Tuesday, December 13, 2005

 

As the Arizona rusts, scientists work to see if it can be saved

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Sign on San Diego
By Scott LaFee
December 07, 2005


National Park Service photo
The USS Arizona Memorial was built in 1962

over the battleship's remains at the bottom
of Pearl Harbor, in Hawaii. Nearly 1,200 officers
and crew were killed when Japanese aircraft
attacked Pearl Harbor on Dec. 7, 1941.

For decades, nobody looked to see what was happening to the battleship Arizona, sunk this day 64 years ago during the Japanese attack at Pearl Harbor, Hawaii.

At first, there simply wasn't time. There was fighting to be done and the Arizona was simply among the first catastrophic casualties of a second World War.

In time, though, the ship became a rallying point, a memorial and finally, an enduring symbol of sacrifice, loss and ultimate victory.

"The Arizona is now a sacred place," said James Delgado, an underwater archaeologist and executive director of the Vancouver Maritime Museum and co-author of the book "The USS Arizona." "I've worked on a lot of sunken vessels. When you add the element of sacrifice and loss, like you do with the Arizona, it transcends everything. The subject is no longer a twisted, scarred, battle-racked hulk of corroding steel. It's an icon."



An icon, nonetheless, made of corroding steel.

Which brings us to the present, to scenes earlier this year of scuba divers probing the wreck of the Arizona, drilling core samples from its hull, sending a remote-controlled submersible as deep as possible into the ship's collapsed innards.

The Arizona is much more than the sum of its sunken, rusting parts, but it has become increasingly crucial to learn how those sunken, rusting parts are faring. How fast is the ship decaying? Is collapse imminent? In what condition are the fuel bunkers, which still contain an estimated 500,000 gallons of No. 6 oil?

More profoundly, can the Arizona be saved? Or will nature reclaim it, reducing the 608-foot vessel to a shapeless mound half buried in Pearl Harbor's fine gray silt, the remainder so encrusted with barnacles, oysters, corals and other marine life as to be unrecognizable?

Launched in 1916, the Arizona was an old but still serviceable battleship in December 1941. It had been modernized and refitted several times, including receiving batteries of new anti-aircraft guns just months before the Pearl Harbor attack. The ship remained a force to be reckoned with at sea.

But it died at its berth, one of seven active battleships damaged by Japanese aircraft that attacked at 7:55 a.m. Dec. 7, 1941. The Arizona was struck by at least eight bombs, including one 1,760-pound projectile that penetrated the forward ammunition magazine. The subsequent blast was massive and fatal, instantly killing much of the ship's crew and hurling tons of debris and body parts across the harbor.


Naval Historical Foundation
The Arizona was hit by at least eight bombs

during the attack. The ship, which launched
in 1916, burned for days before sinking in 38
feet of water.

At 10:32 a.m., the Arizona was abandoned by its surviving crew – 337 men. The ship would burn for another day or so before finally sinking in 38 feet of water, its bent and blackened superstructure rising above the oily surface like a headstone.

Of the 1,177 officers and crew killed aboard the Arizona, only 274 bodies were recovered. The rest remain with the ship.

For years, the Navy didn't quite know what to do with the Arizona. In the months after the attack, the ship's superstructure was removed and dumped on Waipio Peninsula, another part of Pearl Harbor, where it remains today, scarcely recognizable. Most of the guns and other equipment were salvaged for wartime use.

As late as the 1950s, proposals were still being floated of ways to get rid of the wreck, one suggesting that it be reburied in a nearby landfill.

That didn't happen, of course. In 1962, an Alfred Preis-designed memorial was erected over the Arizona's remains at berth F-7. Almost 1.5 million people visit the memorial each year. In 1980, the National Park Service took charge of the memorial, though the ship itself still belongs to the Navy.

The first scientific efforts to assess the Arizona's condition began soon after, with a series of underwater surveys by archaeologists from the National Park Service's Submerged Resources Center. That project was followed up in 2000 with a new set of surveys, the final one scheduled for next year.

"Basically, our goal is to characterize the corrosion process, to determine the rates of decay and project them into the future, to determine how long we have before the Arizona or parts of it are likely to collapse," said Mat thew Russell, an archaeologist and director of the Submerged Resources Center.

Appraising the Arizona has not been easy. The water is murky. Much of the front half of the ship, where the ammunition magazine exploded, collapsed. It is impossible for divers to safely enter or explore most of the ship's interior. There is another reason they don't do so: respect for the dead.

But by extracting core samples from different sections of the ship, by taking precise measurements via Global Positioning Satellite technology and chemically analyzing oil leaking from the Arizona, park service scientists and others have cobbled together a high-tech picture of the state of the Arizona.


BRETT SEYMOUR
Divers took measurements of the Arizona, which

are used to help create a picture of the battleship's
condition. Gathering data has not been an easy feat
because the water is murky and a large portion of
the front half of the ship is collapsed.

"We've built what's called a finite element model," said Dan Lenihan, a semi-retired park service archaeologist who first dived on the Arizona in the 1980s.

"It's a computational model of what's there. Every time we learn something new, every time something changes – the rate of oil release, the thickness of steel in some part of the ship – we work it into the model. Over the years, we've developed quite a cumulative database. We're able to predict with some degree of accuracy what will happen to the ship."

The news is surprisingly good: The ship appears to be structurally sound, relatively speaking, with no threat of imminent collapse. In part, researchers say, this is because marine life now thickly coats much of the ship.

"The marine coating has reduced the amount of oxygen in contact with steel, which means less oxidation and rust," Lenihan said. "The rate of decay, though, is variable. The parts of the ship exposed to air and sea are decaying faster. But there are also places inside the ship and below the mudline where there's apparently little or no oxygen available to fuel decay."

That also bodes well for the problem of what to do about the Arizona's remaining fuel stores.

"Folks are always asking why we don't simply pump out the oil," Russell said. "But that would be a very intrusive, destructive process, even if it were possible. It isn't because the oil is contained in bunkers distrib uted throughout the ship, more than 200."

Compounding the problem: Most of the bunkers are below the mudline.

At the moment, the Arizona releases a quart or two of oil a day – drop by rising drop – from a dozen or so leaks. Eventually, scientists say, the Arizona is likely to spring a serious leak, but it probably won't happen soon.

"If our research is correct, there are decades, if not centuries, before major structural collapse becomes likely," Russell said. "There's no urgency to move forward, to remove the oil or alter the state of the ship."

However slowly, the Arizona is falling apart and disappearing. Silt is filling the interior, 3 to 4 feet deep in some places. Scabs of encrusted hull occasionally fall off, exposing new steel to corrosive seawater.

Those entrusted with preserving the Arizona's memory face a conundrum: How much of that memory revolves around the actual ship?

"The Arizona memorial isn't like a statue," said Paul Stillwell, a retired naval historian. "It's the actual thing itself, with the remains of hundreds of men inside."

As such, should the ship be preserved? Can it be?

The short answer to the latter question is no, not with existing technologies. Some observers have suggested using "sacrificial anodes," an idea first devised by Sir Humphrey Davy in 1824. Zinc anodes would be attached to the Arizona and connected to an electrical current. The anodes would supply a steady stream of new electrons to the steel of the Arizona. The anodes would corrode, the ship's steel would not.

The technology has been used successfully in floating ships and on oil platforms, but Russell doubts it would be effective on the Arizona. The battleship is too big and its architecture too complex. And it would be too expensive.

"The mission of the National Park Service is to preserve," said Douglas Lentz, superintendent of the Arizona Memorial. "If we can extend the life of the ship, we will. But you have to be realistic. If the solution costs $50 million, we can't do it. We don't have the money."

In any event, neither Lentz nor the scientists who have studied the Arizona think the issue is really about corroding steel.

"The slow disintegration of the ship is probably something most of us can live with," Lenihan said.

That's because the Arizona is no longer a ship. Or rather, it's something more than a ship.

"There will come a point when the Arizona Memorial will necessarily change," Delgado said.

"The ship will have changed, the parts above water will have eroded away. The effect of seeing what's there will be different, particularly with the passing of the last people who were at Pearl Harbor or who remember what those times were like.

"But that doesn't mean the Arizona's significance will end. The ideals embodied in the death of that ship and the deaths of the men on her are timeless. There are memorials today that still draw people, even though they mark events that happened hundreds or thousands of years ago."

The emotions that fuel those memories, Delgado said, never corrode or disappear.


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