High-tech hunters close in on lost sub


There's a lonely grave of men, gold and mystery lying three miles under the Atlantic Ocean, and David Jourdan's small Columbia company is using the latest deep-sea technologies to plumb it.

The target for Mr. Jourdan and his company, Meridian Sciences, is a Japanese submarine, the I-52. Historians believe the Navy sank it off the coast of Africa near Cape Verde 50 years ago during World War II.

In early May, Meridian -- a 15-person firm specializing in oceanographic and navigational research -- solved one of the key mysteries of the I-52: exactly where it went down when the Navy pilot said he sank it with a single torpedo.

Using its sophisticated technologies, Meridian late this fall will tackle other mysteries involving the 2,500-ton sub that is longer than a football field. Did a torpedo really strike and sink it? How much gold and other valuable metals are aboard? What kind of sea life inhabits wreckage so deep in the sea?

"It's sort of like detective work," said Mr. Jourdan, Meridian's president and a 1976 Naval Academy graduate who served aboard a Navy submarine. "We have a lot of clues as to where it went down and what happened. But they aren't perfect clues. The key is knowing what to do with them."

How Meridian scientists found the I-52 is a striking example of advances in high-technology that are helping to explore deep oceans, said Paul R. Tidwell, the Virginia maritime researcher and explorer who organized the I-52 project. The I-52 expedition also highlights how technologies once available only to naval powers now are being put to commercial use.

The commercial angle to the search for the I-52 stems from the 2 tons of gold the submarine is believed to have been carrying from Japan to Germany -- a cache that Mr. Tidwell estimates is worth as much $25 million. When the sub and its 100-man crew went down, it also was carrying loads of tungsten and rubber.

Meridian -- which normally works under Navy contracts and has nine years of experience in using the latest sonar and deep-sea imaging technologies -- was brought into the search under a contract with a group of investors organized by Mr. Tidwell of Centreville, Va. The group hopes to recover more than the search's $1 million cost by salvaging the sub's gold.

The man who headed the sea search for the I-52 was Meridian's Tom Dettweiler, widely considered one of the best underwater surveyors in the world. He helped locate the Titanic in 1987 and conducted an unsuccessful search for the German battleship Bismarck sunk in 1941. Mr. Dettweiler now is at sea on a different project.

"What you have here is 'seaQuest' for real," Mr. Tidwell said. "The expedition would not have been possible without the advanced technology and the best people to put that technology to use."

The final stage of the search for the I-52 began in early April when Mr. Dettweiler and two Meridian sonar experts set sail from Barbados aboard a leased Russian research vessel.

Mr. Tidwell had spent years researching decoded and declassified Navy, German and Japanese World War II records to determine the sub's location -- including German intelligence reports verifying it had been sunk carrying gold.

Navy logs of the torpedo attack provided the best coordinates: 15.16 degrees north and 39.55 degrees west, or about 1,200 miles west of the Cape Verde islands.

To explore the ocean floor, Meridian used a vintage Russian version of side-scan sonar, a device widely used in oceanographic research, Navy surveillance and offshore oil exploration. The device, which looks like a fat torpedo encased in a boxy cage, was lowered into the sea and pulled along by a cable.

Moving very slowly through the ocean, the sonar flashed a band of sound signals downward that provided acoustic pictures of the sea floor. The exact location of each of those images was flashed to the ship by other devices dropped into the water around the search site.

But this was not an easy triumph of technology over the elements.

After almost three weeks tediously searching the area, Meridian's scientists had no sighting. Their ship was running dangerously low on fuel and food. "I was growing frustrated and was ready to cancel the operation," recalled Mr. Tidwell.

Back in Columbia, Mr. Jourdan worried the Navy's records were wrong. He put to work his navigational science expertise.

He logged into a Meridian computer and entered the sailing courses of two ships in the area at the time the I-52 is believed to have been sunk -- an American aircraft carrier, USS Bogue, and a German submarine, the U530.

He also entered the coordinates of the Bogue at the time its officers reported seeing an explosion June 23, 1944, the day the I-52 sank, and the I-52's location when it earlier met the German U530, so several German officers could board.

Mr. Jourdan determined that the U.S. Navy's coordinates for the I-52's sinking were off -- "by tens of miles," he said.

Using the Internet, Mr. Jourdan sent his remapping to Mr. Dettweiler and Meridian's sonar and computer expert, David Wyatt, at sea. Four days later, as the sonar slowly crossed above the ocean floor of the new coordinates, a razor thin sliver showed up on the sonar printout. "Found good target . . . very close to Dave Jourdan's position," Mr. Dettweiler noted in the logbook.

The ship made two more passes over the sighting to get better images from three miles deep. It was then that Meridian brought out its key technology for the search: Orion, a highly sophisticated computer program the company developed for Navy sonar work.

Orion enhances sonar signals, providing much more detailed images of the ocean floor and the densities of objects. Using it, the razor thin sliver became an eerie picture of a sunken submarine lying right side up on the ocean floor, its conning tower casting a gloomy, telltale shadow.

"You could clearly see evidence of a 'down blast' area near the sub, where the ocean bottom was forced away by the sheer force it hit with," said Meridian's Jeff Burns, who assisted with sonar readings on the research ship.

Said Mr. Tidwell: "The feeling I had looking at that picture was very strange. We were looking at a part of history much of which has been unknown to the general public."

Sonar pictures enhanced by Orion also showed another important element: an area of debris, probably cargo and hunks of metal as large as a couch, lying nearby.

But Meridian's work was not done: Needed were photos of parts of the sunken vessel to confirm that the hulk of metal on the sonar screen was indeed an I-class Japanese sub.

The crew hooked up to the cable a huge metal "sled" loaded with underwater video and camera equipment, lowered it into the water and then dragged it slowly above the sunken vessel.

Meridian scientists loaded the photographic images of the vessel onto a rare and expensive computer program called an "electric light table." The program -- developed by the National Aeronautics and Space Administration and jet propulsion experts to enhance images taken from outer space -- corrects distortions in images and merges various images into a single photograph.

Meridian's scientists then matched the unified image with drawings and World War II photographs of I-class subs. It was only then that they were certain they'd found the I-52.

There was no champagne or whooping for joy. Just, recalled Mr. Burns, "this enormous sense of relief."

Meridian now is looking to use its expertise to help salvage the sub's gold -- and open a window to a part of the world virtually unexplored by biologists and other scientists. The salvage and research operation, one of the deepest attempted in history, should begin late this fall.

"We will be exploring a part of the world unseen by man since the beginning of the Earth," said Mr. Tidwell. "It's going to be amazing."

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