But as the ravaged hull corrodes and is worn thinner by salty ocean water, researchers are using specialized computer software to model and predict how long it will take before the Arizona 's structure fails and spills greater quantities of the trapped oil and fouls the harbor.

Timothy Foecke, a metallurgist at the Gaitherburg, Md.-based National Institute of Standards and Technology (NIST), has been working for more than three years to model oil leak scenarios from the Arizona for the National Park Service and the USS Arizona Preservation Project to help predict how the wreckage will continue to deteriorate underwater.

Foecke is using finite elements analysis software from Providence, R.I.-based Abaqus Inc., which makes analytical software used in engineering and other industries to design products and evaluate large amounts of data.

Foecke's initial calculations show that there are still 10 to 20 more years before significant shifts begin to happen in the underwater wreckage that will lead to larger spills of the estimated 500,000 gallons of heavy fuel oil that went down with the battleship.

"She was fully fueled to make a Christmas trip back to the West Coast [of the U.S.] when she was sunk," Foecke said.