Figure 1.--

The Germans built several different types of U-boats for service in World War II. This included both small coastal boats and medium-sized ocean-going boats as well as large cargo boats (the Milk Cows) for supplying ships at sea in the Atlantic. Small boats included the Type IIs, small boats of about 250 ton. They were used for training and reconisance. The work horse of Admiral Dönitz's U-boat force was the Type VIIC which fought out the Battle of the Atlantic. Type VII was a medium-sized boat and the principal U-boat deployed by the Kriegsmarine. They were boats from 500-750 ton with a crew of 56. They had twin diesel engines of 1400 HP which could drive the boat on the suface at 17 knots. They also had twin electric engines 750 HP giving speeds 8 knots under water. They carried 11-14 torpedoes which the Germans called eels. (American submariners called them fish.) There were four bow torpedo tubes and one stern tube. They were armed with the German 88-mm gun, the most effective artillery piece of the War. The Type VIIs was the U-boat Döentiz wanted to fight the Battle of the Atlantic. It was an effective boat at the onset of the war, but by 1943 advances in Allied technology redered it into a deathtrap. The principal problems was that design features created a very large and easily detectable sonar signature. And it was not designed to fight underwater. But surfaced it was easily detectable by Allied radar which because of air cover gradually encompased the entire North Atlantic. Cracking the Naval Enigmas also exposed the boats. Dönitz had to withdraw the U-boats fron the North atlantic (mid-1943). The principa large boat was the Type IX. Miliitary experts generally report that the larger Type IXB ws the most successful. The Type IX was the larger boats ranging from 1,100 1,400 tons. OKM insisted on building quite a number of type IX U-boats. They were not the ones was Döentiz wanted. The Germans were constantly trying to improve their U-boats and put some of their best scientists on the effort. They were at a serious disadvantage, however, because most of the U-boats lost to the highly sccessful Allid ASW effort were lost at Sea so the Germans were unsure just what Allied ASW develop,ments were suceedinding in sinking U-boats. They had, however, a fairly good idea. And Dönitz put a techinal genius on designing an improved U-boat--Hellmuth Walter. Earlier German U-bpats were basically a surface ship capable of diving. What Walter set out to produce was a true submarine capable of fighting underwater and remaining submerged for extended periods. His work led to a high performance protype and two advanced U-boat types. The Type XVIII solved the the need to surface by shifting from diesel fuel to hydrogen peroxide. This created, however, a varirety of problems, but the insolvable one was Germany's limited capacity to produce hydrogen peroxide and the priority given to the V-2 program. Walter used the many design innovations developed for the Type-XVIII to produce the Type XXI Elektro boat. Hitler ordered priority given to the TYpe XXI program. They had the capability of remaining submerged for long periods and had a small sonar signature. The Germans did not achieve this on purpose, but the streamline design allowing the boat to increase submerged speeds, also reduced the sonar signature. Some claim that if introduced earlier it could have won the Battle of the Atlantic. There were, however, major design and manufacturing flaws as a result of the rush to produce . The Allied strategic bombing campaign greatly complicated manufacturing projects, especially large operations which slowed the production process. Shipyards were priority targets for the Allied bombers. The Germans launched quite a number of these boats, but only a few were actually deployed by the time the the NAZIs surendered. The Type XXI hull design was highly inflential in the U.S. Navy nuclear Natalus design. The Soviet Navy went down the Type XVIII hydrogen peroxide dead end.

Type II

The Treaty of Versailles ending World War I prohibited Germany from having U-boats. The U-boats had been Germsny's primary naval thret in World War I and the British Royal Navy wanted to preclude any future U-boat campaign. The Germans engaged in a range of evasions even before Hitler and the NAZIs seized power. Fortuntely for the Allies, builing ships was more difficult to hide than other evasions. The Type II U-boat was the first post-War U-boat built in any numbers. It was designed as a coastal U-boat, modeled after the CV-707 submarinedesigned by the Dutch company NV Ingenieurskantoor voor Scheepsbouw den Haag (I.v.S). This was actully German dummy country, but as it operated in the Netherlands it was not limited by the Versailles Treaty. We are not sure why the Dutch Giovernment permitted this, but there was considerabke sympthy toward the Germands during World War I. NV Ingenieurskantoor enabled the the Germans to develop submarine technology during the inter-War period. The first Type IIs were built by the Finnish Crichton-Vulcan shipyard in Turku (1933). They were small boats, about 250 tons. This was not large enough for actul naval operations at any distance from the German coast. Because he had so few U-boats at the onset of the War, Dönitz was fiorced tonuse some vof the Type-IIs fir combat operations. They were useful, however, for trining purposes whiv in 1933 is what the Kriegsmarine required. The German U-boat officers who fought the Battle of the Atlantic developed their skills on Type IIs in the Baltic. The type IIs were also used for reconisance.

Type VII

The work horse of Admiral Dönitz's U-boat force was the Type VIIC which fought out the Battle of the Atlantic. Type VII was a medium-sized boat and the principal U-boat deployed by the Kriegsmarine. They were boats from 500-750 ton with a crew of 56. They had twin diesel engines of 1400 HP which could drive the boat on the suface at 17 knots. They also had twin electric engines 750 HP giving speeds 8 knots under water. They carried 11-14 torpedoes which the Germans called eels. (American submariners called them fish.) There were four bow torpedo tubes and one stern tube. They were armed with the German 88-mm gun, the most effective artillery piece of the War. This meant that on the surface, the Tyupe VIIs actually ougunned many escorts. The Type VIIs were the U-boat Döentiz wanted to fight the Battle of the Atlantic. It was an effective boat at the onset of the war, but by 1943 advances in Allied technology truned it into a deathtrap. The principal problems was that design features created a very large and easily detectable sonar sinature. And it was not designed to fight underwater. Even when surfaced it was easily detectable by Allied radar which because air cover gradually encompased the entire North Atlantic mean thst ther was nolonger any plsce tonhide. Cracking the Naval Enigmas futher exposed the boats. Dönitz had to withdraw the U-boats fron the North Atlantic (mid-1943).

Type IX

The principa large boat used by the German Submarune Service was the Type IX. The Type IX U-boat was designed by by the Kriegsmarine (1935-36). The Abnglo-German Naval Agreement was negotiated (1935). It was prt of Britin's Appasement Policy. At the time, the Royal Navy believed that technologies developed during World War I, like ASDIC (SONAR), meant that submarines were no longer a threat. It was meant to be a large ocean-going submarine for sustained oceanic operations at distance from support bases. At the time the Germans did not conceive of operating from Frenh bases. Type IX boats were sucessfully used for Operation Drumbeat patrols off the eastern United States after Hitle declared war in America (early 1942). It was based on the Type IA U-boats. The type Is were not built in any number. The Type IXs were built in various sub-types. Type IXs had six torpedo tubes, four at the bow and two at the stern. They carried six reloads internally. There were five external torpedo containers (three at the stern and two at the bow). They stored two toroedoes each, meaning ten additional torpedoes. The total number was 22 torpedoes. This allowed U-boat commanders to follow a convoy and do enormous damages, striking repeatedly on multiple nights. Some of the IXC boats were fitted for mine rather than torpedo operations. Mining sea lanes was an important part of U-boat operations. They could carry 44 TMA or 66 TMB mines. The Tyoe IXs secondary armament was one 10.5 cm (4.1 in) deck gun with 180 rounds. This was often used to sink unescorted ships to save the toroedoes. There was also anti-aircraft armament, but this varied thriughout the War. There were two periscopes in the tower. Types IXA and IXB had an additional periscope in the control room, which was removed in Type IXC and afterward. These lrge long-range boats could be equipped with Focke-Achgelis Fa-330, a light weight spotter planes. Miliitary experts generally report that the larger Type IXB was the most successful. The Type IX was the larger boats ranging from 1,100 1,400 tons, depending on the variant. OKM insisted on building quite a number of type IX boats. They were not the ones that Döentiz most wanted.

Type XXI

Walter used the many design innovations developed for the Type-XVIII to produce the Type XXI Elektro boat. Hitler ordered priority given to the Type XXI program. They had the capability of remaining submerged for long periods and had a small sonar signature. The Germans did not achieve this on purpose, but the streamline design allowing the boat to increase submerged speeds, by accident also reduced the sonar signture. Some claim that if introduced earlier it could have won the Battle of the Atlantic. There were, however, major design and manufacturing flaws as a result of the rush to produce. The Allied strategic bombing campaign greatly complicated manufacturing projects, especially large operations which slowed the production process. Shipyards were priority targets for the Allied bombers. The Germans launched quite a number of these boats, but only a few were actually deployed by the time the the NAZIs surendered. The Type XXI hull design was highly inflential in the U.S. Navy nuclear Natalus design. The Soviet Navy during the Cold War went down the Type XVIII hydrogen peroxide dead end.

Type XXIII

A smaller new U-boat the Type XIII was also developed and 63 were actully built. It was one of the most advanced submarine designs of the War. It was, however, generally overshadowed by the ground-breaking developmnt of the larger Type XXI Elektroboat. Dönitz because of his small number of U-boats had used the Tyopes IIs at the onet of the War fir combat patrols. As more U-boats becsme available, most of the Type IIs had been withdrawn from combat operations, except in the Black Sea. Development of the Type XXI Elektroboat began (late-1942). The Admiralty conceived the idea of developing a smaller version utilizing the advanced technology of the Type XXIs. Thy ciuld fill the role the Type II coastal boats had been filling. Dönitz, insusted on two requirements. First that the would have to operate in the Mediterranean and Black Sea and not jut German North Seaa and Baltic coastalk waters. This mean that it had to be transportable by rail and it had to use the standard 21 inch torpedo tubes.

Type XXVIII

The Germans were constantly trying to improve their U-boats and put some of their best scientists on the effort. They were at a serious disadvantage, however, because most of the U-boats lost to the highly successful Allid ASW effort were lost at Sea so the Germans were unsure just what Allied ASW develop,ments were succeedinding in sinking U-boats. They had, however, a fairly good idea. And Dönitz put a techinal genius on designing an improved U-boat--Hellmuth Walter. Earlier German U-boats were basically a surface ship capable of diving. What Walter set out to produce was a true submarine capable of fighting underwater and remaining submerged for extended periods. His work led to a high performance prototype and two advanced U-boat types. The Type XVIII solved the the need to surface by shifting from diesel fuel to hydrogen peroxide. This created, however, a varirety of problems, but the insolvable one was Germany's limited capacity to produce hydrogen peroxide and the priority given tothe V-2 program.

Created: 9:04 PM 12/31/2017
Last updated: 12:50 AM 12/15/2018