A torpedo bulkhead is a type of naval armor common on the more heavily armored warships, especially battleships and battlecruisers of the early 20th century. It is designed to keep the ship afloat even if the hull is struck underneath the belt armor by a shell or by a torpedo.
As early torpedoes had demonstrated their effectiveness at seriously damaging ships below the waterline by the 1880s, naval designers began developing methods to better protect ships against the new weapons. The earliest protection scheme was devised by Sir Edward Reed in 1884; he proposed a double bottom that included an armored inner hull lining that connected to the bottom edges of the belt armor. It was not adopted, as it imposed serious limitations on internal space and reduced the thickness of the belt. Subsequent, early attempts relied primarily on the coal bunkers, on the assumption that the ship's coal would absorb the blast effects, which would be contained by the interior longitudinal bulkhead. A significant problem with these early arrangements was that once the coal was depleted, the empty compartments offered little to no resistance; worse still, coal dust could explode, and given that the bunkers needed to be accessed by boiler room crews, they could not easily be made watertight. [1]
In the 1910s, naval designers began to transition from coal to fuel oil to power their ships; bunkers filled with liquid fuel proved to be much more effective at absorbing the blast effects of an underwater explosion, and unlike coal bunkers, they could be filled with water once emptied. During this period, many designers also began to adopt multi-layered protection schemes, some of which were also coupled with anti-torpedo bulges, to improve the survivability of their ships. The historian Roger Branfill-Cook characterizes the American Tennessee-class battleships, designed in 1915, as having the best layout of the period, which featured three armored bulkheads layered between three liquid-filled compartments, and placed between an empty void and unarmored bulkhead on either side. [2] For example, the last US battleship designs during World War II had up to four torpedo bulkheads and a triple-bottom. [3] During the 1930s, some designers experimented with empty tubes running the length of the torpedo defense system, most notably the Pugliese system, though these proved to be largely ineffective. [4]
In multi-bulkhead systems, the innermost bulkhead is commonly referred to as the "holding bulkhead", [5] and often this bulkhead would be manufactured from high-tensile steel that could deform and absorb the pressure pulse from a torpedo hit without breaking. If the final bulkhead was at least 37 mm thick, it may also be referred to as an "armored bulkhead", as it would be capable of stopping splinters and shells with low striking velocities.
Maine was a United States Navy ship that sank in Havana Harbor on February 15, 1898, contributing to the outbreak of the Spanish–American War in April. U.S. newspapers, engaging in yellow journalism to boost circulation, claimed that the Spanish were responsible for the ship's destruction. The phrase, "Remember the Maine! To hell with Spain!" became a rallying cry for action. Although the Maine explosion was not a direct cause, it served as a catalyst that accelerated the events leading up to the war.
USS Kentucky (BB-66) was an uncompleted battleship intended to be the last ship of the Iowa class. Hull BB-66 was originally to be the second ship of the Montana-class battleships. However, the urgent need for more warships at the outbreak of World War II and the U.S. Navy's experiences in the Pacific theater led it to conclude that rather than battleships larger and more heavily armed than the Iowa class, it quickly needed more fast battleships of that class to escort the new Essex-class aircraft carriers being built. As a result, hulls BB-65 and BB-66 were reordered and laid down as Iowa-class battleships in 1942.
The Wyoming class was a pair of dreadnought battleships built for the United States Navy. Wyoming and Arkansas were authorized in early 1909, and were built between 1910 and 1912. These were the fourth dreadnought design of the US Navy, but only an incremental improvement over the preceding Florida class, and the last US battleships to use 12-inch guns. The primary changes were the adoption of a more powerful 12 in (305 mm)/50 caliber Mark 7 gun, addition of a sixth twin-gun turret and improved armor protection, including the first use of a torpedo bulkhead on American battleships. The Navy considered using more powerful 14-inch (356 mm) guns, but this would have caused delays and required larger docks.
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 for prominent 18th century admirals of the Royal Navy.
Shinano (信濃) was an aircraft carrier built by the Imperial Japanese Navy (IJN) during World War II, the largest such built up to that time. Laid down in May 1940 as the third of the Yamato-class battleships, Shinano's partially complete hull was ordered to be converted to an aircraft carrier following Japan's disastrous loss of four of its original six fleet carriers at the Battle of Midway in mid-1942. The advanced state of her construction prevented her conversion into a fleet carrier, so the IJN decided to convert her into a carrier that supported other carriers.
The torpedo belt was part of the armoring scheme in some warships between the 1920s and 1940s. It consisted of a series of lightly armored compartments, extending laterally along a narrow belt that intersected the ship's waterline. In theory this belt would absorb the explosions from torpedoes, or any naval artillery shells that struck below the waterline, and thus minimize internal damage to the ship itself.
The Gangut-class, also known as the Sevastopol-class, were the first dreadnoughts built for the Imperial Russian Navy before World War I. They had a convoluted design history involving several British companies, evolving requirements, an international design competition, and foreign protests. Four ships were ordered in 1909, Gangut, Poltava, Petropavlovsk, and Sevastopol. Construction was delayed by financing problems until the Duma formally authorized the ships in 1911. They were delivered from December 1914 through January 1915, although they still needed work on the gun turrets and fire-control systems until mid-1915. Their role was to defend the mouth of the Gulf of Finland against the Germans, who never tried to enter, so the ships spent their time training and providing cover for minelaying operations. Their crews participated in the general mutiny of the Baltic Fleet after the February Revolution in 1917, and joined the Bolsheviks the following year.
Belt armor is a layer of heavy metal armor plated onto or within the outer hulls of warships, typically on battleships, battlecruisers and cruisers, and aircraft carriers.
The Richelieu class were fast battleships built for the French Navy between the 1930s and 1950s. Initially two ships were ordered in 1935 in response to Italian orders for the Littorio-class battleships the previous year. The Richelieus were based on the preceding Dunkerque class, but scaled up to accommodate more powerful 380 mm (15 in) guns and armor to protect them from guns of the same caliber. To keep the ships within the displacement limits imposed by the Washington Naval Treaty, they featured the same concentrated arrangement as the Dunkerques for the main battery: two quadruple gun turrets placed forward. They also incorporated new, more compact boilers that allowed for a shorter hull for the desired top speed. After Germany ordered two Bismarck-class battleships, France responded with another pair of Richelieus, to be built to modified designs. The first, Clemenceau, would have received modified secondary and anti-aircraft batteries, while Gascogne would have had had her superfiring main battery turret shifted aft, along with other changes. Clemenceau was never completed, and Gascogne was never laid down.
The Danton-class battleship was a class of six semi-dreadnought battleships built for the French Navy before World War I. The ships were assigned to the Mediterranean Fleet after commissioning in 1911. After the beginning of World War I in early August 1914, five of the sister ships participated in the Battle of Antivari. They spent most of the rest of the war blockading the Straits of Otranto and the Dardanelles to prevent warships of the Central Powers from breaking out into the Mediterranean. One ship was sunk by a German submarine in 1917.
The Sovetsky Soyuz-class battleships, also known as "Stalin's Republics", were a class of battleships begun by the Soviet Union in the late 1930s but never brought into service. They were designed in response to the Bismarck-class battleships being built by Germany. Only four hulls of the fifteen originally planned had been laid down by 1940, when the decision was made to cut the program to only three ships to divert resources to an expanded army rearmament program.
The Normandie class consisted of five dreadnought battleships ordered for the French Navy in 1912–1913. It comprised Normandie, the lead ship, Flandre, Gascogne, Languedoc, and Béarn. The design incorporated a radical arrangement for the twelve 340 mm (13.4 in) main battery guns: three quadruple-gun turrets, the first of their kind, as opposed to the twin-gun turrets used by most other navies. The first four ships were also equipped with an unusual hybrid propulsion system that used both steam turbines and triple-expansion steam engines to increase fuel efficiency.
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. According to naval historians William Garzke and Robert Dulin, the South Dakota design was the best "treaty battleship" ever built.
The Nassau class was a group of four dreadnought battleships built for the German Kaiserliche Marine in the early 1900s. The class comprised Nassau, the lead ship, Rheinland, Posen, and Westfalen. All four ships were laid down in mid-1907, and completed by late 1910. Though commonly perceived as having been built in response to the British Dreadnought, their design traces its origin to 1903; they were in fact a response to Dreadnought's predecessors of the Lord Nelson class. The Nassaus adopted a main battery of twelve 28 cm (11 in) guns in six twin-gun turrets in an unusual hexagonal arrangement. Unlike many other dreadnoughts, the Nassau-class ships retained triple-expansion steam engines instead of more powerful steam turbines.
The anti-torpedo bulge is a form of defence against naval torpedoes occasionally employed in warship construction in the period between the First and Second World Wars. It involved fitting partially water-filled compartmentalized sponsons on either side of a ship's hull, intended to detonate torpedoes, absorb their explosions, and contain flooding to damaged areas within the bulges.
All or nothing is a method of naval warship armor, best known for its employment on dreadnought battleships. The concept involves heavily armoring the areas most important to a ship while the rest of the ship receives no armor. The "all or nothing" concept avoided light or moderate thicknesses of armor: armor was used in the greatest practicable thickness or not at all, thereby providing "either total or negligible protection". Compared to previous armoring systems, "all or nothing" ships had thicker armor covering a smaller proportion of the hull.
The Liberté class consisted of four pre-dreadnought battleships built for the French Navy in the early 1900s. The class comprised Liberté, Justice, Vérité, and Démocratie. They were ordered as part of a naval expansion program directed at countering German warship construction authorized by the German Naval Law of 1898; the French program called for six new battleships, which began with the two République-class battleships. During construction of the first two vessels, foreign adoption of heavier secondary batteries prompted the French to re-design the last four members to carry a secondary battery of 194 mm (7.6 in) guns, producing the Liberté class. Like the Républiques, their main armament consisted of four 305 mm (12 in) guns in two twin-gun turrets, and they had the same top speed of 18 knots.
The République class consisted of a pair of pre-dreadnought battleships—République, the lead ship, and Patrie—built for the French Navy in the early 1900s. They were ordered as part of a naval expansion program directed at countering German warship construction authorized by the German Naval Law of 1898. The French program called for six new battleships; the last four became the very similar Liberté class. République and Patrie, designed by Louis-Émile Bertin, were a significant improvement over previous French battleships. They carried a similar offensive armament of four 305 mm (12 in) guns and eighteen 164 mm (6.5 in) guns, though most of the 164 mm guns were now mounted in more flexible gun turrets rather than in casemates. They also had a much more effective armor protection arrangement that remedied the tendency of earlier battleships to lose stability from relatively minor damage.
The Italia class was a class of two ironclad battleships built for the Italian Regia Marina in the 1870s and 1880s. The two ships—Italia and Lepanto—were designed by Benedetto Brin, who chose to discard traditional belt armor entirely, relying on a combination of very high speed and extensive internal subdivision to protect the ships. This, along with their armament of very large 432 mm (17 in) guns, has led some naval historians to refer to the Italia class as prototypical battlecruisers.
Naval armor refers to the various protections schemes employed by warships, and is distinguished from other kinds of armour. Naval sailing ships have had protection from weaponry since at least ancient times, when Greek and Roman warships used simple cladding. As weapons evolved and became more destructive, naval armour became an important part of warships. Korean and European ships began to use some iron plating in the 1500s. The first ironclad warship was created in 1859, and the pace of armour advancement accelerated quickly thereafter. The emergence of battleships around the turn of the 20th century saw ships become increasingly large and well armoured. Vast quantities of heavily armoured ships were used during the World Wars, and were crucial in the outcome. The emergence of guided missiles in the last part of the 20th century has greatly reduced the utility of armor, and most modern warships are now only lightly armored.