The Montana-class battleships were planned as successors of the Iowa class for the United States Navy, to be slower but larger, better armored, and with superior firepower. Five were approved for construction during World War II, but changes in wartime building priorities resulted in their cancellation in favor of continuing production of Essex-class aircraft carriers and Iowa-class battleships before any Montana-class keels were laid.
USS Hawaii (CB-3) was intended to be the third member of the Alaska-class large cruisers. It was the first United States Navy ship to be named after the then-Territory of Hawaii. Because Hawaii's construction was delayed by higher-priority ships like aircraft carriers, her keel was not laid until December 1943, about two years after her sister ship Guam.
The North Carolina class were a pair of fast battleships, North Carolina and Washington, built for the United States Navy in the late 1930s and early 1940s.
The Alaska class were six very large cruisers ordered before World War II for the United States Navy, of which only two were completed and saw service late in the war. The US Navy designation for the ships of this class was 'large cruiser' (CB) and the majority of leading reference works consider them as such. However, various other works have alternately described these ships as battlecruisers despite the US Navy having never classified them as such. The Alaskas were all named after territories or insular areas of the United States, signifying their intermediate status between larger battleships and smaller heavy and light cruisers.
The Mackensen class was the last class of battlecruisers to be built by Germany in World War I. The design initially called for seven ships, but three of them were redesigned as the Ersatz Yorck class. Of the four ships of the Mackensen class, Mackensen, Graf Spee, and Prinz Eitel Friedrich were launched, and Fürst Bismarck was not—but none were completed, after wartime shipbuilding priorities were redirected towards U-boats—and the ships were broken up in the early 1920s. The lead ship of the class was named for August von Mackensen, a prominent military commander during the war. In response to the Mackensen-class ships, the British Royal Navy laid down the Admiral-class battlecruisers, all but one of which would eventually be cancelled; the sole survivor, HMS Hood, was completed after the end of the war.
The Yamato-class battleships were two battleships of the Imperial Japanese Navy (IJN), Yamato and Musashi, laid down leading up to World War II and completed as designed. A third hull laid down in 1940 was converted to an aircraft carrier, Shinano, during construction.
The Littorio class, also known as the Vittorio Veneto class, was a class of battleship of the Regia Marina, the Italian navy. The class was composed of four ships—Littorio, Vittorio Veneto, Roma, and Impero—but only the first three ships of the class were completed. Built between 1934 and 1942, they were the most modern battleships used by Italy during World War II. They were developed in response to the French Dunkerque-class battleships, and were armed with 381-millimeter (15.0 in) guns and had a top speed of 30 knots. The class's design was considered by the Spanish Navy, but the outbreak of World War II interrupted construction plans.
The Scharnhorst class was a class of German battleships built immediately prior to World War II. The first capital ships of Nazi Germany's Kriegsmarine, it comprised two vessels: Scharnhorst and Gneisenau. Scharnhorst was launched first, and is considered to be the lead ship by some sources; they are also referred to as the Gneisenau class in some other sources, as Gneisenau was the first to be laid down and commissioned. They marked the beginning of German naval rearmament after the Treaty of Versailles. The ships were armed with nine 28 cm (11 in) SK C/34 guns in three triple turrets; plans to replace these with six 38 cm (15 in) SK C/34 guns in twin turrets were never realized.
The Stalingrad-class battlecruiser, also known as Project 82, was a Soviet battlecruiser design from 1941. It was a smaller and less-expensive counterpart to the Kronshtadt-class battlecruisers of 1939. The original role was for a light, fast ship intended to break up attacks by British fast-cruiser forces that might attempt bombardment of Russia's northern ports. In keeping with the battlecruiser design concept, they would have been able to outgun any ship with similar speed, or outrun anything more heavily armed. Design work had just started when the German invasion of the Soviet Union opened and the design was put on hold.
The South Dakota class was a group of four fast battleships built by the United States Navy. They were the second class of battleships to be named after the 40th state; the first were designed in the 1920s and canceled under the terms of the Washington Naval Treaty. Four ships comprised the class: South Dakota, Indiana, Massachusetts, and Alabama. They were designed to the same treaty standard displacement limit of 35,000 long tons (35,600 t) as the preceding North Carolina class and had the same main battery of nine 16"/45 caliber Mark 6 guns in three-gun turrets, but were more compact and better protected. The ships can be visually distinguished from the earlier vessels by their single funnel, compared to twin funnels in the North Carolinas.
The O class was a planned class of three battlecruisers for the Kriegsmarine before World War II. Prompted by a perceived lack in ship numbers when compared with the British Royal Navy, the O class' design was born with the suggestion of modifying the P-class cruiser design with 380 mm (15 in) guns instead of 283 mm (11.1 in).
The M-class cruisers were a class of light cruisers planned, but never built, by Nazi Germany's Kriegsmarine before World War II. The ships were designed for commerce raiding in the Atlantic Ocean. The design for the first four ships suffered from a number of problems, and so the fifth and sixth ships were substantially redesigned.
The BL 14-inch Mk VII naval gun was a breech loading (BL) gun designed for the battleships of the Royal Navy in the late 1930s. This gun armed the King George V-class battleships during the Second World War.
L 20e α was a design for a class of battleships to be built in 1918 for the German Kaiserliche Marine during World War I. Design work on the class of battleship to succeed the Bayern-class battleships began in 1914, but the outbreak of World War I in July 1914 led to these plans being shelved. Work resumed in early 1916 and lessons from the Battle of Jutland, fought later that year, were incorporated into the design. Reinhard Scheer, the commander of the fleet, wanted larger main guns and a higher top speed than earlier vessels, to combat the latest ships in the British Royal Navy. A variety of proposals were submitted, with armament ranging from the same eight 38 cm (15 in) guns of the Bayern class to eight 42 cm (16.5 in) guns.
Design 1047, also known as Project 1047, was a series of plans for a class of Dutch battlecruisers prior to the Second World War. These large capital ships were intended to counter the threat posed by Japanese aggression towards the Dutch colonies in the East Indies.
The D-class cruisers were a pair of German heavy cruisers, classified as panzerschiffe by the Reichsmarine. The ships were improved versions of the preceding Deutschland-class cruisers, authorized by Adolf Hitler in 1933. They were intended to counter a new French naval construction program. Displacement increased to 20,000 long tons (20,000 t), but Hitler allowed only increases to armor, prohibiting additions to the ships' main battery armament. Both ships were laid down in February 1934, but not much work done before work was cancelled pending a significant revision of the design. It was determined that the ships should be enlarged to counter the new French Dunkerque-class battleship. The construction contracts for both ships were superseded by the Scharnhorst-class battleships.
Roma, named after two previous ships and the city of Rome, was the third Littorio-class battleship of Italy's Regia Marina. The construction of both Roma and her sister ship Impero was due to rising tensions around the world and the navy's fear that only two Littorios, even in company with older pre-First World War battleships, would not be enough to counter the British and French Mediterranean Fleets. As Roma was laid down almost four years after the first two ships of the class, some small improvements were made to the design, including additional freeboard added to the bow.
The Bismarck class was a pair of fast battleships built for Nazi Germany's Kriegsmarine shortly before the outbreak of World War II. The ships were the largest and most powerful warships built for the Kriegsmarine; displacing more than 41,000 metric tons normally, they were armed with a battery of eight 38 cm (15 in) guns and were capable of a top speed of 30 knots. Bismarck was laid down in July 1936 and completed in September 1940, while her sister Tirpitz's keel was laid in October 1936 and work finished in February 1941. The ships were ordered in response to the French Richelieu-class battleships. They were designed with the traditional role of engaging enemy battleships in home waters in mind, though the German naval command envisioned employing the ships as long-range commerce raiders against British shipping in the Atlantic Ocean. As such, their design represented strategic confusion that dominated German naval construction in the 1930s.
Scharnhorst was a German capital ship, alternatively described as a battleship or battlecruiser, of Nazi Germany's Kriegsmarine. She was the lead ship of her class, which included her sister ship Gneisenau. The ship was built at the Kriegsmarinewerft dockyard in Wilhelmshaven; she was laid down on 15 June 1935 and launched a year and four months later on 3 October 1936. Completed in January 1939, the ship was armed with a main battery of nine 28 cm (11 in) C/34 guns in three triple turrets. Plans to replace these weapons with six 38 cm (15 in) SK C/34 guns in twin turrets were never carried out.
The H class was a series of battleship designs for Nazi Germany's Kriegsmarine, which were intended to fulfill the requirements of Plan Z in the late 1930s and early 1940s. The first variation, "H-39", called for six ships to be built, essentially as enlarged Bismarck-class battleships with 40.6 cm (16 in) guns and diesel propulsion. The "H-41" design improved the "H-39" ship with still larger main guns, eight 42 cm (16.5 in) weapons, and reinforced deck armor. The Construction Office of the Oberkommando der Marine (OKM) concluded their work with the "H-41" design, and were not involved in subsequent plans. Two of them, "H-42" and "H-43", increased the main battery yet again, with 48 cm (18.9 in) pieces, and the enormous "H-44" design ultimately resulted with 50.8 cm (20 in) guns. The ships ranged in size from the "H-39", which was 277.8 m long on a displacement of 56,444 t, to the "H-44", at 345 m on a displacement of 131,000 t. Most of the designs had a proposed top speed in excess of 30 knots (56 km/h).
Kriegsmarine 
