SM U-46

{{Short description|German and Japanese submarine}} {{Other ships|German submarine U-46}} {{Use dmy dates|date=May 2026}} {{Infobox ship |section1={{Infobox ship/image | image = | image_caption = }}

|section2={{Infobox ship/career | hide_header = | country = [[German Empire]] | flag = {{Shipboxflag|German Empire|naval}} | name = ''U-46'' | ordered = 4 August 1914 | awarded = | builder = Kaiserliche Werft, Danzig | yard_number = 24 | laid_down = | launched = 18 May 1915 | christened = | acquired = | commissioned = 17 December 1915 | recommissioned = | decommissioned = | in_service = | out_of_service = | renamed = | reclassified = | refit = | captured = | struck = | reinstated = | fate = Surrendered to [[Japan]] 26 November 1918 | homeport = }}

|section3={{Infobox ship/career | hide_header = title | country = [[Japanese Empire]] | flag = {{Shipboxflag|Empire of Japan|naval}} | name = ''O-2'' | acquired = 26 November 1918 | commissioned = 1920 | recommissioned = | decommissioned = 1921 | in_service = | out_of_service = | renamed = | reclassified = | refit = | captured = | struck = | reinstated = | fate = *Possibly scrapped 1922; *Possibly foundered on 21 April 1925 or *Scuttled on or after 5 August 1927 | homeport = }}

|section4={{Infobox ship/characteristics | hide_header = | header_caption = {{sfn|Gröner|1991|pp=8–10}} | class = [[Type U 43 submarine|Type ''U-43'']] [[submarine]] | displacement = *{{convert|725|t|LT|abbr=on|lk=on}} surfaced *{{convert|940|t|LT|abbr=on}} submerged | length = {{convert|65.00|m|ftin|abbr=on}} ([[o/a]]) | beam = *{{convert|6.20|m|ftin|abbr=on}} (oa) *{{convert|4.18|m|ftin|abbr=on}} (pressure hull) | height = {{convert|9.00|m|ftin|abbr=on}} | draught = {{convert|3.74|m|ftin|abbr=on}} | power = *2 × {{convert|2000|PS|kW shp|abbr=on|lk=on|0}} surfaced *2 × {{convert|1200|PS|kW shp|abbr=on|0}} submerged | propulsion = 2 shafts | speed = *{{convert|15.2|kn|lk=in}} surfaced *{{convert|9.7|kn}} submerged | range = *{{convert|11400|nmi|abbr=on|lk=in}} at {{convert|8|kn}} surfaced *{{convert|51|nmi|abbr=on}} at {{convert|5|kn}} submerged | test_depth = {{convert|50|m|ftin|abbr=on}} | complement = 36 | armament = *6 × [[torpedo tube]]s (four bow, two stern) {{sfn|Rössler|1981|pp=328–329}} * 8 [[torpedo]]es *1 × [[8.8 cm SK L/30 naval gun|{{convert|8.8|cm|in|sp=us|abbr=on}} SK L/30]] [[deck gun]] | notes = }}

|section5={{Infobox ship/service record |header_caption=Service record<ref name="uboatnet">{{cite Uboat.net |id=46.htm |name=U 46 |type=1sub |accessdate=2 December 2014 }}</ref> |partof=*III Flotilla *29 March 1916 – 11 November 1918 |commanders =*''Kptlt.'' Leo Hillebrand *17 December 1915 - 6 December 1917 *''Kptlt.'' [[Alfred Saalwächter]] *7 December 1916 – 15 January 1917 *''Kptlt.'' Leo Hillebrand *16 January – 11 November 1918 |operations=11 patrols |victories =*51 merchant ships sunk <br />({{GRT|138,942}}) *1 auxiliary warship sunk <br />({{GRT|1,372}}) *1 merchant ship damaged <br />({{GRT|7,378}}) }} }}

'''SM ''U-46''''' was one of the 329 [[submarine]]s serving in the [[Imperial German Navy]] in [[World War I]]. ''U-46'' was engaged in the [[Naval warfare of World War I|combat]] during World War I and took part in the [[First Battle of the Atlantic]]. After the war, she served in the [[Imperial Japanese Navy]] as '''''O-2'''''.

==Imperial German Navy== Ordered on 4 August 1914, ''U-46'' was constructed at the [[Kaiserliche Werft Danzig|Kaiserliche Werft]] in [[Danzig]], [[German Empire|Germany]]. [[Ship naming and launching|Launched]] on 18 May 1915, she was [[Ship commissioning|commissioned]] on 17 December 1915.<ref name=O2>{{cite web |url=http://uboat.net/wwi/boats/index.html?boat=46 |title=U 46|publisher=Uboat.net |accessdate=20 August 2016}}</ref>

Assigned to the III Flotilla, ''U-46'' began her first war patrol on 29 March 1916. Remaining in the III Flotilla for the rest of the war, she conducted a total of 11 war patrols before the war ended on 11 November 1918 and was credited with sinking 51 [[merchant ship]]s totaling 138,942 [[gross register ton]]s and one auxiliary warship of 1,372 gross register tons and damaging one merchant ship of 7,378 gross register tons.<ref name=O2/>

After the end of the war, she surrendered to [[Japan]] on 26 November 1918.<ref name=O2/>

===Summary of raiding history=== {| class="wikitable sortable" |- ! width="140px"|Date ! width="160px"|Name ! width="160px"|Nationality ! width="25px" |Tonnage<ref group=Note name=tonnage>Merchant ship tonnages are in [[gross register tons]]. Military vessels are listed by tons [[displacement (ship)|displacement]].</ref> ! width="120px" |Fate<ref>{{cite Uboat.net |id=u46 |name=U 46 |type=1boat |accessdate=2 December 2014 }}</ref> |- |align="right"|29 September 1916 |align="left" |[[List of shipwrecks in September 1916#29 September|''Ravn'']] |align="left" |{{flag|Norway}} |align="right"|1,260 |align="left" |Sunk |- |align="right"|29 September 1916 |align="left" |[[List of shipwrecks in September 1916#29 September|''Sinsen'']] |align="left" |{{flag|Norway}} |align="right"|1,925 |align="left" |Sunk |- |align="right"|30 September 1916 |align="left" |[[List of shipwrecks in September 1916#30 September|''Hafnia'']] |align="left" |{{flag|Norway}} |align="right"|962 |align="left" |Sunk |- |align="right"|30 September 1916 |align="left" |[[List of shipwrecks in September 1916#30 September|''Hekla'']] |align="left" |{{flag|Norway}} |align="right"|950 |align="left" |Sunk |- |align="right"|4 October 1916 |align="left" |[[List of shipwrecks in October 1916#4 October|''Brantingham'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,617 |align="left" |Sunk |- |align="right"|6 October 1916 |align="left" |[[List of shipwrecks in October 1916#6 October|''Erika'']] |align="left" |{{flag|Russian Empire}} |align="right"|2,430 |align="left" |Sunk |- |align="right"|9 October 1916 |align="left" |[[List of shipwrecks in October 1916#9 October|''Astoria'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|4,262 |align="left" |Sunk |- |align="right"|11 October 1916 |align="left" |[[List of shipwrecks in October 1916#11 October|''Iolo'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,903 |align="left" |Sunk |- |align="right"|16 December 1916 |align="left" |[[List of shipwrecks in December 1916#16 December|''Chassie Maersk'']] |align="left" |{{flag|Denmark}} |align="right"|1,387 |align="left" |Sunk |- |align="right"|16 December 1916 |align="left" |[[List of shipwrecks in December 1916#16 December|''Taki Maru'']] |align="left" |{{flag|Japan}} |align="right"|3,208 |align="left" |Sunk |- |align="right"|16 December 1916 |align="left" |[[List of shipwrecks in December 1916#16 December|''Gerda'']] |align="left" |{{flag|Denmark}} |align="right"|775 |align="left" |Sunk |- |align="right"|17 December 1916 |align="left" |[[List of shipwrecks in December 1916#17 December|''Bayhall'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,898 |align="left" |Sunk |- |align="right"|19 December 1916 |align="left" |[[List of shipwrecks in December 1916#19 December|''Falk'']] |align="left" |{{flag|Norway}} |align="right"|948 |align="left" |Sunk |- |align="right"|23 December 1916 |align="left" |[[List of shipwrecks in December 1916#23 December|''Marques De Urquijo'']] |align="left" |{{flag|Spain}} |align="right"|2,170 |align="left" |Sunk |- |align="right"|25 December 1916 |align="left" |[[List of shipwrecks in December 1916#25 December|''Marie Pierre'']] |align="left" |{{flag|France}} |align="right"|166 |align="left" |Sunk |- |align="right"|27 December 1916 |align="left" |[[List of shipwrecks in December 1916#27 December|''Aislaby'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,692 |align="left" |Sunk |- |align="right"|27 December 1916 |align="left" |[[List of shipwrecks in December 1916#27 December|''Goulfar'']] |align="left" |{{flag|France}} |align="right"|259 |align="left" |Sunk |- |align="right"|21 March 1917 |align="left" |[[List of shipwrecks in March 1917#21 March|''Hindustan'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,692 |align="left" |Sunk |- |align="right"|23 March 1917 |align="left" |[[List of shipwrecks in March 1917#23 March|''Argo'']] |align="left" |{{flag|Portugal}} |align="right"|1,563 |align="left" |Sunk |- |align="right"|24 March 1917 |align="left" |[[List of shipwrecks in March 1917#24 March|''Montreal'']] |align="left" |{{flag|France}} |align="right"|3,342 |align="left" |Sunk |- |align="right"|1 April 1917 |align="left" |{{SS|Aztec||2}} |align="left" |{{flag|United States|1912}} |align="right"|3,727 |align="left" |Sunk |- |align="right"|3 April 1917 |align="left" |[[List of shipwrecks in April 1917#3 April|''Hesperus'']] |align="left" |{{flag|Russian Empire}} |align="right"|2,231 |align="left" |Sunk |- |align="right"|5 April 1917 |align="left" |[[List of shipwrecks in April 1917#5 April|''Benheather'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|4,701 |align="left" |Sunk |- |align="right"|7 April 1917 |align="left" |[[List of shipwrecks in April 1917#7 April|''Fiskaa'']] |align="left" |{{flag|Norway}} |align="right"|1,700 |align="left" |Sunk |- |align="right"|15 May 1917 |align="left" |[[List of shipwrecks in May 1917#15 May|''Grosholm'']] |align="left" |{{flag|Norway}} |align="right"|1,847 |align="left" |Sunk |- |align="right"|17 May 1917 |align="left" |[[List of shipwrecks in May 1917#17 May|''Lewisham'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,810 |align="left" |Sunk |- |align="right"|18 May 1917 |align="left" |[[List of shipwrecks in May 1917#18 May|''Llandrindod'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,841 |align="left" |Sunk |- |align="right"|18 May 1917 |align="left" |[[List of shipwrecks in May 1917#18 May|''Penhale'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,712 |align="left" |Sunk |- |align="right"|20 May 1917 |align="left" |{{HMS|Paxton}}<ref name="onecity">{{cite web |url=http://www.ataleofonecity.portsmouth.gov.uk/firstworldwar/richard-tallack/ |title=Richard Tallack |work=A Tale of one City |accessdate=24 May 2015 |archive-date=5 March 2016 |archive-url=https://web.archive.org/web/20160305100319/http://www.ataleofonecity.portsmouth.gov.uk/firstworldwar/richard-tallack/ |url-status=dead }}</ref> |align="left" |{{navy|United Kingdom}} |align="right"|1,372 |align="left" |Sunk |- |align="right"|22 May 1917 |align="left" |[[List of shipwrecks in May 1917#22 May|''Tansan Maru'']] |align="left" |{{flag|Japan}} |align="right"|2,443 |align="left" |Sunk |- |align="right"|24 May 1917 |align="left" |[[List of shipwrecks in May 1917#24 May|''Jersey City'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|4,670 |align="left" |Sunk |- |align="right"|24 July 1917 |align="left" |[[List of shipwrecks in July 1917#24 July|''Brumaire'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,324 |align="left" |Sunk |- |align="right"|24 July 1917 |align="left" |[[List of shipwrecks in July 1917#24 July|''Zermatt'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,767 |align="left" |Sunk |- |align="right"|25 July 1917 |align="left" |[[List of shipwrecks in July 1917#25 July|''Peninsula'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|1,384 |align="left" |Sunk |- |align="right"|25 July 1917 |align="left" |[[List of shipwrecks in July 1917#25 July|''Purley'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|4,500 |align="left" |Sunk |- |align="right"|27 July 1917 |align="left" |[[List of shipwrecks in July 1917#27 July|''Begona No. 4'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,407 |align="left" |Sunk |- |align="right"|31 July 1917 |align="left" |[[List of shipwrecks in July 1917#31 July|''Shimosa'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|4,221 |align="left" |Sunk |- |align="right"|22 October 1917 |align="left" |[[List of shipwrecks in October 1917#22 October|''Zillah'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,788 |align="left" |Sunk |- |align="right"|24 October 1917 |align="left" |[[List of shipwrecks in October 1917#24 October|''Ilderton'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,125 |align="left" |Sunk |- |align="right"|28 October 1917 |align="left" |[[List of shipwrecks in October 1917#28 October|''Baron Balfour'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|3,991 |align="left" |Sunk |- |align="right"|4 November 1917 |align="left" |[[List of shipwrecks in November 1917#4 November|''Irina'']] |align="left" |{{flag|Russian Empire}} |align="right"|2,210 |align="left" |Sunk |- |align="right"|7 November 1917 |align="left" |[[List of shipwrecks in November 1917#7 November|''Obj'']] |align="left" |{{flag|Norway}} |align="right"|1,829 |align="left" |Sunk |- |align="right"|27 January 1918 |align="left" |{{RMS|Andania|1913|2}} |align="left" |{{flag|United Kingdom|government}} |align="right"|13,405 |align="left" |Sunk |- |align="right"|31 January 1918 |align="left" |[[List of shipwrecks in January 1918#31 January|''Towneley'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,476 |align="left" |Sunk |- |align="right"|1 February 1918 |align="left" |[[List of shipwrecks in February 1918#1 February|''Cavallo'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,086 |align="left" |Sunk |- |align="right"|3 February 1918 |align="left" |[[List of shipwrecks in February 1918#3 February|''Lutece'']] |align="left" |{{flag|France}} |align="right"|1,346 |align="left" |Sunk |- |align="right"|5 February 1918 |align="left" |[[List of shipwrecks in February 1918#5 February|''Cresswell'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|2,829 |align="left" |Sunk |- |align="right"|13 March 1918 |align="left" |[[List of shipwrecks in March 1918#13 March|''Crayford'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|1,209 |align="left" |Sunk |- |align="right"|18 March 1918 |align="left" |[[List of shipwrecks in March 1918#18 March|''Atlantic Sun'']] |align="left" |{{flag|United States|1912}} |align="right"|2,333 |align="left" |Sunk |- |align="right"|30 March 1918 |align="left" |[[List of shipwrecks in March 1918#30 March|''Stabil'']] |align="left" |{{flag|Norway}} |align="right"|538 |align="left" |Sunk |- |align="right"|25 May 1918 |align="left" |''Rathlin Head'' |align="left" |{{flag|United Kingdom|civil}} |align="right"|7,378 |align="left" |Damaged |- |align="right"|16 September 1918 |align="left" |[[List of shipwrecks in September 1918#16 September|''Tasman'']] |align="left" |{{flag|United Kingdom|civil}} |align="right"|5,023 |align="left" |Sunk |- |align="right"|25 September 1918 |align="left" |[[List of shipwrecks in September 1918#25 September|''Gloire a Jesus'']] |align="left" |{{flag|France}} |align="right"|60 |align="left" |Sunk |}

==Imperial Japanese Navy==

Transferred to Japan after surrendering, the submarine was commissioned into the [[Imperial Japanese Navy]] in 1920 as ''O-2''. [[Ship decommissioning|Decommissioned]] in 1921, she was partly dismantled at the [[Kure Naval Arsenal]] in April 1921.<ref name=O2/>

A photo of U-46 apparently at the time of transfer to Japan shows the submarine docked and flying the flag of the Imperial Japanese Navy over the flag of the Imperial German Navy.<ref name="U46DuringTransferToJapan">{{cite web|title=Photo of U-46 at the time of transfer to the Imperial Japanese Navy|url=http://www.iwm.org.uk/history/the-u-boat-campaign-that-almost-broke-britain#&gid=1&pid=1|website=Imperial War Museums (UK)|accessdate=1 August 2017}}</ref>

Some sources claim that ''O-2'' was scrapped in 1922.<ref>Gardiner, p. 177</ref><ref>Gröner, p. 9.</ref> Other sources claim that in 1925, ''O-2'' was rebuilt at [[Yokosuka Naval Arsenal]] to serve as a testbed for submarine salvage operations by the submarine salvage ship ''[[Japanese battleship Asahi|Asahi]]'' and foundered in the [[Pacific Ocean]] in a storm off the coast of Japan during her transfer voyage from [[Yokosuka]] to [[Kure]] on 21 April 1925,<ref name=O2/> adding that an American [[merchant ship]] sighted her derelict hulk floating in the Pacific west of [[Oahu]], [[Hawaii]], on 5 August 1927, and that the hulk subsequently was scuttled.<ref name=O2/>

==References==

===Notes=== {{Reflist|group=Note}}

===Citations=== {{reflist}}

==Bibliography== *{{cite book |last1=Gardiner |first1=Robert |year=1985 |title=Conway's All the World's Fighting Ships 1906-1921 |location=Annapolis, Maryland |publisher=Naval Institute Press |isbn=0-87021-907-3 }} *{{cite book |last1=Gröner |first1=Erich |last2=Jung |first2=Dieter |last3=Maass |first3=Martin |translator-last1=Thomas |translator-first1=Keith |translator-last2=Magowan |translator-first2=Rachel |year=1991 |title=U-boats and Mine Warfare Vessels |volume=2 |series=German Warships 1815–1945 |location=London |publisher=Conway Maritime Press |isbn=0-85177-593-4 |ref=CITEREFGröner1991 }} *{{cite book |last=Rössler |first=Eberhard |title=The U-boat : the evolution and technical history of German submarines |publisher=Cassell |year=1981 |isbn=0304361208 |location=London}}

{{DEFAULTSORT:U0046}} [[Category:World War I submarines of Germany]] [[Category:1915 ships]] [[Category:Ships built in Danzig]] [[Category:U-boats commissioned in 1915]] [[Category:Foreign submarines of the Imperial Japanese Navy]] [[Category:Type U 43 submarines]] [[Category:Maritime incidents in 1925]] [[Category:Maritime incidents in 1927]] [[Category:Shipwrecks in the Pacific Ocean]] [[Category:Scuttled vessels]]