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Boat was carrying two tons of gold for Nazis when sunk in mid-Atlantic by Allied ambush
In a stunning demonstration of cold war technology in the service of private enterprise, a team of Americans on a chartered Russian research ship early this spring found the virtually intact wreck of the Japanese Imperial Navy submarine I-52 at a depth of 17,000 feet in the mid-Atlantic 1200 miles west of the Cape Verde Islands. The large, specially built boat, which was ambushed and sunk June 23, 1944 by Allied Forces, was enroute to Nazi-occupied France with 290 metric tons of strategic metals for delivery to the German war machine, including two metric tons (4,409 lbs.) of gold valued at $25 million.
The discovery was a personal triumph for Paul R. Tidwell, 47, a maritime researcher from Hemphill, Texas who five years ago began his hunt for the warship in the National Archives in Washington, DC, examining newly declassified war documents that held clues to the boat's resting place.
Tidwell and his backers intend to begin salvaging the vessel's gold and artifacts before the end of 1996. They estimate recovery costs at $8 million. Depending on the obstacles, they may eventually attempt to raise the warship as well. If they do, they will not only have completed the deepest commercial salvage on record (the I-52 is 3.2 miles deep compared to the Titanic at 2.5 miles), they will also have brought to the surface the object of one of the great sea stores of World War II.
"The I-52 is a fascinating story, in several ways more interesting, I think, than the Titanic and the Bismarck," said military historian Carl Boyd of Old Dominion University in Norfolk, Va., and a specialist on Japanese-German relations, cryptographic intelligence, and submarine warfare.
Commissioned in December, 1943, the I-52 was one of only three in its class, designed not as attack boats, but cargo submarines capable of carrying hundreds of tons of war materiel, traveling underwater by day and cruising on the surface by night while recharging batteries, thus avoiding Allied detection. At 357 feet long, they were leviathans as long as a football field, far larger than the American subs of the day (which were around 306 feet). While the I-52's propulsion plants was comparatively small (about 6,000 hp. compared to 11,000 hp. for most Japanese subs), the increased fuel capacity gave her an enormous cruising range of 21,000 nautical miles. Flank speed was a respectable 17 knots.
In March, 1944, the I-52 left the sub base at Kure, not far from Hiroshima on Japan's Honshu Island, carrying, in addition to the gold, 228 tons of molybdenum, tungsten and tin - plus 14 experts from Japanese industrial firms such as Mitsubishi. They were aboard to meet with their German counterparts in occupied France to get desperately needed German technology in exchange for raw materials the Nazi's were equally desperate to obtain.
"When the I-52 entered the Atlantic, its ... predicted route was relayed to a special American Navy task force that had Ultra Access."
After a stop in Singapore to refuel and pick up 54 tons of raw rubber and three tons of quinine, the I-52 headed for the Indian Ocean in late April, anticipating an undetected passage around the Horn enroute to Lorient, France. But since the British and Americans had previously broken the top secret military codes of both Germany and Japan, Allied intelligence was intercepting and deciphering the I-52's reports to Tokyo and Berlin.
"That's how we knew what they were carrying," Boyd said. "They'd radioed their manifest to Berlin. We also intercepted the sub's daily position reports so when the I-52 entered the Atlantic, its position and predicted route was relayed to a special American Navy task force that had Ultra Access - the code word for cryptological intelligence."
The principle warship of the task force was the USS Bogue, a Jeep carrier (a small carrier escort less than 10,000 tons displacement) that carried only a few planes, mostly Avenger bombers specially designed to track down and destroy submarines using bombs and torpedoes.
On the night on June 23, 1944, the I-52 rendezvoused with a German sub and took aboard two German radio operators and a radar detector that was intended to be installed and operational by the time the I-52 reached European waters. The great boat continued on the surface at 15 knots on that moonless night, unaware that an Avenger bomber piloted by Lieutenant Commander Jesse D. Taylor launched from the Bogue had picked up the sub on its radar. Minutes later the dark sky around the I-52 suddenly burst into light as the plane dropped flares to illuminate its target. As the sub began a desperate emergency dive, the Avenger dropped two 500-lb bombs. They narrowly missed their target.
The sub disappeared beneath a long boil of white water. But even as it sought safety in a high angle descent, the I -52's fate was sealed. Commander Taylor deployed acoustic buoys over a square mile of sea and within minutes he and his crew could clearly hear in their headsets the rhythmic churning of the I-52's propellers. Taylor maneuvered into position above the fleeing sub and released his one remaining, but formidable, weapon: a powerful torpedo with an acoustic detection and guidance system that was extremely new at the time. After a long tense wait, the Avenger's crew heard a loud explosion - then silence. The following afternoon a Japanese sandal and pieces of silk, presumably debris from the I-52, were found floating in the vicinity.
For nearly half a century the precise location of the I-52's final resting place remained unsolved until Paul Tidwell, researching recently declassified World War II naval records in the National Archives, found the log books of the USS Bogue and related documents that described the events of June 23, 1994, including the location of the attack on the I-52. Armed with his startling discovery, Tidwell convinced a private investor to put upwards of a million dollars into his company, AU Holdings, following which he approached Sound Ocean Systems a Seattle-based company to tackle a formidable technical challenge - locating the wreck using a side scan sonar towed at a precise height of 30 meters above a sea floor characterized by uneven topography that included mountains and ridges. Moreover, even with the reliable Lat-Long coordinates provided by ship's logs, the search area for the I-52 was still roughly 100 square miles, amounting to a lot of unexplored real estate 3.2 miles down.
But these daunting requirements were familiar territory to Sound Ocean Systems. The Seattle, Washington-based company has wide industry experience in deep water search endeavors using state-of-the art sonar technology. SOSI has also designed and built sophisticated robots successfully used in a variety of missions at extreme depths. "Sound Ocean Systems is the real hero in putting this thing together," Tidwell added.
"Paul came to us to put the program together," said Ted Brockett, SOSI's president. "And we recommended Bob Cooke of our staff as project manager. We then sub-contracted with Tom Detweiller of Meridian Sciences to be the overall operational director. Tom would also be in charge of surface processing and post-processing of data."
In addition to providing its powerful Orion computer system to handle the processing tasks, Maryland-based Meridian Sciences regularly contracts with the US Navy to provide re-navigation for American subs, using post-mission data, gyrocompass errors and other factors to derive extremely accurate plots and positions. The company was a natural to do a thorough, computer-assisted, re-calculation of the American fleet's movements the night of the attack to refine the I-52's location and translate it into modern-day GPS coordinates.
"Seeing that image was one hell of a rush."
Equally suited for the mission was the Russian ship Yuzhmorgeologiya, a well-appointed 330-foot research vessel that had seen clandestine service during the cold war detecting and tracking U.S. submarines. Following the break-up of the Soviet Union, the Russian government dumped the vessel with its sophisticated equipment (including 20,000 feet of cable, side scan sonar, and a camera sled) onto the commercial market where, by early 1995, the vessel was in Long Beach, California. Sound Ocean Systems chartered the Yuzhmorgeologiya with her Russian crew of 50.
"We used their sonar, a MAK-1M, and it's pretty good," Brockett explained. "It's a dual frequency system - 30 kilohertz and 100 kilohertz - but they don't have a lot of surface processing capability and/or post-processing capability, which is what Meridian Science's Orion system has. It took a little bit of screwing around to get an interface but not much. We also had two deep water camera systems on board, the Russian Neptune system and a system that we put together."
In early April the Yuzhmorgeologiya left Long Beach and two weeks later picked up Tidwell and 11 other members of the American search team in Barbados. Due to other commitments, Brockett himself couldn't make the voyage. Five days later the vessel reached its planned search area. In calm seas and pre-hurricane season weather that Tidwell called "boringly perfect," the team began a slow methodical survey. The mood was calm and professional with a strong undercurrent of excitement.
"There was a lot of geology down there," Tidwell said. "Mountain ranges ran north and south, created by the Mid-Atlantic Ridge, but after two or three lines of survey we pretty much knew where they were going to be and could anticipate bringing the gear up and down to compensate for depth. the Russians ran that part of the gear and they did remarkably well keeping the side scan about 100 feet off the bottom."
Because configuration limitations in the Russian-American computer interface prevented real-time processing, incoming data (output on strip chart tape) was archived on Exabyte tape, together with date-time and locational information. Tidwell: "All the data was copied to a magneto-optical drive which basically enabled us to playback things faster and post-process data at the end of each survey line. It all turned out to be very accurate. We could see the geological features passing by on the bottom, as well as those on the next line over picked up by the opposite channel. So we could make sure of a one hundred percent overlap."
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At left Still photograph taken from a camera sled at 10 meters showing detail of hull damage. Note absense of rivers of rust that were found on the Titanic (which sank in 1912). Aside from a torpedo hole on the starboard side and minor damange to the bow, the I-52's hull appears intact. © 1995 Paul R. Tidwell
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Only one major uncertainty remained as they began their methodical day and night scanning of a roughly 100 square mile search area. While the searchers were relying on the ships' logbooks of the Allied task force for the I-52's location, they also had the I-52's position from another logbook, this one from the German U-boat whose captain who had seen the bomber's flares while witnessing the attack - but the latter's coordinates disagreed with the Allied location by several miles. In addition, the location of the floating debris found the day following the sinking didn't seem to square with the prevailing wind and current. For this reason, prior to his departure on the voyage, Tidwell had given Meridian Sciences all the ships' logs from the American fleet as well as the logs from the German U-boat, requesting a thorough re-calculation to see if a more reliable position could be developed.
Days of scanning continued without any sign of the I-52. Worry and frustration mounted as Tidwell, together with Tom Detweiller and Bob Cooke spent long hours doing their own recalculations. Then Meridian Sciences checked in by radio with the results of its extensive analysis - their revised position still put the I-52 within the planned search area. Several more days passed. Tension grew as the Yuzhmorgeologiya neared completion of the survey area. Then, suddenly, dramatically, a distinct image appeared on the screen, one that even at 30 kHz showed a recognizable profile. Ted Brockett , a scientist by training, characterized it as "a target of very serious interest." Tidwell described the moment less dispassionately: "Seeing that image was one hell of a rush."
The team went back in and made two high resolution passes at 100 kHz) and the resulting images made them all but certain they had found her. Next, they deployed a Russian-made long base line acoustic navigation system. Called Asmod, the system consists of three or four transponders placed on the sea floor around the site. They can be triggered to transmit a locational signal in response to a interrogation/responder unit mounted on a camera sled. Brockett:
"By the time they found the, it was right at the end of the program. They had unfortunately taken on a load of bad fuel in Panama that was wreaking havoc on the engines. So they only made a couple of camera tows and one of them was right over the sub. We have a half a dozen good pictures of a portion of the sub. Unfortunately that's all we have. But it was enough to tell us we had what we were looking for. There'll be more to follow."
"The German sub's re-navigated position ended up being ten or so miles off," Tidwell explained. "But the Allied fleet's position data was also off. Meridian's re-plot from the American fleet's logs came up with a re-navigated position for the I-52 that was within less than half a mile of her actual location. It was just phenomenal!"
Tidwell sensational find (announced in July and publicized world-wide) has not gone unchallenged. In August, a fellow Texas treasure hunter, Larry Barbernell, claiming that Tidwell and fellow marine researcher Eugene Lyon took research on the I-52 that was his exclusively, said he would seek a restraining order preventing any salvage efforts. Tidwell does not appear seriously concerned. Elsewhere, the Japanese Government has objected to the salvage plans, in part because the wreck is also a grave. Tidwell, a former Army infantryman who served two tours in Vietnam and won a Purple Heart, has pledged to disturb the site as little as possible. He plans to travel to Japan to discuss the matter with Japanese officials.