USS Illinois (BB-65) was the fifth Iowa-class fast battleship that was laid down for the United States Navy during World War II in the 1940s, although she would not be completed. The Navy had initially planned on building four of the Iowas and then developing a new, more powerful ship for what was to be BB-65. The pressing need for more warships at the outbreak of World War II in Europe led the Navy to conclude that new designs would have to be placed on hold to allow the shipbuilding industry to standardize on a small number of designs. As a result, BB-65 was ordered to the Iowa design in 1940. Illinois was laid down in December 1942, but work was given a low priority, and was still under construction at the end of World War II. She was canceled in August 1945, but her hull remained as a parts hulk until she was broken up in 1958.
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 King George V-class battleships were the most modern British battleships in commission during the Second World War. Five ships of this class were built: HMS King George V, HMS Prince of Wales (1941), HMS Duke of York (1941), HMS Anson (1942) and HMS Howe (1942). The names honoured King George V, and his sons, Edward VIII, who had been Prince of Wales, and George VI who was Duke of York before ascending to the throne; the final two ships of the class were named after prominent 18th century admirals of the Royal Navy.
The Trento class was a group of two heavy cruisers built for the Italian Regia Marina in the late 1920s, the first such vessels built for the Italian fleet. The two ships in the class—Trento and Trieste, were named after the redeemed cities of Trento and Trieste annexed from the Austro-Hungarian empire after the victory in World War I. The ships were very lightly armored, with only a 70 mm (2.8 in) thick armored belt, though they possessed a high speed and heavy main battery of eight 203 mm (8 in) guns. Nominally built under the restrictions of the Washington Naval Treaty, the two cruisers nevertheless exceeded the displacement limits imposed by the treaty.
The Conte di Cavour–class battleships were a group of three dreadnoughts built for the Royal Italian Navy in the 1910s. The ships were completed during World War I, but none saw action before the end of hostilities. Leonardo da Vinci was sunk by a magazine explosion in 1916 and sold for scrap in 1923. The two surviving ships, Conte di Cavour and Giulio Cesare, supported operations during the Corfu Incident in 1923. They were extensively reconstructed between 1933 and 1937 with more powerful guns, additional armor and considerably more speed than before.
Vittorio Veneto was the second member of the Littorio-class battleship that served in the Italian Regia Marina during World War II. The ship's keel was laid down in October 1934, launched in July 1937, and readied for service with the Italian fleet by August 1940. She was named after the Italian victory at Vittorio Veneto during World War I, and she had three sister ships: Littorio, Roma, and Impero, though only Littorio and Roma were completed during the war. She was armed with a main battery of nine 381-millimeter (15.0 in) guns in three triple turrets, and could steam at a speed of 30 knots.
Conte di Cavour was the name ship of the three Conte di Cavour-class dreadnought battleships built for the Royal Italian Navy in the 1910s. Completed in 1915 she served during World War I, although she was little used and saw no combat. The ship supported operations during the Corfu Incident in 1923 and spent much of the rest of the decade in reserve. She was rebuilt between 1933 and 1937 with more powerful guns, additional armor and considerably more speed than before.
Littorio was the lead ship of her class of battleship; she served in the Italian Regia Marina during World War II. She was named after the Lictor, in ancient times the bearer of the Roman fasces, which was adopted as the symbol of Italian Fascism. Littorio and her sister Vittorio Veneto were built in response to the French battleships Dunkerque and Strasbourg. They were Italy's first modern battleships, and the first 35,000-ton capital ships of any nation to be laid down under the terms of the Washington Naval Treaty. Littorio was laid down in October 1934, launched in August 1937, and completed in May 1940.
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.
Trento was the first of two Trento-class cruisers; they were the first heavy cruisers built for the Italian Regia Marina. The ship was laid down in February 1925, launched in October 1927, and was commissioned in April 1929. Trento was very lightly armored, with only a 70 mm (2.8 in) thick armored belt, though she possessed a high speed and heavy main battery of eight 203 mm (8 in) guns. Though nominally built under the restrictions of the Washington Naval Treaty, the two cruisers significantly exceeded the displacement limits imposed by the treaty.
Bolzano was a unique heavy cruiser, sometimes considered to be a member of the Trento class, built for the Italian Regia Marina in the early 1930s, the last vessel of the type to be built by Italy. A modified version of the earlier Trento class, she had a heavier displacement, slightly shorter length, a newer model of 203-millimeter (8.0 in) gun, and a more powerful propulsion system, among other differences influenced by the Zara class that had followed the Trentos. Bolzano was built by the Gio. Ansaldo & C. between her keel laying in June 1930 and her commissioning in August 1933.
The Andrea Doria class was a pair of dreadnought battleships built for the Royal Italian Navy between 1912 and 1916. The two ships—Andrea Doria and Duilio—were completed during World War I. The class was an incremental improvement over the preceding Conte di Cavour class. Like the earlier ships, Andrea Doria and Duilio were armed with a main battery of thirteen 305-millimeter (12.0 in) guns.
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).
Andrea Doria was the lead ship of her class of battleships built by the Regia Marina. The class included only one sister ship, Duilio. Andrea Doria was named after the 16th-century Genoese admiral of the same name. Laid down in March 1912, the battleship was launched a year later in March 1913, and completed in March 1916. She was armed with a main battery of thirteen 305 mm (12.0 in) guns and had a top speed of 21 knots.
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.
Fiume was a Zara-class heavy cruiser of the Italian Regia Marina, named after the Italian city of Fiume, she was the second of four ships in the class, and was built between April 1929 and November 1931. Armed with a main battery of eight 8-inch (200 mm) guns, she was nominally within the 10,000-long-ton (10,000 t) limit imposed by the Washington Naval Treaty, though in reality she significantly exceeded this figure.
The Cannone da 381/50 Ansaldo M1934 was a 381-millimeter (15 in), 50-caliber naval gun designed and built for the Royal Italian Navy by Gio. Ansaldo & C. in the 1930s. The gun served as the main armament of Italy's last battleships, the Littorio class. These built-up guns consisted of a liner, a cylinder over the chamber and part of the rifle bore, a full-length cylinder, and a 3/4 length jacket with a hydro-pneumatically operated side-swinging Welin breech block. 40 barrels were produced in total by Ansaldo and O.T.O., but none survive to this day. Each battleship carried nine guns mounted in three triple turrets with maximum elevation of 35°. Time between salvos was approximately 45 seconds.
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.
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).
Italy 
