Iowa Class Battleship - Conversion Proposals

Conversion Proposals

Concept artwork of what Kentucky may have looked like had she been completed as a guided missile battleship.

The Iowa class were the only battleships with the speed required for post-war operations based around fast aircraft carrier task forces. There were a number of proposals in the early Cold War to convert the class to take into account changes in technology and doctrine. These included plans to equip the class with nuclear missiles, add aircraft capability and—in the case of Illinois and Kentucky—a proposal to rebuild both as aircraft carriers instead of battleships.

Initially, the Iowa class was to consist of only four battleships: Iowa, New Jersey, Missouri, and Wisconsin. However, changing priorities during World War II resulted in the battleships Montana and Ohio being reordered as Illinois and Kentucky respectively. At the time these two battleships were to be built a proposal was put forth to have them constructed as aircraft carriers rather than fast battleships. The plan called for the ships to be rebuilt to include a flight deck and an armament suite similar to that placed aboard the Essex-class aircraft carriers that were at the time under construction in the United States. Ultimately, nothing came of the design proposal to rebuild these two ships as aircraft carriers and they were cleared for construction as fast battleships to conform to the Iowa class design, though they differed from the earlier four that were built. Eventually, the Cleveland-class light cruisers were selected for the aircraft-carrier conversion. Nine of these light cruisers would be rebuilt as Independence-class light aircraft carriers.

After the surrender of the Empire of Japan, construction on Illinois and Kentucky stopped. Illinois was eventually scrapped, but Kentucky's construction had advanced enough that several plans were proposed to complete Kentucky as a guided missile battleship (BBG) by removing the aft turret and installing a missile system. A similar conversion had already been performed on the battleship Mississippi (BB-41/AG-128) to test the RIM-2 Terrier missile after World War II. One such proposal came from Rear Admiral W. K. Mendenhall, Chairman of the Ship Characteristics Board (SCB); Mendehall proposed a plan that called for $15–$30 million to be spent to allow Kentucky to be completed as a guided-missile battleship (BBG) carrying eight SSM-N-8 Regulus II guided missiles with a range of 1,000 nautical miles (1,900 km; 1,200 mi). He also suggested Terrier or RIM-8 Talos launchers to supplement the AA guns and proposed nuclear (instead of conventional) shells for the 16-inch guns. This never materialized, and Kentucky was ultimately sold for scrap in 1958, although her bow was used to repair her sister Wisconsin after a collision.

In 1954 the Long Range Objectives Group of the United States Navy suggested converting the Iowa-class ships to BBGs. In 1958 the Bureau of Ships offered a proposal based on this idea. This replaced the 5-inch and 16-inch gun batteries with "two Talos twin missile systems, two RIM-24 Tartar twin missile systems, an RUR-5 ASROC antisubmarine missile launcher, and a Regulus II installation with four missiles", as well as flagship facilities, sonar, helicopters, and fire-control systems for the Talos and Tartar missiles. In addition to these upgrades, 8,600 additional tons of fuel oil was also suggested to serve in part as ballast for the battleships and for use in refueling destroyers and cruisers. Due to the estimated cost of the overhaul ($178–$193 million) this proposal was rejected as too expensive; instead, the SCB suggested a design with one Talos, one Tartar, one ASROC and two Regulus launchers and changes to the superstructure, at a cost of up to $85 million. This design was later revised to accommodate the Polaris Fleet Ballistic Missile, which in turn resulted in a study of two schemes by the SCB. In the end, none of these proposed conversions for the battleships were ever authorized. Interest in converting the Iowa-class battleships into guided-missile battleships began to deteriorate in 1960, because the hulls were considered too old and the conversion costs too high. Nonetheless, additional conversion proposals—including one to install the AN/SPY-1 Aegis Combat System radar on the battleships—were suggested in 1962, 1974 and 1977 but as before, these proposals failed to gain the needed authorization. This was due, in part, to the fact that sensitive electronics within 200 ft of any 16-inch gun muzzle were likely to be damaged.