From: J. Forster (jfor@quik.com)
Date: Wed Dec 07 2005 - 21:41:00 PST
Subject: [Canadian Navy List]
As the Arizona rusts, scientists work to see if it can be saved
Date: Wed, 07 Dec 2005 17:10:25 -0000
From: "navalofficerca" <navalofficerca@yahoo.ca>
By Scott LaFee
UNION-TRIBUNE STAFF WRITER
December 7, 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.
One terrible day
The chaos of that day isn't easily forgotten
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.
Assessing Arizona
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.
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.
"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.
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.
"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.
*************
Thanks Jerry,
-John
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