Editing Colorado-class battleship (section)

===World War II changes===
With the beginning of World War II in Europe, the Navy began to apply lessons learned by the British to U.S. ships.<!--p207--> The Board under [[Ernest J. King]] of 1940–1941 proposed sweeping changes to the secondary armament of the battleships to increase their defense against air attacks. These included the removal of all 5&nbsp;in/25 caliber guns and 5&nbsp;in/51 in favor of the [[dual purpose gun|dual-purpose]] 5&nbsp;in/38, the addition of six quad 1.1-inch guns, and the cutting away of superstructure to clear arcs of fire for the new [[anti-aircraft]] weapons. An ultimate secondary battery of sixteen 5 in/38 in dual mounts, sixteen Bofors 40&nbsp;mm in quadruple mounts and eight single Oerlikon 20&nbsp;mm guns was called for by the board in 1941, although they were not certain the ships could handle the added weight and it would take a large amount of time in dry dock for these modifications to take place. With these concerns, an interim measure of four quad 1.1-inch guns was proposed by the board; however, the gun was not being produced in any great number very quickly, so a second interim solution was implemented. [[3"/50 caliber gun|{{convert|3|in|mm|abbr=on}}/50 caliber guns]] were added to all of the U.S. battleships except for ''Arizona'' and ''Nevada'' by June 1941; these were replaced on the three battleships in the Atlantic by the quad 1.1-inch guns by November—they received them first because they were closer to a war zone.{{sfn|Friedman|1985|pp=207, 353}}

As these modifications were carried out upon the various battleships, much additional weight was added onto the already overweight ships, forcing torpedo bulges to be added so that a decent [[Freeboard (nautical)|freeboard]] could be maintained. These would cost $750,000 and around three or four months in a dry dock. The King Board suggested that the deck armor be bolstered and 5&nbsp;in/38 dual-purpose guns be added, but the [[Chief of Naval Operations]] decreed that any major changes such as these had to wait due to the wars raging around the world at the time. The addition of bulges, however, was approved for the "Big Five", with each ship spending three months in dry dock at the [[Puget Sound Naval Shipyard]]. ''Maryland'' would be first (17 February 1941 to 20 May), followed by ''West Virginia'' (10 May to 8 August), ''Colorado'' (28 July to 28 October), ''Tennessee'' (19 January 1942 to 21 April) and ''California'' (16 March to 16 June).{{efn|name=refits}} However, the estimates for how long the addition of bulges would take were too low; Puget Sound believed that they could complete work on ''Maryland'' in 123 calendar days (about four months)—if the work would be given a priority equal to that of {{USS|Saratoga|CV-3|2}}{{'}}s refit and higher than new construction.{{sfn|Friedman|1985|p=207}}

Only two of the ships had bulges added to them through this program, ''Maryland'' (completed 1 August 1941) and ''Colorado'' (26 February 1942); the attack on Pearl Harbor interrupted the refits intended for ''West Virginia'' and the two ''Tennessee''s. The surprise strike did not touch ''Colorado'', which was at Puget Sound, and did not hurt ''Maryland'' very badly; however, ''West Virginia'' was severely damaged and needed a major refit at minimum.{{sfn|Friedman|1985|pp=207, 345}}

[[File:USS Maryland 9 Feb 1942.jpg|thumb|''Maryland'' on 9 February 1942, little changed from her pre-war configuration]]

Little to no major modifications were made to the two active ''Colorado''s in the opening months of the U.S.'s entry into the war; all of the battleships in the Pacific Fleet had a constant order to be ready to sail within 48 hours in case of a Japanese attempt to invade Hawaii or the West Coast and could not be spared for any major yard work. ''Colorado'' was hurried through the rest of her refit with the addition of essential items like [[radar]], splinter protection, fourteen Oerlikon 20&nbsp;mm and four quad 1.1-in guns; ''Maryland'' received a similar treatment later, the only difference being sixteen 20&nbsp;mm guns and no 1.1-in guns. Although tower masts were constructed for ''Colorado'' and ''Maryland'' and a majority of their aft [[cage mast]]s were cut down by the ships' crews in the beginning of 1942, the ships could not be spared the time needed to install the new masts. The tower masts were placed into storage and not used until early 1944.{{sfn|Friedman|1985|p=356}}

''Colorado'' and ''Maryland'' were greatly needed in the war zone, and as such did not undergo a major refit until 1944, although minor additions and removals, mainly to the anti-aircraft weaponry, were made in-between. Throughout the war, both ships saw their anti-aircraft battery changed constantly. Beginning in 1942, they carried eight 5&nbsp;in/25, four quad 1.1-in guns, a greatly varying number of 20&nbsp;mm guns, and eight .50 caliber machine guns. In June 1942, ''Colorado'' had fourteen 20&nbsp;mm guns; just five months later, this was upped to twenty-two, with thirty-six temporarily approved for a later time. By February 1943, both ''Colorado'' and ''Maryland'' had two more quad 1.1-in guns added (for a total of six mounts) and forty-eight total 20&nbsp;mm guns; a month later she was given an additional ten .50 caliber machine guns. November 1943 saw the removal of two of the single-purpose 5&nbsp;in/51, the six quad 1.1-in guns, and a small number of 20&nbsp;mm guns (six on ''Colorado'' and eight on ''Maryland'') in favor of thirty-two Bofors 40&nbsp;mm guns – six quad and two twin.{{sfn|Friedman|1985|p=364}}

Both ships finally underwent major refits in 1944. Here their remaining aft cage masts were taken off in favor of the tower masts, the two twin 40&nbsp;mm replaced by quads, a quadruple 20&nbsp;mm added, and a new radar fitted. Although more extensive refits were proposed by Admiral [[Ernest King|Ernest J. King]], including the addition of eight twin 5&nbsp;in/38, more advanced fire control systems, and a second protective deck plating, the [[Bureau of Ships]], after demonstrating what would have to be removed as compensation for the weight added for King's ideas, counter-proposed that a smaller reconstruction, like the ones given to the ''New Mexico'' class, would be more desirable. However, no action was taken until ''Maryland'' was struck by a kamikaze aircraft. While undergoing repair, eight twin 5&nbsp;in/38 were added, but nothing else; her [[conning tower]] was removed and replaced by a {{convert|50|lb|kg|abbr=on}} special-treated steel structure to balance the additional weight of the 5&nbsp;in guns.{{sfn|Friedman|1985|pp=364, 368}}