Chapter III: Archeological Record
(continued)

USS ARIZONA

Site Description and Analysis

The ARIZONA (BB 39), a Pennsylvania-class battleship designed for operation in the Pacific, was launched in June 1915. Like most warships, it was built to accomplish specific missions that reflect concepts and strategies operative at the time of design, while later alterations reflect changes in technology and strategies.

The first impression of the ARIZONA is its size -- the vessel is 608 feet long with a beam of 97 feet. The ship was built much bigger than contemporary battleships designed for operation in the Atlantic, which demanded a cruising distance of hundreds of miles, primarily under British, French and German strategies. On the contrary, Pacific operations were conditioned primarily by American and Asian strategies, and required cruising capabilities of thousands of miles. Enormous distances in the Pacific between port facilities, repairs, fueling stations and naval engagements imposed initial design considerations that included speed, reliability, protection, long-range guns, and the ability to carry huge supplies of fuel. Later alterations reinforced one or the other design requirements as a result of changing strategies and technologies balanced against ancient requirements for any seaworthy vessel.

The Naval General Board of 1910 set battleship design parameters for new vessels including the ARIZONA. The ship would have 12 14-inch guns mounted in triple turrets in the main battery, oil-burning engines, "all or nothing" armor, and a speed of 21 knots. Torpedoes and armor-piercing shells were considered the main threats. These specifications would produce some of the fastest long-ranging battleships in the world.

The ARIZONA's armor reflects the interplay between technology, strategy and seaworthy requirements. Armor-piercing shells had to pass through the armor to become armed, and if they passed through ordinary hull or deck plate they would not become armed. Medium armor plate would arm shells, and it offered no protection for the added weight. Only very thick steel plate could offer full protection, hence, the "all or nothing" armor strategy. "All" meant 13.5 inches of steel plate, which is found in areas such as the turrets and armor belt at the water line. If sufficient armor was used all over the vessel topside to thwart armor-piercing shells, the ship would be dangerously unstable. A 3-inch-thick deck was used to ward off most shells and to arm those that passed through. A lower deck was installed of 1.5-inch armor, called the splinter deck, and was sufficient to contain the explosion of shells that passed through the upper deck. The combination provided lightweight, effective protection from most shells.

The ARIZONA underwent a major rebuilding program in 1929-31. Deck armor was increased to 5 inches and an inch was added to the turret tops. The alteration that changed the vessel's appearance was the addition of a steel tank outboard extending from below the turn of the bilge to the top of the armor belt on the side, which is the main deck level. The tank was added to increase torpedo protection. The tank, or torpedo blister, contained an outer void and an inner tank for additional fuel oil. In addition to increased protection from torpedo damage, the blister increased hull displacement, which offset the weight of the added armor, and tripled the ship's cruising range by augmenting fuel capacity. Post-1931 alterations mostly involved upgrade of armament, particularly antiaircraft weapons.

The present appearance of the ARIZONA is a culmination of all the many contributive aspects. The archeological remains are the result of physical changes from alterations during the ship's life, post-attack salvage activities, memorialization and submergence for half a century. A swim over the site starkly reveals these changes and forces a consideration of the history of the vessel and the thinking it represents.

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