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Skybird
Joined: 21 Sep 2001
Posts: 4131
Location: Germany
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 Posted: Sun Apr 16, 2006 6:06 pm Post subject: Re: Nuclear vs AIP |
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| Smaragdadler wrote: | | amrcg wrote: | | I thought that fuel cells were still not efficient enough to allow full autonomy. I thought they operated more like "more efficient batteries" in modern diesel subs. What is the current autonomy of a fule-cell-only sub? |
We had talked about it a little bit in the u31-pic thread. There are lot of rumors but nobody came with hard facts.
This is what Skybird wrote about u212:
| Skybird wrote: | The Diesel is very much only an emergency backup. They are not expected to "charge batteries" under normal conditions during a trip, for all energy for board systems and engine is not coming from batteries, but directly from the fuel cells, the traditional diesel-battery-engine-concept cannot be compared to in this case - this is NOT a normal diesel sub with an added fuel cell. The engine is directly powered by the fuel cells. The energy in these fuel cells can only be replenished at harbour, by replacing and/or loading the cylindrical modules that store these ressources (they do indeed look like giant AAA battery cells,  ) Normal operation of the the engine and screw is energized by the fuel cell only - always. Top secret propeller and fuel cell makes for so little noise at up to medium speed settings that the sub is described to be "undetectable by contemporary passive sonar even if sensors are just a "Katzensprung" away" (quoting a leading engineer of HDW in an interview with a defense affairs journalist at the beginniong of this year, a guy I once talked to). The same source told him that the "212 is easily the most "non-existing" sub in the water today."
The limited hull size (still much more room than in the 206 and 209) is referring to the roots of the project in the cold war. The 212 hull design was once meant for exclusive Eastern sea operations.
The duration of the sub beeing able to remain submerged without snorkeling or taking ressupplies is top secret, and various sources indicate various time frames from up to 3 weeks to up to 4 months. Since the sub is Germany's top intel gathering platform is is now meant to serve in that role globally, if wanted, and that requires long endurance capabilities. time and again German medias have pointed out that this sub can operate completely indepedent from surface (snorkelling, ressuplying) for "many, many weeks". That'S why some tend to think of it as "a nuclear sub without a nuclear engine."
but whatever - it looks damn sexy. |
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However, I have red different information in different medias, and saw different info on TV docus. Even dedicated online defense sites are not telling identical information. 3 weeks submerged at medium speed, and the currently most silent sub out there, these statements I would take as safe minimum of valid information only. But it must not be that the maximum is far beyond that. As said, the information situation is contradictory. And that is probably wanted by the German navy. Best advise is to take any info on these boats with extreme caution.
But the best point in their design is still this: that once the American navy wanted their hands on these boat's technology so desperately, that they were willing to buy the complete shipyard and company. Today another American investor has his hands in it, too, but he is not interested in the knowhow, but has economical and profit interests only. The Verteidgungsministerium has a very sharp eye on it. |
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SeaQueen
Joined: 23 Jun 2005
Posts: 358
Location: Washington, DC
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| Posted: Sun Apr 16, 2006 8:17 pm Post subject: Re: Nuclear vs AIP |
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| amrcg wrote: | My dumb question: Theoretically, couldn't nuclear submarines also have batteries that would be charged by the steam-driven turbine? That would make nuclear submarines even quiter during an action.
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They didn't really explain correctly why nuclear submarines tend to be louder than diesel electric ones. Nuclear submarines have to circulate water through their reactors to cool them. That's generally the source of noise. There was a lot of experimentation with reactors that used convection instead of pumps to circulate the water. These tended to be MUCH more quiet.
Some nuclear powered submarines do have electric motors and batteries, but they still have to keep their reactor cool, so there's only so much they can do.
Some AIPs are just as loud as air-breathing diesels. There's a really interesting description of the history and development of air independent propulsion in Cold War Submarines by Norman Palomar. There's some that are Sterling-cycle engines, others are basically just diesel engines with some kind of oxygen scrubber attached. Others are powered by the chemical decomposition of things like hydrogen peroxide. It's all neat stuff. |
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Smaragdadler
Joined: 29 Apr 2005
Posts: 93
Location: Thuringia
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| Posted: Thu Apr 27, 2006 10:50 am Post subject: |
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| Quote: | Europe News
German submarine sets world record for conventional dive
Apr 26, 2006, 13:14 GMT
Gluecksburg, Germany - One of Germany's crack new fuel-cell-powered submarines has set a world record with a two-week-long dive, the German Navy said Wednesday.
The trip by the U212A-class sub with a crew of 27 from Eckernfoerde in Germany to Rota in Spain involved the longest period that any non-nuclear vessel had ever spent under water.
The navy did not say what the previous record had been. US and Russian nuclear submarines can stay under water for longer.
Germany, which has no nuclear weapons and no nuclear-powered ships, developed the high-tech hybrid-powered submarines to replace diesel-electric vessels that need to surface more often to obtain air for the engines.
The U212A vessels have a hybrid propulsion system made up of an electric motor which is fed power from fuel cells that burn hydrogen. They must also keep air in their tanks, but need less than diesels do.
The vessel, the U 32, made the trip April 11-25 and had proved the capability of the propulsion system, a naval spokesman said in Gluecksburg, northern Germany. The U 32 is to protect the Straits of Gibraltar and Mediterranean as part of the war against terrorism.
The stealthy hybrid-powered vessels are almost noiseless and do not release any exhaust gases when under water.
© 2006 dpa - Deutsche Presse-Agentur
http://news.monstersandcritics.com/europe/article_1158610.php/German_submarine_sets_world_record_for_conventional_dive
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Last edited by Smaragdadler on Thu Apr 27, 2006 10:53 am; edited 1 time in total |
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Smaragdadler
Joined: 29 Apr 2005
Posts: 93
Location: Thuringia
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| Posted: Thu Apr 27, 2006 10:52 am Post subject: |
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| Quote: | The Wrong Sub for New Warfare Era
With the paradigm shift from strategic to tactical warfare operations, the United States Navy has found itself with an aging fleet of virtually obsolete nuclear submarines designed to fight a war that never happened – and which they played a significant role in preventing. (For a review of the post-Cold War state of our nuclear submarine fleet and the modern alternatives waiting in the wings to supplement or even replace these aging behemoths, see my 2002 article, “Tomorrow’s Submarine Fleet – The Non-nuclear Option,” DefenseWatch, Feb. 6, 2002).
In the two and a half years since that article appeared, the world of submarine warfare has changed significantly. This month, on Sept. 3, the nuclear submarine that eventually will be commissioned as the USS Virginia (SSN 774) underwent sea trials off the coast of New England .
According to Adm. Frank Bowman, director of naval nuclear propulsion, “This sea trial was an absolute success, a clean sweep, as we say in the Navy. It met every expectation of mine, for the propulsion plant and for the ship.”
It was, as the Navy says, a “clean sweep.”
The Virginia is the result of several years of round-the-clock efforts by thousands of people from 3,500 companies located in 46 states. It is an extraordinarily stealthy, futuristically high-tech, astonishingly expensive underwater marvel. To the tune of $2 billion.
What did we get for our hard-earned bucks?
The sub is 377 feet long with a beam of 34 feet, and it displaces 7,300 tons submerged. Compare this to the other “new” submarine – the USS Seawolf (SSN 21) – 353 feet long, 40 feet beam, displacing 9,137 tons submerged.
The Virginia carries a plethora of systems and weapons designed to keep the sub quiet, and to allow it to operate near-shore for battlefield support and for unmanned vehicle and Seal Team deployments.
A major element in the argument for canceling all but three of the proposed twenty-nine Seawolf Class subs was the substantial per-sub cost of about $2 billion. The new Virginia Class was supposed to cost less, but at you can see, it didn’t work out that way. Furthermore, the smaller Virginia Class was supposed to be better suited for operating close inshore, but – again as you can see – these subs are 24 feet longer. Because they displace significantly less, they are more maneuverable, but their added length limits their maximum angle when operating in waters about as deep as they are long.
In my earlier article discussing the non-nuclear submarine option, I pointed out that a typical modern Air Independent Propulsion (AIP) submarine costs about $250 million. As I related in that article, AIP design since the end of World War II has followed on four different fronts:
* German Thyssen Nordseewerke (TNSW) developed a closed-cycle diesel using liquid oxygen, diesel oil, and argon. The same diesel is used as a conventional air-breathing engine for surface propulsion. These systems are suitable for both retrofitting and new construction.
* Howaltswerke-Deutsche Werft (HDW) in Germany has developed a hybrid fuel cell system for a diesel-electric sub. High-speed operations run off the conventional battery, while the fuel cell recharges the battery, and provides energy for low-speed operations. Typical submarine cost using either HDW or TNSW AIP systems is $250 million.
* Hybrid diesel-electric units propel Swedish Gotland Class subs, supplemented with Kockum Stirling engines running on liquid oxygen and diesel oil to turn a generator to produce electricity for propulsion and to charge the vessel's batteries. Typical cost for a Gotland class sub is $100 million.
* The French “MESMA” (Module d’Energie Sous-Marine Autonome) AIP steam-turbine system burns ethanol and liquid oxygen to make steam to drive a turbo-electric generator. The design permits retrofitting into existing submarines by adding an extra hull section. Typical cost for a new submarine powered by MESMA is $250 million.
One could argue, therefore, that a potential enemy who is willing to spend $2 billion on submarine technology could deploy eight subs against a Virginia Class that are significantly quieter than a Virginia Class, significantly more maneuverable than a Virginia Class, and with every bit as capable in their weaponry as a Virginia Class.
Do I need to play out the battle scenario for you?
This potential enemy probably could do the same thing with just two or three AIP subs. In fact, even in a one-on-one situation, all other things being equal, he still has the advantage.
So tell me: Exactly why are we spending eight times as much for less than one-eighth the capability? It really doesn’t make a lot of sense.
The London-based International Institute for Strategic Studies says that at least 300 foreign submarines ply the world’s oceans today. Unnamed Pentagon officials put the number at more than 400 owned by Great Britain , France , Germany , Russia , Sweden , Norway , Canada , Poland , Italy , Spain , Singapore , Indonesia , Algeria , Colombia , Croatia , Vietnam , Pakistan , India , Egypt , Chile and Turkey .
If we factor out our certain allies (as I see it: Great Britain , France , Germany , Sweden , Norway , Canada , Poland , Italy , and Spain ), and our probable friends ( Russia , Singapore , India , and Turkey ), that still leaves us a formidable list of potential adversaries with submarine capability: Indonesia , Algeria , Colombia , Croatia , Vietnam , Pakistan , Egypt and Chile .
France and Germany have been selling AIP submarines as fast as they can produce them. Sweden is about to enter the market. Russia has “leased” a nuclear submarine to India , and has plenty more in stock.
At least half of the known foreign submarines are in the hands of friendlies or are of the older, strictly diesel variety that pose no match for anything we have – even our oldest missile subs. That still leaves 200 or so highly capable submarines that are potentially every bit as good as anything we have. As an ex-submariner (pronounced submarine-er), I will pit our guys against anyone out there, even at two-to-one odds. Our guys are absolutely as good as they get.
But the odds aren’t two-to-one. They’re more like four-to-one. The bad guys can station one of the new ultra-quiet AIP subs at a choke point, and seriously damage or even sink a carrier. An AIP sub can sneak up on a Virginia Class deploying a Seal Team with devastating results. A hunter-killer pack of several AIP subs can take out any nuke we have, once they find it. They don’t have our sophisticated locating technology, but you don’t need sophistication at choke points – all you need is numbers, and they’ve got those, in spades.
Following the end of the Cold War, we downgraded the underwater SOSUS surveillance system, putting much of it in standby (see “Confronting Maritime Terrorism”, DefenseWatch, May 12, 2004 ), but even if it were fully functioning, I’m not certain it could detect a properly configured AIP submarine.
In a phone interview early this month with the Newhouse News Service, Capt. Tom Abernethy, who commands the sub-hunting Destroyer Squadron 22 based in Norfolk , Va. , said: “Shallow water, you get a lot of noise reverberation and additional traffic, and you're fighting in somebody else’s back yard which they know pretty well …. [In that environment, even a diesel sub] is absolutely a real threat, a formidable threat …. ” By implication, he said that AIP subs were equal to or better than anything we have.
Vice Admiral Albert H. Konetzni Jr. of the Navy’s Fleet Forces Command wrote in the June 2004 issue of the U.S. Naval Institute Proceedings: “The uncontested undersea superiority experienced during recent conflicts is not likely to be repeated against determined and capable adversaries.”
It’s time to reexamine our reexamination of our submarine fleet. We mustn’t allow our nuclear superiority to overcome technological common sense. We are spending eight times as much for arguably one-eighth the capability.
I know our school systems are not producing math whizzes, but even a Los Angeles South Central drop-out can figure this one out.
http://www.argee.net/DefenseWatch/The%20Wrong%20Sub%20for%20New%20Warfare%20Era.htm
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Smaragdadler
Joined: 29 Apr 2005
Posts: 93
Location: Thuringia
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| Posted: Thu Apr 27, 2006 10:54 am Post subject: |
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| Quote: | Admiral: Diesel Subs OK for Others, Not U.S.
InsideDefense.com NewsStand | Christopher J. Castelli | April 25, 2006
Diesel submarines have near-shore and stealth capabilities that may make them suitable for other countries but they do not meet U.S. requirements to project and sustain forces far beyond coastal waters, according to the Navy's submarine director, Rear Adm. William Hilarides.
The Navy has long opposed acquiring diesel subs, arguing nuclear-powered subs are superior. The subject came up again when Hilarides briefed reporters about submarines at the Washington Navy Yard April 17.
“If we were defending our coast from high-end ships, then a diesel submarine might make sense for that, but we project our submarines out to the far corners of the world and need them to stay there for long periods of time,” Hilarides said.
He said the short-range capabilities of diesel subs may be appropriate for countries that conduct naval operations close to shores. One country that Hilarides cited was Taiwan, which for the last few years has been considering whether to buy eight diesel subs from the United States (see related article).
While the service currently has more than 50 nuclear submarines, only one diesel sub remains in the fleet, the Dolphin (AGSS-555). The Dolphin is used exclusively for research purposes. The Navy decided to stop constructing diesel subs in 1956 and decommissioned the last diesel sub used for standard practices in 1990, according to the March 2006 issue of Proceedings.
But not everyone agrees the Navy should shun diesel subs. Author and analyst Norman Polmar said the short-range, stealth capabilities of non-nuclear subs would add needed capabilities to the United States.
“I would certainly think for special operations . . . especially when you look at the shallow waters around Korea and certain other countries in the Pacific, a few special purpose diesel submarines based in Japan could be very effective,” he told Inside the Navy. Polmar emphasized that non-nuclear subs would also be effective for anti-submarine missions and research and development projects.
He touted the effectiveness of non-nuclear subs that operate on air independent propulsion. Polmar said that while nuclear subs may be more effective than their non-nuclear counterparts in many aspects, non-nuclear subs are often less detectable than nuclear vessels. Even the United States has trouble detecting non-nuclear subs, Polmar said. He noted that putting ashore a handful of special operations troops makes more sense with a vessel manned by 35 people than with an 18,000-ton vessel manned by 140 people.
“The U.S. cannot detect non-nuclear submarines when they're operating on battery,” he said. “It's very difficult to find them, almost impossible in coastal operations, and that's where we're going to be in the future.”
Hilarides acknowledged that diesel subs often have more stealth qualities once they reach their destination, but said getting diesel subs to their place of operation and maintaining them there can be a problem.
“A diesel submarine sitting on the bottom is relatively quiet thing, but it has to get there, and it has to be relatively supportive there,” he said.
Hilarides and Polmar also had some disconnect on the cost of non-nuclear submarines.
The admiral said that diesel subs would cost $1 billion for the hull and for installing modern U.S. equipment on the vessel. While nuclear submarines are projected to cost $2.4 billion, Hilarides suggested that savings for diesel subs would be inadequate.
“So it would be two-for-one . . . if you were to buy a submarine like that,” he said. “And it has nowhere near the stealth, endurance, deployability and on-station time that we need for our submarines.”
Polmar said that the cost for non-nuclear subs would be even lower. He speculated that cost for the lead-boat would be about a $500 million and then the cost “would go down precipitously.”
Inexpensive submarines would be helpful, he said, predicting the Navy would not be able to meet its $2 billion per-submarine cost goal for the nuclear-powered Virginia class subs (see related article).
“The cost of SSNs and the cost of training their crews and the added on cost of handling their reactor cores and handling the submarines themselves . . . is just a tremendous cost,” he said.
Polmar said the Energy Department picks up the cost for fueling reactor cores, so energy costs are not included in the Defense Department budget, making nuclear sub costs seem smaller than they actually are.
http://www.military.com/features/0,15240,95378,00.html
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Bellman
Joined: 14 Feb 2004
Posts: 1724
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| Posted: Fri Apr 28, 2006 12:03 am Post subject: |
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Thank you for your statement Admiral Kapitan - the senior voice of the Kapitan team ? 
Kapitan: | Quote: | Im not being youthfull but you do what you do to protect your country and family and i will do the same.
Together we are the same people doing the same thing just diffrent ways, we dont go out there looking for the problem we let it come to us. |
Father Kapitan ? 
Henson: | Quote: | | ''Trust me, that respect is reciprocated by all but the youthful, ignorant, or unwise. '' |
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Kapitan
Joined: 10 Mar 2005
Posts: 5385
Location: essex england also st petersburg russia
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| Posted: Fri Apr 28, 2006 3:45 am Post subject: |
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Yes my child. |
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Sub Sailor
Joined: 14 Sep 2002
Posts: 295
Location: Orofino, Idaho
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| Posted: Sun Apr 30, 2006 10:41 am Post subject: Noise |
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Since Nautilus the US Navy has constantly worked on noise reduction. We have been quite successful at it.
What I would point out is there are some really quite subs, but weight that against the advantage of Nuclear power.
Fast, endurance, flexibility are some of them. A nuke boat can operate with a CVBG, or stalk other subs. Sonar 732 can be more specific on this, but I have read and been told a Ohio Class answering a standard bell can hardly be heard a 100 yards. I never operated against an Ohio so I can not offer first hand knowledge.
Nuclear power made subs truly independent of the out side environment. In 1964, on the Swordfish we submerged on may 15th and surfaced again on August 20th. The only thing every raised was periscope and radio mast. I don't know if we ventilated or not. Probably did because we were still using the old O2 candles back then.
Nukes are quiet, they are fast, and they can go for a long time. Let me tell you 90 plus days submerged is long enough, none of the super quiet subs can do that, not that they have a place in Naval warfare. The U.S. Navy is an offensive weapon and Nuke Boats are the best for that.
Good discussion,
Ron Banks MMCM(SS), USN(Ret)
Sub Sailor
P.S. In all fairness I never served on Diesel Boats so all my knowledge of them is from reading and talking. On I went out on one is Sub School, back when Moby Dick was a minnow. |
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