Editing Colorado-class battleship (section)

===Inter-war modernization===
Plans for modernization of the ''Tennessee'' and ''Colorado'' classes were made in October 1931, in part to take advantage of loopholes in the [[Washington Naval Treaty]]. While reconstruction under this treaty was allowed only to increase protection from air and underwater attack, it could include improvements in fire control and increased elevation for main armament as these items were not listed in the treaty. Also, any changes made inside the hull could be justified as meant to increase protection, even if the outcome meant increased speed or longer operational range, since the term "blister" had been specified to limit changes only outside the hull, such as main armor belt thickness and main gun caliber. Modifications to the secondary battery were also outside the purview of the Washington Treaty.{{sfn|Friedman|1985|p=189}}

Included in initial plans was some protection against [[Shell (projectile)#Chemical|chemical shells]] which contained poisonous gas,<!--p203--> although the General Board stated in the late 1920s that decontaminating a battleship hit with these shells would not be possible—the ship would have to be [[Scuttling|scuttled]].<!--p139--> Also, the deck armor was to be bolstered with {{convert|80|lb|kg|abbr=on}}-[[special treatment steel]] (STS)—which would add {{convert|1319|LT|t ST|abbr=on}} to the displacement of the ships—the armor on the tops of the main turrets was to be made thicker, [[fire control system|fire controls]] were to be improved with the latest technology, and new shells for the main guns were to be designed.<!--p203--> Two (later four) quad 1.1-inch guns were to be added, and all of the machinery in place would be removed in favor of newer equipment so that the ships would not lose any speed with the great increase in weight.<!--p203--> [[Anti-torpedo bulge]]s were also to be installed to improve buoyancy but not to increase the ships' beams any greater than {{convert|106|ft|m}} so they could still use the [[Panama Canal]] when transferring from the Atlantic to the Pacific and vice verse.<!--p203--> These improvements were estimated to cost about [[U.S. dollar|$]]15,000,000 per ship ($71,723,000&nbsp;total). However, with the country in the throes of the [[Great Depression]], not much money was available for the Navy. Savings of $26,625,000 could be realized by reconditioning the propulsion machinery rather than replacing it, which would lower the ships' speed. Adding protection against chemical shells could be dropped, along with development of the new shells. Nevertheless, the cost-saving elements of the later proposal were later dropped. The Navy asked the [[Secretary of the Navy]] to request money in the fiscal year 1933 to modernize the two classes from [[Congress of the United States|Congress]], but the depression worsened. Although proposals for modifications were still made, plans were put on hold and never carried out.{{sfn|Friedman|1985|pp=139, 203}}

[[File:USS West Virginia Oct 1935.jpg|thumb|left|''West Virginia'' in October 1935 off Hawaii]]

In the beginning of 1934, the Bureau of Construction and Repair proposed that the "Big Five"—the two ''Tennessee''s and three ''Colorado''s—be fitted with anti-torpedo bulges so that the ships could benefit from increased [[buoyancy]]; because of, among other factors, the normal procedure of leaving port with the maximum amount of fuel possible on board, the five ships were quite overweight and rode low in the water. For example, in June 1935, ''Tennessee'' had a normal operating [[Displacement (ship)|displacement]] of {{convert|38200|LT|t ST|abbr=on}}—more than {{convert|2000|LT|t ST|abbr=on|0}} above the maximum emergency load her original design called for. This made her draft higher—meaning that the ship's waterline was down {{convert|5|ft|4|in|mm|abbr=on}}. Construction and Repair called for a bulge on the ''Colorado''s that would displace about {{convert|2000|LT|t ST|abbr=on|0}} and raise the ships' draft by {{convert|20|in|mm|abbr=on}}. Installing these would be a year's worth of work, with each ship spending six months of that in a [[dry dock]]—the first month docked so that the hull shape could be determined, the next six sailing while the bulge was built, and the last five back in the dock so it could be added to the ship.{{sfn|Friedman|1985|p=207}}

Three years later (1937), the various [[United States Navy bureau system|Navy bureaus]] held a joint meeting to discuss a possible partial modernization of the ''Tennessee''s and ''Colorado''s. They were much different than the changes proposed in 1933; there were no provisions for extra deck armor, but many additions and replacements. To gain space for newer fire control systems, the ships were to be reboilered. The main and secondary battery fire controls were to be replaced, including new rangefinders and plotting room instruments for the main, while new [[Ship Gun Fire Control Systems#MK 33 Gun Fire Control System (GFCS)|Mark 33]] anti-aircraft fire control directors were planned. The mainmast and [[M2 Browning]]s would be removed, and studies of the feasibility of a torpedo bulge, the addition of which Construction and Repair believed to be paramount, which would increase the beam to {{convert|108|ft|m|abbr=on}} and displacement to {{convert|39600|LT|t ST|abbr=on}}. Varying plans for these were complete by October 1938. None was a full reconstruction; costs ranged from $8,094,000 to $38,369,000 per ship. However, as the money for the improvements would lessen the amount available for new battleship construction, and these would be better than any reconstructed old battleship, the Secretary of the Navy rejected these plans in November. Congress did appropriate $6,600,000 in 1939 for some of these improvements, including the bulges.{{sfn|Friedman|1985|p=207}}