German Type XXIII submarine
Encyclopedia

German Type XXIII submarines were the first so-called elektroboats
Elektroboot
An elektroboot was the first submarine designed to operate entirely submerged, rather than as submersibles that could submerge as a temporary means to escape detection or launch an attack.- History :...

 to become operational. They were small coastal submarines designed to operate in the shallow waters of the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

, Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

 and Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

, where larger Type XXI Elektro boats were at risk in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. They were so small they could carry only two torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

es, which had to be loaded externally. As with their far larger brothers — the Type XXI — they were able to remain submerged almost all of the time and were faster than all previous designs worldwide, due to the improved streamlining of their shape, batteries with larger capacity and the snorkel
Submarine snorkel
A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. Navy personnel often refer to it as the snort.-History:...

, which allowed the diesel engines to be used while submerged. The Type XXI and XXIII U-boats revolutionized post-war submarine design.

Background

When development began on the Type XXI U-boat in late 1942, it was proposed to simultaneously develop a smaller version incorporating the same advanced technology to replace the Type II
German Type II submarine
The Type II U-boat was designed by Germany as a coastal U-boat, modeled after the CV-707 submarine, which was designed by the Dutch dummy company NV Ingenieurskantoor voor Scheepsbouw den Haag and built in 1933 by the...

 coastal submarine. Admiral Karl Dönitz
Karl Dönitz
Karl Dönitz was a German naval commander during World War II. He started his career in the German Navy during World War I. In 1918, while he was in command of , the submarine was sunk by British forces and Dönitz was taken prisoner...

 added two requirements: as the boat would have to operate in the Mediterranean and the Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

, it had to be able to be transported by rail, and it had to use the standard 53.3-cm torpedo tubes.

The development of the Type XXIII was given a high priority, with an emphasis on using existing components as much as possible. To reduce development time, Hellmuth Walter
Hellmuth Walter
Hellmuth Walter was a German engineer who pioneered research into rocket engines and gas turbines...

 designed the new submarine based on the previous Type XXII
Uncompleted U-boat projects
During World War II the German Navy considered a number of submarine designs for specialized operations or improving U-boat performance. However, many of these designs did not come to fruition for various reasons. Some were abandoned due to practical considerations...

 prototype. By 30 June 1943 the design was ready and construction began in parallel at several shipyards in Germany, France, Italy and German-occupied Russia. The lead contractor was Deutsche Werft
Deutsche Werft
Deutsche Werft was a German shipbuilding company, located in Hamburg, Germany. It was founded in 1918 on initiative by Albert Ballin and with Gutehoffnungshütte , Allgemeine Elektricitäts-Gesellschaft and Hamburg Amerikanische Packetfahrt Actien Gesellschaft as investors.During World War II...

 in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

.

As with the Type XXI, the Type XXIII was intended to be constructed in sections, various modules being produced by different subcontractors. Some were to be assembled at foreign yards, including U-2446 through U-2460 at the Deutsche Werft yard at Mykolaiv
Mykolaiv
Mykolaiv , also known as Nikolayev , is a city in southern Ukraine, administrative center of the Mykolaiv Oblast. Mykolaiv is the main ship building center of the Black Sea, and, arguably, the whole Eastern Europe.-Name of city:...

. These were reassigned to the Linzner yard on 1 May 1944 and subsequently cancelled. In the end, circumstances meant that construction was concentrated at Germaniawerft in Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...

 and Deutsche Werft
Deutsche Werft
Deutsche Werft was a German shipbuilding company, located in Hamburg, Germany. It was founded in 1918 on initiative by Albert Ballin and with Gutehoffnungshütte , Allgemeine Elektricitäts-Gesellschaft and Hamburg Amerikanische Packetfahrt Actien Gesellschaft as investors.During World War II...

 in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

, Germaniawerft building 51 and Deutsche Werft 49. Of the 280 submarines ordered, only 61 entered service, and only 6 ever carried out a war patrol.

Description

The Type XXIII had an all-welded single hull design, the first submarine to use a single hull. It had a fully streamlined outer casing and apart from the relatively small conning tower and a fairing which housed the Diesel exhaust silencer, it had an uncluttered upper deck. In line with Walter's design practice, there were no forward hydroplane
Planing (sailing)
Planing is the mode of operation for a waterborne craft in which its weight is predominantly supported by hydrodynamic lift, rather than hydrostatic lift .-History:...

s, although these were added later.

The submarine was propelled by a single three-bladed propeller and steered by a single rudder. As with the Type XXI, the lower section of the figure-of-eight hull was used to house a large 62-cell battery.

In order to allow the boat to be transported by rail, the hull sections had to be limited in size to fit the standard loading gauge
Loading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...

. For transportation, the hull was broken into four sections and the bridge was removed. Due to the space restrictions, the forward bow section had to be made as short as possible, which meant that only two torpedo tubes could be fitted and no reload torpedoes could be carried. The torpedoes were loaded by ballasting the submarine down at the stern so that the bow lifted clear of the water and the torpedoes could be loaded directly into their tubes from a barge.

The Type XXIII proved to have excellent handling characteristics, and was highly maneuverable both on the surface and underwater. Its crash dive
Crash dive
A crash dive is a maneuver performed by a submarine to submerge as quickly as possible to avoid attack. Crash diving from the surface to avoid attack has been largely rendered obsolete with the advent of nuclear-powered submarines as they operate constantly submerged and are unlikely to be found on...

 time was 9 seconds, and its maximum diving depth was 180 m (590.6 ft). Speed submerged was 12.5 kn (6.8 m/s), while surfaced speed was 9 kn (4.9 m/s). A submerged speed of 10.5 kn (5.7 m/s) could be attained while snorkeling.

Construction

The first Type XXIII, U-2321, was launched from Deutsche Werft
Deutsche Werft
Deutsche Werft was a German shipbuilding company, located in Hamburg, Germany. It was founded in 1918 on initiative by Albert Ballin and with Gutehoffnungshütte , Allgemeine Elektricitäts-Gesellschaft and Hamburg Amerikanische Packetfahrt Actien Gesellschaft as investors.During World War II...

 in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

 on April 17, 1944. It was one of six XXIIIs that went on operational patrol around the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

 in early 1945. Forty-eight others followed from Deutsche Werft
Deutsche Werft
Deutsche Werft was a German shipbuilding company, located in Hamburg, Germany. It was founded in 1918 on initiative by Albert Ballin and with Gutehoffnungshütte , Allgemeine Elektricitäts-Gesellschaft and Hamburg Amerikanische Packetfahrt Actien Gesellschaft as investors.During World War II...

 and 13 from Germaniawerft of Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...

. U-4712 was the last one launched, on April 19, 1945.

Service history

None of the six operational Type XXIIIs — U-2321, U-2322, U-2324, U-2326, U-2329 and U-2336
German submarine U-2336
German submarine U-2336 was a Type XXIII U-boat of the German Kriegsmarine during World War II.U-2336 had a very short career. She only conducted one war patrol and sank only three vessels, one of which was another German U-boat...

 — were sunk by the Allies ships but they sank or damaged five ships for a total of 14,601 tons.

The first war patrol of a Type XXIII began late in the war when U-2324 sailed from Kiel on 18 January 1945. Although she was to survive the war, she sank no enemy vessels. The first Type XXIII to achieve combat success was U-2322, commanded by Oberleutnant zur See Fridtjof Heckel. Sailing from a Norwegian base on 6 February 1945, she encountered a convoy off Berwick
Berwick-upon-Tweed
Berwick-upon-Tweed or simply Berwick is a town in the county of Northumberland and is the northernmost town in England, on the east coast at the mouth of the River Tweed. It is situated 2.5 miles south of the Scottish border....

, Northumberland
Northumberland
Northumberland is the northernmost ceremonial county and a unitary district in North East England. For Eurostat purposes Northumberland is a NUTS 3 region and is one of three boroughs or unitary districts that comprise the "Northumberland and Tyne and Wear" NUTS 2 region...

, and sank the coaster Egholm on 25 February. U-2321, operating from the same base, sank the coaster Gasray on 5 April 1945 off St Abbs Head. U-2336
German submarine U-2336
German submarine U-2336 was a Type XXIII U-boat of the German Kriegsmarine during World War II.U-2336 had a very short career. She only conducted one war patrol and sank only three vessels, one of which was another German U-boat...

, under the command of Kapitänleutnant Emil Klusmeier, later sank the last Allied ships lost in the European war on 7 May 1945, when he torpedoed and sank the freighters Sneland and SS Avondale Park
SS Avondale Park
Avondale Park was a 2,872 GRT Park cargo ship which was built in 1944. She was the last merchant ship to be sunk by Germany in the Second World War, on 7 May 1945, the day of German surrender.-Description:...

 off the Isle of May
Isle of May
The Isle of May is located in the north of the outer Firth of Forth, approximately off the coast of mainland Scotland. It is 1.8 km long and less than half a kilometre wide...

 inside the Firth of Forth
Firth of Forth
The Firth of Forth is the estuary or firth of Scotland's River Forth, where it flows into the North Sea, between Fife to the north, and West Lothian, the City of Edinburgh and East Lothian to the south...

.

The Sneland and the Avondale Park were sunk around 23:03, less than an hour before the official German surrender, and the Avondale Park was the last merchant ship to be sunk by a U-boat. At the time it was felt that Kapitänleutnant Klusmeier, who was on his first patrol, had deliberately ignored Donitz’s ceasefire order, however Klusmeier claimed that he had never received the order.

Losses

Eight Type XXIIIs were lost to various causes.
  • U-2323 was sunk by a naval mine
    Naval mine
    A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

     on July 26, 1944.
  • U-2331 was lost in a training accident on October 10, 1944.
  • U-2338 was sunk by British Beaufighter aircraft which killed 12 crewmen and sank the boat east-northeast of Fredericia
    Fredericia
    Fredericia is a town located in Fredericia municipality in the eastern part of the Jutland peninsula in Denmark, in a sub-region known locally as Trekanten, or The Triangle...

     on May 4, 1945, before she ever went on combat patrol.
  • U-2342 was mined
    Naval mine
    A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

     and sunk on December 26, 1944.
  • U-2344
    German submarine U-2344
    German submarine U-2344 was a Type XXIII U-boat of the German Kriegsmarine during World War II.-Construction:U-2344 was ordered on 20 September 1943, and was laid down on 4 September 1944 at Deutsche Werft, Hamburg, as 'werk 498'...

     was accidentally rammed and sunk by U-2336
    German submarine U-2336
    German submarine U-2336 was a Type XXIII U-boat of the German Kriegsmarine during World War II.U-2336 had a very short career. She only conducted one war patrol and sank only three vessels, one of which was another German U-boat...

     on February 18, 1945.
  • U-2351 was paid off in April 1945 after bomb damage.
  • U-2359 was sunk by Allied aircraft on May 2, 1945.
  • U-2367 was accidentally rammed and sunk by an unidentified U-boat on May 5, 1945.


In early May 1945, 31 XXIIIs were scuttled by their crews. Twenty surrendered to the Allies and were sunk in Operation Deadlight
Operation Deadlight
Operation Deadlight was the code name for the scuttling of U-boats surrendered to the Allies after the defeat of Germany near the end of World War II....

. Only three — U-2326 (later British submarine N35), U-2353 (later British submarine N37), and U-4706 (later Norwegian submarine Knerten) — survived the war.

Postwar

One Type XXIII was allocated to the Soviet Union under the terms of the Potsdam Agreement
Potsdam Agreement
The Potsdam Agreement was the Allied plan of tripartite military occupation and reconstruction of Germany—referring to the German Reich with its pre-war 1937 borders including the former eastern territories—and the entire European Theatre of War territory...

, and a second unit was reportedly salvaged in 1948.

In 1956, the German Federal Navy raised two Type XXIII boats, U-2365 (scuttled in the Kattegat
Kattegat
The Kattegat , or Kattegatt is a sea area bounded by the Jutland peninsula and the Straits islands of Denmark on the west and south, and the provinces of Västergötland, Scania, Halland and Bohuslän in Sweden on the east. The Baltic Sea drains into the Kattegat through the Øresund and the Danish...

 in 1945) and U-2367 (which sank near Schleimünde following a collision with another U-boat), and recommissioned them as U-Hai (Shark) and U-Hecht (Pike), with pennant numbers S 170 and S 171 respectively. U-Hai sank in a gale off the Dogger Bank
Dogger Bank
Dogger Bank is a large sandbank in a shallow area of the North Sea about off the east coast of England. It extends over approximately , with its dimensions being about long and up to broad. The water depth ranges from 15 to 36 metres , about shallower than the surrounding sea. It is a...

 in September 1966, taking 19 of her 20 crewmen with her. Her loss is the greatest maritime disaster that both the Bundesmarine and the Deutsche Marine have suffered during the more than 50 years of their existence. The experience gained from the two recommissioned submarines led to the construction of the Type 206 submarine
Type 206 submarine
The Type 206 is a class of diesel-electric submarines developed by Howaldtswerke-Deutsche Werft . Its design is based on the preceding Type 205 submarine class. These small and agile submarines were built during the Cold War to operate in the shallow Baltic Sea and attack Warsaw Pact shipping if...

, still in use today.

Boats in class

  • U-2321
  • U-2322
  • U-2323
  • U-2324
  • U-2325
  • U-2326
  • U-2327
  • U-2328
  • U-2329
  • U-2330
  • U-2331
  • U-2332
  • U-2333
  • U-2334
  • U-2335
  • U-2336
    German submarine U-2336
    German submarine U-2336 was a Type XXIII U-boat of the German Kriegsmarine during World War II.U-2336 had a very short career. She only conducted one war patrol and sank only three vessels, one of which was another German U-boat...


  • U-2337
  • U-2338
  • U-2339
  • U-2340
  • U-2341
  • U-2342
  • U-2343
  • U-2344
    German submarine U-2344
    German submarine U-2344 was a Type XXIII U-boat of the German Kriegsmarine during World War II.-Construction:U-2344 was ordered on 20 September 1943, and was laid down on 4 September 1944 at Deutsche Werft, Hamburg, as 'werk 498'...

  • U-2345
  • U-2346
  • U-2347
  • U-2348
  • U-2349
  • U-2350
  • U-2351
  • U-2352

  • U-2353
  • U-2354
  • U-2355
  • U-2356
  • U-2357
  • U-2358
  • U-2359
  • U-2360
  • U-2361
  • U-2362
  • U-2363
  • U-2364
  • U-2365
  • U-2366
  • U-2367
  • U-2368

  • U-2369
  • U-2371
  • U-4701
  • U-4702
  • U-4703
  • U-4704
  • U-4705
  • U-4706
  • U-4707
  • U-4709
  • U-4710
  • U-4711
  • U-4712


See also

  • British R class submarine
    British R class submarine
    The R-class submarines were a class of 12 small British diesel-electric submarines built for the Royal Navy during World War I, and were forerunners of the modern hunter-killer submarines, in that they were designed specifically to attack and sink enemy submarines, their battery capacity and hull...


Video from the only located type XXIII - U2359
http://www.u2359.com/?p=733

External links

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