Type XXIII submarine
from Wikipedia
German Type XXIII submarines were the first so-called
elektroboats to become operational. They were small coastal submarines
designed to operate in the shallow waters of the North Sea, Black Sea and
Mediterranean Sea, where larger Type XXI Elektro boats were at risk in
World War II. They were so small they could carry only two torpedoes, 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, 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 coastal
submarine. Admiral Karl Dönitz added two requirements: as the boat
would have to operate in the Mediterranean and the Black Sea, 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 designed the new
submarine based on the previous Type XXII 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 in Hamburg. |
Postwar photo of German submarine
U-Hecht S171, former Type XXIII submarine U-2367
Builder: |
Deutsche Werft 48 boats
Germaniawrft
13 boats |
Completed: |
61 |
Launched: |
1944 |
Speed: |
9.7 knots surfaced
12.5 knots submerged |
Displacement:
surfaced
submerged |
230 long tons
254 long tons |
Length: |
113 ft 10 in |
Beam: |
9 ft 10 in |
Complement: |
14 to 18 |
|
|
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. 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 and Deutsche Werft in Hamburg, 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 hydroplanes,
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. 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 time was 9 seconds, and its maximum diving depth was 180
m (590 ft). Speed submerged was 12.5 kn (23.2 km/h; 14.4 mph), while surfaced
speed was 9 kn (17 km/h; 10 mph). A submerged speed of 10.5 kn (19.4 km/h;
12.1 mph) could be attained while snorkeling.
Construction
The first Type XXIII, U-2321, was launched from
Deutsche Werft in Hamburg on April 17, 1944. It was one of six XXIIIs that
went on operational patrol around the British Isles in early 1945. Forty-eight
others followed from Deutsche Werft and 13 from Germaniawerft of Kiel.
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 -- 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, Northumberland, 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, 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 off the Isle of May inside the Firth of Forth.
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 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 on May 4, 1945, before she ever went on combat patrol.
U-2342 was mined and sunk
on December 26, 1944.
U-2344 was accidentally rammed
and sunk by U-2336 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. 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, 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 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 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, which was in use until 2011.
Boats in class
Main article: List of German Type XXIII submarines
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 |
U-2337
U-2338
U-2339
U-2340
U-2341
U-2342
U-2343
U-2344
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 |
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