View source for Japanese submarine I-52 (1942)

{{short description|1st class submarine of the Imperial Japanese Navy}}
{{Other ships|Japanese submarine I-52|Japanese ship Momi}}
{{Use dmy dates|date=September 2020}}
{|{{Infobox ship begin}}
{{Infobox ship image
| Ship image = I-52-submarine.jpg
| Ship caption = ''I-52'' on sea trials, December 1942
}}
{{Infobox ship career
| Hide header = 
| Ship country = Japan
| Ship flag = [[Image:Naval Ensign of Japan.svg|45px]]
| Ship name = ''I-52'', code-named ''Momi'' (樅, Japanese for "evergreen" or "fir tree")
| Ship namesake = 
| Ship ordered = 
| Ship builder = [[Mitsubishi Heavy Industries]]
| Ship laid down = 18 March 1942
| Ship launched = 
| Ship acquired = 
| Ship commissioned = 28 December 1943
| Ship decommissioned = 
| Ship in service = 
| Ship out of service = 
| Ship struck = 10 December 1944
| Ship reinstated = 
| Ship fate = Sunk on 24 June 1944
}}
{{Infobox ship characteristics
| Hide header = 
| Header caption = 
| Ship class = [[I-52-class submarine|Type C2]] cargo [[submarine]]
| Ship displacement = 2,095 [[long ton]]s standard, 2,564 long tons surface, 3,644 long tons submerged
| Ship length = 108.5 m (356 ft)
| Ship beam = {{convert|9.3|m|ft|0|abbr=on}}
| Ship draught = {{convert|5.12|m|ft|0|abbr=on}}
| Ship draft = 
| Ship propulsion = 2-shaft diesel and electric motor, {{convert|4700|bhp|kW|-1|abbr=on}} surface, {{convert|1200|shp|kW|-1|abbr=on}} submerged
| Ship speed = {{convert|17.7|kn|km/h|0}} surface, {{convert|6.5|kn|km/h|0}} submerged
| Ship range = {{convert|21000|nmi|km}} at {{convert|16|kn|km/h}}
| Ship range (submerged) = {{convert|105|nmi|km}} at {{convert|3|kn|km/h}}
| Ship endurance = 
| Ship test depth = {{convert|100|m|ft|0|abbr=on}}
| Ship complement = 94 officers and men, 18 civilians
| Ship sensors = 
| Ship EW = 
| Ship armament = 6 x 53 cm [[torpedo tube]]s, 2 x [[14 cm/40 11th Year Type naval gun]]s,<ref name="campbell">Campbell, John ''Naval Weapons of World War Two'' {{ISBN|0-87021-459-4}} p.191</ref> 2 x [[Type 96 25&nbsp;mm AT/AA Gun|Type 96 {{convert|25|mm|in|abbr=on}}]] anti-aircraft guns
| Ship notes = Cargo: 300 metric tons
}}
{{Infobox service record
|is_ship=yes
|label =Service record<ref name="ijnsubsite">{{cite web
 |url=http://ijnsubsite.info/I-Sub%20Details/I-52.htm
 |archive-url=https://web.archive.org/web/20170301140541/http://ijnsubsite.info/I-Sub%20Details/I-52.htm
 |url-status=usurped
 |archive-date=1 March 2017
 |title=I-52
 |website=IJN Submarine Service – Ijnsubsite.info
 |access-date=21 October 2023
}}</ref>
|partof=
*11th Submarine Squadron
*28 December 1943 – 10 March 1944
*[[8th Submarine Squadron (Imperial Japanese Navy)|8th Submarine Squadron]]
*10 March – 24 June 1944
|commanders=
*''[[Sa (rank)|Kaigun-chūsa]]'' Kameo Uno
*28 December 1943 – 24 June 1944
|operations=
*1st patrol
*10–21 March 1944
*2nd patrol
*21 March – 24 June 1944
|victories=None
}}
|}
{{Nihongo|'''''I-52'''''|伊号第五二潜水艦 (伊52)|I Gō Dai Gojūni Sensuikan (I Gojūni)|I-52 submarine (I-52)}}, code-named {{nihongo|''Momi''|樅||"[[fir tree]]"}} was a [[I-52-class submarine|Type C2]] cargo [[submarine]] of the [[Imperial Japanese Navy]] used during [[World War II]] for a secret mission to [[Lorient]], France, then occupied by Germany, during which she was sunk.

==Valuable cargo==
She is also known as Japan's "Golden Submarine", because she was carrying a cargo of gold to Germany as payment for [[matériel]] and technology. There has been speculation that a peace proposal to the Allies was contained on board the ''I-52'' as well, but this is unlikely on two counts: there is no evidence that the Japanese government was interested in peace proposals or negotiated settlements at that stage in the war; and the Japanese kept an open dialogue with their diplomatic attachés via radio and diplomatic voucher through Russia, and had no need for long and uncertain transfer via a submarine bound for a Nazi-controlled area of western Europe.

It is believed that 800&nbsp;kg (1,760-lbs) of [[uranium oxide]] awaited ''I-52'' for her return voyage at [[Lorient]] according to [[Ultra (cryptography)|Ultra]] decrypts. It has been speculated that this was for the Japanese to develop a [[radiological weapon]] (a so-called "[[dirty bomb]]") for use against the United States. (The amount of unenriched uranium oxide would not have been enough to create an atomic bomb, though if used in a [[nuclear reactor]] it could have created poisonous [[fission products]]).<ref>Billings, Richard N. Battleground Atlantic: How The Sinking of a Single Japanese Submarine Assured the Outcome of World War II, NAL Hardcover, 2006, 311pp, {{ISBN|0-451-21766-7}}</ref>

She was also to be fitted with a [[Submarine snorkel|snorkel]] device at Lorient. In addition, 35 to 40 tons of secret documents, drawings, and strategic cargo awaited ''I-52''{{'}}s return trip to Japan: [[G7es torpedo|T-5 acoustic torpedoes]], a [[Junkers Jumo 213|Jumo 213-A motor]] used on the long-nosed [[Focke-Wulf Fw 190#Fw 190D|Focke-Wulf Fw 190D fighter]], radar equipment, vacuum tubes, ball bearings, bombsights, chemicals, alloy steel, and optical glass.

==Type C2 submarines==
This class of submarines was designed and built by [[Mitsubishi]] Corporation, between 1943 and 1944, as cargo carriers. They were quite long and carried a crew of up to 94. They also had a long cruising range at a speed of {{convert|12|kn|km/h|0}}. The Japanese constructed only three of these submarines during World War II (''I-52'', {{ship|Japanese submarine|I-53|1943|2}} and {{ship|Japanese submarine|I-55|1944|2}}), although twenty were planned.<ref>[https://archive.today/20120709165330/http://homepage2.nifty.com/nishidah/e/stc0546.htm C2 type 1st class submarines]</ref> They were the largest submarines ever built at that time, before the enormous [[I-400-class submarine|''Sentoku'' subs]] were built, and were known as the most advanced Japanese submarines of their time.

The keel of ''I-52'' was laid on 18 March 1942, and she was commissioned on 28 December 1943 into the 11th Submarine Squadron, [[Kure Naval District]], with [[Commander (naval)|Commander]] Kameo Uno as the commanding officer. In January 1944, Admiral [[Mineichi Koga]], the commander of the [[Combined Fleet]], selected ''I-52'' for a special mission to Germany.<ref name="ijnsubsite" /><ref name="combined" />

==Yanagi missions==
[[Yanagi missions]] were enabled under the [[Axis powers]]' [[Tripartite Pact]] to provide for an exchange of [[strategic material]]s and manufactured goods between Germany, Italy and Japan. Initially, cargo ships made the exchanges, but when that was no longer possible submarines were used.

Only five other submarines had attempted this intercontinental voyage during World War II: {{ship|Japanese submarine|I-30||2}} (April 1942), {{ship|Japanese submarine|I-8||2}} (June 1943), {{ship|Japanese submarine|I-34||2}} (October 1943), {{ship|Japanese submarine|I-29||2}} (November 1943), and {{GS|U-511}} (August 1943). Of these, ''I-30'' was sunk by a [[naval mine|mine]], ''I-34'' by the British submarine {{HMS|Taurus|P399|6}}, and ''I-29'' by the United States submarine {{USS|Sawfish|SS-276|2}} (assisted by [[Ultra (cryptography)|Ultra]] intelligence).

==Fatal voyage==
[[File:Uno Kameo.jpg|thumb|Commander Kameo Uno, the captain of ''I-52'']]
On 10 March 1944, on her maiden voyage, ''I-52'', led by Commander Kameo Uno, departed [[Kure, Hiroshima|Kure]] via [[Sasebo, Nagasaki|Sasebo]] for Singapore. Her cargo from Japan included 9.8 tons of [[molybdenum]], 11 tons of [[tungsten]], 2.2 tons of gold in 146 bars packed in 49 metal boxes, 3 tons of [[opium]] and 54&nbsp;kg of [[caffeine]].<ref>{{cite web |url=http://www.de220.com/History/History%20Documents/Rohwer%20Letter.htm |archive-url=https://web.archive.org/web/20080518095838/http://www.de220.com/History/History%20Documents/Rohwer%20Letter.htm |archive-date=18 May 2008 |title=Letter from Dr. Rohwer |access-date=21 July 2011|url-status=usurped}}</ref> The gold was payment for German technology. She also carried 14 passengers, primarily Japanese technicians, who were to study German technology in anti-aircraft guns and engines for torpedo boats.<ref name="combined" />

In Singapore she picked up a further 120 tons of [[tin]] in ingots, 59.8 tons of [[caoutchouc]] (raw rubber) in bales and 3.3 tons of [[quinine]], and headed through the Indian Ocean, to the Atlantic Ocean.

On 6 June 1944, the Japanese naval attaché in Berlin, Rear Admiral Kojima Hideo, signaled the submarine that the Allies had landed in Normandy, thus threatening her eventual destination of Lorient on the coast of France. She was advised to prepare for Norway instead. She was also instructed to rendezvous with a German submarine on 22 June 1944 at 21:15 (GMT) at the co-ordinates {{coord|15|N|40|W}}. ''I-52'' responded with her position, being {{coord|35|N|23|W}}. The message was intercepted and decoded by US intelligence; ''I-52'' had been closely watched all the way from Singapore. Guided by the F-21 Submarine Tracking Room and F-211 "Secret Room" of the Tenth Fleet which was in charge of the Atlantic section, a hunter-killer task force was targeted towards her.<ref>{{cite web |url=http://www.mariner.org/atlantic/gg.htm |archive-url=https://web.archive.org/web/20080513001805/http://www.mariner.org/atlantic/gg.htm |archive-date=13 May 2008 |title=Punching the Convoys Through: "Hunter-Killers" in the Atlantic, 1943–1945 |access-date=21 July 2011}}</ref>

On the night of 22 June 1944 about {{convert|850|nmi|km|0}} west of the [[Cape Verde Islands]] off the coast of Africa, ''I-52'' rendezvoused with {{GS|U-530||2}}, a [[Type IX U-boat|Type IXC/40 U-boat]] commanded by Kapitänleutnant Kurt Lange.<ref>{{cite news |first= Helen|last= O'Neill|title=When treasure and technology meet, who gets the gold? |url=https://www.post-gazette.com/healthscience/19981129wrecks2.asp |agency=[[Associated Press]]|date=29 November 1998 |access-date=7 July 2009 }}</ref> ''U-530'' provided her with fuel, and also transferred a [[Naxos radar detector|Naxos]] FuMB 7 radar detector, and an [[Enigma machine|Enigma]] coding machine, along with two radar operators, Petty Officers Kurt Schulze and Rolf Behrendt, and a German liaison officer for the trip through the [[Bay of Biscay]], Kapitänleutnant Alfred Schafer.<ref name="combined">Hackett, Bob; Kingsepp, Sander (2014). [http://www.combinedfleet.com/I-52.htm IJN Submarine I-52: Tabular Record of Movement]. ''combinedfleet.com''. Retrieved 20 October 2023.</ref>

===US task force===
A US task force assembled as a submarine hunter-killer group, consisting of the escort carrier [[USS Bogue (CVE-9)|USS ''Bogue'']] and five destroyer escorts, en route to the United States from Europe, was ordered to find and destroy the Japanese submarine. This task force departed from [[Casablanca]] on 15 June 1944, and was commanded by Captain Aurelius B. Vosseller.<ref>{{cite web|url=https://www.history.navy.mil/research/library/research-guides/modern-biographical-files-ndl/modern-bios-v/vosseller-aurelius-bartlett.html |title= Aurelius Bartlett Vosseller / 25 January 1903 – 27 November 1981 |access-date=2 June 2020}}</ref> It also had 9 [[Grumman F4F Wildcat|General Motors FM-2 Wildcats]] and 12 [[Grumman TBF Avenger|Grumman TBF-1C Avenger]]s of VC-69 on board. The task force, while on its way from [[Hampton Roads]] to [[Casablanca]], had sunk another Japanese submarine, the [[Type IX U-boat|Type IX]] ''RO-501'' (formerly ''U-1224'') on 13 May 1944. This was a very effective force, sinking 13 German and Japanese submarines between February 1943 and July 1945.

The five destroyer escorts were:
* {{USS|Francis M. Robinson|DE-220|6}}, Lieutenant J. E. Johansen.
* {{USS|Haverfield|DE-393|6}}, Commander T. S. Lank, TF 51 commander.
* {{USS|Swenning|DE-394|6}}, Lieutenant R. E. Peek.
* {{USS|Willis|DE-395|6}}, Lieutenant Commander G. R. Atterbury.
* {{USS|Janssen|DE-396|6}}, Lieutenant Commander H. E. Cross.

Arriving in the area of the meeting on the evening of 23 June, the carrier began launching flights of [[Grumman TBF Avenger|Avenger]]s at around 23:00 GMT to search for the submarines. ''U-530'' escaped undetected.

At approximately 23:40, Ed Whitlock, the [[radar]] operator in Lieutenant Commander Jesse D. Taylor's Avenger aircraft, detected a surface contact on his malfunctioning radar (only the right half of its sweep was working). Taylor immediately dropped flares, illuminating the area, and attacked. After his first pass, he saw the depth charge explosions just to starboard of the submarine – a near miss – and the submarine dived. Taylor dropped a purple [[sonobuoy]], a newly developed underwater microphone that floated on the surface to pick up underwater sounds and transmit them to the aircraft. A searching aircraft usually drops these in packs of five, code-named purple, orange, blue, red and yellow (POBRY). The operator is able to monitor each buoy, in turn, to listen for sounds emitted by the enemy craft.

Hearing what sounded like submarine propeller sounds, Taylor began a [[torpedo]] attack, dropping a [[Mark 24 FIDO Torpedo|Mark 24 "mine"]]. The Mark 24, code-name "Fido" and designated a "mine" for secrecy, was actually the first Allied acoustic torpedo, developed by the [[Harvard Underwater Sound Lab]], which homed in on noises made by the submarine. Within minutes of dropping the torpedo, Taylor's sonobuoys detected the sounds of an explosion and a hull breaking up.

As Commander Taylor's watch ended, the operators on ''USS Bogue'' and Taylor all thought he had sunk the sub. However, as Taylor's patrol ended, he was relieved by Lieutenant Junior Grade William "Flash" Gordon, accompanied by civilian underwater sound expert Price Fish. They arrived on the scene just after midnight and circled with Taylor for some time. At about 0100 on 24 June 1944, Fish reported hearing some faint propeller noise in the area.

Captain Vosseller ordered a second attack; Gordon checked with Taylor about the exact position of the sonobuoy and dropped another "Fido" torpedo where he believed the submarine to be. Taylor departed the area at 0115, but Gordon stayed to circle the area and listen for any sign of activity. He heard nothing and was relieved by Lieutenant (junior grade) Brady, who continued to watch and listen, but no further activity was reported. Next morning, ''USS Janssen'' reached the site ({{coord|15|16|N|39|55|W|}}) and found [[flotsam]]: a ton of raw rubber, a piece of silk, and human flesh.

The sonobuoy recording of the last few moments of ''I-52{{'}}s'' sound still survives in the [[US National Archives]] in [[Washington D.C.]] in the form of two thin-film canisters marked "Gordon wire No. 1" and "Gordon wire No. 2" dated 24 June 1944. The wire from Taylor's attack has not been found; however, a set of [[Phonograph record#78 rpm disc developments|78 rpm vinyl recordings]] that include segments of Taylor's wire recordings has been located. These records were produced during the war for training pilots. On the wire and vinyl recordings, Lieutenant Gordon can be heard talking to his crew, along with the sound of a torpedo exploding, and metal twisting.<ref>{{cite web|url=https://maritime.org/sound/index.htm#i52wire |title=Two recordings from the second aircraft sent by the ''USS Bogue''|website=maritime.org|accessdate=April 4, 2024}}</ref> Subsequent to the discovery of the wreck (see below), analysts at the Johns Hopkins University Applied Physics Laboratory, experts in analyzing modern submarine sounds, studied these recordings and concluded that the ''I-52'' was sunk by Taylor. The propeller sounds heard by Gordon were actually from ''[[German submarine U-530|U-530]]'', nearly {{convert|20|mi|km}} away, reaching Gordon's sonobuoys through a "surface duct". This quirk of underwater sound propagation traps sounds in a channel near the surface and can transmit them for many miles. At the time, the Navy credited the sinking of the ''I-52'' to both Gordon and Taylor, as it was uncertain whether the ship was sunk on the first attack.

===Aftermath===
On 30 August 1944, the [[Kriegsmarine]] officially declared ''I-52'' sunk in the [[Bay of Biscay]] as of 25 July 1944, with all 95 crew, 14 passengers, and three German personnel. The Imperial Japanese Navy declared ''I-52'' missing on 2 August 1944, and struck her from service on 10 December 1944 as sunk.<ref name="combined" />

==Recent salvage operations==
In late 1994, a salvage operation named Project Orca was launched to try to locate the ''I-52'' and retrieve her valuable cargo of gold. Despite the commissioning of the Russian research ship ''[[Akademik Mstislav Keldysh|Akademik Keldysh]]'' for the project and an extensive search, by March 1995 the search had proved to be a failure (Hamilton-Paterson 1998). Very shortly afterwards, however, in the spring of 1995, [[Paul Tidwell]], working with the ocean exploration company Meridian Sciences, Inc. (later renamed Nauticos Corp.) located the wreck {{convert|17000|ft|m mi|abbr=off}} deep, mostly upright.<ref>{{Cite news |url=https://www.nytimes.com/1995/07/18/science/lost-japanese-sub-with-2-tons-of-axis-gold-found-on-floor-of-atlantic.html?pagewanted=all&src=pm |title=Lost Japanese Sub With 2 Tons of Axis Gold Found on Floor of Atlantic |date=18 July 1995 |author=William J. Broad|work=The New York Times }}</ref> The vessel was found nearly {{convert|20|mi|km}} from the datum quoted by the U.S. Navy at the time of the sinking, but within {{convert|1/2|mile}} of the coordinates computed by Meridian. Meridian's analysts used historical ship logs from the U.S. task force as well as from the German U-boat to reconstruct the events of the battle and correct navigation errors using a process called "re-navigation," or RENAV. Her [[conning tower]] is intact and her [[hull number]] is still visible. The bow is broken up, probably due to impact on the bottom, and a large hole, probably caused by one of the torpedoes, is aft of the conning tower. Debris was scattered over a large area. Plans were made to raise the sub and recover the gold. The Japanese government objected, indicating that they considered the wreck site a grave. Tidwell worked on the proper procedures with the Japanese government and received the approval of the war graves authorities in Japan. Tidwell's team took down a Japanese [[Ensign (flag)|naval ensign]] and affixed it to the wrecked submarine. A metal box from the debris field was brought to the surface in the hope that it would contain some of the sunken gold (worth US$25 million at that time – US$109,085,000 in 2020<ref>Calculation: 2.2 tons; 29167 troy-ounces per ton = 64167 troy-ounces × US$1700.00/troy-ounce in 2020</ref>), but when opened, the salvors were disappointed to find not gold, but opium. It was dumped overboard.

The plan was to recover the entire conning tower, diplomatic pouches, gold, coding equipment, (Japanese and German) and more. The recovered items would be taken to [[New Orleans]] for cleaning, conservation, and corrosion treatment to prepare for an exhibition. [[Mandalay Bay]] [[Casino]] had offered $20 million for the exhibition. After three years in Las Vegas everything except the gold would be returned to Japan to be placed at the city of [[Kure, Hiroshima|Kure]] in a permanent exhibition.<ref>[https://ahoy.tk-jk.net/Letters/WebsiteforJapanesesubmari.html Ahoy – Mac's Web Log] – email from Paul Tidwell<!-- this reference corroborates the info in this entire paragraph --></ref>

There are no full-size Japanese World War II submarines on display anywhere in the world; however, captured Japanese [[midget submarine]]s are on display at the [[Admiral Nimitz State Historic Site - National Museum of the Pacific War|Admiral Nimitz Museum]] in [[Fredericksburg, Texas|Fredericksburg]], Texas, at the [[USS Bowfin (SS-287)|USS Bowfin Submarine Museum & Park]], close to [[Pearl Harbor]], Hawaii, and at the [[Australian War Memorial]], [[Canberra]].

''[[The Japan Times]]'' reported that Tidwell intended to return to the site and raise the submarine in November 2005 or May 2006.<ref>{{Cite news |url=https://search.japantimes.co.jp/cgi-bin/nn20050419f3.html |date=19 April 2005 |title=American to salvage Japanese sub full of gold, opium sunk in Atlantic in '44 |author=Eric Talmadge |publisher=Associated Press |work=The Japan Times}}</ref> However, as of March 2021, Tidwell's plans have not been fulfilled.

==Media coverage==
* In 2000 the [[National Geographic Society]] commissioned and produced a documentary called, ''Submarine I-52: Search for WWII Gold'', on the ''I-52'' and Tidwell's salvage effort.
* The October 1999 issue of the ''[[National Geographic (magazine)|National Geographic]]'' featured an article on the ''I-52'' sinking and salvage.

==References==
{{Reflist}}
* Boyd, Carl. ''U.S. Navy Radio Intelligence During the Second World War and the Sinking of the Japanese Submarine I-52'', Journal of Military History 63 (2): 339–354, April 1999.
* Hamilton-Paterson, James. (1998) Three Miles (5&nbsp;km) Down: A Hunt for Sunken Treasure, New York: Lyons Press.
* Listen to the training records [http://maritime.org/sound/#sonobuoy2]
* Listen to the wire recording from the aircraft [http://maritime.org/sound/#i52wire]

==External links==
* [http://piquetjm.free.fr/I28/I52/missioni521944.html Pictures from various sources related to I-52 (captions in French)]
* [http://www.i-52.com/ Paul Tidwell's website about the ongoing recovery & salvage operation]

{{C2 type submarine}}
{{June 1944 shipwrecks}}

{{DEFAULTSORT:I-052 (1942)}}
[[Category:Type C2 submarines]]
[[Category:Ships built by Kure Naval Arsenal]]
[[Category:1943 ships]]
[[Category:World War II submarines of Japan]]
[[Category:World War II shipwrecks in the Atlantic Ocean]]
[[Category:Submarines sunk by aircraft]]
[[Category:Japanese submarines lost during World War II]]
[[Category:Maritime incidents in June 1944]]
[[Category:Warships lost in combat with all hands]]
[[Category:Japanese submarines lost with all hands]]
[[Category:Ships sunk by US aircraft]]