CV-2 Lexington Class - Design
Saratoga and sister ship USS Lexington (CV 2) were the world’s largest aircraft carriers until late in World War II and the “Sara” was the world’s fastest capital ship of her era, reaching 34.99 knots.
Shortly before the United States’ entry into World War I, Congress authorized the construction of six large battle cruisers—each to be 35,300-ton, 874-foot warships mounting 10 14-inch guns. Massive turboelectric machinery, with exhaust gases carried away by seven funnels, was to drive the ships at 35 knots. None of the six ships had commenced construction before hostilities ceased in November 1918, and none had been launched when construction was halted on 8 February 1922, in accordance with the terms of the Washington Naval Treaty. The treaty, however, permitted two capital ships to be converted to aircraft carriers. On 1 July 1922, Congress authorized the completion of the battlecruisers Lexington (33.8 percent complete) and Saratoga (35.4 percent) as carriers. Their four unfinished sister ships were scrapped on the building ways.
“Lex” and “Sara” each measured 888 feet overall in length and had an official standard displacement of 33,000 tons. In reality, each displaced some 3,000 tons more as the Navy Department claimed that additional tonnage was allowed under a provision of the Washington treaty that did not count weight for defenses against air and submarine attacks. At full load, Saratoga eventually displaced some 41,000 tons. The carriers had turboelectric propulsion designed to produce 180,000 horsepower, or six times that of a contemporary battleship. This type of propulsion was larger, heavier, and more expensive than an equivalent steam turbine plant. Still, turboelectric drive permitted more compartmentalization for damage control and was, in theory, more resistant to damage. In practice, however, turboelectric drive was highly vulnerable to electrical short circuits from battle damage. The “Lex” and “Sara” were the world’s largest warships built with electric propulsion during the 20th century. The carriers’ design speed was 33.25 knots, but both ships exceeded that figure. Lexington once attained a speed of 34.5 knots for one hour; Saratoga exceeded that speed by almost half a knot.
At first it was proposed to leave the flight decks of the huge carriers unobstructed by superstructures, but after wind tests with ship models it was decided to have their control stations, funnels, and guns combined into massive island structures on the starboard side of each ship’s flight deck. These structures stretched almost one-third the length of the ship and included a funnel to carry away exhaust gases from the ship’s 16 boilers, venting the gases high above the flight deck where they would not interfere with landing operations.
As completed, “Lex” and “Sara” each had a main battery of eight 8-inch guns arranged in twin turrets, two forward and two abaft the island structure. These were to defend the carriers should they be attacked by enemy cruisers when their aircraft were off on missions. Each carrier also had a dozen 5-inch anti-aircraft guns in galleries along the edge of the flight deck, plus several machine guns.
USS Saratoga (CV-3) was a steel-hulled vessel with a waterline length of 830 feet. The cruiser hull of Saratoga was wedded to the flight deck, which as built was 874 feet long (later extended to 888 feet) and overhung the hull forward and aft. "Above the water line the hull shape was determined by the requirements for as wide a flying deck as possible. This has given a very pronounced flare both forward and aft. Each had a 901-foot overall length, a beam of 111 feet, 9 inches, a mean draft of 32 feet, and 16 boilers, as opposed to the eight aboard most current carriers. Their engines produced 180,000 hp, and their speed was 33¼ knots. Armament included eight eight-inch and 12 fiveinch guns. From keel to flight deck, the depth of the hull was 74-1/2 feet. The hangar deck below was built to accommodate 90 aircraft maximum; Saratoga usually carried 81 to 83 planes. Saratoga's maximum beam was 105-1/2 feet, with a mean draft of 31 feet.
Saratoga's characteristics as an aircraft carrier were influenced by the ship's original design as a cruiser. Partially completed as cruisers when the order was given to convert Saratoga and its sister Lexington to carriers, they could not be economically torn apart and rebuilt. The principal dimensions of the hull, the primary features of protection against gunfire and underwater explosion, and the design of the propelling machinery were thus determined before the plans for conversion to airplane carriers was undertaken. This situation forced the acceptance of elements which in a new design might have been changed. The development of the machinery and ammunition handling spaces was practically complete, and the airplane carrier development took place almost entirely above the protective deck.
The original hull design was unchanged; a large hangar was fitted, exhaust was routed through a large starboard side funnel and a massive island structure sat forward of the funnel. These ships actually listed slightly to starboard due to the weight of their funnel and island. They had a long, narrow flight deck and as mentioned, carried gun armament equivalent to that of a heavy cruiser.
Saratoga's four shafts were driven by a GE turbo-electric drive. Eight engines, two on each shaft, produced 180,000 shaft horsepower at 32.25 knots. Saratoga delivered 32.28 knots on its initial trials and 34.99 knots on its final trials. Steam was produced by 16 White-Foster oil-burning boilers. The uptakes were swept together into a single, flat-sided, 105-foot long, 80-foot tall (later cut down some 15 feet) funnel abaft the island. The flight deck, 47 feet above the waterline, was covered with wood planking, caulked and painted.
Under provision of the Washington Naval treaty, carrier conversions were limited to 33,000 tons maximum standard displacement, and no more than ten low-angle guns with a maximum caliber of eight inches. Both the United States and Japan interpreted a clause in the Treaty to permit adding 3,000 tons of antiaircraft and torpedo defenses to capital ships, to apply to their carrier conversions. As a result, while listed "officially" at 33,000 tons, Lexington and Saratoga carried weight in excess of the treaty limit, even after sacrificing some of their cruiser armor. Saratoga "officially" displaced 33,000 standard tons in compliance with the Washington Naval Treaty. The vessel actually displaced (full combat load) 43,500 tons -- later alluded to by "official" tonnage upgrades to 36,000, later increased to 40,000, tons. The ship's trial displacement was 38,957 tons.
At the start of America's war in the Pacific they were both in need of modernization but could not be spared from operations. Lexington (CV-2) was lost at the Battle of Coral Sea in May 1942.
The Lexington-class carriers had one major design flaw -- the inclusion of their four twin 8-inch/55 caliber gun mounts, which could only be fired in starboard broadsides. The 8-inch guns, intended to battle a surface enemy, were also out of place on a carrier. This was corrected after the outbreak of war. In January-April 1942, following the carrier's return to the Puget Sound Navy Yard after being torpedoed, Saratoga underwent its first major wartime refit, when the 8-inch guns were replaced with 5-inch/38 caliber guns, the correct weapon against the carrier's true foe: enemy carrier aircraft.
Saratoga's gun armament also included an antiaircraft array of twelve 5-inch/25 caliber guns and eight .50 caliber machine guns. In the 1930s their AA armament was modernized with the eight .50 caliber machine guns replaced with quad-mount 1.1-inch machine guns. During the January-April 1942 refit, single 5-inch/38 caliber guns were added to the sponsons, replacing the original 5-inch/25 caliber weapons. Thirty 20mm Oerlikon antiaircraft guns were added, and four quad 40mm Bofors guns were installed.
Torpedoed in August 1942, Saratoga after repairs was again modified; the 1.1-inch guns were removed and replaced with 40mm Bofors, making nine such mounts, and twenty-two additional 20mm guns were installed, making 52 of these single-barrel weapons on board. The hull was modified for the first time in 1942; a torpedo blister was added to the starboard side, increasing the beam to 108 feet and fixing a list caused by the heavy island, guns, and funnel on that side.
In another refit in December 1943, Saratoga received 16 more Bofors mounts; two in new portside sponsons abeam the island, seven in the boat recesses to port, two in the boat recess to starboard, three outboard of the flight deck off the island, and two in the bow machine gun galleries. Other modifications included reducing the island structure, cutting it down to an open bridge for air operations, with the original flag plot one deck below, followed by the pilothouse and navigating bridge, conning tower, and at flight deck level, the meteorological platform and air intelligence office. The original tripod foremast was replaced by a pole mast mounting SK radar. In the summer of 1944, Saratoga received an SM fighter-director set of radar on the forward end of the funnel, and a pair of H Mk II hydraulic catapults were installed forward on the flight deck (previously the ship had a single hydraulic catapult). Other modifications included the installation of a portside torpedo blister.
Saratoga was heavily damaged off Iwo Jima by Japanese bomb hits on February 21, 1945, which holed the flight deck and the starboard hull near the bow, starting fires on the hangar deck. Repairs at Puget Sound hastily patched the hull and deck, removed the after elevator, fitted a new 44-foot square elevator forward, and filled the aft end of the hangar deck with two decks of berths.
