Semi-dreadnought
Semi-dreadnoughts were the last, quasi-experimental, intermediate stage in the transition from the standard ship of the line to the dreadnought . Some semi-dreadnoughts were still completed after the beginning of the dreadnought era. Since its technical obsolescence was already clear, the completion was often done for cost reasons, because its construction was too far advanced, and even then only with little urgency. Most of the large navies followed this development at the turn of the 19th to the 20th century, only the German navy had only planned a semi-dreadnought type with the first drafts for the Nassau class, but did not implement it.
Comparison with a standard ship of the line and a dreadnought
The specialty of these ships lies in the use of two different main calibers. The strongest caliber corresponded to the main armament of the standard ships of the line (30.5 cm or twelve English inches) and was usually stationed in twin towers. The second main caliber or the intermediate caliber corresponded in its strength to the main armament of the armored cruiser (between 20.3 and 25.4 cm or eight to ten English inches), it could be installed in double and / or single towers and / or in casemates be. For this, however, one (as a rule) did without the middle artillery built into casemates (between 127 and 178 mm or five to seven inches). The armament with light artillery less than 127 mm caliber and possibly flak corresponded to the respective national customs of the time and the armament of the standard ships of the line with artillery of this caliber.
In terms of tonnage, these ships with 13,000 to 20,000 tons of water displacement were between the standard ships of the line and the dreadnoughts, thus following the general trend towards the enlargement of warships. As a rule, piston steam engines were used as propulsion; only the French Danton class and the Japanese Aki received steam turbines.
Classes of semi-dreadnoughts put into service
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In 1904 Great Britain laid the Lord Nelson class ( Lord Nelson , Agamemnon ) on keel, which were armed with two twin towers of 30.5 cm, four twin towers of 23.4 cm and two single towers of 23.4 cm caliber as the main armament. The design displacement of these ships was approximately 16,000 tons. Because the launch of the Dreadnought fell into the construction phase of the Lord Nelson class, the two units were not completed until two years after the Dreadnought and were therefore obsolete by the way. Lord Nelson was scrapped in 1921, Agamemnon in 1926.
A second class of British semi-dreadnoughts was the King Edward VII class from 1905. The eight units of this class each displaced 16,350 tons standard and were powered by piston steam engines that allowed a speed of 18.5 knots. As armament, in addition to two twin towers of 30.5 cm, they had four single towers of 23.4 cm as intermediate caliber and ten pieces of medium artillery of 152 mm caliber in individual installation below deck. Two ships of this class (HMS Britannia, HMS King Edward VII) were lost during the First World War, the rest were sold for scrapping until 1922.
The United States submitted to the Connecticut class of 1903 ( Connecticut , Louisiana , Vermont , Kansas , Minnesota , New Hampshire ), a whole squadron Semi-Dreadnoughts, each with 16,000 tons displacement construction keel. Their main armament consisted of two twin towers of 30.5 cm and four twin towers of 20.3 cm caliber as well as twelve pieces of 17.8 cm middle artillery in casemates. In between, two more ships with the same main armament (with only eight 17.8 cm medium artillery), but smaller (13,000 tons) and armor, were inserted with the Mississippi class, which from 1914 sailed under the Greek flag as Lemnos and Kilkis . While the US squadron had no immediate war operations and was scrapped from 1923 to 1924, the ships surrendered to Greece remained active until 1932 ( Lemnos ex Idaho (BB 23)) and 1941 ( Kilkis ex Mississippi (BB 24)) Service.
With the Satsuma class (1903), Japan forced two semi-dreadnoughts ( Satsuma , Aki ) each with 19,500 tons of construction displacement on the keel, but these were not completed until 1907. Originally only 30.5 cm cannons in four single and four double turrets were planned as armament, but this was not feasible due to severe financial bottlenecks as a result of the Russo-Japanese War of 1905. Instead, both units received two twin towers of 30.5 cm and six twin towers of 25.4 cm caliber, both from English production. The mechanical equipment of these ships also made a direct comparison of the types of propulsion possible, because Satsuma was equipped with piston steam engines, which allowed a speed of only 18.25 knots, while the sister ship Aki received steam turbines, which gave a speed of 20 knots. Both ships were removed from the list of active ships in 1922 and scrapped in 1924.
With the Vittorio Emanuele class of 1901 ( Regina Elena , Vittorio Emanuele , Napoli , Roma ), Italy laid the keel of the smallest semi-dreadnoughts with a construction displacement of 13,000 tons per ship. Their main armament consisted of two single turrets with 30.5 cm and six twin turrets with 20.3 cm caliber. In their time, these ships were considered successful, mainly because of the superior speed of 20 to 22 knots compared to standard ships of the line. In 1921 these ships were reclassified as coastal armored ships, the first two ships ( Regina Elena , Vittorio Emanuele ) were scrapped in 1923, the other two in 1927.
With the Andrej Perzovannyj class of 1903 ( Andrej Perzovannyj , Imperator Pavel I ), tsarist Russia laid two semi-dreadnoughts on keel, the main armament of which consisted of two twin turrets measuring 30.5 cm, four twin turrets measuring 20.3 cm and six individual guns consisted of 20.3 cm in a large casemate. The ships each displaced 17,100 tons (construction displacement). Both ships were in service with the Baltic Fleet until 1920/1921 and were scrapped around 1923.
Austria-Hungary put the Radetzky class ( Radetzky , Archduke Franz Ferdinand , Zrinyj ) on Kiel in 1907 and put it into service until 1911. Their main armament consisted of two twin turrets of 30.5 cm and four twin turrets of 24 cm caliber. They each displaced 14,500 tons (constructive) and were considered well done. Radetzky and Zrinyj were briefly in Yugoslav hands after the end of the war, but were then awarded to the USA and scrapped in Italy in 1920 as part of the terms of the Versailles Treaty.
France put the Danton class ( Danton , Condorcet , Diderot , Voltaire , Mirabeau , Vergniaud ) into service with a design displacement of 17,600 tons until 1911 . Their main armament consisted of two twin turrets of 30.5 cm and six twin turrets of 24 cm caliber. It was propelled by steam turbines, which enabled speeds of 19.25 knots. The Danton was lost in World War I, the Condorcet survived as a barge or Hulk until 1959, the other units were scrapped between the two world wars.
The German Empire did not have any semi-dreadnoughts in its inventory. The Imperial German Navy recognized the sources of the problem in good time and decided not to take this step. However, in the course of the development of the Nassau class , drafts were also planned for it as a semi-dreadnought.
Parallel developments
On the way from the armored cruiser to the battle cruiser, there were also intermediate forms analogous to the semi-dreadnoughts, which, however, were not listed as a subclass even afterwards. The different conception of the armored cruisers, depending on the time, nationality or navy, alternating between traffickers, reconnaissance or second-class ships of the line, ensured that several navies did not get into the confusion of building intermediate forms of ships of the line or battleships and armored cruisers or battle cruisers. Examples of parallel developments are the British Minotaur (two twin towers of 23.4 cm and ten 19 cm caliber towers) and Warrior class (which are retrofitted with four 19 cm cannons instead of the 15.24 cm medium artillery was), as well as the Italian Pisa class (including the Greek Georgios Averoff ). A similar intermediate position took from 1902 to 1904 originally for Chile built Swiftsure class , which was armed with two twin towers to 25.4 cm and fourteen pieces in 19-cm caliber.
Reasons for retirement
Problems with the fire control of the two different main calibers played a major role in both classes of ship; the impacts of the main and intermediate calibers could not be clearly distinguished from one another with the means at the time. The hoped-for increase in combat value therefore did not materialize and usually led to early decommissioning, also as a result of the results of the Washington Fleet Conference of 1922. In addition, there was the now outdated propulsion with piston steam engines, which barely allowed speeds of more than twenty knots. Even if individual units were able to operate successfully and remained in service for a long time, most ships were scrapped before 1930.
A central problem was the large number of large deck openings (six to eight) for the main and intermediate calibers, which resulted in too many structural weak points even in successful designs. During the First World War, the European navies only allowed three to four main gun turrets or the necessary deck openings for new ships or conversions. Units intended for use abroad were not subject to this restriction; Non-European navies only switched to this after the end of the First World War.
During the Second World War, the idea of armament with two heavy calibers experienced a brief planning renaissance after Japan had provided eight 8 8-inch cannons in four twin towers for its Yamato class . However, since the twin towers were more urgently needed for upgrading the Mogami-class cruisers, the Yamato-class received the vacated 15.5 cm treble towers instead.
literature
- Siegfried Breyer: Battleships and battle cruisers 1905-1970 . ISBN 3-88199-474-2 .