USS Iowa was a pre-dreadnought battleship built for the United States Navy in the mid-1890s. The ship was a marked improvement over the previous s, correcting many of the defects in the design of those vessels. Among the most important improvements were significantly better seaworthiness owing to her greater freeboard and a more efficient arrangement of the armament. Iowa was designed to operate on the high seas, which had been the impetus to increase the freeboard. She was armed with a battery of four guns in two twin-gun turrets, supported by a secondary battery of eight guns.
Upon entering service in June 1897, Iowa conducted training operations in the Atlantic Ocean before moving to the Caribbean in early 1898 as tensions between the United States and Spain over Cuba grew, leading to the Spanish–American War. The ship took part in the bombardment of San Juan, Puerto Rico, and then participated in the blockade of Cuba during the war, and after the Spanish cruiser squadron was found in Santiago de Cuba, she patrolled off the harbor to block their escape. In the Battle of Santiago de Cuba on 3 July, Iowa assisted in the destruction of three of the four Spanish cruisers. After the war, Iowa spent the next several years conducting routine training exercises, serving with the Pacific Squadron from 1898 to 1902, the South Atlantic Squadron until 1904, and the North Atlantic Squadron until 1906, when the latter two units were merged to form the Atlantic Fleet.
Iowa was modernized between 1908 and 1910; she thereafter served as a training ship for naval cadets from the United States Naval Academy and for naval militia crews. Removed from service in 1913 and decommissioned in 1914, she was reactivated after the United States entered World War I in April 1917, initially serving as a receiving ship and then as a training vessel and guard ship. She was decommissioned again in 1919, renamed Coast Battleship No. 4, and converted into a radio-controlled target ship. She was used in bombing experiments off the Virginia Capes in 1921 before being sunk as part of Fleet Problem I off the coast of Panama in March 1923 by the battleship .
Design
In the early 1880s, the United States Navy began to grapple with the question of coastal defense; the United States at that time had a significant isolationist streak and naval strategy had historically been grounded in commerce raiding. After building the interim armored vessels and , the navy requested funding for additional ships in 1887, and one vessel was authorized for the following year. Conflicting ideas about the vessel that would be built delayed construction and led the Secretary of the Navy, Benjamin F. Tracy, to convene a Policy Board in January 1890. Tracy wanted to build sea-going battleships that could project American naval power overseas, though significant elements in the Navy and the United States Congress preferred shallow-draft coastal-defense ships.
The Board concluded that the distance between Europe and North America would hamper European naval attacks, but the power of the British Royal Navy and the possibility of future political developments warranted the construction of a powerful American battle fleet. The Policy Board issued a call for a fleet that would consist of eight first-class battleships, ten slightly smaller second-class battleships, and five third-class ships, along with substantial numbers of lesser craft to support them. The fleet would be tasked with defending the East Coast of the United States, which required an operational range that could cover as far south as the Caribbean Sea, as the Board had determined that any hostile power would need to seize advance bases there to effectively operate against the United States. The three vessels already authorized—Maine, Texas, and what became the armored cruiser fit in the third category, so larger and more powerful vessels would have to be built to meet the Board's recommendations.
Congress, dismayed by the Board's conclusions, nevertheless approved funding for three of the first-class battleships in April 1890, which became the s. These were low-freeboard vessels intended for local, coastal defense. They were badly overweight when completed, and as a result suffered from serious problems, including belt armor that was fully submerged when the ships were fully loaded, a tendency to ship excessive amounts of water, and poor handling characteristics. Changes in the control of Congress in late 1890 led to delays for the next ship to be authorized until 19 July 1892, when funds were allocated for a "seagoing coastline battleship". The vessel was to be built with a displacement of around .
The Policy Board had intended in its original plan that the seagoing ship would trade armor for greater range, but the Bureau of Construction and Repair, responsible for the design of the vessel, decided to reduce the gun armament compared to the Indianas to free up displacement for greater fuel storage. The main battery of the Indiana class would be replaced with guns, while some of the secondary guns would be replaced with faster-firing quick-firing guns. Weight would also be saved by the adoption of Harvey armor, which was significantly more effective than compound armor; a thinner belt could thus be used to achieve the same level of protection. The intention to use the new ship for long-range deployments required other changes, in addition to increased coal storage. Since the vessel would necessarily have to operate on the high seas, seaworthiness would have to be improved. This required a greater freeboard, so the ship that was to become Iowa was given a raised forecastle deck that extended from the bow to amidships. The hull was lengthened and displaced more than the Indianas. In addition, the heavy 8-inch gun turrets were moved closer together amidships, which reduced the amount of weight toward the ends of the ship, also contributing to improved sea-keeping. The arrangement also reduced blast interference between the 8-inch and the 12-inch guns.
General characteristics and machinery
Iowa had a length at the waterline of and an overall length of . Her beam measured and she had an average draft of . She had a metacentric height of and a righting arm of . She displaced as designed and up to at full load. Steering was controlled with a single rudder; while steaming at , she could make a 180-degree turn in , and at a speed of , she could make the turn in .
Her hull featured a tumblehome shape, the only time an American battleship was designed that way. She was fitted with a ram bow, a customary feature of capital ships of the period. It had much greater freeboard than the Indianas, providing her with significantly better sea-keeping qualities. She was completed with a single heavy military mast fitted with fighting tops, which was placed atop the forward conning tower. A large derrick was placed abreast the aft funnel to handle the boats carried aboard. She had a crew of 36 officers and 540 enlisted men.
The ship was powered by a pair of 3-cylinder, vertical triple-expansion steam engines that each drove a screw propeller. Steam was provided by five coal burning fire-tube boilers; three were double-ended boilers while the other two were single-ended versions. The boilers produced steam at . They were ducted into a pair of very tall funnels; these were adopted to improve draft to the boilers. Like the Indiana class, Iowa was fitted for forced draft, and she had mechanical hoists to remove ash from the boiler rooms. The propulsion system was rated to produce for a top speed of , though on speed trials she reached and a maximum speed of . Coal storage amounted to . At a speed of 10 knots, she could steam for .
Armament
Iowa was armed with a main battery of four /35 caliber guns mounted in two twin-gun turrets that were mounted on the centerline, one forward and the other aft of the superstructure. The built-up guns were the Mark II type, which were placed in elliptical Mark III turrets. The training gear was hydraulically operated, but elevation was hand-operated only. The gun mounts allowed elevation to 14 degrees and depression to −5 degrees; to reload the guns, they had to be returned to 3 degrees elevation. The ammunition hoists that retrieved shells and propellant charges from the magazines were also hydraulically operated. The guns fired an shell with a charge of brown powder. Muzzle velocity was , and at the muzzle, the shells could penetrate up to of mild steel; at a range of , their penetration capability fell to . The average rate of fire was one shot every five minutes, though fresh, well-trained crews could achieve rates as fast as one shot every three minutes.
The primary armament was supported by a secondary battery of eight /35 cal guns that were carried in four twin-gun wing turrets. Two were placed on either side of the ship, abreast of the funnels. Since the 12-inch guns had a long reloading time, the 8-inch guns were incorporated to increase the number of weapons that could defeat light armor. The 8-inch guns were the Mark IV version, which had a rate of fire of one shot per minute. They had a muzzle velocity of , firing armor-piercing shells. They were initially supplied with brown powder charges, but after the advent of smokeless powder, new, smokeless charges were adopted that increased the rate of fire by twenty seconds. Mounted in Mark VIII turrets with a range of elevation from −7 to 13 degrees, reloading was fixed at 0 degrees.
Six /40 cal quick-firing guns rounded out the secondary battery; these were intended to use their high rate of fire, coupled with high-explosive shells to damage unarmored parts of enemy warships. Four of these were placed in individual casemates in the forecastle deck, two in sponsons in the bow and the other two located amidships. The remaining two guns were in open shielded mounts on the aft superstructure, superfiring over the rear main battery turret. They fired a high-explosive shell at a muzzle velocity of . For defense against torpedo boats, the ship carried a battery of twenty 6-pounder Hotchkiss guns and four 1-pounder guns These guns were dispersed around the ship in a variety of individual mounts, including in the fighting top of the military mast, the superstructure, and in sponsons in the hull. She also carried four M1895 Colt–Browning machine guns chambered in 6mm Lee Navy.
As was standard practice for capital ships of the era, Iowa carried four above-water, torpedo tubes in her hull, two on each broadside. These launched the Howell torpedo, which had a range of and traveled at a speed of . They carried a warhead.
Armor Iowa was protected with Harvey armor, which was fabricated with a new type of process that produced steel that was significantly stronger than traditional compound armor. The main armor belt was 14 in thick in the central portion, where it protected the magazines and propulsion machinery spaces. It extended from above the waterline and below the line, and it extended for a length of of the hull. The belt tapered to at the lower edge. At either end of the belt, angled bulkheads that were 12 in thick connected the belt to the barbettes for the main battery turrets. She had a thick armor deck that was level with the top edge of the belt. On either end of the belt, the deck sloped down on the sides and was increased slightly to to provide the bow and stern with a measure of protection against light guns. Above the belt was a thinner strake of armor that was thick where it protected the 4-inch guns and reduced to where it covered the 57 mm and 37 mm guns.