USS Illinois (BB-65)

The passage of the Second Vinson Act in 1938 cleared the way for construction of the four South Dakota-class battleships and the first two Iowa-class fast battleships (hull numbers BB-61 and BB-62). Hull numbers BB-63 and BB-64, cleared for construction in 1940, were to have been the final members of the Iowa class, while BB-65 and BB-66, also cleared in 1940,[1] were intended to be the first ships of the larger, more heavily armed Montana class.[2][3]

Originally, the Montanas were designed to return to the United States Navy's traditional battleship philosophy of maximum firepower and armor.[4] Considerations were also given to counter to the new battleships of the Empire of Japan, eventually known to be Yamato-class battleships, whose construction was shrouded by secrecy; furthermore, rumors of the Japanese ships' ability to carry guns of up to 18-inch (460 mm) were known at the time to the highest-ranking members of the United States Navy.[5] To achieve these goals, the United States Navy began designing a 45,000 ton "slow" battleship with maximum speed of 27-28 knots and an intended main battery of twelve 16-inch (406 mm) guns, three more than the Iowa-class. This battleship design took shape in the late-1930s and early-1940s and evolved into the 60,500-long-ton (61,500 t) Montana-class. She would also have a more powerful secondary battery of 5-inch (127 mm)/54 caliber Mark 16 dual purpose mounts, and an increase in armor designed to enable her to withstand the effects of enemy guns comparable to her own.[6][7][8]

The increase in the Montanas firepower and armor came at the expense of her speed and ability to utilize the Panama Canal, but transit between the Atlantic and Pacific oceans without having to round South America would have been eliminated through the construction of a third, much wider set of locks there. As the situation in Europe deteriorated in the late-1930s, concern arose over the possibility of the canal being put out of action by enemy bombing. Nevertheless, in 1939, construction began on the wider locks.[6][lower-alpha 1]

After the successes of carrier combat achieving air supremacy in both 1942's Battle of the Coral Sea, and, to a greater extent, Battle of Midway,[9][10] the Navy was forced to shift its building focus from battleships to aircraft carriers. As a result, construction of the fleet of Essex-class aircraft carriers had been given highest priority.[11] In the process, the United States found the high speed of 33 knots of the Iowas valuable; this allowed them to steam with the Essex-class while providing the carriers with maximum anti-aircraft protection.[9][12]

When BB-65 was redesignated an Iowa-class, she was assigned the name Illinois and reconfigured to adhere to the "fast battleship" designs planned in 1938, by the Preliminary Design Branch at the Bureau of Construction and Repair.[lower-alpha 2][13] Her funding was authorized via the passage of the Two-Ocean Navy Act by the US Congress on 19 July 1940, and she would now be the fifth Iowa-class built for the United States Navy.[13][14] Her contract was assigned on 9 September 1940, the same date as Kentucky.[15]

Illinois's keel was laid down at the Philadelphia Naval Shipyard, on 6 December 1942;[16] her projected completion date was 1 May 1945.[15] This amounted to a construction time of about 30 months. Based on wartime experience, she would have been tasked primarily with the defense of the US fleet of Essex-class aircraft carriers. In adherence with the Iowa-class design, Illinois would have a maximum beam of 108 ft 2 in (32.97 m) and a waterline length of 860 ft (260 m), permitting a maximum speed of 33 knots (61.1 km/h; 38.0 mph). In addition to a main battery of nine 16-inch (406 mm) guns and secondary battery of twenty 5-inch (127 mm) guns, she would also have carried forty-nine 20-millimeter (0.79 in) and eighty 40-millimeter (1.57 in) anti-aircraft guns,[2]

Like Iowa-class ships from Missouri (hull number BB-63) onward, the frontal bulkhead armor was increased from the original 11.3 in (287 mm) to 14.5 in (368 mm) in order to better protect against fire from frontal sectors.[17][18] Furthermore, like Kentucky, Illinois differed from her earlier sisters in that her design called for an all-welded construction, which would have saved weight due to increased strength over a combination riveted/welded hull used on the four completed Iowas. Additionally, engineers revised the torpedo protection system scheme of the Iowa-class to address some of the design flaws, such as excessive rigidity of the lower belt armor causing leakage in adjacent compartments in the event of a torpedo hit; the revised scheme had improvements such as removing knuckles in certain holding bulkheads; these alterations were estimated to improve both Illinois and Kentucky's torpedo protection by as much as 20%.[19][20] Funding for the battleship was provided in part by "King Neptune", a Hereford swine auctioned across the state of Illinois as a fundraiser, ultimately helping to raise $19 million in war bonds.[21]

The ship's bell from Illinois at Memorial Stadium, University of Illinois at Urbana–Champaign

Illinois's construction was put on hold in 1942, after the Battles of the Coral Sea and Midway, while the Bureau of Ships considered an aircraft carrier conversion proposal for Illinois and Kentucky. As proposed, the converted Illinois would have had an 864-foot (263 m) long by 108-foot (33 m) wide flight deck, with an armament identical to the carriers of the Essex class: four twin 5-inch gun mounts and four more 5-inch guns in single mounts, along with six 40 mm quadruple mounts. It was abandoned after the design team decided that the converted carriers would carry fewer aircraft than the Essex class, that more Essex-class carriers could be built in the same amount of time to convert the battleships, and that the conversion project would be significantly more expensive than new Essexes. Instead, Illinois and Kentucky were to be completed as battleships, but their construction was given very low priority.[22]

Ultimately, the ship was canceled on 11 August 1945, when she was about 22% complete.[14] She was struck from the Naval Vessel Register on 12 August 1945.[23][24] Her incomplete hulk initially was retained on the belief that it could be used as a target in nuclear weapons tests. However, the some $30 million it would cost to complete the ship enough to be able to launch her proved too great and the plan was abandoned. She remained in the dockyard until September 1958, when she was broken up on the builder's ways.[14][25]

The ship's bell, inscribed USS Illinois 1946, is now at Memorial Stadium at the University of Illinois at Urbana–Champaign. The bell is on loan from the Naval Historical Center (Accession #70-399-A), Washington Navy Yard, Washington DC, to the Naval Reserve Officers Training Corps (NROTC) at the university. The bell is traditionally rung by NROTC members when the football team scores a touchdown or goal.[26]

• Barrett, John (1913). The Panama Canal, what it is, what it means. Washington, D.C.: Pan American Union. OCLC 244998670.
• McCullough, David G. (1977). The Path Between the Seas: The Creation of the Panama Canal, 1870–1914. New York: Simon & Schuster. ISBN 978-0-671-22563-6. OCLC 2695090.

Wikimedia Commons has media related to USS Illinois (BB-65).

• Iowa Class (BB-61 through BB-66), 1940 & 1941 Building Programs
• Photo gallery of Illinois (BB-65) at NavSource Naval History