USS Duluth was a light cruiser of the United States Navy, which were built during World War II. The class was designed as a development of the earlier s, the size of which had been limited by the First London Naval Treaty. The start of the war led to the dissolution of the treaty system, but the dramatic need for new vessels precluded a new design, so the Clevelands used the same hull as their predecessors, but were significantly heavier. The Clevelands carried a main battery of twelve guns in four three-gun turrets, along with a secondary armament of twelve dual-purpose guns. They had a top speed of .
She was launched 13 January 1944 by Newport News Shipbuilding & Dry Dock Company, Newport News, Virginia; sponsored by Mrs. E. H. Hatch, wife of the Mayor of Duluth, Minnesota; and commissioned 18 September 1944, Captain Donald Roderick Osborn, Jr., US Naval Academy class of 1920, in command.
Design
The Cleveland-class light cruisers traced their origin to design work done in the late 1930s; at the time, light cruiser displacement was limited to by the Second London Naval Treaty. Following the start of World War II in September 1939, Britain announced it would suspend the treaty for the duration of the conflict, a decision the US Navy quickly followed. Though still neutral, the United States recognized that war was likely and the urgent need for additional ships ruled out an entirely new design, so the Clevelands were a close development of the earlier s, the chief difference being the substitution of a two-gun dual-purpose gun mount for one of the main battery gun turrets.
Duluth was long overall and had a beam of and a draft of . Her standard displacement amounted to and increased to at full load. The ship was powered by four General Electric steam turbines, each driving one propeller shaft, using steam provided by four oil-fired Babcock & Wilcox boilers. Rated at , the turbines were intended to give a top speed of . Her crew numbered 1285 officers and enlisted men.
The ship was armed with a main battery of twelve 6 in /47 caliber Mark 16 guns in four 3-gun turrets on the centerline. Two were placed forward in a superfiring pair; the other two turrets were placed aft of the superstructure in another superfiring pair. The secondary battery consisted of twelve /38 caliber dual-purpose guns mounted in twin turrets. Two of these were placed on the centerline, one directly behind the forward main turrets and the other just forward of the aft turrets. Two more were placed abreast of the conning tower and the other pair on either side of the aft superstructure. Anti-aircraft defense consisted of twenty-eight Bofors guns in four quadruple and six double mounts and ten Oerlikon guns in single mounts.
The ship's belt armor ranged in thickness from , with the thicker section amidships where it protected the ammunition magazines and propulsion machinery spaces. Her deck armor was thick. The main battery turrets were protected with faces and sides and tops, and they were supported by barbettes 6 inches thick. Duluths conning tower had 5-inch sides.
Service history
Construction and World War II
The keel for Duluth was laid down in November 1942 at the Newport News Shipbuilding & Dry Dock Company in Newport News, Virginia, with the hull number CL-87. Her completed hull was launched on 13 January 1944, and fitting-out work was completed by September. The ship was commissioned on 18 September and thereafter began sea trials. Duluth operated as a training cruiser based in Newport, Rhode Island, from 14 December to 2 March 1945 as her crew familiarized themselves with the ship. She thereafter steamed to Norfolk, Virginia, for a short refit. On 7 April, Duluth got underway to join the war effort in the Pacific. After transiting the Panama Canal, she arrived in Pearl Harbor on 29 April.
Duluth left Pearl Harbor on 8 May to join 5th Fleet, which she met on 27 May. While cruising with the fleet off Okinawa on 5 June, Duluth was damaged by a severe typhoon, along with a number of other vessels. She had to sail south to Guam for repairs, which lasted for more than a month. She returned to the Fast Carrier Task Force on 21 July, which had by that time passed to 3rd Fleet, being renamed Task Force 38. Duluth was assigned to the subordinate unit Task Group 38.1, along with five aircraft carriers, three fast battleships, four other cruisers, and several destroyers. She served as part of the anti-aircraft screen that protected the carriers as they carried out a series of air strikes on various targets in Japan. These operations continued until the end of the war on 14 August.