U.S. striving to detect diesel submarines

Star Tribune ^ | July 08, 2006 – 11:00 PM | Eric Rosenberg Hearst Newspapers

[sukhoi-30mki]

U.S. striving to detect diesel submarines

The Navy is concentrating its efforts to find the quiet, difficult-to-detect crafts in Asia and the Pacific region.

Eric Rosenberg Hearst Newspapers

Last update: July 08, 2006 – 11:00 PM

WASHINGTON - The U.S. Navy is stepping up its program for detecting new diesel-powered submarines that are extremely quiet, hard to find and increasingly relied upon by China, Iran and North Korea.

[roaddog727]

Diesel powered at the surface - battery powered under water.

VERRRRRRRRRRRRRY quiet under water where silence counts.

[FreedomPoster]

To follow up on ArrogantBustard's diesel-electric explanation, to get some idea of what a D-E boat sound like, running on batteries, go out to your garage, open your hood, and listen to your battery.

Obviously this is a bit tongue-in-cheek, but not all that much.

[Salo]

Toshiba.

[FreedomPoster]

I'm no submariner, but you've got it pretty good.

[kAcknor]

Hollweird knew it first. ;)

[ArrogantBustard]

To be fair, you should probably hook up a fan to your battery, then listen to it. Start backing away and note at what distance you can no longer distinguish the sound of your fan from the rest of the background noises.

[FreedomPoster]

>>That's the one the Swedes developed, the air-independent propulsion vessel (AIP)? I recall a story where they were loaning one to NATO to see if they could detect it.

Actually, I think we've leased one of those boats, with crew, to run training exercises against. I remember reading the story of it getting transported to San Diego, I believe.

Yep, here's one story about it:
http://www.news.navy.mil/search/print.asp?story_id=17621&VIRIN=&imagetype=0&page=1

[FreedomPoster]

And as long as that prop doesn't move fast enough to cavitate, it's *really* quiet.

[stuartcr]

In simple terms, that's sort of what the LFA program is about...a remote active platform.

[Still Thinking]

Toshiba sold advanced milling machines to the Sovs in the 80's.

[pfflier]

How can a diesel sub be quiet?

The Diesel is only used on ot near the surface when charging the batteries, because it is air aspirated. The battery set(s) run electric motors. The rest of the time, when the sub us submerged, it is running on batteries. The electric motors are verrrrry quiet.

[DustyMoment]

I seem to recall a while back some company sold some quiet propeller technology to the Russians or maybe the Chinese.

Yep. In the 80s, I think it was Toshiba(?) that had been contracted by the US to build our new super-quiet screws for the subs. They turned around and sold the technology to the Russians. We imposed sanctions on them for a couple of years, then let them come right back and do more business in the US.

[reagandemo]

That's the one. does not require noisy motors to circulate coolant like the nukes. Reports are that this boat is a stealthy as it gets.

[pepperdog]

That is absolutely sickening!

[thinking]

When the sub is running the diesel, patrol aircraft probes, can analyze the air, for exhaust fumes....as I understand the technique, fumes tend to be caught in atmospheric layers... also I would think that the diesel would have a big IR signature....but, when running deep, I understand that they are super quiet....the germans have a sub, that is powered with fuel cells...

[bmwcyle]

I was a BQQ-5 tech. They now run the Busy-2. It is a much better system but if you have no engine, reactor or reduction gear noise. Your dead. Four to 10 knot cavitation is just not heard well. Let's hope they are looking for new types of sensing. I think we have reached the limits of passive sonar. The fly boys can still go active but the sound absorbing tiles are showing up more and more. Underwater wake detection is limited by the target speed underwater. These new non-nuke boats can stay down longer. We need to work hard on this problem.

[Jeff Head]

The USN has been working with European nations, and some of the best and quietest DE's from those countries on lease to the USN for the last several years. You can bet that significant advances in finding, tracking, and destroying them are being made.

It is clear, a few years ago, that the USN leaderhip was very concerned about what the initial tests were showing.

Having said that, the DEs are slow when compared to blue water surface vessels or the SSNs, and therefore their ability to target these vessels is limited to litoral waters, or confined passages...or laying in wait for where they may transit in the blue waters based on intelligence. All of these can be taken into account with various ASW and transit methodologies to reduce the risk.

Nonetheless, the DEs are a very dangerous tool in the hands of a committed adversary. it is why the PLAN is acquiring and building so many of the KIlos, SOng, and Yuan class.

[puppypusher]

Deisel subs are quieter because they run on batteries when they are submerged so there is No powerplant noise to detect.

[Fitzcarraldo]

Maybe a strong nose could detect them.

[puppypusher]

Yes!your right the company that sold the classified milling machines was Toshiba,the Japanese conglomermate.They use those milling machines to create the screws for the subs.

That was one of the benefits American subs had before Toshiba gave away the goods.We had very quiet submarines.