Omaha-class cruiser


The Omaha-class cruisers were a class of light cruisers built for the United States Navy. They were the oldest class of cruiser still in active service with the Navy at the outbreak of World War II, being an immediate post-World War I design.

History

Maneuvers conducted in January 1915, made it clear that the US Atlantic Fleet lacked the fast cruisers necessary to provide information on the enemy's position, deny the enemy information of the fleet's own position, and screen friendly forces. Built to scout for a fleet of battleships, the Omaha class featured high speed for cooperation with destroyers, and guns to fend off any destroyers the enemy might send against them. Displacing, they were just over long.
The Omaha class was designed specifically in response to the British subclass of the. Although from a modern viewpoint, a conflict between the US and Great Britain seems implausible, US Navy planners during this time, and up to the mid-1930s, considered Britain to be a formidable rival for power in the Atlantic, and the possibility of armed conflict between the two countries plausible enough to merit appropriate planning measures.
The Omaha class mounted four smokestacks, a look remarkably similar to the s. Their armament showed the slow change from casemate-mounted weapons to turret-mounted guns. They carried twelve /53 caliber guns, of which four were mounted in two twin turrets, one fore and one aft, and the remaining eight in casemates; four on each side. Launched in 1920, had a displacement of 7,050 long tons. The cruisers emerged with a distinctly old-fashioned appearance owing to their World War I-type stacked twin casemate-mount cannons and were among the last broadside cruisers designed anywhere.
Additional torpedo tubes and hydrophone installation was ordered. As a result of the design changes placed on the ship mid-construction, the vessel that entered the water in 1920, was a badly overloaded design that, even at the beginning, had been rather tight. The ships were insufficiently insulated, too hot in the tropics and too cold in the north. Sacrifices in weight savings in the name of increased speed led to severe compromise in the habitability of the ship. While described as a good ship in a seaway, the low freeboard led to frequent water ingestion over the bow and in the torpedo compartments and lower aft casemates. The lightly built hulls leaked, so that sustained high-speed steaming contaminated the oil tanks with sea water.
These drawbacks notwithstanding, the US Navy took some pride in the Omaha class. They featured improved compartmentalization; propulsion machinery was laid out on the unit system, with alternating groups of boiler rooms and engine rooms, to prevent immobilization by a single torpedo hit. Magazines were the first to be placed on centerline, below the waterline. A serious flaw in these ships' subdivision was the complete lack of watertight bulkheads anywhere above the main deck or aft on the main deck.
Originally designed to serve as scouts, they served throughout the interwar period as leaders of fleet flotillas, helping them resist enemy destroyer attack. Tactical scouting became the province of cruiser aircraft, and the distant scouting role was taken over by the new heavy cruisers spawned by the Washington Naval Treaty. Thus, the Omaha class never performed their designed function. They were relegated to the fleet-screening role, where their high speed and great volume of fire were most appreciated.

Armament changes

During their careers the Omahas went through several armament changes. Some of these changes were to save weight, while others were to increase their AA armament. On 8 September 1926, the Chief of Naval Operations, Admiral Edward W. Eberle, along with the Commanders in Chief of the United States Fleet and Battle Fleet, and their subordinate commanding officers, the Secretary of the Navy, Curtis D. Wilbur, ordered that all mines and the tracks for laying the mines be removed from all of the Omaha-class cruisers, as the working conditions had been found to be very "wet". In 1933-1934, their 3-inch AA guns were increased from two to eight, all mounted in the ship's waist. The lower torpedo tube mounts, which had also proved to be very wet, were removed and the openings plated over before the start of World War II. After 1939, the lower aft 6-inch guns were removed from most of the Omahas and the casemates plated over for the same reason as the lower torpedo mounts. The ships' AA armament was first augmented by three quadruple /75 gun mounts by early 1942, however, these did not prove reliable and were replaced by twin Bofors guns later in the war. At about the same time they also received Oerlikon cannons.

World War II service

Both and were at Pearl Harbor during the Japanese surprise attack, with Raleigh being torpedoed. Detroit, along with and, were the only large ships to get out of the harbor during the attack.
The ships of the Omaha class spent most of the war deployed to secondary theaters and in less vital tasks than those assigned to more recently built cruisers. The Omaha class were sent in places where their significant armament might be useful if called upon, but where their age and limited abilities were less likely to be tested. These secondary destinations included patrols off the east and west coasts of South America, convoy escort in the South Pacific far from the front lines of battle, patrols and shore bombardment along the distant and frigid Aleutians and Kuril Islands chains, and bombardment duty in the invasion of Southern France when naval resistance was expected to be minimal. The most significant action that any of the ships of the class saw during the war was s participation in early war actions around the Dutch East Indies, and s engagement in the Battle of the Komandorski Islands.
None of the ships were wartime losses. Raleighs torpedo damage at Pearl Harbor and Marbleheads damage at Makassar Strait were the only significant wartime combat damage suffered by the class.
The ships of the class were considered obsolete as the war ended, and were decommissioned and scrapped within seven months of the surrender of Japan.

Ships of the class

The following ships of the class were constructed.
Ship NameHull No.BuilderLaid DownLaunchedCommissionedDecommissionedFate
OmahaCL-4Todd Dry Dock & Construction Co., Tacoma, Washington6 December 191814 December 192024 February 19231 November 1945Struck 28 November 1945; Scrapped February 1946
MilwaukeeCL-5Todd Dry Dock & Construction Co., Tacoma, Washington13 December 191824 March 192220 June 192316 March 1949Struck 18 March 1949; Sold for scrap, 10 December 1949
CincinnatiCL-6Todd Dry Dock & Construction Co., Tacoma, Washington15 May 192023 May 19211 January 19241 November 1945Scrapped February 1946
RaleighCL-7Bethlehem Shipbuilding Corporation, Fore River Shipyard, Quincy, Massachusetts16 August 192025 October 19226 February 19242 November 1945Struck 28 November 1945; Scrapped, February 1946
DetroitCL-8Bethlehem Shipbuilding Corporation, Fore River Shipyard, Quincy, Massachusetts10 November 192029 June 192231 July 192311 January 1946Struck 21 January 1946; Scrapped, February 1946
RichmondCL-9William Cramp & Sons, Philadelphia16 February 192029 September 19212 July 192321 December 1945Struck 21 January 1946; Sold for scrap, 18 December 1946
ConcordCL-10William Cramp & Sons, Philadelphia29 March 192015 December 19213 November 192312 December 1945Struck 8 January 1946; Sold for scrap, 21 January 1947
TrentonCL-11William Cramp & Sons, Philadelphia18 August 192016 April 192319 April 192420 December 1945Struck 21 January 1946; Sold for scrap, 29 December 1946
MarbleheadCL-12William Cramp & Sons, Philadelphia4 August 19209 October 19238 September 19241 November 1945Struck 28 November 1945; Sold for scrap 27 February 1946
MemphisCL-13William Cramp & Sons, Philadelphia14 October 192017 April 19244 February 192517 December 1945Struck 8 January 1946; Sold for scrap, 18 December 1947

''Omaha'' alternatives

The U.S. Navy was not entirely pleased with the Omaha class, so a new design was drawn up that was derived from it. This new class replaced the 6-inch guns with four turrets each with two 6-inch guns.
Two other Omaha versions were also designed. The first, intended to function as a monitor, had two 14-inch guns in 2 single turrets, while the other design had four 8-inch guns in two twin turrets. The second design eventually evolved into the.