SENSUIKAN!

© 2001-2007 Bob Hackett & Sander Kingsepp

28 December 1943:
1-52 is completed at the Kure Navy Yard, commissioned in the IJN and assigned to SubRon 11, First Fleet. She is based in the Kure Naval District. Cdr Uno Kameo (former CO of I-175) is the Commanding Officer.

February 1944:
1-52's Type 96 AA suite is increased from two to six (three dual mounts) 25-mm guns.

10 March 1944:
I-52 is reassigned to SubRon 8, SubDiv 11, Sixth Fleet at Penang, Malaya. She departs Kure via Sasebo for Singapore on a Yanagi mission according to standing Taikai Order No. 322. [1]

I-52 carries strategic metals including 9.8-tons of molybdenum, 11-tons of tungsten, 2.2-tons of gold in 146 bars packed in 49 metal boxes and 3-tons of opium and some caffeine. The gold is to be used to purchase German optical technologies. I-52 also carries 14 passengers including engineers and technicians from Nihon Kogaku K.K. who are to study German AAA gun sights and from the Denki K. K. and the Mitsubishi Instrument Company who are to study German AAA directors. Another engineer aboard is to study Daimler Benz's techniques for building engines for torpedo boats.

April 1944:
I-52 arrives at Singapore and loads 120-tons of tin in ingots, 59.8-tons of caoutchouc (raw rubber) in bales and 3.3-tons of quinine.

23 April 1944:
1-52 sorties from Singapore via the Sunda Strait for the Indian Ocean to attempt a passage around Cape Horn, Africa, enroute to the German U-boat base at Lorient, France. I-52, code-named "Momi" (Evergreen), is the fifth IJN submarine to attempt such a passage to France. Cdr Uno travels submerged during the day and surfaces at night to charge I-52's batteries.

15 May 1944:
After passing the Cape of Good Hope and entering the Atlantic, Cdr Uno sends his first message to the Germans. By this time in the war, the British and Americans have broken both Germany and Japan's military codes. Allied intelligence intercepts and deciphers Uno's reports to Tokyo and Berlin including his daily noon position reports. When the I-52 enters the Atlantic, the code-breakers relay her position and predicted route to an American Navy task force.

6 June 1944:
Berlin. Rear Admiral Kojima Hideo (former CO of KASHII), the Naval Attache, signals Tokyo and I-52. He indicates that the Allies have landed at Normandy. Kojima notes that arrival at Lorient will be dangerous and, depending on the situation, I-52 may have to proceed to Norway. He further instructs the Captain of the Momi to rendezvous on 22 June with a U-boat at 2115 (GMT) at 15N, 40W.

Kojima indicates that on 6 June I-52's position is approximately 35N, 23W. The radio transmission is intercepted, decoded and passed by special- intelligence "Ultra" signals to an American ASW group operating near the Azores.

16 June 1944:
Off Western Africa. I-52 sends a coded transmission that her position is 10N, 31W and she is making 11 knots.

22 June 1944:
850 miles W of the Cape Verde Islands. At 2115, I-52 makes a rendezvous with Kapitanleutnant Kurt Lange's U-530 that departed Lorient on 22 May 1944 for Trinidad, West Indies.

I-52 takes Leutnant Schafer aboard to help navigate the end-leg of the journey. I-52 also takes aboard two radio operators, Petty Officers Schulze and Behrendt and a Naxos FuMB 7 radar detector. The Naxos is to be installed and operational by the time I-52 reaches European waters. The exchange goes well except the radar detector falls into the sea, but a Japanese seaman jumps in and retrieves it.

U-530 is detached and heads for Trinidad.

23 June 1944:
850 miles W of the Cape Verde Islands. I-52 is running on the surface at night in bad weather at 15 knots. About 2340, a Grumman TBF "Avenger" torpedo bomber of VC-69 from Captain A. B. Vosseller's escort carrier USS BOGUE (CVE-9) piloted by LtCdr Jesse D. Taylor picks up the I-52 on radar. Taylor drops flares that illuminate the huge 2,564-ton Type C3 submarine on the surface making about 12 knots. He drops two 354-pound Mark 54 depth bombs, but I-52 dives and successfully evades his attack.

Taylor and his crew lay sonobuoys over a square mile of sea and track the submarine. Within minutes, the Avenger's crew can hear clearly I-52's propellers in their headsets. Taylor maneuvers into position and drops a new top secret Mark 24 "Fido" acoustic homing torpedo. After a long wait, Taylor's crew hears a loud explosion.

24 June 1944:
Another Avenger, piloted by Lt William D. Gordon, arrives and drops more sonobuoys. They pick up the sounds of the damaged submarine's propellers. At about 0100, Gordon drops another Fido that finds the submarine. Gordon and his crew hear the submarine breaking up underwater. I-52 sinks with all 95 crewmen, 14 passengers and the three German sailors near 15-16N, 39-55W. [2]

25 June 1944:
USS JANSSEN (DE-396) one of BOGUE's escorts finds a large oil slick at the site of the sinking and salvages over a ton of raw rubber bales and other debris floating on the surface.

30 July 1944:
A coded signal is received that indicates the I-52 is 36 hours from port. Later, it is determined that the signal is false, perhaps a ruse by the British.

1-4 August 1944:
Lorient. I-52's planned arrival date passes. A German ship stands by in vain waiting to escort I-52. Diplomats are scheduled to return to Japan aboard I-52. At dockside, 35 to 40-tons of secret documents and drawings and strategic cargo await loading for I-52's return trip to Japan: T-5 acoustic torpedoes, a Jumo 213-A motor used on the long-nosed FW-190D, radars, vacuum tubes, ball bearings, bombsights, chemicals, alloy steel, optical glass and 1,000-lbs of uranium oxide. The Germans also intended to equip the I-52 with a snorkel. [3]

8 August 1944:
Berlin. Rear Admiral Kojima radios in the blind to I-52 that since the Allied landings at Normandy in June, arrival at Lorient is too dangerous and directs I-52 to proceed to Norway .

30 August 1944:
The Kriegsmarine officially declares I-52 as presumed sunk in the Bay of Biscay as of 25 Jul 1944 with her crew of 95 and 14 passengers. After the failure of I-52's mission, the Imperial Japanese Navy no longer tries to send its submarines to Europe.

10 December 1944:
Removed from the Navy List.

3 May 1995:
1,200 miles W of the Cape Verde islands. A team of Americans led by Mr. Paul Tidwell charter the Russian research vessel AKADEMIK MSTISLAV KELDYSH and using a MAK-1M side-scan sonar find the wreck of I-52 virtually intact at a depth of 17,000 feet. [4]

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Authors' Notes:
[1] When Japan enters the war, the Axis Tripartite agreement is amended to provide for an exchange of strategic materials and manufactured goods between Europe and the Far East. Cargo ships make the initial "Yanagi" exchanges, but when that is no longer possible submarines are used.

[2] Meridian Sciences locates I-52's wreck and determines that the U. S. Navy's sinking coordinates are inaccurate "by tens of miles".

[3] Uranium oxide is used in the manufacture an atomic bomb. It is probable that the uranium, originally earmarked for shipment aboard I-52, later is loaded aboard the German U-234 that surrenders in the North Atlantic to USS SUTTON (DE-771) on 15 May 1945.

[4] See the October 1999 issue of the National Geographic Magazine for photographs and coverage of this remarkable expedition to recover I-52's gold.

-Bob Hackett and Sander Kingsepp

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