Battlecruiser - Large Cruisers or "cruiser Killers"

Large Cruisers or "cruiser Killers"

See also: Alaska class cruiser and Design 1047 battlecruiser

On the eve of World War II, there was a late renaissance in popularity of ships between battleships and cruisers. While some considered them battlecruisers, they were never classified as capital ships, and they were variously described as "super-cruisers", "large cruisers" or even "unrestricted cruisers". They were optimised as cruiser-killers, fleet scouts and commerce raiders. The Dutch, Japanese, Soviets and Americans all planned new classes specifically to counter the large heavy cruisers being built by their naval rivals – especially the Japanese Mogami class cruisers. The Germans also designed a class of lightly protected battlecruisers.

The first such battlecruisers were the Dutch Design 1047. Never officially assigned names, the Dutch wanted them to protect their colonies in the East Indies in the face of Japanese aggression. Designed with the assistance of the Germans and Italians, they broadly resembled the German Scharnhorst class and had the same main battery, but would have been considerably lighter and only protected against 8-inch (203 mm) gunfire. Although the design was mostly completed, work on the vessels never commenced as the Germans overran the Netherlands in May 1940, while the first ship would have been laid down in June of that year.

The Germans planned to build three battlecruisers of the O Class as part of the expansion of the Kriegsmarine (Plan Z). With six 15 inch (38 cm) guns, high speed, excellent range but very thin armour, they were intended as commerce raiders. Only one of these was ordered shortly before World War II broke out and no work was ever done on it. No names were assigned, and they were known as O, P, and Q. The new class was not universally welcomed in the Kriegsmarine, their abnormally light protection gaining the class the derogatory nickname Ohne Panzer Quatsch (without armour nonsense) within certain circles of the Navy.

The only class of these late battlecruisers to be laid down were the United States Navy's three Alaska class "large cruisers", Alaska, Guam and Hawaii—of which only Alaska and Guam were completed. The Alaskas were classified as "large cruisers" instead of battlecruisers, and their status as non-capital ships is evidenced by the fact that they were named for territories or protectorates (as opposed to battleships, which were named after states, or cruisers, which were commonly named after cities). But with a main armament of nine 12-inch (305 mm) guns in three triple turrets and a displacement of 27,000 tons, the Alaskas were twice the size of the preceding Baltimore class cruisers and had guns some 50% larger in diameter. They lacked the thick armoured belt and torpedo defense system of true capital ships and, unlike most battlecruisers, they were considered a balanced design (according to cruiser standards) as their protection could withstand fire from their own caliber of gun, albeit only in a very narrow range band. They were designed to hunt down Japanese heavy cruisers, though by the time they entered service most Japanese cruisers had been sunk by American aircraft or submarines. Like the contemporary Iowa-class fast battleships, their speed ultimately made them more useful as carrier escorts and bombardment ships than as the sea combatants they were developed to be. Hawaii was 84% complete when hostilities ceased, and was laid up for years while various plans were debated to convert her large hull into a missile ship or a command vessel; she would eventually be scrapped incomplete. Three additional hulls, to be named Philippines, Puerto Rico and Samoa, were cancelled outright.

The Japanese started designing the B64 class, which were similar to the Alaska but with 12.2-inch (310 mm) guns. News of the Alaskas led them to upgrade the design, creating the B65. Armed with 14-inch (356 mm) guns, the B65's would have been the best armed of the new breed of battlecruisers, but they still would have had only sufficient protection to keep out 8-inch shells. Much like the Dutch battlecruisers, the Japanese got as far as completing the design for the B65s, but never laid them down. By the time the designs were ready the Japanese Navy recognised that they had little use for the vessels and that their priority for construction should lie with aircraft carriers. Like the Alaskas, the Japanese did not call these ships battlecruisers, referring to them instead as supersized heavy cruisers.