View source for Seehund

{{Short description|Type of midget submarine}}
{{about|the World War II era submarine|the modern minesweeping ROV|Ensdorf-class minesweeper}}
{{More footnotes needed|date=November 2017}}
{|{{Infobox ship begin |display title=ital}}
{{Infobox ship image
|Ship image= Seehund, Wilhelmshaven, 2016 (01).jpg
|Ship image size= 
|Ship caption=A ''Seehund'' midget submarine, on display at the [[:de:Deutsches Marinemuseum|Deutsches Marinemuseum]], [[Wilhelmshaven]], [[Lower Saxony]], Germany
|image alt=
}}
{{Infobox ship class overview
|Name=''Seehund''
|Builders=[[Germaniawerft]], [[Kiel]]
|Operators=*{{navy|Nazi Germany}}
*{{navy|France}}
|Class before=
|Class after=
|Subclasses=
|Cost=
|Built range=1944–1945
|In service range=
|In commission range=1944–1953
|Total ships planned=1,000
|Total ships completed=285
|Total ships cancelled=
|Total ships active=138
|Total ships lost=35
|Total ships preserved=
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=
|Ship type=[[Midget submarine]]
|Ship displacement={{convert|17|LT|t|lk=on|0}} (submerged)
|Ship length={{convert|12|m|ftin|abbr=on}} 
|Ship beam={{convert|1.5|m|ftin|abbr=on}} 
|Ship draught= 
|Ship propulsion=*1 × {{cvt|60|bhp|lk=on}} [[Büssing]] [[diesel engine]]
*{{cvt|25|bhp}} [[AEG (German company)|AEG]] [[electric motor]]
|Ship speed=*{{convert|7|kn|lk=in}} (surfaced)
*{{convert|6|kn}} (submerged)
|Ship range=*{{cvt|270|nmi|lk=in}} at {{convert|7|kn}} (surfaced)
*{{convert|63|nmi|abbr=on}} at {{convert|4|kn}} (submerged)
|Ship test depth=
|Ship complement=2
|Ship armament=2 × G7e(TIIIc) torpedoes
|Ship notes=
}}
|}

'''''Seehund''''' (German: "seal"), also known as '''Type XXVII''', was a [[midget submarine]] built by [[Nazi Germany]] during [[World War II]]. Designed in 1944 and operated by two-man crews, it was used by the ''[[Kriegsmarine]]'' (German Navy) during the closing months of the war, sinking nine merchant vessels and damaging an additional three, while losing 35 boats, mostly attributed to bad weather. The [[French Navy]] used four captured boats after the war until 1953.

==History==
The origin of the ''Seehund'' began with the salvage of the two British [[X class submarine]]s {{HMS|X6}} and {{HMS|X7||2}} which had been lost by the [[Royal Navy]] during [[Operation Source]], an attempt to sink the [[German battleship Tirpitz|German battleship ''Tirpitz'']]. ''Hauptamt Kriegschiffbau'' subsequently produced a design for a two-man submarine based on inspection of the British boats, designated Type XXVIIA and named ''Hecht'' ("[[Pike (fish)|Pike]]").

===XXVIIA (Hecht)===
{{main|Hecht (submarine)}}
Like the British X class boats, the Type XXVIIA was designed to carry explosive charges to be laid beneath enemy ships, but it was markedly smaller and had substantial differences from the X class. It dispensed with a dual diesel/electric propulsion system, relying instead solely on electrical power in the form of a {{convert|12|bhp|adj=on|sp=us|lk=on}} [[AEG (German company)|AEG]] [[torpedo]] motor, on the basis that since it would operate submerged there was no need for a [[diesel engine]]. However, this resulted in a very low endurance of {{convert|69|nmi|lk=in}} at {{convert|4|kn|lk=in}}.

Since the boat would need to be able to pass through [[anti-submarine net]]s and similar obstacles, it was designed without [[Diving plane|hydroplane]]s or fins, her trim being controlled with adjustable weights within the pressure hull. In practice this proved totally ineffective since the weights could not be moved quickly enough, and hydroplanes and fins were subsequently fitted. Submerged control was still poor, since ''Hecht'' was not fitted with [[ballast tank]]s.
[[File:Interior of a salvaged Seehund submarine, Bundeswehr Military History Museum, Dresden.jpg|thumb|upright=0.7|Interior of a salvaged Seehund submarine, Bundeswehr Military History Museum, Dresden]]
[[File:Salvaged Seehund submarine, Bundeswehr Military History Museum, Dresden.jpg|thumb|upright=0.7|Salvaged Seehund submarine, Bundeswehr Military History Museum, Dresden]]
Even though ''Hecht'' had been designed to transport an explosive charge, [[Karl Dönitz]] insisted that a torpedo be carried so that attacks could be carried out on vessels in coastal waters.

Externally, ''Hecht'' resembled the British [[Welman submarine]]. The detachable explosive charge was fitted to the nose of the submarine, while the forward section held the battery and a [[gyrocompass]], the first to be fitted to a German midget submarine and considered essential for navigation if the craft was to operate submerged. Behind this was the control compartment with seats for the two-man crew arranged one behind the other on the centerline with the engineer in front and the commander behind him. The commander was provided with a periscope and a clear acrylic dome for navigational purposes.

On 18 January 1944, Dönitz discussed the new design with Adolf Hitler who expressed his approval, and on 9 March contracts were placed with [[Germaniawerft]] of [[Kiel]] for construction of a prototype, followed by a further contract for 52 submarines on 28 March.

The 53 ''Hechts'' were constructed between May and August 1944: in the event, none saw active service but were instead used to train ''Seehund'' crews.

===Type XXVIIB===
As the orders were being placed, ''Hecht'' variants were under construction. The first was the Type XXVIIB, which had a greater range, could carry two [[G7e torpedo|G7e(TIIIc) torpedo]]es, and had diesel/electric propulsion. The design was completed at the end of June 1944 and resembled ''Hecht'' but had a better boat-shaped external casing for improved seakeeping while surfaced, and saddle tanks. Additional room had been made inside the pressure hull by moving the batteries to the keel, while the two torpedoes were mounted externally in recesses in the lower hull. A {{convert|22|bhp|adj=on|sp=us}} diesel engine was fitted for surface use and was estimated to give a surfaced speed of {{convert|5.5|kn}}, with a {{convert|25|bhp|adj=on|sp=us}} [[electric motor]] providing a submerged speed of {{convert|6.9|kn}}.

The final variant of the Type XXVII was the Type XXVIIB5, better known as the ''Seehund'' ("Seal") or Type 27. ''Seehund'' had a small [[sail (submarine)|sail]] midships with the air-intake mast, magnetic compass, periscope, and a clear dome which could survive depths of {{convert|45|m|sp=us}}. The submarine's fixed {{convert|3|m|adj=on|sp=us}} periscope incorporated lenses which let the commander check the sky above for aircraft before surfacing.<ref>Kemp, p.</ref>

==Production==
[[File:Seehund 075 next to USS Salem 28 June 2008.jpg|thumb|Seehund 075 at the [[United States Naval Shipbuilding Museum]]]]

The first contract for ''Seehund'' construction was placed on 30 July 1944, before the design was completed. A total of 1,000 boats were ordered, of which [[Germaniawerft]] and [[Schichau-Werke]] were to build 25 and 45 boats per month respectively. Other shipyards that were intended to participate in ''Seehund'' production were [[Cantieri Riuniti dell'Adriatico]] at [[Monfalcone]], Italy, and [[Klöckner-Humboldt-Deutz]] at [[Ulm]]. However, Dönitz would not consent to the production of the [[Type XXIII U-boat|Type XXIII]] submarine being held up for ''Seehund'' construction, while shortages of raw material, labor and transport problems, and conflicting priorities in Germany's economy all combined to reduce ''Seehund'' production. In the end ''Seehund'' production was undertaken by Germaniawerft at Kiel in the ''Konrad'' bunker which was no longer needed for production of [[Type XXI U-boat|Type XXI]] or Type XXIII submarines. A total of 285 ''Seehunds'' were constructed and allocated numbers in the range ''U-5001'' to ''U-6442''.<ref>Kemp, pp. 100–101</ref>

==Operational service==
[[File:Seehund Kriegsmarine.jpg|thumb|right|Captured ''Seehund'' submarines, 1945]]
The first ''Seehund'' operation took place on 31 December 1944, when 18 craft set out from
[[IJmuiden]] in the Netherlands. However, this was a disaster – the submarines encountered a storm and only two returned. The first sinking by a ''Seehund'' did not occur until February 1945, when a freighter was sunk off [[Great Yarmouth]].<ref name="Stille2014">Stille, p. 27</ref>

''Seehunds'' operated mainly around the German coast and in the [[English Channel]], and could attack on the surface in turbulent weather, but had to be almost stationary for submerged attacks. From January to April 1945 ''Seehunds'' performed 142 sorties, and accounted for about 93,000 gross tons of shipping (British sources estimate 120,000 tons).<ref>Blocksdorf, p. 135</ref> Administratively, the ''Seehund''s were under the command of ''Lehrkommandos'', which were part of the German Navy's [[Organization of the Kriegsmarine#Special operations|special operations branch]]. Within each ''Lehrkommando'' were subordinate ''K-Flotilla''; K-Flottille 311 was specifically designated to oversee deployment of the [[Hecht (submarine)|Hecht]] miniature submarine while the ''Seehund'' submarines were dispersed between K-Flottille 312, 313, and 314.<ref>Blocksdorf, p. 21</ref>

From the Allied point of view, the ''Seehund''{{'}}s small size made it almost impossible for [[Asdic]] to get a return from her hull, while her very quiet slow-speed running made her almost immune to detection by [[hydrophone]]. As Admiral Sir [[Charles Little (Royal Navy officer)|Charles Little]], [[Commander-in-Chief, Portsmouth]], put it, "Fortunately for us these damn things arrived too late in the war to do any damage".{{citation needed|date=May 2016}}

The last ''Seehund'' sorties took place on 28 April and 2 May 1945, when two special missions were performed to resupply the [[Siege of Dunkirk (1944–45)|besieged German garrison at Dunkirk]] with rations. The boats carried special food containers (nicknamed "butter torpedoes") instead of torpedoes, and on the return voyage used the containers to carry mail from the Dunkirk garrison.<ref>Rohwer & Hummelchen, p. 344</ref>

The [[French navy]] received four units as war reparations, and commissioned them as ''S 621'', ''S 622'', ''S 623'' and ''S624''. They were used until August 1953.

==Survivors==
[[File:Submarine S622.jpg|thumb|''U-S622'', at the ''Musée national de la Marine'', Brest, France (2004)]]
[[File:Wehrtechnische Sammlung der Bundeswehr (38740790675).jpg|thumb|Cutaway of ''Seehund'', at the ''Bundeswehr Museum of German Defense Technology'', Koblenz, Germany]]
One of the boats used by the French navy post-war, ''U-5622'', is preserved and on display at the [[Musée national de la Marine]] in [[Brest, France]].

''U-5075'' is on display at the [[United States Naval Shipbuilding Museum]], part of the Massachusetts Military Research Center, in [[Quincy, Massachusetts]].<ref>[http://www.hnsa.org/ships/seehund.htm German Seehund (KU-5075)] {{webarchive|url=https://web.archive.org/web/20060806055510/http://www.hnsa.org/ships/seehund.htm |date=2006-08-06 }}</ref>  Occasional [[amateur radio]] events are conducted by this museum ship, using the [[callsign]] WW2MAN.

In Germany, ''Seehunds'' are displayed at several museums, the [[Technik Museum Speyer]], the [[Deutsches Museum]], Munich, the Marinemuseum Wilhelmshaven and the [[German Maritime Museum]] (''Deutsches Schiffahrtsmuseum''), Bremerhaven, and Curioseum Willingen (which has been test operated by the owners in a local lake). A cutaway of a ''Seehund'' is in the exhibition of the [[Bundeswehr Museum of German Defense Technology]] located in [[Koblenz]].

In April 2002 the wreck of ''U-5095'' was recovered by the [[Royal Dutch Navy]] and a civilian salvage team lying buried beneath a beach at [[Egmond aan Zee]] in the [[Netherlands]], after having been run aground there by its crew in February 1945, and the remains are now on display at the IJmuiden bunker museum.<ref>'Seehund U50595 Found', published on 'Uboat.net', 3 April 2002. https://uboat.net/forums/read.php?3,15663</ref> Its two onboard torpedoes were found to be still active and their [[warhead]]s were separated from their delivery systems and [[controlled explosion|control-detonated]] at sea.<ref>'The Seehund Recovery', published on YouTube 19 March 2014. https://www.youtube.com/watch?v=OZLf-nW338s</ref>

== References ==
=== Notes ===
{{Reflist|30em}}

=== Bibliography ===
*{{cite book|last= Blocksdorf |first=Helmut|title= Hitler's Secret Commandos: Operations of the K-Verband | publisher = Pen & Sword Books| year = 2008 | location = Great Britain|isbn = 978-1-84115-783-2}}
*{{cite book |last1=Kemp |first1=Paul |title=Midget Submarines of the Second World War |date=1999 |publisher=Caxton Editions |location=London |isbn=1-84067-521-7}}
*{{cite book |last1=Paterson |first1=Lawrence |title=Weapons of Desperation: German Frogmen and Midget Submarines of the Second World War|date=2018|location=Yorkshire, UK |isbn=978-1-52671-347-6}}
*{{cite book|last1=Prenatt |first1=Jamie|last2=Stille|first2=Mark |title=Axis Midget Submarines: 1939–45 |publisher=Osprey Publishing |location=Oxford, UK |year=2014 |isbn=978-1-4728-0122-7|name-list-style=amp}}
*{{cite book | author1-last= Rohwer| author1-first= Jürgen |author2-first=Gerhard |author2-last=Hummelchen | title= Chronology of the War at Sea 1939–1945 | publisher= Naval Institute Press | year= 1992| isbn= 1-55750-105-X|author-link=Jürgen Rohwer|name-list-style=amp}}
*{{cite book|last= Rossler| first= Eberhard| title= The U-Boat: The Evolution and Technical History of German Submarines | publisher= Cassell |year= 2001 | location=London |isbn=0-304-36120-8}}

== Further reading ==
* {{cite book |title=The Last Year of the Kriegsmarine |last=Tarrant |first=V. E. |year=1994 |publisher=Arms and Armour Press |isbn=1-85409-176-X }}

==External links==
{{Sister project links|auto=y}}
*{{cite web | title= Uboat.net| work= Information on the Seehund class and its operations| url=http://www.uboat.net/types/seehund.htm| access-date=July 16, 2006}}
*{{cite web| title= Historic Naval Ships Association: Seehund in Quincy, MA| work= Information on the Seehund class| url= http://www.hnsa.org/ships/seehund.htm| access-date= July 16, 2006| url-status= dead| archive-url= https://web.archive.org/web/20060806055510/http://www.hnsa.org/ships/seehund.htm| archive-date= August 6, 2006}}
* [https://web.archive.org/web/20071014044149/http://hnsa.org/ships/seehundnj.htm HNSA Ship Page: ''Seehund'' in Hackensack, NJ]
*[http://www.uboataces.com/midget-seehund.shtml Extended Seehund information]
{{uboat}}
{{Kriegsmarine midget submarines}}

[[Category:Midget submarines]]
[[Category:Type XXVII submarines| ]]
[[Category:World War II submarines of Germany]]