BB-38 Pennsylvania Class
The Pennsylvania class numbered two ships, both built on the east coast. The Pennsylvania class battleships were an enlargement of the preceding Nevada class, with two more 14"/45 main battery guns, greater length and displacement, four propellers and slightly higher speed. They also had a very large secondary battery of 5"/51 guns, which was soon reduced when many of the guns' locations proved to be impossibly wet.
The dimensions of the ship were quite impressive for the time. Its overall length was 608 feet (two American football fields long) with a beam of 97 feet 1 inch. It displaced 31,400 tons with a mean draft of 28 feet 10 inches. The ARIZONA's four shafts were driven by four paired Parsons turbines and 12 Babcock and Wilcox boilers that developed 33,375 horsepower, enabling a top speed of 21 knots. The designed complement was 55 officers and 860 men. The ARIZONA was well-armed for ships of its period. The original armament consisted of 12 14-inch 45-caliber guns; 22 5-inch 51-caliber guns; four 3-inch 50-caliber guns; and two 21-inch submerged torpedo tubes.
They were protected by 18 inches of armor at its maximum thickness. The ARIZONA and its sister ship PENNSYLVANIA represented a modest improvement of the previous NEVADA-class battleships: length and displacement were somewhat increased and two additional 14-inch guns were shipped, the main armament now being arranged in four triple turrets. The significant change was concentrated in the firepower of the vessel: The ARIZONA's four turrets (labeled No. 1, 2, 3 and 4) each mounted three 14-inch naval guns.
Serving in the western Atlantic in 1916-18, these ships visited Europe just after the November 1918 Armistice and were thereafter stalwart members of the Navy's Battle Fleet. Reconstructed in 1929-31, they received greater main battery gun elevation, tripod masts to support improved gun directors and modern aircraft catapults. The ships' secondary gun batteries were updated, as was protection against gunfire, aircraft bombs and torpedoes. Pennsylvania, assigned to duty as a fleet flagship, was given a greatly enlarged armored conning tower. Now capable of long-range gunfire in an age when the role of aircraft was steadily growing, the ships spent another decade in the Nation's battle line.
On 01 May 1929 Arizona returned to Norfolk in preparation for modernization overhaul. On May 4, 1929 it entered the yard at Norfolk for that purpose and was placed in reduced commission until July 1929. During this modernization the ARIZONA received a massive facelift. First to go were the traditional cage masts that were replaced fore and aft by tripod types. New 5-inch antiaircraft guns replaced the outdated 3-inch mounts. New armor was added below the upper decks to guard against the fall of shot by high-angle gunfire and bombs dropped by aircraft. Extra compartments called "blisters" were added to the outer hull to increase the ship's protection against torpedo attack. In an effort to offset the additional weight, a brand-new power plant consisting of modern boilers and turbines was installed to allow it to maintain normal fleet speed. The engines were upgraded with new geared units, and the original boilers were replaced with six Bureau Express three-drum boilers. The ARIZONA's fuel capacity was increased from 2,332 to 4,630 tons of oil. On March 1, 1931 modernization was completed, and the ARIZONA was placed in full commission once again.
The USS ARIZONA's configuration changed very little since the 1931 modernization. However, in April 1939 and January 1941 alterations had been done to ready the vessel for war.
In that effort, an exposed pair of 5-inch, 51-caliber guns was removed so that new 1.1-inch quadruple machine-gun mounts could be installed on the superstructure deck abreast of the conning tower. Another set of the 1.1-inch mounts was also to be installed on the quarterdeck between the mainmast and gun turret No. 3. Foundations, ballistic shields, ammunition hoists, and ready-service lockers were in stalled. At the time of the attack, those areas were vacant of any armament -- the guns had been scheduled for installation in early 1942.
A variety of 50-caliber machine guns was installed to increase antiaircraft fire power. It was quite common to relocate such weapons from time to time to increase their arc of fire. Originally four were placed on the main platforms of each mast. In 1939 search lights carried on the funnel were removed, and two machine guns from the mainmast replaced them. In January 1941 at Puget Sound the vessel was fitted with a "birdbath" platform atop the main mast director tower. The "birdbath" was filled with four 50-caliber guns, two from the foremast and two from the mainmast. Leaving two guns on the foremast platform and two on the funnel platform, searchlights were placed on the former gun platform of the mainmast. Splinter shields were mounted on the superstructure deck to protect the crews manning the eight 5-inch, 25-caliber guns located there.
Coupled with increased antiaircraft fire power was the installation of new Mark 28 antiaircraft directors that were supposed to increase the firing efficiency for the 5- inch 25-caliber guns. The location of the directors was on the range-finder platform level of the bridge. Here adequate support of the superstructure deck could be found via their heavy wiring tubes. This site afforded sufficient sky arc coverage for the directors' use. Early in 1942 the ARIZONA was scheduled to receive fire control and air search radar equipment. At the time of her loss, most of the structural modifications had been accomplished.
The Pennsylvanias were both present during Japan's 7 December 1941 attack on Pearl Harbor. Arizona blew up in action, the most dramatic and costly casualty of the raid. Pennsylvania was only lightly damaged, and she served in the Pacific throughout the Second World War. Fitted with a new secondary battery of twin-mounted 5"/38 guns in late 1942, she supported many amphibious invasions and was present during the World's last battle between big-gun warships, the Battle of Surigao Strait on 25 October 1944. A torpedo hit in August 1945 proved that her watertight integrity, like that of other old warships, could not be relied upon. With other obsolete battleships, Pennsylvania was an atomic bomb target in 1946 and was scuttled at sea two years later.
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