A high pressure watertube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam. High Pressure Water Tube Boiler: The heated water rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In some services, the steam will reenter the furnace through a superheater to become superheated. Superheated steam is defined as steam, heated above the boiling point at a given pressure. Superheated steam is a dry gas and therefore used to drive turbines, since water droplets can damage turbine blades. Cool water at the bottom of the steam drum returns to the feedwater drum via large-bore'downcomer tubes', where it pre-heats the feedwater supply.. To increase economy of the boiler, exhaust gases are used to pre-heat the air blown into the furnace and warm the feedwater supply.
Such watertube boilers in thermal power stations are called steam generating units. The older fire-tube boiler design, in which the water surrounds the heat source and gases from combustion pass through tubes within the water space, is a much weaker structure and is used for pressures above 2.4 MPa. A significant advantage of the watertube boiler is that there is less chance of a catastrophic failure: there is not a large volume of water in the boiler nor are there large mechanical elements subject to failure. A water tube boiler was patented by Blakey of England in 1766 and was made by Dallery of France in 1780. “The ability of watertube boilers to generate superheated steam makes these boilers attractive in applications that require dry, high-pressure, high-energy steam, including steam turbine power generation”. Owing to their superb working properties, the use of watertube boilers is preferred in the following major areas: Variety of process applications in industries Chemical processing divisions Pulp and Paper manufacturing plants Refining unitsBesides, they are employed in power generation plants where large quantities of steam having high pressures i.e. 16 megapascals and high temperatures reaching up to 550 °C are required.
For example, the Ivanpah solar-power station uses two Rentech Type-D watertube boilers. Modern boilers for power generation are entirely water-tube designs, owing to their ability to operate at higher pressures. Where process steam is required for heating or as a chemical component there is still a small niche for fire-tube boilers, their ability to work at higher pressures has led to marine boilers being entirely water-tube. This change began around 1900, traced the adoption of turbines for propulsion rather than reciprocating engines – although watertube boilers were used with reciprocating engines. There has been no significant adoption of water-tube boilers for railway locomotives. A handful of experimental designs were produced, but none of these were successful or led to their widespread use. Most water-tube railway locomotives in Europe, used the Schmidt system. Most were compounds, a few uniflows; the Norfolk and Western Railway's Jawn Henry was an exception, as it used a steam turbine combined with an electric transmission.
LMS 6399 FuryRebuilt after a fatal accidentLNER 10000 "Hush hush"Using a Yarrow boiler, rather than Schmidt. Never successful and re-boilered with a conventional boiler. A more successful adoption was the use of hybrid water-tube / fire-tube systems; as the hottest part of a locomotive boiler is the firebox, it was an effective design to use a water-tube design here and a conventional fire-tube boiler as an economiser in the usual position. One famous example of this was the USA Baldwin 4-10-2 No. 60000, built in 1926. Operating as a compound at a boiler pressure of 2,400 kilopascals it covered over 160,000 kilometres successfully. After a year though, it became clear that any economies were overwhelmed by the extra costs and it was retired to become a stationary plant. A series of twelve experimental locomotives were constructed at the Baltimore and Ohio Railroad's Mt. Clare shops under the supervision of George H. Emerson, but none of them was replicated in any numbers; the only railway use of water-tube boilers in any numbers was the Brotan boiler, invented in Austria in 1902 by Johann Brotan and found in rare examples throughout Europe.
Hungary, was a keen user and had around 1,000 of them. Like the Baldwin, this combined a water-tube firebox with a fire-tube barrel; the original characteristic of the Brotan was a long steam drum running above the main barrel, making it resemble a Flaman boiler in appearance. While the traction engine was built using its locomotive boiler as its frame, other types of steam road vehicles such as lorries and cars have used a wide range of different boiler types. Road transport pioneers Goldsworthy Gurney and Walter Hancock both used water-tube boilers in their steam carriages around 1830. Most undertype wagons used water-tube boilers. Many manufacturers used variants of the vertical cross-tube boiler, including Atkinson, Clayton and Sentinel. Other types include the Clarkson'thimble tube' and the Foden O-type wagon's pistol-shaped boiler. Steam fire-engine makers such as Merryweather used water-tube boilers for their rapid
The Pacific War, sometimes called the Asia–Pacific War, was the theater of World War II, fought in the Pacific and Asia. It was fought over a vast area that included the Pacific Ocean and islands, the South West Pacific, South-East Asia, in China; the Second Sino-Japanese War between the Empire of Japan and the Republic of China had been in progress since 7 July 1937, with hostilities dating back as far as 19 September 1931 with the Japanese invasion of Manchuria. However, it is more accepted that the Pacific War itself began on 7/8 December 1941, when Japan invaded Thailand and attacked the British colonies of Malaya and Hong Kong as well as the United States military and naval bases in Hawaii, Wake Island and the Philippines; the Pacific War saw the Allies pitted against Japan, the latter aided by Thailand and to a much lesser extent by the Axis allied Germany and Italy. The war culminated in the atomic bombings of Hiroshima and Nagasaki, other large aerial bomb attacks by the Allies, accompanied by the Soviet declaration of war and invasion of Manchuria on 9 August 1945, resulting in the Japanese announcement of intent to surrender on 15 August 1945.
The formal surrender of Japan ceremony took place aboard the battleship USS Missouri in Tokyo Bay on 2 September 1945. After the war, Japan lost all rights and titles to its former possessions in Asia and the Pacific, its sovereignty was limited to the four main home islands. Japan's Shinto Emperor was forced to relinquish much of his authority and his divine status through the Shinto Directive in order to pave the way for extensive cultural and political reforms. In Allied countries during the war, the "Pacific War" was not distinguished from World War II in general, or was known as the War against Japan. In the United States, the term Pacific Theater was used, although this was a misnomer in relation to the Allied campaign in Burma, the war in China and other activities within the Southeast Asian Theater. However, the US Armed Forces considered the China-Burma-India Theater to be distinct from the Asiatic-Pacific Theater during the conflict. Japan used the name Greater East Asia War, as chosen by a cabinet decision on 10 December 1941, to refer to both the war with the Western Allies and the ongoing war in China.
This name was released to the public on 12 December, with an explanation that it involved Asian nations achieving their independence from the Western powers through armed forces of the Greater East Asia Co-Prosperity Sphere. Japanese officials integrated what they called the Japan–China Incident into the Greater East Asia War. During the Allied military occupation of Japan, these Japanese terms were prohibited in official documents, although their informal usage continued, the war became known as the Pacific War. In Japan, the Fifteen Years' War is used, referring to the period from the Mukden Incident of 1931 through 1945; the Axis states which assisted Japan included the authoritarian government of Thailand, which formed a cautious alliance with the Japanese in 1941, when Japanese forces issued the government with an ultimatum following the Japanese invasion of Thailand. The leader of Thailand, Plaek Phibunsongkhram, became enthusiastic about the alliance after decisive Japanese victories in the Malayan Campaign and in 1942 sent the Phayap Army to assist the invasion of Burma, were former Thai territory, annexed by Britain were reoccupied.
The allies supported and organized an underground anti-Japanese resistance group, known as the Free Thai Movement, after the Thai ambassador to the United States had refused to hand over the declaration of war. Because of this, after the surrender in 1945, the stance of the United States was that Thailand should be treated as a puppet of Japan and be considered an occupied nation rather than as an ally; this was done in contrast to the British stance towards Thailand, who had faced them in combat as they invaded British territory, the United States had to block British efforts to impose a punitive peace. Involved were members of the Greater East Asia Co-Prosperity Sphere, which included the armies of the Japanese puppet states of Manchukuo, the collaborationist Wang Jingwei regime. In the Burma Campaign, other members, such as the anti-Britsh Indian National Army of Free India and Burma National Army of the State of Burma were active and fighting alongside their Japanese allies. Moreover, Japan conscripted many soldiers from its colonies of Taiwan.
Collaborationist security units were formed in Hong Kong, the Philippines, Dutch East Indies, British Malaya, British Borneo, former French Indochina as well as Timorese militia. These units the assisted Japanese war effort in their respective territories. Germany and Italy both had limited involvement in the Pacific War; the German and the Italian navies operated submarines and raiding ships in the Indian and Pacific Oceans. The Italians had access to concession territory naval bases in China. After Japan's attack on Pearl Harbor and the subsequent declarations of war, both navies had access to Japanese naval facilities; the major Allied participants were the United States and their colonies, the Republic of China, engaged in bloody war against Japan since 1937, the United Kingdom (mos
The Russo-Japanese War was fought during 1904-1905 between the Russian Empire and the Empire of Japan over rival imperial ambitions in Manchuria and Korea. The major theatres of operations were the Liaodong Peninsula and Mukden in Southern Manchuria and the seas around Korea and the Yellow Sea. Russia sought a warm-water port on the Pacific Ocean for maritime trade. Vladivostok was operational only during the summer, whereas Port Arthur, a naval base in Liaodong Province leased to Russia by China, was operational all year. Since the end of the First Sino-Japanese War in 1895, Japan feared Russian encroachment on its plans to create a sphere of influence in Korea and Manchuria. Russia had demonstrated an expansionist policy in the Siberian Far East from the reign of Ivan the Terrible in the 16th century. Seeing Russia as a rival, Japan offered to recognize Russian dominance in Manchuria in exchange for recognition of Korea as being within the Japanese sphere of influence. Russia refused and demanded Korea north of the 39th parallel to be a neutral buffer zone between Russia and Japan.
The Japanese government perceived a Russian threat to its plans for expansion into Asia and chose to go to war. After negotiations broke down in 1904, the Japanese Navy opened hostilities by attacking the Russian Eastern Fleet at Port Arthur, China, in a surprise attack. Russia suffered multiple defeats by Japan, but Tsar Nicholas II was convinced that Russia would win and chose to remain engaged in the war. Russia ignored Japan's willingness early on to agree to an armistice and rejected the idea to bring the dispute to the Arbitration Court at The Hague; the war concluded with the Treaty of Portsmouth, mediated by US President Theodore Roosevelt. The complete victory of the Japanese military surprised world observers; the consequences transformed the balance of power in East Asia, resulting in a reassessment of Japan's recent entry onto the world stage. It was the first major military victory in the modern era of an Asian power over a European one. Scholars continue to debate the historical significance of the war.
After the Meiji Restoration in 1868, the Meiji government endeavored to assimilate Western ideas, technological advances and ways of warfare. By the late 19th century, Japan had transformed itself into a modernized industrial state; the Japanese wanted to be recognized as equal with the Western powers. The Meiji Restoration had been intended to make Japan a modernized state, not a Westernized one, Japan was an imperialist power, looking towards overseas expansionism. In the years 1869–73, the Seikanron had bitterly divided the Japanese elite between one faction that wanted to conquer Korea vs. another that wanted to wait until Japan was more modernized before embarking on a war to conquer Korea. Worse, the Western Powers were conquering small pieces of China and China had dominated Korea with its military for centuries; the Japanese were doing what they could to emulate the West in every way possible, including conqering and occupying its neighbors. In much the same way that Europeans used the "backwardness" of African and Asian nations as a reason for why they had to conquer them, for the Japanese elite the "backwardness" of China and Korea was proof of the inferiority of those nations, thus giving the Japanese the "right" to conquer them.
Inouye Kaoru, the Foreign Minister, gave a speech in 1887 saying "What we must do is to transform our empire and our people, make the empire like the countries of Europe and our people like the peoples of Europe", going to say that the Chinese and Koreans had forfeited their right to be independent by not modernizing. Much of the pressure for an aggressive foreign policy in Japan came from below, with the advocates of "people's rights" movement calling for an elected parliament favoring an ultra-nationalist line that took it for granted the Japanese had the "right" to annex Korea, as the "people's right" movement was led by those who favored invading Korea in the years 1869–73; as part of the modernization process in Japan, Social Darwinian ideas about the "survival of the fittest" were common in Japan from the 1880s onward and many ordinary Japanese resented the heavy taxes imposed by the government to modernize Japan, demanding something tangible like an overseas colony as a reward for their sacrifices.
Furthermore, the educational system of Meiji Japan was meant to train the schoolboys to be soldiers when they grew up, as such, Japanese schools indoctrinated their students into Bushidō, the fierce code of the samurai. Having indoctrinated the younger generations into Bushidō, the Meiji elite found themselves faced with a people who clamored for war, regarded diplomacy as a weakness; the British Japanologist Richard Storry wrote the biggest misconception about Japan in the West was that the Japanese people were the "docile" instruments of the elite, when in fact much of the pressure for Japan's wars from 1894 to 1941 came from below, as ordinary people demanded a "tough" foreign policy, tended to engage in riots and assassination when foreign policy was perceived to be pusillanimous. Though the Meiji oligarchy refused to allow democracy, they did seek to appropriate some of the demands of the "people's rights" movement by allowing an elected Diet in 1890 (with limited powers and an equally
Siege of Tsingtao
The Siege of Tsingtao, sometimes Siege of Tsingtau, was the attack on the German port of Tsingtao in China during World War I by Japan and the United Kingdom. The siege took place between 7 November 1914 against Imperial Germany; the siege was the first encounter between Japanese and German forces and the first Anglo-Japanese operation of the war. Throughout the late 19th century, Imperial Germany joined other European powers in an imperialist scramble for colonial possessions; as with the other world powers, Germany began to interfere in Chinese local affairs. After two German missionaries were killed in the Juye Incident in 1897, China was forced to agree to the Kiautschou Bay concession in Shantung to Germany in 1898 on a 99-year lease. Germany began to assert its influence across the rest of the province and built the city and port of Tsingtao, which became the base of the German East Asiatic Squadron of the Kaiserliche Marine, which operated in support of the German colonies in the Pacific.
Britain viewed the German presence in China as a threat and leased Weihaiwei in Shantung, as a naval port and coaling station. Russia leased its own station at Port France at Kwang-Chou-Wan. Britain began to forge close ties with Japan, whose developments in the late 19th century mirrored that of the European imperialist powers as Japan acquired colonial footholds on the Asian mainland. Japanese and British diplomatic relations became closer and the Anglo-Japanese Alliance was signed on 30 January 1902. Japan saw the alliance as a necessary deterrent to Russia. Japan demonstrated its potential by its victory in the 1904–1905 Russo-Japanese War, the alliance continued into World War I; when the war in Europe began in August 1914, Britain promptly requested Japanese assistance. On 15 August, Japan issued an ultimatum, stating that Germany must withdraw her warships from Chinese and Japanese waters and transfer control of its port of Tsingtao to Japan; the next day, Major-General Mitsuomi Kamio, General Officer Commanding, 18th Infantry Division, was ordered to prepare to take Tsingtao by force.
The ultimatum expired on 23 August, Japan declared war on Germany. At the beginning of hostilities, the ships of the East Asia Squadron under Vice Admiral Maximilian von Spee were dispersed at various Pacific colonies on routine missions. Spee's ships rendezvoused in the Northern Mariana Islands for coaling. SMS Emden headed for the Indian Ocean, while the rest of the squadron made their way to the west coast of South America; the squadron engaged and destroyed a Royal Navy squadron at the Battle of Coronel, before being destroyed at the Battle of the Falkland Islands in the South Atlantic. The Boxer Rebellion at the beginning of the century had led Germany to consider the defense of Tsingtao; the port and town were divided from the rest of the peninsula by steep hills. The natural line of defense lay from the Kaiserstuhl to Litsuner Heights. A second 17 km line of defense was set up along a closer line of steep hills; the final line of defense was along hills 200 m above the town. A network of trenches and other fortifications had been built in preparation for the coming siege.
Germany had strengthened the defenses from the sea, laying mines in the approaches to the harbour and building four batteries and five redoubts. The fortifications were well manned. On 27 August, the Imperial Japanese Navy sent ships under Vice-Admiral Sadakichi Kato, flying his flag in the pre-dreadnought Suwo, to blockade the coast of Kiaochow; the British Royal Navy strengthened the Japanese fleet by sending the China Station's pre-dreadnought HMS Triumph and the destroyer HMS Usk. According to a German press report after the siege, the Triumph was damaged by the German shore batteries; the blockading fleet consisted of nearly obsolete warships, though it did at times include a few modern vessels. These included the dreadnoughts Kawachi, the battlecruiser Kongō, her sister Hiei, the seaplane carrier Wakamiya, whose aircraft became the first of its kind in the world to attack land and sea targets; these Japanese aircraft would take part in another military first, a night-time bombing raid. The 18th Infantry Division was the primary Japanese Army formation that took part in the initial landings, numbering some 23,000 soldiers with support from 142 artillery pieces.
They began to land on 2 September at Lungkow, experiencing heavy floods at the time and at Lau Schan Bay on 18 September, about 29 km east of Tsingtao. China protested against the Japanese violation of her neutrality but did not interfere in the operations; the British Government and the other European great powers were concerned about Japanese intentions in the region and decided to send a small symbolic British contingent from Tientsin in an effort to allay their fears. The 1,500-man contingent was commanded by Brigadier-General Nathaniel Walter Barnardiston and consisted of 1,000 soldiers of the 2nd Battalion, The South Wales Borderers. Following a friendly fire incident, British troops were given Japanese kimonos to wear so they would be more identifiable to the Japanese; the Germans responded to the threat against Tsingtao by concentrating all of their available East Asian troops in the city. Kaiser Wilhelm II made the defense of Tsingtao a top priority, saying that "... it would shame me more to surrender Tsingtao to the Japanese than Berlin to the Russians".
The German garrison, commanded by naval Captain and Governor Alfred Meyer-Waldeck, consisted of the marines of III Seebataillon, naval personnel
Kure Naval District
Kure Naval District was the second of four main administrative districts of the pre-war Imperial Japanese Navy. Its territory included the Inland Sea of Japan and the Pacific coasts of southern Honshū from Wakayama to Yamaguchi prefectures and northern Kyūshū and Shikoku; the area of the Kure Naval District encompassed Hashirajima Anchoring Area located at the south end of Hiroshima Bay, 30-40 kilometers southwest of Kure. When not in need of repairs ships anchored in this area to free up pier space at Kure. Hashirajima was a major staging area for fleet operations. Tokuyama port, was part of Kure Naval District, had the largest fuel depot in the Japanese Navy; the location of Kure within the sheltered Inland Sea of Japan was recognized of strategic importance in controlling the sea lanes around western Japan by the Meiji government and early Imperial Japanese Navy. With the formation of the navy in 1886, Japan was divided into five naval districts for recruiting and supply. During the administrative re-organization of the Japanese Navy in 1889, Kure was designated as the “Second Naval District”, its harbor was dredged, a breakwater constructed and docking facilities for warships were established.
The following year, work began on the Kure Naval Arsenal, which would expand to become one of the largest shipyards in Japan for the construction of large capital ships. The facilities of Kure Naval District included armories, production factories for torpedoes, naval mines and naval artillery, a naval hospital and training centers; the Imperial Japanese Naval Academy and Naval Staff College were relocated from Tokyo to nearby Etajima, thus came within the borders of the Kure Naval District, but did not come under the command of Kure Naval District itself. In 1920, the Japanese navy established its main submarine base and submarine warfare training school in Kure. An air wing was established in 1932, a telecommunications center in 1937. At the time of the attack on Pearl Harbor in 1941, Kure Naval District encompassed the following Kure Naval District HQ Kure Naval Base Kure Naval Guard Unit Destroyer Yakaze Submarine I-52, Ro-30, Ro-31, Ro-32 Minelayer Katsuriki Kaibokan Yakumo Kure Naval Arsenal Kure Naval Hospital Kure Naval Prison Kure Naval Fuel Deport Kure Special Naval Landing Forces Kure Submarine Base Otake Naval Infantry Barracks Tokuyama Naval Fuel Depot Kure Security SquadronC.
M. Cruiser Saigon Maru, Bangkok Maru C. M. gunboat Hong Kong Maru Kure Local Defence SquadronDestroyer Division 13 Destroyer Wakatake, Sanae Submarine chaser No. 19, No. 20, No. 21 C. M. cruiser Kinjōsan Maru Minesweeper Division 31 C. M. minesweeper Takunan Maru No. 3, Takunan Maru No. 8, Tama Maru, Tama Maru No. 6, Tama Maru No. 7, Ōi Maru Minesweeper Division 33 C. M. minesweeper Bizan Maru, Meshima Maru, Tokuhō Maru No. 5, Dai-2-Gō Asahi Maru, Kiri Maru No. 5, Miyo Maru Saeki Defence Unit Shimonoseki Defence Unit 12th Combined Air Group Ōita Naval Air Group Usa Naval Air Group Hakata Naval Air Group Ōmura Naval Air Group Kure Naval Air Group Saeki Naval Air Group Submarine Division Six Submarine Ro-57 Submarine Ro-58 Submarine Ro-59Kure was bombed by United States Navy and United States Army Air Forces bombers in the final stages of the Pacific War, many of its facilities were destroyed. The Kure area came under occupation by Australian and British forces during the occupation of Japan, was demilitarized.
A small portion of the area continued to be occupied by the modern post-war Japanese Maritime Self-Defense Force, which has preserved a portion of the original red brick gates and couple of buildings as commemorative museums. Rear-Admiral Shizuo Sato Fleet Admiral Marquis Heihachiro Togo Rear-Admiral Tokiyasu Yoshijima Rear-Admiral Fukusaburo Hirao Rear-Admiral Katsumi Miyoshi Vice-Admiral Baron Masamichi Togo Captain Isamu Yajima Rear-Admiral Hisamaro Oinoue Vice-Admiral Baron Tokutaro Nakamizo Rear-Admiral Ichiro Nijima Admiral Motaro Yoshimatsu Rear-Admiral Shinjiro Uehara Rear-Admiral Heitaro Takeuchi Admiral Matahichiro Nawa Admiral Kaneo Nomaguchi Rear-Admiral Kishichiro Osawa Vice-Admiral Naoe Nakano Admiral Kenji Ide Vice-Admiral Shibakichi Yamanaka Vice-Admiral Junichi Matsumura Vice-Admiral Shichigoro Saito Vice-Admiral Yoshimoto Masaki Vice-Admiral Naomoto Komatsu Vice-Admiral Naotaro Nagasawa Rear-Admiral Bekinari Kabayama Vice-Admiral Tokujiro Tateno Vice-Admiral Kiyohiro Ijichi Admiral Koshirō Oikawa Vice-Admiral Giichi Suzuki Vice-Admiral Choji Inoue Vice-Admiral Tokutaro Sumiyama Vice-Admiral Umataro Tanimoto Vice-Admiral Masaichi Niimi Vice-Admiral Ichiro Sato (1 April 1936 – 1 Dec
The dreadnought was the predominant type of battleship in the early 20th century. The first of its kind, the Royal Navy's HMS Dreadnought, made such a strong impression on people's minds when launched in 1906 that similar battleships built subsequently were referred to generically as "dreadnoughts", earlier battleships became known as "pre-dreadnoughts". Dreadnought's design had two revolutionary features: an "all-big-gun" armament scheme, with more heavy-calibre guns than previous ships, steam turbine propulsion; as dreadnoughts became a symbol of national power, the arrival of these new warships was a crucial catalyst in the intensifying naval arms race between the United Kingdom and Germany. With the launch of a single ship, the scales of naval power were reset overnight; as a result, dreadnought races sprang up around the world, including in South America, during the lead up to World War I. Successive designs increased in size and made use of improvements in armament and propulsion throughout the dreadnought era.
Within five years, new battleships had outclassed Dreadnought. These more powerful vessels were known as "super-dreadnoughts". Most of the original dreadnoughts were scrapped after the end of World War I under the terms of the Washington Naval Treaty, but many of the newer super-dreadnoughts continued to be used throughout World War II; the only surviving dreadnought is USS Texas, located near the San Jacinto Battleground State Historic Site. Dreadnought-building consumed vast resources in the early 20th century, but there was only one battle between large dreadnought fleets. In the 1916 Battle of Jutland, the British and German navies clashed with no decisive result; the term "dreadnought" dropped from use after World War I after the Washington Naval Treaty, as all remaining battleships shared dreadnought characteristics. The distinctive all-big-gun armament of the dreadnought was developed in the first years of the 20th century as navies sought to increase the range and power of the armament of their battleships.
The typical battleship of the 1890s, now known as the "pre-dreadnought", had a main armament of four heavy guns of 12-inch calibre, a secondary armament of six to eighteen quick-firing guns of between 4.7 inches and 7.5 inches calibre, other smaller weapons. This was in keeping with the prevailing theory of naval combat that battles would be fought at some distance, but the ships would approach to close range for the final blows, when the shorter-range, faster-firing guns would prove most useful; some designs had an intermediate battery of 8-inch guns. Serious proposals for an all-big-gun armament were circulated in several countries by 1903. All-big-gun designs commenced simultaneously in three navies. In 1904, the Imperial Japanese Navy authorized construction of Satsuma designed with twelve 12-inch guns. Work began on her construction in May 1905; the Royal Navy began the design of HMS Dreadnought in January 1905, she was laid down in October of the same year. The US Navy gained authorization for USS Michigan, carrying eight 12-inch guns, in March 1905, with construction commencing in December 1906.
The move to all-big-gun designs was accomplished because a uniform, heavy-calibre armament offered advantages in both firepower and fire control, the Russo-Japanese War of 1904–1905 showed that naval battles could, would, be fought at long distances. The newest 12-inch guns had longer range and fired heavier shells than a gun of 10-inch or 9.2-inch calibre. Another possible advantage was fire control. There is still debate as to. In naval battles of the 1890s the decisive weapon was the medium-calibre 6-inch, quick-firing gun firing at short range. At these ranges, lighter guns had good accuracy, their high rate of fire delivered high volumes of ordnance on the target, known as the "hail of fire". Naval gunnery was too inaccurate to hit targets at a longer range. By the early 20th century and American admirals expected future battleships would engage at longer distances. Newer models of torpedo had longer ranges. For instance, in 1903, the US Navy ordered a design of torpedo effective to 4,000 yards.
Both British and American admirals concluded. In 1900, Admiral Sir John "Jackie" Fisher, commanding the Royal Navy Mediterranean Fleet, ordered gunnery practice with 6-inch guns at 6,000 yards. By 1904 the US Naval War College was considering the effects on battleship tactics of torpedoes with a range of 7,000 yards to 8,000 yards; the range of light and medium-calibre guns was limited, accuracy declined badly at longer range. At longer ranges the advantage of a high rate of fire decreased. On 10 August 1904 the Imperial Russian Navy and the Imperial Japanese Navy had one of the longest-range gunnery duels to date – over 13km – during the Battle of the Yellow Sea; the Russian battleships were equipped with Liuzhol range finders with an effective range of 4km
15 cm/45 41st Year Type
The 15 cm/45 41st Year Type was a British naval gun designed by the Elswick Ordnance Company for export in the years before World War I that armed warships of the Imperial Japanese Navy. These guns served aboard Japanese ships during World War I and as coastal artillery during World War II; the 15 cm/45 41st Year began life as a design produced by the parent company of Elswick, Armstrong Whitworth for export customers and called the Pattern GG. These guns did not serve aboard ships of the Royal Navy. On 5 October 1917 the Japanese designation system for artillery changed from inches 6 in/45 41st Year Type to centimeters 15 cm/45 41st Year Type. Whether the guns originated in Britain or were built in Japan they still shared the same 41st Year designation; the 15 cm/45 41st Year was constructed of an A wire wound with a protective outer jacket. Ships built in British shipyards for Japan were armed with Pattern GG guns and Japan produced their own versions under license at the Kure Naval Arsenal.
Four different models were produced at Kure. Although sometimes referred to as QF guns, they were BL guns which used separate loading bagged charges and projectiles. 15 cm/45 41st Year guns equipped armored cruisers, predreadnought battleships and protected cruisers of the Imperial Japanese Navy. Armored cruisers: Tsukuba-class cruisers - The two ships of this class had a secondary armament of twelve EOC Pattern GG guns in single casemated mounts amidships. Japanese cruiser Aso - This ship was the former Bayan of the Imperial Russian Navy sunk and captured at Port Arthur in 1905; the ship was recommissioned into the Imperial Japanese Navy in 1908 as the Aso. The Bayan's secondary armament of eight single casemated 152 mm 45 caliber Pattern 1892 guns were replaced with eight EOC Pattern GG guns. Predreadnought battleships: Kawachi-class battleships - The two ships of this class had a secondary armament of ten 15 cm/45 41st Year guns in single casemated mounts amidships. Japanese battleship Aki - This ship had a secondary armament of eight 15 cm/45 41st Year guns in single casemated mounts amidships.
Japanese battleship Kashima - This ship had a secondary armament of ten EOC Pattern GG guns in single casemated mounts amidships. Japanese battleship Mikasa - This ship had a secondary armament of fourteen 15 cm/45 41st Year guns in single casemated mounts amidships after a 1908 refit. Protected cruisers: Chikuma-class cruisers - The three ships of this class had a primary armament of six 15 cm/45 41st Year guns. There was one single shielded mount fore and aft, three shielded mounts per side in sponsons amidships. Japanese cruiser Tsugaru - This ship was the former Pallada of the Imperial Russian Navy sunk and captured at Port Arthur in 1905; the ship was recommissioned into the Imperial Japanese Navy in 1908 as the Tsugaru. The Pallada's primary armament of eight 152 mm 45 caliber Pattern 1892 guns were replaced with eight 15 cm/45 41st Year guns. Ammunition was of separate loading bagged projectile; the bagged charges weighed 22 kg. The gun was able to fire: Norman. Naval Weapons of World War One.
Barnsley, South Yorkshire, UK: Seaforth. ISBN 978-1-84832-100-7. Http://www.navweaps.com/Weapons/WNJAP_6-45_EOC.php http://navalhistory.flixco.info/H/125881x54503/8330/a0.htm