ocean at high rates of speed. It is arguable that they(carriers) may be in more danger if transiting a littoral area..such as the Luzon straits to enter the South China Sea. On your second point, I've heard in the field a Kilo being referred to as a mobile minefield. For this very reason, it (diesel sub) is most dangerous when put at strategic waterways to await an unsuspecting vessel. Trying to use it like a high endurance/high speed sub will only make the diesel dead meat. I think that's why the USN is working so hard to develop the best tactics to confront these diesels. They intend to move carriers through littoral areas and ensure protection of forces by denying diesel subs use of the area. It's rather obvious. And it's looking like they are getting better at doing this.

I see the Gotland class with AIP and all the subs in that category as defensive systems. The purpose is not to use them for invading, but for waiting for the attacker to come into our backyard where we have the advantage of support from our airforce and coastal defences. I assume that the Chinese will use them in the same way, to protect their territorial waters and patrol their exclusive economical zone to defend it against enemies...

I hope i misunderstood something here but if it is, in fact, claimed that a sub running on battery, going 10 knots, (yes it can do so) is noisier or even as noisy as a nuke sub going 10 knots - then i have to say that's not true. That being said, battery power achieved speed of 10 knots is, of course of short duration and would give miniscule range, before the batteries would need to completely recharged. So yeah, again, one on one, with no ambush situation, nuke sub has a definite edge.

But there's the question of numbers. Nuke subs are expensive to develop, produce, maintain. One virginia class sub costs over 2 billion (ive seen figures ranging from 1,7 to 2,6 billion, so 2.1 seems fair) and that's the sub USN chose over seawolf cause they're cheaper, so i can't even imagine how much seawolf costs. On the other hand - take the kilo or yuan class subs. 200 million for bought kilos. Lets assume yuans cost the same. You get 10 diesel electrics for the price of one nuke sub.

Who's willing to bet that one virginia sub, running into a loose formation of 10 kilos would come out a victor, with all 10 kilos dead? I'm definitely not. As long as diesels can have at least some kind of air cover, so USN can't just freely use its aircraft to detect/attack subs at will and aid its nuke subs - those diesels would be a force to fear.

I'm not a proponent of diesels at any cost - they're a very bad choice if you're attacking someone half way across the world and need speed. But for defense of your coastline, when you have time to position them some 1000-1500 km away from your coast - they're much more cost effective, i'd say. Providing they can stumble upon the enemy, of course But hey, that's luck, always a factor in war. Just knowing there are packs of diesels out there limits one's ability to wage war the way they'd like.

All this is ture of diesel subs. Yet everytime Rumsfeld makes a speech, he constantly bickers about how China's subs(kilos, in particular)are offensive weapons, and claims them to be part of an "agressive" build up. It amazing what lies som research can unmask. Why does the u.s.a fear chinese kilos"? because the u.s.a is afraid it will not longer be able to send fleets coasting around asia at will. Not a very reasonable accusation, you see.