Posted on 01/30/2007 12:10:32 AM PST by sukhoi-30mki
Return of the wolf pack
German U-boats are back, and they’re stealthier and deadlier than ever
By Tim Mahon January 04, 2007
Although Russia continues to build diesel-electric hunter-killer submarines (SSKs) based on the venerable but capable Kilo design — and is marketing the ultra-quiet Amur class — Germany has now taken on the mantle of world leader in the manufacture of diesel-electric submarines. The German navy (Bundesmarine) possesses one of the most capable conventional submarine designs in service today, the Type 212A. A product of ThyssenKrupp Marine Systems, the first of four 212As entered service with the Bundesmarine in 2004 after sea trials the previous year. Named U-31 through U-34, they carry on a tradition of numeric designation that began before World War I.
All are home-ported at the submarine flotilla operating base at Eckernförde, west of Kiel on Germany’s Baltic coast. In late September, almost coincident with the commissioning of the last boat of the first batch, the German Federal Office of Defense Technology (BWB) contracted for two additional boats incorporating design improvements. With enhanced surface and subsurface sensors and improved communications, the new boats are scheduled to enter service in 2012 and 2013. Destined to replace aging Type 206A boats also based at Eckernförde, the intent had been to procure a class of eight boats, but escalating costs have led the BWB to reduce this number to six.
Stealthiness is the 212A’s defining characteristic. Virtual invisibility from the standpoint of both physical and acoustic signatures is the goal of every SSK designer, because the SSK relies on this trait to fulfill its strategic role as a killer of larger, nuclear-powered submarines.
Type 212A designers set out to ensure it incorporated the most advanced stealth characteristics, thus providing potential operators with a machine capable of multiple missions and a very high first-shot kill probability. The design philosophy focused on two critical aspects of the boat’s capabilities — propulsion and weapons.
Another notable feature of the Type 212A is its method of locomotion. Most SSKs rely on advanced diesel-engine technology, backed up by high-capacity modern battery banks powering electric motors for submerged propulsion — an environment in which the diesels cannot operate because of their oxygen requirement. The Type 212A, however, incorporates an advanced air independent propulsion (AIP) system that provides for greater speed, greater flexibility in operating environment and a significantly lower acoustic signature than traditional propulsion methods.
AIR INDEPENDENT PROPULSION AIP has been the Holy Grail of SSK designers for decades. The oldest technology — the Stirling engine — provided for lower noise-emission levels, although the requirement for pistons still contributed to a significant acoustic signature. The Swedish Navy has been using Stirling engines in its submarines for more than a decade, demonstrating the technology’s reliability and maturity, although it does suffer from a relatively low power output. Kockums in Sweden, recently acquired by HDW, markets this technology. Closed-cycle diesel engines that can operate using stored liquid oxygen (LOX) as well as atmospheric oxygen also offer advantages for SSK operators but with high noise levels at high speeds. Coupled with the problems of underwater exhausts for the engine’s emissions, the closed-cycle solution has been largely abandoned. France’s MESMA technology, which uses a closed-cycle ethanol/LOX steam turbine, provides for high power availability but also for a high noise level because of the high count of moving parts and extensive plumbing requirements.
Perhaps the most efficient and quietest AIP technology is based on fuel cells — the solution chosen for the Type 212A propulsion system. With no moving parts and the ability to drive electric motors directly, fuel cell AIP systems are the quietest systems around.
Their principal disadvantage is the use of large quantities of highly combustible fuels, including LOX. Tanks that hold this substance are mounted outside the Type 212A’s pressure hull, but the risk of accidentally igniting a Lox fire remains a concern among U-boat crews. Nevertheless, the Type 212A fuel-cell propulsion system is the characteristic that sets the class apart from its competitors. But the designers of the Russian Amur class have also followed the fuel cell technology design path.
The fuel cell component of the Type 212A system, comprised of nine 34-kilowatt Siemens polymer electrolyte membrane (PEM) cells, produces electricity from the combination of oxygen and hydrogen and permits almost soundless underwater movement. The low-noise, high-performance permanent-magnet electric motor drives a single propeller, contributing further to making the boat appear “like a hole in the water.” When surfaced, a 16-cylinder MTU diesel provides motive power.
Type 212As can remain submerged for extended periods (some reports indicate months, but a period of two to three weeks before needing to surface is generally regarded as the maximum safe period), thus setting aside two of the traditional weaknesses of SSKs: range and endurance. Its torpedo launch system was also designed with stealth in mind. The boat mounts six 533mm (21 inch) torpedo tubes in the bow and carries a normal wartime loadout of 12 Atlas Elektronik DM2A4 heavyweight torpedoes, giving it a reach of up to 27 nautical miles against surface or submarine targets. These high-speed torpedoes (maximum speed is about 50 knots) are ejected from the boat using a water-ram expulsion system, which reduces the launch transient noises associated with the more common compressed air system used on most submarines, including the U.S. Navy’s Los Angeles-class attack boats.
Physical characteristics of the boat include a length of 56 meters (184 feet) and a draft of 6.4 meters (21 feet). Surface displacement is 1,450 tons, while submerged displacement rises to 1,830 tons. Maximum speed on the surface is 12 knots, rising to about 20 knots when submerged, and cruising ranges are 8,000 miles at 8 knots surfaced, 420 miles at 8 knots submerged. Endurance is listed at 30 days, although in practice a shorter time period would be considered safe, except in severe operational conditions. The crew complement of 27 includes eight officers. The highly integrated command and weapons control system is based on the MSI-90U system developed and supplied by Kongsberg Aerospace and Defence of Norway and features a high performance databus and distributed computer system. Countermeasures for both German and Italian Type 212As include the EADS/Thales FL1800U electronic warfare system already in service on Bundesmarine frigates of the Bremen and Brandenburg classes. Atlas Elektronik and ELAC are leading development of the TAU 2000 torpedo countermeasures system, which ejects small underwater vehicles, similar in appearance to a normal torpedo, that employ active acoustic emitters and hydrophones to attract and divert hostile torpedoes. Sensors include an integrated DBQS sonar system for passive detection at medium frequencies and a TAS-3 low-frequency towed array. An FAS-3 flank sonar array provides low and medium frequency detection, and an Atlas Elektronik MOA 3070 sonar provides active mine detection capabilities.
Zeiss periscopes provide optical and laser range finding facilities for surface vessel attack — the SERO 14 search periscope and the SERO 15 attack periscope. The class has generated significant interest among other navies and it and its derivatives are in increasing demand. The Italian Navy ordered two identical Type 212A boats, which have already entered service — the Salvatore Todaro and the Scire — in 2005 and 2006, respectively. Fincantieri built them under license.
A derivative of the Type 212A, the Type 214 boat has been sold to a variety of navies, including those of Greece (four), and South Korea (three). In the case of Greece, the first boat was built in Germany, launched in April 2004 and commissioned in 2006. The second and third boats are being built at Hellenic Shipyards in Skaramanga (acquired by HDW in May 2002) and will be commissioned in 2008 and 2009, while the fourth — ordered separately in June 2002 — will be commissioned in 2010.
Greek 214s feature a conventional diesel-electric propulsion system rather than AIP and will have eight rather than six torpedo tubes, carrying the Whitehead Alenia Sistemi Subaquei Black Shark torpedo. The Greek hulls also feature enhanced elasticity and flexibility because of the incorporation of advanced steels and material technology. Maximum design depth is said by industry observers to be in the region of 400 meters (1,300 feet) compared with the submerged stated depth of “over 300 meters” (985 feet) for the Type 212A. South Korea’s Type 214s, under construction at Hyundai Heavy Industries, will commission in 2007, 2008 and 2009. Other navies that have expressed potential interest in becoming Type 214 operators include those of Turkey and India.
Submarines remain controversial in Germany, however. A planned sale of two Dolphin-class submarines to Israel was shelved in 1990, but after the Persian Gulf crisis of 1991, the issue was revived and three boats were provided to Israel with German government funding support in 1999-2000.
These boats have 10 torpedo tubes, including four of larger (650mm) caliber, which makes them capable of launching nuclear-tipped cruise missiles.
Potential use of these submarines as an aspect of Israel’s nuclear deterrent has played long in the German press and weighs heavily on foreign sales. Attention to this issue has been renewed in recent months. Virtually the last foreign policy act of outgoing Chancellor Gerhard Schroeder in November 2005 was to reinstate an order for two further Dolphins for Israel — again with extensive funding support from the German taxpayer — and the boats are now under construction at HDW’s Kiel yard. German government spokesmen say the boats will not be delivered till 2010 and that strenuous efforts are being made to ensure there is no possibility of their use as nuclear platforms.
Controversy, however, is nothing new to Germany’s U-boat fleet, now deadlier than ever. •
Wow. What in the German water supply makes such great engineers?
Now if they could produce small, stealthy nuke-powered subs, they could rid themselves of the EU.
German Buddy Ping.
Why should they seek N-subs??Most D/E boats when submerged are quieter than Nuke subs & these new German boats will have considerably enhanced endurance.Their smaller size makes them optimal for littoral & special ops unlike a bigger Virginia class boat.
These things are smaller,cheaper & quieter when submerged-unless you plan on have sub launched ballistic missiles,these capabilities are more than enough.
Fuel Cell boats would be quieter than Nuke boats when sumberged. If they could achieve a three month endurance without having to reload Hydrogen, these debsigns would probably get support from the U.S. Navy. The U.S. Navy has so far been reluctant to endorse any design that could take funding away from nuke boats
Endurance wouldn't be the only issue.Speed & power is also a serious consideration where N-boats are still way ahead.An N-boat can push 30 knots+ when submerged with ease.These AIP equipped subs depend on speeds of less than 10 knots for an underwater stay of over 15 days.
Excellent points, all (and a great airframe for a screenname).
What a smaller nuke-class could offer (if reverse-engineered), idealistically, would be a small acoustic footprint with relative stealth, suitable for a tactical weapons platform over a longer term, if given adequate support.
I'm just a civilian accountant, so debunk at your leisure. Subs are tre-cool.
LOX is a nasty, nasty thing to have locked inside a sardine can with you.
Still, we should probably buy one of the 212A's for evaluation/training purposes.
""The U.S. Navy has so far been reluctant to endorse any design that could take funding away from nuke boats""
This frustrates me although I know it is true. This can be the same kind of groupthink that had all the fancypant Air Force brass wanting to can the A-10 cause it was'nt sexy (fast and fancy) enough.
I know our subs have an impressive track record but I don't want anything ruled out when it comes to our defense. It seems like these boats could do a great job in certain situations at much less expense.
You're right about the advantages of N-subs.But the Germans(& pretty much the rest of Europe) are stretched for funding their defense programmes.Even a short-range tactical strike missile for these Type-212 subs was cancelled a few years ago.So launching an expensive programme like for N-subs or amphibious assault ships is risky.
Looks like what Taiwan should be buying...IMNSHO.
Thanks Man. I know I'm talking well above my paygrade, here.
The D/E 214 will, obviously, suit many purposes accordingly, but what kind of forward-projection capabilities does/can the existing fleet have? Sure, the big loud nukes can lob king hell ballistics, but what about the strategic AO on a smaller scale? Barring China, I really doubt we'll be throwing multiple warheads at anyone any time soon.
Short burst of speed can be very important, particularly when there is a torpedo in the water, but when subs are on station, they tend to go pretty slow. They don't call it the silent service for nothing. Most Sub guys will tell you that a submerged electric boat is the thing they fear most.
Nuclear energy is not really needed for subs.
These boats are quieter then a nuclear powered one (no turbines) and the PEM Cells are only the beginning of fuel cell technology.
But I guess Germany ran into trouble setting up a blue water navy.
To find out, that this is a dangerous threat to your carrier groups? Germany is not going to deliver in rouge countries, but Russia and France (!) will. If Iran or China will obtain such boats they have the potential to turn your CVNs into a mountain of burning rubble.
It is a turnpoint in naval technology like the appearance of the carrier was in the beginning 40ties.
Greetings from good old Germany. A.B.
Germany, or anybody else with decent diesel-electric designs, isn't willing to sell to them for fear of making the PRC mad.
True,but raw speed also helps N-boats deploy to their theatre much faster without losing endurance,esp in crisis situations.An N-boat after sprinting to it's station at 20-25 knots can stay there for a month or 2 without surfacing.But you can't even say the same about these AIP subs,though these systems are still evolving.
While the 212s feature a host of innovations incl. it's non-magnetic stell hull & integrated combat systems,it's AIP system is the most attractive thing on it for many people.If Im not mistaken,it is offered as a retrofit for both German origin(Type 209 class) & non-German subs.Pretty much everyone with an eye on enhancing his navy is working on AIP systems & China is no exception to it.Russia has a similar fuel cell based AIP system for it's AMUR class boats,though it's capabilites are unclear.
Thus the threat to carrier groups isn't as bad as it would have been if we were facing a Soviet-style enemy.
Caveat: It is common knowledge that countries like China and Iran would love to be able to take down a carrier. And they have taken delivery of systems that they believe might enable them to do so, although it remains to be seen if that is a possiblity (while some of the systems are potent, just because something can kill doesn't mean it will be given the opportunity to do its job. Last time I checked the US Navy doesn't send its sailors off to die ...).
The only danger to CVNs stems from the likelihood that nations like Iran and China know very well they do not need to sink many carriers. They only need to sink one, and even at that they don't need to sink the darn thing. Simply pull off a mission kill ....leave it crippled in the water with some several hundred men injured or dead.
Once that happens then the US public, right on cue, will go up in arms and demand withdrawal. Political pressure will mount, and the war is over. Basically another Tet Offensive (where the enemy launches a strike that is a military disaster for them, but all the same manages to create friction among the American public that causes the enemy to turn an outright military defeat into a strategic win).
In such an environment China could easily decide to sacrifice several of their Kilo boats for the chance to kill/mission-kill a US carrier. Taking down a carrier wouldn't cause a nuclear strike from the US (no CURRENT administration, Dem or Repub, would have the balls to use nukes unless the enemy bl@@dy took out a city), and thus China wouldn't really be worried about significant backlash. Furthermore the sinking of the carrier would be a profound blow to the public's psyche back home .....you'd have all sorts of people protesting outside the White House.
Anyways, while it is very hard for a CVN to be taken down (outside training scenarios), you can be certain that if a US carrier is ever sunk the reason for that WILL BE a Diesel-Electric Submarine. Now, the weapon of choice may be different (eg sub-launched mine, sub-launched missile, a torpedo, etc), but it will be a submarine doing the deed.
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