{"id":1108,"date":"2017-02-07T08:00:43","date_gmt":"2017-02-07T08:00:43","guid":{"rendered":"http:\/\/www.naval-encyclopedia.com\/?p=1108"},"modified":"2017-02-07T08:00:43","modified_gmt":"2017-02-07T08:00:43","slug":"type-ii-class-submarine","status":"publish","type":"post","link":"https:\/\/dbodesign.com\/ww2\/germany\/type-ii-class-submarine.php","title":{"rendered":"Type II U-Boats (1935)"},"content":{"rendered":"
\n

Type II U-Boats (1935)<\/h2>\n

<\/a> Germany (1935), 50 Submarines Types IIa, IIb, IIc, IId<\/strong>
\n\n<\/div>\n

The Type II U-Boats were the first mass-produced submersibles of the Kriegsmarine. They were derived from the CV 707 design, better known as the Vesikko, Finnish submarine designed by IvS, the famous covert submarine design bureau of the Hague, Netherlands, in operation from 1922 to 1935. The Type II was a coastal submarine built in four successive series, fifty total, with some improvements along the way. They took part in Baltic Operations for the majority of their career, and the first series became training boats.<\/p>\n

Development<\/h2>\n

The role played by IvS.<\/h3>\n

In 1930, the proxy\/screen Dutch company NV Ingenieurskantoor voor Scheepsbouw den Haag set out to design a new class of submarine as a means of coastal patrol and defense. This submarine was bought by the Finnish government and was called the CV-707 Vesikko<\/strong>. This became the basis for the development of a new class of submarine for the German Kriegsmarine. To recall, IvS had been created back in July 1922. NV Ingenieurskantoor voor Scheepsbouw (abbreviated in Germany as INKAVOS) was an umbrella organization for the German Reichsmarine essentially. It was estabished to maintain and develop German knowledge of submarine construction, and practical experience would begained by exports. The Versialles treaty indeed forbade Germany to have submarines indeed. This Dutch company successfully circumvented the restrictions until Hitler in 1933 decided to rip off the treaty and restart Germany’s armament in a more open way.<\/p>\n

<\/p>\n

IvS had a partnership with the German shipyards AG Vulcan in Stettin, Krupp Germaniawerft in Kiel, and AG Weser in Bremen, the major shipyards that also backed financially each operations. Many parts were manufactured in a network of German companies, some in the Netherlands as well, then sent to the countries that would build these exported submarines long with engineers detached from IvS. By the late 1920s the company had been unmasked in The Hague, in a brick Art Deco building on Wagenstraat, at the corner of Gedempte Burgwal 1, right in the middle of The Hague’s Jewish quarter (admire the irony there). Both French and British inspectors knew about it. So by 1931, IvS moved to Kneuterdijk No. 8.<\/p>\n

The first commission was for Spain. These were related to the UB III of the former Kaiserliche Marine. Between 1925 and 1927, Fijenoord built two submarines designed by IvS for Turkey (the capabilities did not existed there), under license from Krupp. From 1927 to 1933, five more of a completely different design, were built in Finland. In 1931, “Het Volk” published an article about torpedo tubes, manufactured by the Utrecht factory M.E.A.F., based on the IvS design for sale to ‘foreign countries’ and mentioned that IvS was German operated, this was the main reason that pushed it to change address and after the 1935 Anglo-German naval agreement, all designs activities were repatriated and the bureau was closed off. Submariner training also existed there, and was repatriated from 1933 in Kiel. Most engineers and assets ended at Kiel as well.<\/p>\n

The “Finnish Connection”<\/h3>\n

\"\"
\nFinnish Vesikko, CV-707 prototype submarine in service and camouflage livery during the war.<\/em><\/p>\n

The three Vetehinen class<\/a> were the first Finnish submarines ordered from the covert IVS design bureau in the Hague, partly inspired by the German WWI 1917 UC-III class, but they were minelaying, medium size models. The first true design that was at the root of the Type II program was Saukko<\/a>. Following secret German-Finnish talks, Finland commissioned a 500-ton submarine, which was then built at the Crichton-Vulcan shipyard in Turku starting in 1929. A total of five submarine orders were placed in Turku, including CV 707, later renamed Vesikko<\/a>, the prototype of the German Type IIA submarines. In 1928, Finland also ordered two 3,900-ton coastal defense ships, which were likewise built in Turku. If Saukko was the world’s smallest submarine and a feat in itself, it was only fitted to lakes, not the Baltic and even less the North Sea. The Kriegsmarine never left the need to make it useful for other use, even on the Volga.<\/p>\n

<\/p>\n

Now, the Vesikko was the real deal. Indeed, Ingenieurskantoor voor Scheepsbouw (IvS) promoted the construction of Vesikko to the Finnish government, despite there was no need for it and it was not planned. This was indeed a purely German developmental program out the Finnish Naval Act behind the the Vetehinen class and Saukko. Since R&D and construction were paid for by the German Government, it was eventually still purchased by the Finns only to be tested and evaluated by and with German crews. It was a German prototype tested under Finnish flag essentially. Construction and trials were all supervised by the Reischmarine. <\/p>\n

Official decision to build her was made in 1930, after several meetings with the Finnish Government, without any mention of Germany as it obviousmy broke the Versailles Treaty terms and the Reichsmarine was not willing to break them openly. It was argued this affordable, small submarine type would be exported, at least that was mirrorred to Turku to sweet up the deal, to nations belonging to the League of Nations only. <\/p>\n

Would-be buyers would operate these submarines hands-free, without strings attached. The Finnish Government earned the primary rights to purchase the submarine, build it independently for export on the international market that did not lacked potentiual customers. Since Germany submarine warfare in WWI, submarines were considered the new deterrent most navies could afford, far more relevant than Torpedo Boats. The fact it was German design was also hardly a mistery for anyone, and that came up with the prestige attached. <\/p>\n

Tests of vesikko allo brought an immense treasure trove of practical experience to the Kriegsmarine. Finland had a primary purchase option until 1937. Completed in April 1934, it was trialled intensively, with the future Finnish crew also training on board, and the Finnish Government took over Vesikko officially on August 1934, with an official ceremony, but no flag change. To avoid any quesitons, it flew the Finnish flag all along. It’s lilely Kriegdmarine officers and advisors remained until the Finnish Parliament approved the acquisition in 1936, and she joined the Finnish Navy “marder”, operating in the Baltic until 1945 and disarmed in 1947 after the Paris Peace Treaty.<\/p>\n

CV 707 design<\/h3>\n

The CV 707 was a very modern design.
\nConstruction of CV 707 started in 1931 at Crichton-Vulcan dock in Turku and among the world’s most advanced submarine designs, with a much stronger hull for twice the usual operating depth of its contemporaries, made all by electric welding, in a modular way. Modules could be build anywhere, ferried by train to the assembly point. Without rivets, there was better resistance to water pressure, it decreased oil leakages and made the construciton process faster.<\/p>\n

Its legacy was immense, as the Germans themselves tested CV 707 in the Archipelago of Turku in 1933\u201334. Vesikko became the prototype for the German Type II submarines in 1935. Six Type IIA submarines (U-1 to U-6) almost identical to Vesikko were built at the Deutsche Werke dock in Kiel after Hitler came to power, tearing down the Versailles treaty as announced, and afterwards, some forty-four Type IIB, IIC, and IID U-Boats were also built before and during World War II. They did not took part in the Atlantic campaign but still roamed the Baltic and North sea and made themselves useful. Also in 1939 they constituted the bulk of the German U-Boat arm before the Type VII took it over. <\/p>\n\n

With the rearmament accelerated by Adolf Hitler from 1933, the first Type II U-boat were authorized and integrated in a the new naval plan in 1934, and the first six were ordered from Deutsche Werke. The first, U-1, was laid down on 11 February 1935. Hitler reached an agreement with Britain to build a navy up to 35% of the size of the Royal Navy in surface vessels, equal to the British in terms of submarines, so that essentially nullified all naval clauses of the Versailles treaty and aligned Germany on the 1922 Washington Treaty limitations, with the global tonnage already defined and all other qualitative limitations applied, including for submarines. <\/p>\n

This agreement was signed on 18 June 1935, U-1 was commissioned 11 days later. U-1 and U-6 were a first batch as direct copies of CV 707, but it was gradually improved for the next three series, twenty Type IIB, U-7 to U-121 (it was interlapped with Type VIIA and later VIIB orders) built at Deutsche Werke AG of Kiel (4 1935-1936), Germaniawerft, Kiel (14 1935-1936), Flender Werke AG, L\u00fcbeck (2 1938-40), then the six Type IIC from Deutsche Werke AG of Kiel, U-56 to U-63, and then a final batch of sixteen Type IID, U-137 to U-152 at Deutsche Werke AG of Kiel in 1939-1940. They were all intended for the Baltic first, and North Sea second. Technical details of the next series are seen below.<\/p>\n

Design<\/h2>\n

\"U-1,<\/p>\n

<\/div>\n
<\/div>\n

It was the Finnish order that was at the origin of the Type II. Work on Finnish submarines started in 1927, so by 1933, NV Ingenieurskantoor voor Scheepsbouw den Haag designed a new and improved CV-707 that would be built for the German navy at the Kiel shipyard. This class became the Type IIA, with the U-1 being the first built. It’s primary roles were training of new crews and coastal defense. That early in U-Boat development and officialized, this meant Germany did not longer care abouyr Versaille’s submarine interdiction. It was also theorized that a defensive submarine would be more “tolerable” within this apparent violation, albeit this was alleviated by the 1935 naval treaty with Britain, part of the appeasement policy, which infuriated France. On the German side, until then with IvS designs, this was part of the general policy of rearming Germany through a “smoke and mirrors” campaign, as Luftwaffe bombers were at first presented as postal and passenger aircraft.<\/p>\n

Hull and general design<\/h3>\n

The Type IIA had a length of 134 feet, a beam of 13 feet, and a draft of 12 feet, meaning that the sub was small and could only operate in coastal waters. A conning tower was located in the center and housed the periscopes that the sub would use to see while underwater. A single anti-aircraft gun may be mounted here. Displacement for the Type IIA was 250 tons surfaced and 298 tons submerged. A test depth of 150 meters could safely be reached, although captains of submarines would regularly take their subs deeper than the test depth. With a crew of up to 25 men, the Type II was cramped and uncomfortable, although proportionate as other submarines such as the American Gato Class were 3 times the size and had 3 times the crew.
\nThe Type IIA was basically a repeat of the CV-707 alias Vesikko design, they had the same hull size, 40.90 x 4.076 x 4.026 meters (134 ft 2 in x 13 ft 4.5 in x 12 ft 5 in). The Type IIA had a displacement of 254 tonnes (250 long tons) surfaced, light, 303 t (298 long tons) submerged and 381 t (375 long tons) total, fully loaded and submerged, also the same.<\/p>\n

Powerplant<\/h3>\n

\"Type
\nCutaway plans of the U Boat type II<\/em>
\nGerman submarines, while having diesel and electric engines, were not true diesel-electrics. They used their louder diesel engines on the surface and their electric engines underwater.
\nPowering the Type II were 2 diesel engines and 2 electric motors allowing for up to 13 knots surfaced and 7 knots submerged. Vesikko had two diesels rated for 350 PS (257 kW; 345 bhp) and two double-acting electric motors rated for 180 PS (132 kW; 178 shp) each. The 350 HP Motoren-Werke-Mannheim (MWM RS 127 S) Diesels were from Germany as were the 180 HP Siemens electric motors and the 62 cell battery group rated for 6,380 Ah total. This was enough for 13 knots (24 km\/h; 15 mph) surfaced, 8 knots (15 km\/h; 9.2 mph) submerged making her the fastest small submarine for her category. She carried 9.6 tons of fuel for a Range 1,500 nautical miles at 10 knots surfaced, or 1,350 nmi (2,500 km; 1,550 mi) at 8 knots surfaced, 40 nmi (74 km; 46 mi) at 4 knots (7.4 km\/h; 4.6 mph) submerged, and her strong pressure hull was good good for a service depth or 150 m, crushing depth calculated below 220 m, making her the deepest diving small submarine of her time as well.
\nNow, the Type IIa had the same twp Motoren-Werke-Mannheim (MWM) RS 127 S 6-cylinder diesel engines for 700 PS (690 shp; 515 kW) and two SSW PG VV 322\/36 double-acting electric motors, for 402 PS (397 shp; 296 kW) intead of 360\u2013375 PS (355\u2013370 shp; 265\u2013276 kW) on the previous boats, and same battery capacity. Top speed for the IIA was thus 13 knots (24 km\/h; 15 mph) surfaced and also 6.9 knots (12.8 km\/h; 7.9 mph) submerged. Same performances underwter as well. Type IIA subs could travel 1,600 nmi (3,000 km; 1,800 mi) at 8 knots (15 km\/h; 9.2 mph) while surfaced and 35 nautical miles (65 km; 40 mi) at 4 knots (7.4 km\/h; 4.6 mph) while submerged. Evything was improved on the next classes. <\/p>\n

Armament<\/h3>\n

Armament of most Type II submarines was three 21-inches or 533mm torpedo tubes, all in the bow, with two spares, five total. In addition, there was a 20mm FLAK anti-aircraft cannon on later types but no deck gun. The crew also carried small arms such as MP-40 submachine guns and P-38 handguns for self-defense and boarding. All German submarine crews were trained in land combat, so it can be assumed that the crews were at least somewhat skilled with their small arms. Those proved handy in 1945 in the defence of Hambourg and other ports, largely made by “dismounted” Kriegsmarine crews.<\/p>\n

Torpedoes: G7<\/h4>\n

The Type II had only three bow torpedo tubes, two either sides and one below making for a triangular pattern. Two reloads only in the froward torpedo froom, making for five total with the three already in the tubes. As for the torpedoes and tubes, direct involvement of Spain in the development of German torpedoes started in the late 1920s when the Spanish businessman Horacio Echevarrieta decided to start a torpedo factory in C\u00e1diz (F\u00e1brica Nacional de Torpedos, F.N.T. \/ National Torpedo Factory) with a theoretical production capacity of 100 torpedoes per year and license-build German torpedoes. But the G7 was created in WWI. The lineage comprised the pre-WWII G7A (T1) using compressed air and thus leaving a visible trail of bubble. After 1933, torpedo manufacturing was repatriated in Germany.<\/p>\n

G7a<\/h5>\n

The G7a (TI) torpedo calibre was the standard 533.4 mm (21 in), for a length of 7163 mm (23 ft 6 in), fitted with a Ka or Kb warhead, Pi1 or Pi2 pistol. The warhead carried 280 kg (617lbs) Schie\u00dfwolle 36. The model remained standard issue from 1936 to the end of WW2. This model was of a straight-running unguided model only controlled by a gyroscope. It could be set at a variable speed, 5,000 m at 81 km\/h or 7,500 m at 74 km\/h (8,250 yd at 40 kt) but also “long course” 12,000 m at 55.6 km\/h. The 44 knots model setting was only used by Schnellboote with a reinforced engine. Later were introduced the G7a (T2) electric, T3, T4, T5 (Zaunk\u00f6ning), and T11, but the latter remained a prototype. <\/p>\n

G7E Torpedo (T2)<\/h5>\n

They had a unique setting of 5000m at 30kts. Standard torpedo of the war, it suffered from early issues with the internal depth-keeping equipment and firing pistol, solved after the Norwegian Campaign. Full effectiveness on the T2 was obtained when preheated electrically to 30 degrees Cent (86 F) before firing. If not, speed was down to 28 knots for 3000m.<\/p>\n

G7E Torpedo (T3)<\/h5>\n

By mid-1942 the improved version had an increased battery capacity, asking for a 50% superior range as the T3a. Range was now, 7500m at 30 knots, but in a preheated state it was 4,500m at 28 knots. More detail to come for the next articles on the Type VII. <\/p>\n

2cm Flak 30<\/h4>\n

The original Flak 30 design inherited the Swiss Solothurn ST-5 as a project for the Kriegsmarine, as the 2 cm C\/30. It fired the “Long Solothurn” 20 \u00d7 138 mm belted cartridge developed for the ST-5, a powerful 20 mm round. It had a barrel length of 65 calibres, had a fire rate of about 120 rounds per minute. It developed feeding problems and would often jam, offset to some degree by its undersized 20 round-magazine making reloading a frequent necessity. It became the primary shipborne light AA weapon, equipping a large variety of German ships. <\/p>\n

TMA Mines<\/h4>\n

In alternative to their torpedoes, the Type II U-Boats could also carry twelve TMA mines. The Type IIs did managed a few minelaying missions, but the size of their individual minefields was fairly limited, so losses were few. The TMA mines were shaped as cylinders, they were moored mines, attached by cable to float above the surface, while the anchor secured its position. The correct depth setting needed to be applied depending on the observed depths. Two could be carried in each torpedo tube.
\nLength\/Diameter: 11.1ft (3.38m)\/21in (533mm), Maximum Depth: 270m, Warhead: 215kg.<\/p>\n

Sensors: GHG<\/h3>\n

The GHG was an early acoustic system, a hydrophone array used on all models, including the Type VII. It was developed in WWI already following Pierre Curie discovery in 1880 using the piezoelectric principle. Atlas Werke AG in Bremen and Electroacustik (ELAC) in Kiel worked on transducers, detectors and amplifiers and found the best being the Seignette crystal formed from a mixture of different salts. From 1935, crystal receivers were permanently installed on German submarines.<\/p>\n

The GHG was the final product, GHG made of two groups of 24 sensors, one on each side of the boat. Each sensor had a tube preamplifier. These 48 low frequency signals were routed to a switching matrix and the sonar operator could determine the side and direction of the sound source. To improve resolution, a frequency of 1, 3 and 6 kHz could be setup. There was however a dead zone of 40\u00b0 fore and aft, but range was 20 km to individual ships and 100 km against a full Convoy. The Search area was 2 \u00d7 140\u00b0 with a resolution of less than a degree at 6 kHz, 1.5\u00b0 for 3 kHz, 4\u00b0 for 1 kHz and without crossover 8\u00b0.<\/p>\n

Assessment<\/h3>\n

The first Type IIA submarines were completed in 1934, although most of the world did not know of their existence until 1935, when Germany and Great Britain signed a treaty allowing Germany to match England’s submarine fleet. Type II submarines would be used in the beginning years of the war as a training and coastal patrol boat until a shortage of U-Boats in 1942 and 1943 would see them supplementing the larger Type VII class in anti-ship roles. In total, there were at least 4 combat flotillas that operated the Type II. These included the 1st, 3rd, 5th, and 30th Flotillas. Most of these operated out of Kiel, with one notable exception.<\/p>\n

Starting in 1942 with the formation of the 30th U-Boat Flotilla, Type IIBs would be used in the Black Sea, attacking Russian shipping and reinforcements making their way to the front line. The Flotilla was disbanded in 1944 after the destruction of all remaining U-Boats. At the start of hostilities with France and England, the Type II was more used for coastal patrol and training, but as the war dragged on, it saw more combat in the English Channel. Eventually, the Type II was to be replaced by the Type XXIII “Elektroboot”, although the Type II was never fully replaced in the Kriegsmarine.<\/p>\n

\"U-Boat
\nU-Boat Type IIa waterline profile (1\/400)<\/em><\/p>\n

\"U-Boat
\nU-Boat Type IIc full profile for comparison<\/em><\/p>\n

\"U1
\nU1 in service with the Kriegsmarine before the war<\/em><\/p>\n

\"U9,
\nU9, of the following IIb class.<\/em><\/p>\n

\"Vesikko
\nThe Vesikko preserved at Susisaari island in Suomenlinna near Helsinki as of today. It has been restored and opened as a museum in 1973<\/em>.<\/p>\n

U-Boote Type IIa<\/h2>\n

Single hull, all welded, internal ballast tanks, small bridge type, carried the German G7a, G7e torpedoes, TM “torpedo mines”. Serrated net cutters in the bow. All built at Deutsche Werke AG of Kiel in 1934-35.<\/p>\n

\n

\"Kriegsmarine\" U1 (1935)<\/h3>\n<\/div>\n


\nU-1, the first official submarine of the Kriegsmarine, was ordered from Deutsche Werke AG under Yard number 236, laid down on 11 February 1935, launched on 15 June and commissioned on the 29th of the same year and month, for a global cost of 1,500,000 Reichsmark. The speedy construction, in just five months reflected on the modular construction, and was intended for wartime mass-production, albeit this was later applied to the Type VII and even though on the Type XXI and XXIV despite the former were much larger. This was toned done on the next sub-classes after the trials of U-1. That type of construction brought also some issues.
\nShe was first under command of Oblt.z.S.\/Kptlt. Klaus Ewerth. Same observation as above, Her first skipper until 30 September 1936 was Oblt.z.S. \/ Kptlt. Klaus Ewerth, follwoed by Kptlt. Alexander Gelhaar until 2 February 1938, and another until 28 October 1938. Then Kptlt.\/K.Kapt. J\u00fcrgen Deeck until her loss.
\nHer pre-war service was however pretty unremarkable. On trials she developed the reputation as a poor ship, rapid construction, combined with a still immature modular construction technology used to create her, made her uncomfortable, leaky and slow. So she was tested and trialled in until 1939 with plans to shelve her while her sisters were reassigned for training only, for crews of the Type IIB and next ones. Thus, she served in the Kiel’s U-boat School Flotilla.<\/p>\n

However, since the head of the submarine arm, Karl D\u00f6nitz, was desperate seeing the shortage of available units, she was reconfigured for combat use, retrained intensively and sent on 29 March 1940 to operate against British shipping off Norway before Operation weser\u00fcbing took place. She was already close to her effective operating range. She failed to find any target of opportunity in her frirst war patrol. Despite of this she was sent out again on 4 April, for Operation Weser\u00fcbung. In this second patrol, she sent a brief radio signal on 6 April, giving her position, but was never heard of again. Her fats and locations were unsure until her crewk was rediscovered in June 2007 by divers. She apparently had struck a mine in British minefield Field No. 7, North Sea, north of Terschelling (54\u00b014\u2032N 05\u00b007\u2032E). The mine blasted off the entire aft section of the boat along the module welding line. She filled very quickly and all all hands were lost.<\/p>\n

\n

\"Kriegsmarine\" U2 (1935)<\/h3>\n<\/div>\n


\nU-2 was ordered under Yard number 237, laid down on 11 February 1935, launched on 1st July, Commissioned on the 25th under her first skipper Oblt.z.S. Hermann Michahelles until 60 Sept. 1936, then Kptlt. Heinrich Liebe until 31 January 1938 and Oblt.z.S. Herbert Schultze until 16 March 1938. She showed the same limitations as her other sisters, revealing herself on trials uncomfortable, leaky and slow. She was used as training boat in 1935-40. In 1939 she was under command of Oblt.z.S.\/Kptlt. Helmut Rosenbaum from 17 March 1939 to 5 August 1940. D\u00f6nitz was however eager to have more hulls at sea in 1940 and recalled the while Type IIa to combat in the west. She left the Kiel’s U-boat School Flotilla in February, was reconfigured and retrained and took part in a first war patrol from on 15 March, and until the 29th without finding a target off Norway, and then an 2nd patrol from 4 to 15 April 1940 for Operation Weser\u00fcbung also off Norway, close to her effective operating range and again, found no target.<\/p>\n

She was then sent back to training at Kiel under Oblt.z.S. Hans Heidtmann from 7 July to 5 August 1940; Kptlt. Georg von Wilamowitz-Moellendorff (deputy) (6 August \u2013 October 1941), Karl K\u00f6lzer (October 1941 \u2013 15 May 1942), Oblt.z.S. Werner Schwaff (16 May \u2013 19 November 1942), Oblt.z.S. Helmut Herglotz (20 November \u2013 12 December 1943) and eventually Oblt.z.S. Wolfgang Schwarzkopf
\nfrom 13 December 1943 to 8 April 1944. She was surfaced when that day, 8 April, she collided with the German steam trawler Helmi S\u00f6hle west of Pillau (Baltiysk) and sank. 17 went down but 18 on deck on in the CT survived. The wreck was raised a day later and stricken. It was not even considered worthwile to repair her.<\/p>\n

\n

\"Kriegsmarine\" U3 (1935)<\/h3>\n<\/div>\n

\"\" U-3 was ordered on 2 February 1935 from Deutsche Werke, Kiel under Yard number238, laid down on 11 February 1935, launched on 19 July 1935 and commissioned on 6 September 1935 under command of Oblt.z.S. Hans Meckel until 29 September 1937, then Kptlt. Ernst-G\u00fcnter Heinicke until July 1938, and Oblt.z.S.\/Kptlt. Joachim Schepke until 2 January 1940. In 1939 she was used for training, showing the same poor qualities as her sisters, but it was decided to prepare her for operations in 1939 anyway. Her was first patrol in 4\u20138 September was relatively uneventful. <\/p>\n

Same for her second one on 13\u201324 September toward the British east Anglian coast. But her third patrol from 27 September to 3 October 1939 saw her sinking the Danish ship Vendia and the Swedish vessel Gun for a total of 2,348 gross register tons (GRT) on 30 September. U-3 ordered Vendia to stop after a few warning shots, boarded her, inspect her, released the crew and fired a torpedo than sank her afterwards as claimed. But her fate is disputed. “Gun” was attacked in the Skagerrak, 30 nmi (56 km; 35 mi) northwest of Hanstholm. She sent a boarding party but meanwhile U3 was forced to dive as HMS Thistle arrived. She fired a torpedo at the British submarine but missed. Thistle left the area, came across the lifeboat from Gun. The boarding party had left the ship in a lifeboat, later picked up by the Danish merchant ship Dagmar. U-3 later recovered them found back the “Gun” and sank her.<\/p>\n

Her 4th patrol started on 16 March 1940 and until the 29th. Itw as uneventful, now under command of Kptlt. Helmut Franzke from January. Her fifth patrol was on 12\u201319 April 1940 off Norway in support of the invasion. She crossed the path of a another British submarine, HMS Porpoise, which firing six torpedoes at her some 10 nmi (19 km; 12 mi) west of Egersund on 16 April but missed. Afterwards she was retired from active service and sent back to the U-Boat Flotilla school at Kiel. Her newt skiopers were Kptlt. Otto von B\u00fclow (11 November 1940 \u2013 2 July 1941), Oblt.z.S. Hans-Hartwig Trojer (3 July 1941 \u2013 2 March 1942), Oblt.z.S. Joachim Zander (3 March \u2013 30 September 1942), Oblt.z.S. Herbert Zoller (1 October 1942 \u2013 18 May 1943), Oblt.z.S. Ernst Hartmann (19 May 1943 \u2013 9 June 1944), and Lt.z.S. Hermann Neumeister (10 June \u2013 16 July 1944). She was stricken on 1 August 1944 in Gotenhafen to free crews for more modern submarines and captured by British troops on 3 May 1945, scrapped.<\/p>\n

\n

\"Kriegsmarine\" U4 (1935)<\/h3>\n<\/div>\n

U4 was on Ordered on 2 February 1935 at Deutsche Werke, Yard number 239, laid down on 11 February 1935, launched on 31 July 1935 and commissioned on 17 August 1935 under commmand of Oblt.z.S. \/ Kptlt. Hannes Weing\u00e4rtner. She joined the U-boat School Flotilla until 1 February 1940 under successive commands of Oblt.z.S.\/Kptlt. Hans-Wilhelm von Dresky until 28 October 1938 and Oblt.z.S.\/Kptlt. Harro von Klot-Heydenfeldt until 16 January 1940, and was turned to combat patrols due to shortages of submarines. She already departed Wilhelmshaven for her first patrol on 4 September 1939, and sailed to the south of Norway and and North Sea west of Denmark, along the Dutch coast, and back on the 14th. <\/p>\n

No sport, no kill. A second patrol later that months allowed her to spot three neutral vessels heading to Britain and sank all three in three days, the Martti Ragnar (22nd) Walma on (23rd) and Gertrud Bratt (24th), the first two by boarded and sunk with scuttling charges. U-4 towed lifeboats to the coast an ensured they were taken on by trawlers. Gertrud Bratt was boarded, but sunk with a single G7a torpedo. Her crew reported U-4 promised to tow the lifeboats but dove after spotting an aircraft. <\/p>\n

She started her third patrol from 16 to 29 March 1939, during this operation she spotted and sank the T-class sub HMS Thistle<\/a>. But this was not a walk in the park given U4 mediocre speed and endurance. Thistle spotted and attacke dher first, barely missing with a four-torpedo spread on 9 April. U-4 evade and started a hunt. She eventally caught her a da later and sank her with all hands as she recharged her batteries, surfaced and stopped. Her 4th patrol was 4\u201314 April 1940, bore no results. Once Norway fallen Admiral D\u00f6nitz knew they could outfight outrun any foe or had the range and endurance to prey on Allied shipping so from 1 July 1940, under command of Oblt.z.S. Hans-Peter Hinsch until 7 June 1940, she was sent to the 21st U-boat Flotilla for training, until 1944, in the Baltic Sea. Her successive skippers were Oblt.z.S. Hans-J\u00fcrgen Zetzsche
\nuntin 2 February 1941, Oblt.z.S. Hinrich-Oscar Bernbeck until 8 December 1941, Oblt.z.S. Wolfgang Leimk\u00fchler until 15 June 1942, Lt.z.S. \/ Oblt.z.S. Friedrich-Wilhelm Marienfeld until 23 January 1943, Joachim D\u00fcppe until 31 May 1943, Oblt.z.S. Paul Sander until 22 August 1943, Lt.z.S. \/ Oblt.z.S. Herbert Mumm until May 1944 and Oblt.z.S. Hubert Rieger until 9 July 1944 and she was still in Gotenhafen on 1 August 1944 to be scrapped for parts in 1945.<\/p>\n

\n

\"Kriegsmarine\" U5 (1935)<\/h3>\n<\/div>\n

Ordered\ton 2 February 1935, U5 was laid down at Deutsche Werke, Kiel under Yard number 240, laid down on 11 February 1935, launched on 14 August 1935 and commissioned on 31 August 1935. from 1st Sept. 1935\tto 1 Setp. 1939\tshe ws at the U-Bootschulflottille (school boat) under Kptlt. Rolf Dau (until 27 Sept 1936), then Kptlt. Gerhard Glattes until 2 Feb. 1938, and Kptlt. G\u00fcnter Kutschmann until 4 December 1939. But from 1st October 1939 she was retained in the U-Bootschulflottille (school boat) until 1 February 1940. By then she was under command of Kptlt. Heinrich Lehmann-Willenbrock (Knights Cross) active until 11 August 1940, and during which command she had her first war patrol in the Baltic, from 1st Mar 1940 to 1 April 1940, albeit sitll listed in the U-Bootschulflottille and active service. <\/p>\n

From 1st May 1940 to 30 June 1940 she was passed onto the U-Bootschulflottille (school boat) and from 1 July 1940, and until 19 March 1943 she was in the 21. Flottille (school boat), never leaving the Baltic sea. Her commanders were Oblt. Herbert Opitz (until 6 Jan 1942), Oblt. Friedrich Bothe (until 23 March 1942), Oblt. Karl Friederich
\n (until May 1942), then Oblt. Hans-Dieter Mohs (German Cross in Gold) until 9 Nov 1942, Oblt. Kurt Pressel and until 19 March 194 Oblt. Hermann Rahn, her last captain, when lost was Ltn. Alfred Radermacher (German Cross in Gold) which took command in March 1943. Indeed, for all her service, she only made twp combat patorls, the 1st between 24 August and 8 September 1939 in the west, and the 2nd on 4\u201319 April 1940, seeing no target, sinking no ship. She was lost on 19 March 1943 in a diving accident west of Pillau (now Baltiysk, Russia) with 16 of her 37-man crew surviving, the ones already on deck when it happened.<\/p>\n

\n

\"Kriegsmarine\" U6 (1935)<\/h3>\n<\/div>\n

U6 was ordered on 2 February 1935, from Deutsche Werke, Kiel, under Yard number\t241. She was laid down on 11 February 1935, launched on 21 August 1935 and commissioned on 7 September 1935 for a Cost of 1,500,000 Reichsmark. Like her sisters her career was short. Her first commander was Oblt.z.S. \/ Kptlt. Ludwig Mathes until 30 September 1937. He was a WW1 vet captain, like many others for this class. Meanwhile U6 remained with the U-boat School Flotilla from 1 September 1935 to 1 September 1939. Her next skippers were Oblt.z.S. Werner Heidel from 1 October 1937 to 17 December 1938, Oblt.z.S. Kptlt.Joachim Matz until 26 November 1939 and Oblt.z.S. Hans-Bernhard Michalowski until December 1939. <\/p>\n

He was in command for her first war patrol from 24 August to 13 September 1939. On 31 August she spotted three destroyers of the Polish Navy, Burza, B\u0142yskawica, and Grom that were starting Peking Plan<\/strong>, trying to sail to Great Britain to avoid destruction or capture, but there were strict orders not to attack. U-6 after that initial patrol in the Baltic Sea, was not deployed again until March 1940, with all the Kriegsmarine sent to support the invasion of Norway, from 4\u201319 April 1940 under command of Oblt.z.S. Adalbert Schnee. withdrawn to a training squadron in the Baltic for the remainder of the war. She was sent into the Baltic, back into the U-Schule from 1 May to 30 June 1940 and then after a reoganization, spent the war in the 21st U-boat Flotilla. U-6 resumed training officer cadets for Battle of the Atlantic. Some patrols were pushed to Soviet waters after Operation Barbarossa started though, but she had no sport, no kill. From 1 July 1940 to 7 August 1940 she under command of Kptlt.Georg Peters, Oblt.z.S. Johannes Liebe (March 1941), Oblt.z.S. Kptlt. Eberhard Bopst (September 1941), Herbert Br\u00fcninghaus (August 1942), Oblt.z.S. Paul Just (September 1942), Oblt.z.S. Herbert Br\u00fcninghaus (October 1942), Lt.z.S. Oblt.z.S. Otto Niethmann (June 1943), Lt.z.S. Horst Heitz (October 1943), Lt.z.S. Oblt.z.S. Alois K\u00f6nig ( until16 April 1944), and her last skipper Lt.z.S. Erwin Jestel until 9 July 1944. By the summer of 1944, fuel and resources were rare and fatal accidents multiplied so U-6 was laid up at Gotenhafen, having a skeleton crew for basic maintenance until May 1945, scuttled to avoid capture.
\n<\/p>\n

Sources:<\/h3>\n

https:\/\/uboat.net\/types\/iia.htm
\nhttps:\/\/uboat.net\/types\/iib.htm
\nhttps:\/\/uboat.net\/types\/iic.htm
\nhttps:\/\/uboat.net\/types\/iid.htm
\nHet Vilk 27-06-1931 article about IvS<\/a>
\nhttps:\/\/en.wikipedia.org\/wiki\/Type_II_submarine
\nhttps:\/\/www.uboataces.com\/uboat-type-ii.shtml
\nhttps:\/\/en.wikipedia.org\/wiki\/2_cm_Flak_30,_Flak_38_and_Flakvierling_38
\nhttp:\/\/www.u-boot-archiv.de\/dieboote\/u0005.html<\/p>\n

⚞⚟ Note:<\/strong> This old 02 Feb. 2017 guest post no longer fits 2026 standards, and was rewritten and massively expanded.<\/div>\n","protected":false},"excerpt":{"rendered":"

Type II U-Boats (1935) Germany (1935), 50 Submarines Types IIa, IIb, IIc, IId The Type II U-Boats were the first mass-produced submersibles of the Kriegsmarine. They were derived from the CV 707 design, better known as the Vesikko, Finnish submarine designed by IvS, the famous covert submarine design bureau of the Hague, Netherlands, in operation … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":50624,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15,2],"tags":[],"class_list":["post-1108","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-u-boats","category-ww2-kriegsmarine"],"_links":{"self":[{"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/posts\/1108","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/comments?post=1108"}],"version-history":[{"count":0,"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/posts\/1108\/revisions"}],"wp:attachment":[{"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/media?parent=1108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/categories?post=1108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dbodesign.com\/index.php\/wp-json\/wp\/v2\/tags?post=1108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}