The Indian Navy is the naval branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy; the Chief of Naval Staff, a four-star admiral, commands the navy. The Indian Navy traces its origins back to the East India Company's Marine, founded in 1612 to protect British merchant shipping in the region. In 1793, the East India Company established its rule over eastern part of the Indian subcontinent i.e. Bengal, but it was not until 1830 that the colonial navy was titled as His Majesty's Indian Navy; when India became a republic in 1950, the Royal Indian Navy as it had been named since 1934 was renamed to Indian Navy. The primary objective of the navy is to safeguard the nation's maritime borders, in conjunction with other Armed Forces of the union, act to deter or defeat any threats or aggression against the territory, people or maritime interests of India, both in war and peace. Through joint exercises, goodwill visits and humanitarian missions, including disaster relief, Indian Navy promotes bilateral relations between nations.
As of 1 July 2017, 67,228 personnel are in service with the Navy. As of March 2018, the operational fleet consists of one aircraft carrier, one amphibious transport dock, eight landing ship tanks, 11 destroyers, 13 frigates, one nuclear-powered attack submarine, one ballistic missile submarine, 14 conventionally-powered attack submarines, 22 corvettes, one mine countermeasure vessel, four fleet tankers and various other auxiliary vessels; the maritime history of India dates back to 6,000 years with the birth of art of the navigation and navigating during the Indus Valley Civilisation. A Kutch mariner's log book from 19th century recorded that the first tidal dock India has been built at Lothal around 2300 BC during the Indus Valley Civilisation, near the present day harbour of Mangrol on the Gujarat coast; the Rig Veda, credits Varuna, the Hindu god of water and the celestial ocean, with knowledge of the ocean routes and describes the use of ships having hundred oars in the naval expeditions by Indians.
There are references to the side wings of a ship called Plava, which stabilizes the vessel during storms. Plava is considered to be the precursor of modern-day stabilizers; the first use of mariner's compass, called as Matsya Yantra, was recorded in 4 and 5 AD. Alexander the Great during his conquest over India, built a harbour at Patala, his army retreated to Mesopotamia on the ships built at Sindh. In the of his conquest, records show that the Emperor of Maurya Empire, Chandragupta Maurya, as a part of war office, established an Admiralty Division under the Superintendent of Ships. Many historians from ancient India recorded the Indian trade relations with many countries, with countries as far as Java and Sumatra. There were references to the trade routes of countries in the Pacific and Indian Ocean. India had trade relations with the Greeks and the Romans. At one instance Roman historian Gaius Plinius Secundus mentioned of Indian traders carrying away large masses of gold and silver from Rome, in payment for skins, precious stones, indigo, herbs and spices.
During 5–10 AD, the Kalinga and the Vijayanagara Empires conquered Western Java and Malaya. The Andaman and Nicobar Islands served as an important halt point for trade ships en route to these nations and as well as China. During 844 -- 848 AD. During 984–1042 AD, under the reign of Raja Raja Chola I, Rajendra Chola I and Kulothunga Chola I, the naval expedition by Chola dynasty captured lands of Burma, Sri Lanka, Malaya, repressing pirate activities by Sumatran warlords. During 14th and 15th centuries, Indian shipbuilding skills and their maritime ability was sophisticated enough to produce ships with a capacity to carry over hundred men. Ships had compartments included in their design, so that if one compartment was damaged, the ship would remain afloat; these features of were developed by Indians before Europeans were aware of the idea. However, by the end of thirteenth century Indian naval power had started to decline, had reached its low by the time the Portuguese entered India. Soon after they set foot in India, the Portuguese started to hunt down all Asian vessels not permitting their trade.
Amidst this, in 1529, a naval war at Bombay Harbour resulted in the surrender of Thane and Bandora. By 1534, the Portuguese took complete control over the Bombay Harbour; the Zamorin of Calicut challenged the Portuguese trade when Vasco da Gama refused to pay the customs levy as per the trade agreement. This resulted in two major naval wars, the first one—Battle of Cochin, was fought in 1504, the second engagement happened four years off Diu. Both these wars, exposed the weakness of Indian maritime power and helped the Portuguese to gain mastery over the Indian waters. In the seventeenth century Indian naval power observed remarkable revival; the alliance of the Moghuls and the Sidis of Janjira was marked as a major power on the west coast. On the southern front, the 1st Sovereign of the Maratha Empire, Shivaji Bhosale, started creating his own fleet, his fleet was commanded by notable admirals like Kanhoji Angre. The Maratha Navy under the leadership of Angre kept the English and Portuguese away from the Konkan coast.
However, the Marathas witnessed remarkable decline in their naval capabilities following the death of Angre in 1729. The origins of the Indian Navy date to 1612, when an English vessel under the command of Captain Best encountered the Portuguese. Although the Portuguese were defeated, this incident along with the trouble caused by the pirates to th
The Royal Navy is the United Kingdom's naval warfare force. Although warships were used by the English kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years War against the Kingdom of France; the modern Royal Navy traces its origins to the early 16th century. From the middle decades of the 17th century, through the 18th century, the Royal Navy vied with the Dutch Navy and with the French Navy for maritime supremacy. From the mid 18th century, it was the world's most powerful navy until surpassed by the United States Navy during the Second World War; the Royal Navy played a key part in establishing the British Empire as the unmatched world power during the 19th and first part of the 20th centuries. Due to this historical prominence, it is common among non-Britons, to refer to it as "the Royal Navy" without qualification. Following World War I, the Royal Navy was reduced in size, although at the onset of World War II it was still the world's largest.
By the end of the war, the United States Navy had emerged as the world's largest. During the Cold War, the Royal Navy transformed into a anti-submarine force, hunting for Soviet submarines and active in the GIUK gap. Following the collapse of the Soviet Union, its focus has returned to expeditionary operations around the world and remains one of the world's foremost blue-water navies. However, 21st century reductions in naval spending have led to a personnel shortage and a reduction in the number of warships; the Royal Navy maintains a fleet of technologically sophisticated ships and submarines including two aircraft carriers, two amphibious transport docks, four ballistic missile submarines, six nuclear fleet submarines, six guided missile destroyers, 13 frigates, 13 mine-countermeasure vessels and 22 patrol vessels. As of November 2018, there are 74 commissioned ships in the Royal Navy, plus 12 ships of the Royal Fleet Auxiliary; the RFA replenishes Royal Navy warships at sea, augments the Royal Navy's amphibious warfare capabilities through its three Bay-class landing ship vessels.
It works as a force multiplier for the Royal Navy doing patrols that frigates used to do. The total displacement of the Royal Navy is 408,750 tonnes; the Royal Navy is part of Her Majesty's Naval Service, which includes the Royal Marines. The professional head of the Naval Service is the First Sea Lord, an admiral and member of the Defence Council of the United Kingdom; the Defence Council delegates management of the Naval Service to the Admiralty Board, chaired by the Secretary of State for Defence. The Royal Navy operates three bases in the United Kingdom; as the seaborne branch of HM Armed Forces, the RN has various roles. As it stands today, the RN has stated its 6 major roles as detailed below in umbrella terms. Preventing Conflict – On a global and regional level Providing Security At Sea – To ensure the stability of international trade at sea International Partnerships – To help cement the relationship with the United Kingdom's allies Maintaining a Readiness To Fight – To protect the United Kingdom's interests across the globe Protecting the Economy – To safe guard vital trade routes to guarantee the United Kingdom's and its allies' economic prosperity at sea Providing Humanitarian Aid – To deliver a fast and effective response to global catastrophes The strength of the fleet of the Kingdom of England was an important element in the kingdom's power in the 10th century.
At one point Aethelred II had an large fleet built by a national levy of one ship for every 310 hides of land, but it is uncertain whether this was a standard or exceptional model for raising fleets. During the period of Danish rule in the 11th century, the authorities maintained a standing fleet by taxation, this continued for a time under the restored English regime of Edward the Confessor, who commanded fleets in person. English naval power declined as a result of the Norman conquest. Following the Battle of Hastings, the Norman navy that brought over William the Conqueror disappeared from records due to William receiving all of those ships from feudal obligations or because of some sort of leasing agreement which lasted only for the duration of the enterprise. More troubling, is the fact that there is no evidence that William adopted or kept the Anglo-Saxon ship mustering system, known as the scipfryd. Hardly noted after 1066, it appears that the Normans let the scipfryd languish so that by 1086, when the Doomsday Book was completed, it had ceased to exist.
According to the Anglo-Saxon Chronicle, in 1068, Harold Godwinson's sons Godwine and Edmund conducted a ‘raiding-ship army’ which came from Ireland, raiding across the region and to the townships of Bristol and Somerset. In the following year of 1069, they returned with a bigger fleet which they sailed up the River Taw before being beaten back by a local earl near Devon. However, this made explicitly clear that the newly conquered England under Norman rule, in effect, ceded the Irish Sea to the Irish, the Vikings of Dublin, other Norwegians. Besides ceding away the Irish Sea, the Normans ceded the North Sea, a major area where Nordic peoples traveled. In 1069, this lack of naval presence in the North Sea allowed for the invasion an
Skjold-class corvettes are a class of six large, stealth missile corvettes in service with the Royal Norwegian Navy. The boats were classed as MTBs but, from 2009, the Royal Norwegian Navy has described them as corvettes because their seaworthiness is seen as comparable to corvettes, because they do not carry torpedoes, they were built at the Umoe Mandal yard. With a maximum speed of 60 knots, the Skjold-class corvettes were the fastest combat ships afloat at the time of their introduction; the Skjold-class vessels began with the development of the Royal Norwegian Navy's "Project SMP 6081", the first preproduction version was ordered on 30 August 1996. The first ship of its class, P960, was launched on 22 September 1998 and commissioned 17 April 1999. A Norwegian Parliamentary White Paper of 2001 recommended building five additional boats, this was agreed to in 2002. Six Skjold-class vessels replaced the Royal Norwegian Navy's previous fourteen Hauk-class patrol boats; the Skjold design is a surface effect craft, constructed of glass fibre/carbon composite materials.
Buoyancy is augmented underway by a fan-blown skirted compartment between the two rigid catamaran-type hulls. This provides an alternative solution to the planing hull/vee hull compromise: the air cushion reduces wave slam at high speeds while presenting a low-drag flat planing profile at the waterline. To ensure stealth capabilities, anechoic coatings of radar absorbent materials have been used in the load-bearing structures over large areas of the ship; this strategy leads to significant weight saving compared to the conventional construction technique of applying RAM cladding to the external surfaces. The ship's profile has a faceted appearance with no right angle structures and few orientations of reflective panels. Doors and hatches are flush with the surfaces and the windows are flush without visible coaming and are fitted with radar reflective screens; the vessels are additionally protected by the Rheinmetall MASS sensor / decoy system. The final design was changed compared to the prototype Skjold, which itself was rebuilt to the new specifications.
Most notably, the vessels use 4 gas turbines combined by Renk COGAG gear units built in a lightweight design. The smaller gas turbines rated. For sprint speed a second, larger gas turbine is combined providing a total of 6,000 kW to the waterjet on each shaft line. Two MTU 123 cruise diesel propulsion units used at loiter speeds were removed; the foredeck was strengthened to accommodate the addition of a 76 mm Otobreda Super Rapid gun. The hull material was produced by a different method to improve strength and minimize vulnerability to fire; the bridge saw. The U. S. Navy and Coast Guard expressed interest in the design and leased the P960 for a period of one year, from 2001 until 2002. During that time it was operated by a 14-man Norwegian crew out of Naval Amphibious Base Little Creek. List of ships of the Norwegian Navy Baynunah-class corvette Hamina-class missile boat Steregushchiy-class corvette Type 022 missile boat Milgem-class corvette Roussen-class fast attack craft Visby-class corvette Tuo Chiang-class corvette Saunders, Stephen "Jane's Fighting Ships 2003–2004" ISBN 0-7106-2546-4.
Leo Lazauskas Performance characteristics of a 260t displacement SES. Dept. Applied Mathematics Report, The University of Adelaide, 19 February 2008. Norwegian Skjold class corvettes storm and steil in Plymouth Sound. 9 July 2015
Royal Norwegian Navy
The Royal Norwegian Navy is the branch of the Norwegian Armed Forces responsible for naval operations of the state of Norway. As of 2008, the RNoN consists of 3,700 personnel and 70 vessels, including 5 heavy frigates, 6 submarines, 14 patrol boats, 4 minesweepers, 4 minehunters, 1 mine detection vessel, 4 support vessels and 2 training vessels; the navy includes the Coast Guard. The Royal Norwegian Navy has a history dating back to 955. From 1509 to 1814, it formed part of the navy of Denmark-Norway referred to as the "Common Fleet". Since 1814, the Royal Norwegian Navy has again existed as a separate navy. In Norwegian, Royal Norwegian Navy vessels have since 1946 been given the ship prefix "KNM", short for Kongelig Norske Marine. In English, they are given the prefix "HNoMS", short for "His/Her Norwegian Majesty's Ship". Coast Guard vessels are given the prefix "KV" for KystVakt in Norwegian and "NoCGV" for Norwegian Coast Guard Vessel in English; the history of Norwegian state-operated naval forces is long, goes back to the leidang, first established by King Håkon the Good at the Gulating in 955, although variants of the Leidang had at that time existed for hundreds of years.
During the last part of the Middle Ages the system of levying of ships and manpower for the leidang was used to levying tax and existed as such into the 17th Century. During most of the union between Norway and Denmark the two countries had a common fleet; this fleet was established by King Hans in 1509 in Denmark. A large proportion of the crew and officers in this new Navy organisation were Norwegian. In 1709 there were about 15,000 personnel enrolled in the common fleet; when Tordenskjold carried out his famous raid at Dynekil in 1716 more than 80 percent of the sailors and 90 percent of the soldiers in his force were Norwegian. Because of this the Royal Norwegian Navy shares its history from 1509 to 1814 with the Royal Danish Navy; the modern, separate Royal Norwegian Navy was founded on April 12, 1814 by Prince Christian Fredrik on the remnants of the Dano-Norwegian Navy. At the time of separation, the Royal Dano-Norwegian Navy was in a poor state and Norway was left with the lesser share.
All officers of Danish birth were ordered to return to Denmark and the first commander of the Norwegian navy became Captain Thomas Fasting. It consisted of 39 officers, seven brigs, one schooner-brig, eight gun schooners, 46 gun chalups and 51 gun barges. April 1, 1815 the RNoN's leadership was reorganized into a navy ministry, Fasting became the first navy minister. Norway retained its independent armed forces, including the navy, during the union with Sweden. During most of the union the navy was subjected to low funding though there were ambitious plans to expand it. In the late 19th century, the fleet was increased to defend a possible independent Norway from her Swedish neighbours. In 1900, just five years prior to the separation from Sweden, the navy, maintained for coastal defense, consisted of: two British-built coastal defence ships, four ironclad monitors, three unarmored gun vessels, twelve gunboats, sixteen small gunboats, a flotilla of twenty-seven torpedo boats; these were operated by 700 petty officers and seamen.
Norway was neutral during World War I, but the armed forces were mobilised to protect Norway's neutrality. The neutrality was sorely tested – the nation's merchant fleet suffered heavy casualties to German U-Boats and commerce raiders. World War II began for the Royal Norwegian Navy on April 8, 1940, when the German torpedo boat Albatross attacked the guard ship Pol III. In the opening hours of the Battle of Narvik, the old coastal defence ships HNoMS Eidsvold and HNoMS Norge, both built before 1905 and hopelessly obsolete, attempted to put up a fight against the invading German warships; the German invasion fleet heading for Oslo was delayed when Oscarsborg Fortress opened fire with two of its three old 28 cm guns, followed by the 15 cm guns on Kopås on the eastern side of the Drøbak strait. The artillery pieces inflicted heavy damage on the German heavy cruiser Blücher, subsequently sunk by torpedoes fired from Oscarsborg's land based torpedo battery. Blücher sank with over 1,000 casualties among its crew and the soldiers it carried.
The German invasion fleet – believing Blücher had struck a mine – retreated south and called for air strikes on the fortress. This delay allowed King Haakon VII of Norway and the Royal family, as well as the government, to escape capture. On June 7, 1940, thirteen vessels, five aircraft and 500 men from the Royal Norwegian Navy followed the King to the United Kingdom and continued the fight from bases there until the war ended; the number of men was increased as Norwegians living abroad, civilian sailors and men escaping from Norway joined the RNoN. Funds from Nortraship were used to buy new ships and equipment. Ten ships and 1,000 men from the Royal Norwegian Navy participated in the Normandy Invasion in 1944. During the war the navy operated 118 ships, at the end of the war it had 58 ships and 7,500 men in service, they lost 27 ships, 18 fishing boats and 933 men in World War II. The Royal Norwegian Navy had its own air force from 1912 to 1944; the building of a new fleet in the 1960s
Hyūga-class helicopter destroyer
The Hyūga-class helicopter destroyer is a class of helicopter carrier built for the Japan Maritime Self-Defense Force. Two - Hyūga and Ise - were built. Hyūga was described in a PBS documentary as the "first Japanese aircraft carrier built since WWII."The Hyūgas were followed by the larger Izumo class, the first being commissioned in March 2015. The Izumos will replace the Shirane-class helicopter destroyers; the specifications of the Hyūga class are comparable to light aircraft carriers, such as the Italian Italian aircraft carrier Giuseppe Garibaldi and Spanish Príncipe de Asturias. Under the JMSDF's naming conventions, the ships are called Goei-kan in Japanese and destroyer in English, as same as all the other combatant ships of JMSDF. During development, Hyūga and Ise were provisionally named "16DDH" and "18DDH" respectively; the numbers derived from the Japanese calendar the 16th year and 18th year of the Heisei reign, when the provisional name were given. The Hyūgas are anti-submarine warfare carriers operating SH-60K anti-submarine helicopters.
They have enhanced command-and-control capabilities to serve as flagships. During peacetime, Hyūgas and Ōsumi-class ships could operate together to conduct military operations other than war and relief operations; the ships are armed with a 16-cell VLS carrying the Evolved Sea Sparrow Missile surface-to-air missile, Phalanx close in weapon system for self-defense. They are equipped with the ATECS command system and FCS-3 fire control with active electronically scanned array radar system. Globalsecurity.org suggests a maximum capacity of 18-24 H-60 class helicopters, or a smaller number of larger helicopters though the official complement was reported as three SH-60 and one EH-101 helicopters, or three SH-60J and one CH-53E helicopters. It has been speculated that future modifications may allow the operation of VTOL/STOVL fixed-wing aircraft, such as Harriers or F-35 Lightning II. In 2013, USMC V-22 Ospreys practiced operations on Hyūga. In 2016, MV-22 Ospreys operated off Hyūga in the participation of relief efforts following the Kumamoto earthquake.
Construction of the first ship, JS Hyūga, was started in 2006 and it was launched on 23 August 2007. The second was launched and named JS Ise on 21 August 2009. Hyūga was named after Hyūga Province on the east coast of Kyūshū, Ise after Ise Province, they inherited the names of the Ise-class battleships Ise of the Imperial Japanese Navy. These two ships had been built during World War I and served in World War II. Following the Battle of Midway, Hyūga and Ise were converted into a hybrid battleship/aircraft carriers in 1943 with the replacement of the aft gun turrets and barbettes by a small flight deck and hangar deck with which they could launch a squadron of Yokosuka D4Y dive-bombers and Aichi E16A seaplanes. In November 2009, Hyūga participated in Annualex 21G joint naval exercise with the US aircraft carrier USS George Washington and other USN and JMSDF ships to maintain the interoperability between the two navies. On 11 March 2011, the 2011 Tōhoku tsunami struck the northeast part of Japan.
Hyūga moved to off the coast of Miyagi prefecture and started search and rescue operations. Ise, which went into service on 16 March will join aid delivery operation for refuge shelters. On 8 November 2013, Super-Typhoon Haiyan crossed Philippines. Ise joined the relief operation, using its helicopters to provide relief supplies to remote areas cut off by the storm. Herman, Arthur. "Pacific armadas: growing Far East navies mean new challenges for U. S." New York Post. Retrieved 2008-07-13. Koda, Yoji. "A New Carrier Race? Strategy, Force Planning, JS Hyuga". Naval War College Review. Archived from the original on 2012-03-20. Shaplen, Jason T.. "Washington's Eastern Sunset". The New York Times. Retrieved 2008-07-13. "Helicopter carrier commissioned: MSDF's largest combat vessel may raise concerns within Asia". The Japan Times Online. 2009-03-19. Retrieved 2009-03-19. Hyuga Class helicopter destroyer Japan Launches Carrier... Sorta Color Image Photos
A drive shaft, driving shaft, propeller shaft, or Cardan shaft is a mechanical component for transmitting torque and rotation used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them. As torque carriers, drive shafts are subject to torsion and shear stress, equivalent to the difference between the input torque and the load, they must therefore be strong enough to bear the stress, while avoiding too much additional weight as that would in turn increase their inertia. To allow for variations in the alignment and distance between the driving and driven components, drive shafts incorporate one or more universal joints, jaw couplings, or rag joints, sometimes a splined joint or prismatic joint; the term drive shaft first appeared during the mid 19th century. In Stover's 1861 patent reissue for a planing and matching machine, the term is used to refer to the belt-driven shaft by which the machine is driven.
The term is not used in his original patent. Another early use of the term occurs in the 1861 patent reissue for the Watkins and Bryson horse-drawn mowing machine. Here, the term refers to the shaft transmitting power from the machine's wheels to the gear train that works the cutting mechanism. In the 1890s, the term began to be used in a manner closer to the modern sense. In 1891, for example, Battles referred to the shaft between the transmission and driving trucks of his Climax locomotive as the drive shaft, Stillman referred to the shaft linking the crankshaft to the rear axle of his shaft-driven bicycle as a drive shaft. In 1899, Bukey used the term to describe the shaft transmitting power from the wheel to the driven machinery by a universal joint in his Horse-Power. In the same year, Clark described his Marine Velocipede using the term to refer to the gear-driven shaft transmitting power through a universal joint to the propeller shaft. Crompton used the term to refer to the shaft between the transmission of his steam-powered Motor Vehicle of 1903 and the driven axle.
The pioneering automobile industry company, was the first to use a drive shaft in a gasoline-powered car. Built in 1901, today this vehicle is in the collection of the Smithsonian Institution. An automobile may use a longitudinal shaft to deliver power from an engine/transmission to the other end of the vehicle before it goes to the wheels. A pair of short drive shafts is used to send power from a central differential, transmission, or transaxle to the wheels. In front-engined, rear-drive vehicles, a longer drive shaft is required to send power the length of the vehicle. Two forms dominate: The torque tube with a single universal joint and the more common Hotchkiss drive with two or more joints; this system became known as Système Panhard after the automobile company Panhard et Levassor patented it. Most of these vehicles have a clutch and gearbox mounted directly on the engine, with a drive shaft leading to a final drive in the rear axle; when the vehicle is stationary, the drive shaft does not rotate.
Some vehicles, seeking improved weight balance between rear, use a rear-mounted transaxle. In some non-Porsche models, this places the clutch and transmission at the rear of the car and the drive shaft between them and the engine. In this case the drive shaft rotates continuously with the engine when the car is stationary and out of gear. However, the Porsche 924/944/928 models have the clutch mounted to the back of the engine in a bell housing and the drive shaft from the clutch output, located inside of a hollow protective torque tube, transfers power to the rear mounted transaxle, thus the Porsche driveshaft only rotates when the rear wheels are turning as the engine-mounted clutch can decouple engine crankshaft rotation from the driveshaft. So for Porsche, when the driver is using the clutch while briskly shifting up or down, the engine can rev with the driver's accelerator pedal input, since with the clutch disengaged, the engine and flywheel inertia is low and is not burdened with the added rotational inertia of the driveshaft.
The Porsche torque tube is solidly fastened to both the engine's bell housing and to the transaxle case, fixing the length and alignment between the bell housing and the transaxle and minimizing rear wheel drive reaction torque from twisting the transaxle in any plane. A drive shaft connecting a rear differential to a rear wheel may be called a half-shaft; the name derives from the fact. Early automobiles used chain drive or belt drive mechanisms rather than a drive shaft; some used electrical motors to transmit power to the wheels. In British English, the term "drive shaft" is restricted to a transverse shaft that transmits power to the wheels the front wheels. A drive shaft connecting the gearbox to a rear differential is called a propeller shaft, or prop-shaft. A prop-shaft assembly consists of a slip joint and one or more universal joints. Where the engine and axles are separated from each other, as on four-wheel drive and rear-wheel drive vehicles, it is the propeller shaft that serves to transmit the drive force generated by the engine to the axles.
Several different types of drive shaft are used in the automotive industry: One-piece drive shaft Two-piece drive shaft Slip-in-tube drive shaftThe slip-in-tube drive shaft is a new type that improves crash safety. It can be compressed to absorb energy in the event of a crash, so is known as a collapsible drive shaft
Republic of Korea Navy
The Republic of Korea Navy known as the ROK Navy, is the naval warfare service branch of the South Korean armed forces, responsible for naval and amphibious operations. The ROK Navy includes the Republic of Korea Marine Corps. Established in 1945, the ROK Navy is the oldest branch of the South Korean armed forces. Since the end of the Korean War, the South Korean navy had concentrated its efforts on building naval forces to counteract the North Korean navy, which has littoral naval capabilities; as South Korea's economy grew, the ROK Navy was able to locally build larger and better equipped fleets to deter aggression, to protect the sea lines of communication, to support the nation's foreign policy. As part of its mission, the ROK Navy has engaged in several peacekeeping operations since the turn of the 21st century; the ROK Navy has about 70,000 regular personnel including 29,000 Republic of Korea Marines. There are about 150 commissioned ships with the ROK Navy; the naval aviation force consists of about 70 rotary-wing aircraft.
The ROK Marine Corps has about 300 tracked vehicles including assault amphibious vehicles. The ROK Navy aims to become a blue-water navy in 2020s; the main duties of the Navy shall be operations on the sea, including landing operations, the main duties of the Marine Corps shall be landing operations, the Navy and Marine Corps shall be formed and equipped for that purpose and shall provide education and training necessary therefor. The objectives of the ROK Navy as core strength for the National Security are: Establishing self-reliant naval forces to deter war Securing maritime superiority to gain victory Promoting national interests through protection of maritime activities Enhancing the national prestige through naval presence Korea has a long history of naval activity. In the late 4th century during the Three Kingdoms Period, Goguryeo defeated Baekje, fielding amphibious forces of 40,000 men in the process. In the 9th century, Commissioner Chang Bogo of Unified Silla established a maritime base called Cheonghaejin on an island to foster trading with China and Japan, to eradicate pirates.
In 1380, naval forces of the Goryeo Dynasty defeated 500 invading Japanese pirate vessels by deploying shipboard guns, devised by Choi Moosun. This is the first use of shipboard guns in naval history. In 1389 and 1419, Korean naval forces invaded Tsushima Island to suppress Japanese piracy. In the early years of the Joseon Dynasty, the naval force reached its peak of 50,000 personnel, in order to combat the ongoing piracy issue. During the Japanese invasions of Korea, the Korean naval force commanded by Admiral Yi Sunshin, who became the head of the Navy, cut off the invaders' naval lifeline and defeated the Japanese fleet, reversing the war in favor of Joseon. Admiral Yi is credited with the creation of the Turtle Ship. By the end of 19th century, the Joseon Navy had no significant naval force other than coastal defense fortresses. Although there was an attempt to modernize the navy by establishing a royal naval school, the Joseon Navy was brought to an end in 1895. In 1903, the government of the Korean Empire purchased the Yangmu.
Korean naval tradition was disrupted after Korea was annexed by the Empire of Japan in 1910. During the Japanese occupation period, the Imperial Japanese Navy built a naval base - Chinkai Guard District in southern Korea. Shortly after Korea was liberated from the Empire of Japan on August 15, 1945, Sohn Won-yil, a former merchant mariner and son of the methodist minister and independence activist Sohn Jung-do, led the Maritime Affairs Association; the Association evolved into the Marine Defense Group on November 11, 1945, the Group became the Korean Coast Guard, formed at Jinhae in June 1946. After the new Republic of Korea government was established on August 15, 1948, the Korean Coast Guard was formally renamed the Republic of Korea Navy, Sohn became the first Chief of Naval Operations of the ROK Navy on September 5, 1948. On April 15, 1949, the Republic of Korea Marine Corps was founded in Jinhae. In October 1949, the ROK Navy purchased a 600-ton submarine chaser, the former USS PC-823 with funds raised among its personnel.
She was renamed ROKS Baekdusan after Paektu Mountain, became "the first significant warship of the newly independent nation". The Korean War started with the North Korean army's surprise attack on Sunday, June 25, 1950; the ROK Navy confronted threats from the North Korean navy: "Perhaps the most aggressive and effective, if smallest, member of the South Korean armed services during the first year of the Korean War was the Republic of Korea Navy. At the outset of the conflict, the 6,956-man ROKN, with naval vessels of various types, was outnumbered by the 13,700 men and 110 naval vessels of the North Korean navy." With its UN allies, dominated by U. S. forces, the ROK Navy was able to gain control in the seas surrounding the country. On July 27, 1953, the three-year-long war was brought to an end when an armistice agreement was signed. During the war, Canada, Philippines, the Netherlands, New Zealand, the United Kingdom, the United States contributed naval vessels as UN allies; the Commander-in-Chief Republic of Korea Fleet, the highest operational command, was established in September 1953.
After the Korean War, the ROK Navy built up its surface fleet with World War II-era warships loaned from the United States Navy. In May 1963, the ROK Navy acquired its first destroyer, ROKS Chungmu, a Fletcher-class destroyer