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. •
Don't buy the "short-range" sound byte too quickly.
WWI and WWII diesel boats did just fine crossing the Atlantic in large numbers running conventional diesels and limited batteries.
Granted, they can't get to India in 1 week at 30+ knots like a nuke can, but if you can buy 6 to 1 with a proven n-nuke design ....
And, as pointed out, mines can be dropped from any merchant by the dozens as it crosses
Germany has distanced itself from seeking nuclear-run subs or boats. We also don´t get carriers or - very badly - strategic bombers!
It is clear that this could give the navies of smaller powers like China, Iran, Pakistan etc. etc. etc. a immense enhancement of their capabilities. We all know that the Kilos are not bad and we also know that the Russians sell them to anybody who has enough money to buy them.
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).
I agree that it will be very hard to take a US carrier down but I am sure that it is possible with a DE-sub. The political impact would be enormous since the CVNs are the medium of the US to prevail its power. In the 30ties nobody believed that it could be possible to penetrate the harbour of the Royal Navy, Scapa Flow until the German Korvettenkapitaen Guenter Prien and his submarine U 47 sank the British battleship Royal Oak there in 1939.
You are right. The loss of a carrier could cause a fundamental change in the US strategy and politics. Hillarys and Obamas do not have the nuts (espechially not Hillary ;) ) to stand such a political storm.
Since you Indians already bought 4 209s from HDW you have now the possibility to change them into the super-silent and therefore most effective subs of your fleet.
Nevertheless I would prefer to sail in the larger 212 or in a Kilo since the 209 is for sure among the most cramped ships you can think of. The crew is packed like sardines in a can. Only the 206 class is even more narrow.
:-)
Most all of them were sunk. After 1943, U-boats suffered tremendously. True enough that conventional subs can go along way, but they cannot hunt down their prey. They must hope to place themselves in front of it. This works well, if you are defensive protecting a choke point, or offensive against a poorly equipped enemy.
Snorkeling is a perilous period for a deisel boat, and any type of transit is going to require frequent snorkeling. Additionally, once discovered, a conventional boat can only go moderately fast for a very short period of time.
Granted, they can't get to India in 1 week at 30+ knots like a nuke can, but if you can buy 6 to 1 with a proven n-nuke design ....
This used to be the argument of the MiG-21 vs the F-15. Turns out though, that it was better to have one F-15.
I think conventional subs make a great deal of sense for defensive operations, but come up short as an offensive platform if any sort of distance is involved.
If we were to attempt to operate conventional subs on the other side of the Atlantic, let alone the Pacific or Indian Ocean, we would have to have sub tenders and/or bases to support them, and we would have to have a lot more of them, just to cover the same area.
Most of our adversaries can simply be outrun by an SSN.
The Kilo is no better when it comes to comfort(it's Russian after all!!).It's got a much larger crew of 50 or so,which itself negates any advantage in space & most models barring recent ones have poor climate controls,which means that operating in places like the Arabian Sea is like staying in an Oven.The Type-209s are better in that regard.
Pakistan is buying the French MESMA Steam turbine based AIP system for it's Agostas & China is looking at Russian & indegnious systems.None of these as of now match the German system in endurance or quietness,but the point is that all their ships are getting a big qualitative boost.
That picture looks like the sub has windows in the front.
Old German empire coming back ?
I wrote a paper back in college (1987) about using diesel subs as defensive elements to protect our shores against Soviet subs. But today that same situation doesn't exist.
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