The Galápagos Islands, part of the Republic of Ecuador, are an archipelago of volcanic islands distributed on either side of the equator in the Pacific Ocean surrounding the centre of the Western Hemisphere, 906 km west of continental Ecuador. The islands are known for their large number of endemic species and were studied by Charles Darwin during the second voyage of HMS Beagle, his observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection. The Galápagos Islands and their surrounding waters form the Galápagos Province of Ecuador, the Galápagos National Park, the Galápagos Marine Reserve; the principal language on the islands is Spanish. The islands have a population of over 25,000; the first recorded visit to the islands happened by chance in 1535, when Fray Tomás de Berlanga, the Bishop of Panamá, was surprised with this undiscovered land during a voyage to Peru to arbitrate in a dispute between Francisco Pizarro and Diego de Almagro.
De Berlanga returned to the Spanish Empire and described the conditions of the islands and the animals that inhabited them. The group of islands was shown and named in Abraham Ortelius's atlas published in 1570; the first crude map of the islands was made in 1684 by the buccaneer Ambrose Cowley, who named the individual islands after some of his fellow pirates or after British royalty and noblemen. These names were used in the authoritative navigation charts of the islands prepared during the Beagle survey under captain Robert FitzRoy, in Darwin's popular book The Voyage of the Beagle; the new Republic of Ecuador took the islands from Spanish ownership in 1832, subsequently gave them official Spanish names. The older names remained in use in English-language publications, including Herman Melville's The Encantadas of 1854. Volcanism has been continuous on the Galápagos Islands for at least 20 myr, even longer; the mantle plume beneath the east-ward moving Nazca Plate has given rise to a 3-kilometre-thick platform under the island chain and seamounts.
Besides the Galápagos Archipelago, other key tectonic features in the region include the Northern Galápagos Volcanic Province between the archipelago and the Galápagos Spreading Center 200 km to the north at the boundary of the Nazca Plate and the Cocos Plate. This spreading center truncates into the East Pacific Rise on the west and is bounded by the Cocos Ridge and Carnegie Ridge in the east. Furthermore, the Galápagos Hotspot is at the northern boundary of the Pacific Large Low Shear Velocity Province while the Easter Hotspot is on the southern boundary; the Galápagos Archipelago is characterized by numerous contemporaneous volcanoes, some with plume magma sources, others from the asthenosphere due to the young and thin oceanic crust. The GSC caused structural weaknesses in this thin lithosphere leading to eruptions forming the Galápagos Platform. Fernandina and Isabela in particular are aligned along these weaknesses. Lacking a well-defined rift zone, the islands have a high rate of inflation prior to eruption.
Sierra Negra on Isabela Island experienced a 240 cm uplift between 1992 and 1998, most recent eruption in 2005, while Fernandina on Fernandina Island indicated an uplift of 90 cm, most recent eruption in 2009. Alcedo on Isabela Island had an uplift of greater than 90 cm, most recent eruption in 1993. Additional characteristics of the Galápagos Archipelago are closer volcano spacing, smaller volcano sizes, larger calderas. For instance, Isabela Island includes 6 major volcanoes, Wolf, Alcedo, Sierra Negraa and Cerro Azul, with most recent eruptions ranging from 1813 to 2008; the neighboring islands of Santiago and Fernandina last erupted in 2009, respectively. Overall, the 9 active volcanoes in the archipelago have erupted 24 times between 1961 and 2011; the shape of these volcanoes is that of an "overturned soup bowl" as opposed to the "overturned saucer plate" of the Hawaiian Islands. The Galápagos's shape is due to the pattern of radial and circumferential fissure, radial on the flanks, but circumferential near the caldera summits.
It is the circumferential fissures. The volcanoes at the west end of the archipelago are in general, younger, have well developed calderas, are composed of tholeiitic basalt, while those on the east are shorter, lack calderas, have a more diverse composition; the ages of the islands, from west to east are 0.05 Ma for Fernandina, 0.65 Ma for Isabela, 1.10 Ma for Santiago, 1.7 Ma for Santa Cruz, 2.90 Ma for Santa Fe, 3.2 Ma for San Cristobal. The calderas on Sierra Negra and Alcedo have active fault systems; the Sierra Negra fault is associated with a sill 2 km below the caldera. The caldera on Fernandina experienced the largest basaltic volcano collapse in history, with the 1968 phreatomagmatic eruption. Fernandina has been the most active volcano since 1790, with recent eruptions in 1991, 1995, 2005, 2009, the entire surface has been covered in numerous flows since 4.3 Ka. The western volcanoes have numerous tuff cones; the islands are located in the eastern Pacific Ocean, 973 km off the west coast of South America.
The closest land mass is that of mainland Ecuador, the country to which they belong, 926 km to the east. The islands are found at the coordinates 1°40'N–1°36'S, 89°16'–92°01'W. Straddling the equator, islands in the chain are located in both the northern and southern hemispheres, with Volcán Wolf and Volcán Ecuador on Isla Isabela being directly on the equator. Española Island, the southernmost islet of the archipelago, Darwin Island, the northernmost
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. It is the largest and most capable navy in the world and it has been estimated that in terms of tonnage of its active battle fleet alone, it is larger than the next 13 navies combined, which includes 11 U. S. allies or partner nations. With the highest combined battle fleet tonnage and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction. With 319,421 personnel on active duty and 99,616 in the Ready Reserve, the Navy is the third largest of the service branches, it has 282 deployable combat vessels and more than 3,700 operational aircraft as of March 2018, making it the second-largest air force in the world, after the United States Air Force. The U. S. Navy traces its origins to the Continental Navy, established during the American Revolutionary War and was disbanded as a separate entity shortly thereafter.
The U. S. Navy played a major role in the American Civil War by blockading the Confederacy and seizing control of its rivers, it played the central role in the World War II defeat of Imperial Japan. The US Navy emerged from World War II as the most powerful navy in the world; the 21st century U. S. Navy maintains a sizable global presence, deploying in strength in such areas as the Western Pacific, the Mediterranean, the Indian Ocean, it is a blue-water navy with the ability to project force onto the littoral regions of the world, engage in forward deployments during peacetime and respond to regional crises, making it a frequent actor in U. S. foreign and military policy. The Navy is administratively managed by the Department of the Navy, headed by the civilian Secretary of the Navy; the Department of the Navy is itself a division of the Department of Defense, headed by the Secretary of Defense. The Chief of Naval Operations is the most senior naval officer serving in the Department of the Navy.
The mission of the Navy is to maintain and equip combat-ready Naval forces capable of winning wars, deterring aggression and maintaining freedom of the seas. The U. S. Navy is a seaborne branch of the military of the United States; the Navy's three primary areas of responsibility: The preparation of naval forces necessary for the effective prosecution of war. The maintenance of naval aviation, including land-based naval aviation, air transport essential for naval operations, all air weapons and air techniques involved in the operations and activities of the Navy; the development of aircraft, tactics, technique and equipment of naval combat and service elements. U. S. Navy training manuals state that the mission of the U. S. Armed Forces is "to be prepared to conduct prompt and sustained combat operations in support of the national interest." As part of that establishment, the U. S. Navy's functions comprise sea control, power projection and nuclear deterrence, in addition to "sealift" duties, it follows as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, with it, everything honorable and glorious.
Naval power... is the natural defense of the United States The Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia; the rationale for establishing a national navy was debated in the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, make it easier to seek out support from foreign countries. Detractors countered that challenging the British Royal Navy the world's preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchant ships and reported the captures to the Congress. On 13 October 1775, the Continental Congress authorized the purchase of two vessels to be armed for a cruise against British merchant ships. S. Navy; the Continental Navy achieved mixed results.
In August 1785, after the Revolutionary War had drawn to a close, Congress had sold Alliance, the last ship remaining in the Continental Navy due to a lack of funds to maintain the ship or support a navy. In 1972, the Chief of Naval Operations, Admiral Elmo Zumwalt, authorized the Navy to celebrate its birthday on 13 October to honor the establishment of the Continental Navy in 1775; the United States was without a navy for nearly a decade, a state of affairs that exposed U. S. maritime merchant ships to a series of attacks by the Barbary pirates. The sole armed maritime presence between 1790 and the launching of the U. S. Navy's first warships in 1797 was the U. S. Revenue-Marine, the primary predecessor of the U. S. Coast Guard. Although the USRCS conducted operations against the pirates, their depredations far outstripped its abilities and Congress passed the Naval Act of 1794 that established a permanent standing navy on 27 March 1794; the Naval Act ordered the construction and manning of six frigates and, by October 1797, the first three were brought into service: USS United States, USS Constellation, USS Constitution.
Due to his strong posture on having a strong standing Navy during this period, John Adams is "often called the father of the American Navy". In 1798–99 the Navy was involved in an undeclared Quasi-War with France. From 18
World War II
World War II known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries; the major participants threw their entire economic and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China, it included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, the only use of nuclear weapons in war. Japan, which aimed to dominate Asia and the Pacific, was at war with China by 1937, though neither side had declared war on the other. World War II is said to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom.
From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. Following the onset of campaigns in North Africa and East Africa, the fall of France in mid 1940, the war continued between the European Axis powers and the British Empire. War in the Balkans, the aerial Battle of Britain, the Blitz, the long Battle of the Atlantic followed. On 22 June 1941, the European Axis powers launched an invasion of the Soviet Union, opening the largest land theatre of war in history; this Eastern Front trapped most crucially the German Wehrmacht, into a war of attrition. In December 1941, Japan launched a surprise attack on the United States as well as European colonies in the Pacific. Following an immediate U. S. declaration of war against Japan, supported by one from Great Britain, the European Axis powers declared war on the U.
S. in solidarity with their Japanese ally. Rapid Japanese conquests over much of the Western Pacific ensued, perceived by many in Asia as liberation from Western dominance and resulting in the support of several armies from defeated territories; the Axis advance in the Pacific halted in 1942. Key setbacks in 1943, which included a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, Allied victories in the Pacific, cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned toward Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in Central China, South China and Burma, while the Allies crippled the Japanese Navy and captured key Western Pacific islands; the war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the German unconditional surrender on 8 May 1945.
Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings, the Soviet entry into the war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. Tribunals were set up by fiat by the Allies and war crimes trials were conducted in the wake of the war both against the Germans and the Japanese. World War II changed the political social structure of the globe; the United Nations was established to foster international co-operation and prevent future conflicts. The Soviet Union and United States emerged as rival superpowers, setting the stage for the nearly half-century long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia.
Most countries whose industries had been damaged moved towards economic expansion. Political integration in Europe, emerged as an effort to end pre-war enmities and create a common identity; the start of the war in Europe is held to be 1 September 1939, beginning with the German invasion of Poland. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred and the two wars merged in 1941; this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935; the British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the fo
Norfolk is an independent city in the Commonwealth of Virginia in the United States. At the 2010 census, the population was 242,803. Norfolk is located at the core of the Hampton Roads metropolitan area, named for the large natural harbor of the same name located at the mouth of Chesapeake Bay, it is one of nine cities and seven counties that constitute the Hampton Roads metro area known as the Virginia Beach-Norfolk-Newport News, VA-NC MSA. The city is bordered to the north by the Chesapeake Bay, it shares land borders with the independent cities of Chesapeake to its south and Virginia Beach to its east. Norfolk is one of the oldest cities in Hampton Roads, is considered to be the historic, urban and cultural center of the region; the city has a long history as a strategic transportation point. The largest Navy base in the world, Naval Station Norfolk, is located in Norfolk along with one of NATO's two Strategic Command headquarters; the city has the corporate headquarters of Norfolk Southern Railway, one of North America's principal Class I railroads, Maersk Line, which manages the world's largest fleet of US-flag vessels.
As the city is bordered by multiple bodies of water, Norfolk has many miles of riverfront and bayfront property, including beaches on the Chesapeake Bay. It is linked to its neighbors by an extensive network of interstate highways, bridges and three bridge-tunnel complexes, which are the only bridge-tunnels in the United States. In 1619 the Governor of the Virginia Colony, Sir George Yeardley, incorporated four jurisdictions, termed citties, for the developed portion of the colony; these formed the basis for colonial representative government in the newly minted House of Burgesses. What would become Norfolk was put under the Elizabeth Cittie incorporation. In 1634 King Charles I reorganized the colony into a system of shires; the former Elizabeth Cittie became Elizabeth City Shire. After persuading 105 people to settle in the colony, Adam Thoroughgood was granted a large land holding, through the head rights system, along the Lynnhaven River in 1636; when the South Hampton Roads portion of the shire was separated, Thoroughgood suggested the name of his birthplace for the newly formed New Norfolk County.
One year it was divided into two counties, Upper Norfolk and Lower Norfolk, chiefly on Thoroughgood's recommendation. This area of Virginia became known as the place of entrepreneurs, including men of the Virginia Company of London. Norfolk developed in the late-seventeenth century as a "Half Moone" fort was constructed and 50 acres were acquired from local natives of the Powhatan Confederacy in exchange for 10,000 pounds of tobacco; the House of Burgesses established the "Towne of Lower Norfolk County" in 1680. In 1691, a final county subdivision took place when Lower Norfolk County split to form Norfolk County and Princess Anne County. Norfolk was incorporated in 1705. In 1730, a tobacco inspection site was located here. According to the Tobacco Inspection Act, the inspection was "At Norfolk Town, upon the fort land, in the County of Norfolk. In 1736 George II granted it a royal charter as a borough. By 1775, Norfolk developed into what contemporary observers argued was the most prosperous city in Virginia.
It was an important port for exporting goods beyond. In part because of its merchants' numerous trading ties with other parts of the British Empire, Norfolk served as a strong base of Loyalist support during the early part of the American Revolution. After fleeing the colonial capital of Williamsburg, the Royal Governor of Virginia, John Murray, 4th Earl of Dunmore, tried to reestablish control of the colony from Norfolk. Dunmore secured small victories at Norfolk but was soon driven into exile by the Virginia militia, commanded by Colonel Woodford, his departure brought an end to more than 168 years of British colonial rule in Virginia. On New Year's Day, 1776, Lord Dunmore's fleet of three ships shelled the city of Norfolk for more than eight hours; the gunfire, combined with fires started by the British and spread by the Patriots, destroyed more than 800 buildings, constituting nearly two-thirds of the city. The Patriot forces destroyed the remaining buildings for strategic reasons the following month.
Only the walls of Saint Paul's Episcopal Church survived subsequent fires. A cannonball from the bombardment remains within the wall of Saint Paul's. Following recovery from the Revolutionary War's burning and her citizens struggled to rebuild. In 1804, another serious fire along the city's waterfront destroyed some 300 buildings and the city suffered a serious economic setback. During the 1820s, agrarian communities across the American South suffered a prolonged recession, which caused many families to migrate to other areas. Many moved further into Kentucky and Tennessee; such migration followed the exhaustion of soil due to tobacco cultivation in the Tidewater, where it had been the primary commodity crop for generations. Virginia made some attempts to phase out slavery and manumissions increased in the two decades following the war. Thomas Jefferson Randolph gained passage of an 1832 resolution for gradual abolition in the state. However, by that time the increased demand fr
Solomon Islands is a sovereign state consisting of six major islands and over 900 smaller islands in Oceania lying to the east of Papua New Guinea and northwest of Vanuatu and covering a land area of 28,400 square kilometres. The country's capital, Honiara, is located on the island of Guadalcanal; the country takes its name from the Solomon Islands archipelago, a collection of Melanesian islands that includes the North Solomon Islands, but excludes outlying islands, such as Rennell and Bellona, the Santa Cruz Islands. The islands have been inhabited for thousands of years. In 1568, the Spanish navigator Álvaro de Mendaña was the first European to visit them, naming them the Islas Salomón. Britain defined its area of interest in the Solomon Islands archipelago in June 1893, when Captain Gibson R. N. of HMS Curacoa, declared the southern Solomon Islands a British protectorate. During World War II, the Solomon Islands campaign saw fierce fighting between the United States and the Empire of Japan, such as in the Battle of Guadalcanal.
The official name of the British administration was changed from "the British Solomon Islands Protectorate" to "the Solomon Islands" in 1975, self-government was achieved the year after. Independence was obtained in 1978 and the name changed to just "Solomon Islands", without the "the". At independence, Solomon Islands became a constitutional monarchy; the Queen of Solomon Islands is Elizabeth II, represented by Sir Frank Kabui. The prime minister is Rick Houenipwela. In 1568, the Spanish navigator Álvaro de Mendaña was the first European to visit the Solomon Islands archipelago, naming it Islas Salomón after the wealthy biblical King Solomon, it is said that they were given this name in the mistaken assumption that they contained great riches, he believed them to be the Bible-mentioned city of Ophir. During most of the period of British rule the territory was named "the British Solomon Islands Protectorate". On 22 June 1975 the territory was renamed "the Solomon Islands"; when Solomon Islands became independent in 1978, the name was changed to "Solomon Islands".
The definite article, "the", is not part of the country's official name but is sometimes used, both within and outside the country. It is believed that Papuan-speaking settlers began to arrive around 30,000 BC. Austronesian speakers arrived c. 4000 BC bringing cultural elements such as the outrigger canoe. Between 1200 and 800 BC the ancestors of the Polynesians, the Lapita people, arrived from the Bismarck Archipelago with their characteristic ceramics; the first European to visit the islands was the Spanish navigator Álvaro de Mendaña de Neira, coming from Peru in 1568. Some of the earliest and most regular foreign visitors to the islands were whaling vessels from Britain, the United States and Australia, they came for food and water from late in the 18th century and took aboard islanders to serve as crewmen on their ships. Relations between the islanders and visiting seamen was not always good and sometimes there was violence and bloodshed. Missionaries began visiting the Solomons in the mid-19th century.
They made little progress at first, because "blackbirding" led to a series of reprisals and massacres. The evils of the slave trade prompted the United Kingdom to declare a protectorate over the southern Solomons in June 1893. In 1898 and 1899, more outlying islands were added to the protectorate. Traditional trade and social intercourse between the western Solomon Islands of Mono and Alu and the traditional societies in the south of Bougainville, continued without hindrance. Missionaries settled in the Solomons under the protectorate, converting most of the population to Christianity. In the early 20th century several British and Australian firms began large-scale coconut planting. Economic growth was slow and the islanders benefited little. Journalist Joe Melvin visited as part of his undercover investigation into blackbirding. In 1908 the islands were visited by Jack London, cruising the Pacific on his boat, the Snark. With the outbreak of the Second World War most planters and traders were evacuated to Australia and most cultivation ceased.
Some of the most intense fighting of the war occurred in the Solomons. The most significant of the Allied Forces' operations against the Japanese Imperial Forces was launched on 7 August 1942, with simultaneous naval bombardments and amphibious landings on the Florida Islands at Tulagi and Red Beach on Guadalcanal; the Battle of Guadalcanal became an important and bloody campaign fought in the Pacific War as the Allies began to repulse the Japanese expansion. Of strategic importance during the war were the coastwatchers operating in remote locations on Japanese held islands, providing early warning and intelligence of Japanese naval and aircraft movements during the campaign. Sergeant-Major Jacob Vouza was a notable coastwatcher who, after capture, refused to divulge Allied information in spite of interrogation and torture by Japanese Imperial forces, he was awarded a Silver Star Medal by the Americans, the United States' third-highest decoration for valor in combat. Islanders Biuku Gasa and Eroni Kumana were the first to find the shipwrecked John F. Kennedy and his crew of the PT-109.
They suggested writing a rescue message on a coconut, delivered the coconut by paddling a dug
The Hedgehog was a forward-throwing anti-submarine weapon, used during the Battle of the Atlantic in the Second World War. The device, developed by the Royal Navy, fired up to 24 spigot mortars ahead of a ship when attacking a U-boat, it was deployed on convoy escort warships such as destroyers and corvettes to supplement the depth charges. As the mortar projectiles employed contact fuzes rather than time or barometric fuzes, detonation occurred directly against a hard surface such as the hull of a submarine making it more deadly than depth charges, which relied on damage caused by hydrostatic shockwaves. Statistics show that during WWII out of 5,174 British depth charge attacks there were 85.5 kills: a ratio of 60.5 to 1. In comparison, the Hedgehog made 268 attacks for 47 kills: a ratio of 5.7 to 1. The "Hedgehog", so named because the empty rows of its launcher spigots resembled the spines of a hedgehog, was a replacement for the unsuccessful Fairlie Mortar, trialled aboard HMS Whitehall in 1941.
Although a failure, the Fairlie was designed to fire depth charges ahead of a ship when attacking a submarine. This principle of forward-firing projectiles was considered viable; this secret research by the Directorate of Miscellaneous Weapons Development led to the development of the Hedgehog. The weapon was a multiple'spigot mortar' or spigot discharger, a type of weapon developed between the wars by Lieutenant Colonel Stewart Blacker, RA; the spigot mortar was based on early infantry trench mortars. The spigot design allowed a single device to fire warheads of varying size; the propelling charge was part of the main weapon and worked against a rod set in the baseplate which fitted inside a tubular tail of the'bomb'. This principle was first used on the Blacker Bombard 29 mm Spigot Mortar and the PIAT anti-tank weapon; the adaptation of the bombard for naval use was made in partnership with MIR under Major Millis Jefferis who had taken Blacker's design and brought it into use with Army. The weapon fires a salvo of 24 bombs in an arc, aimed to land in a circular or elliptical area about 100 feet in diameter at a fixed point about 250 yards directly ahead of the attacking ship.
The mounting was fixed but was replaced by a gyro-stabilised one to allow for the rolling and pitching of the attacking ship. The system was developed to solve the problem of the target submarine disappearing from the attacking ship's ASDIC when the ship came within the sonar's minimum range. Due to the speed of sound in water, the time taken for the'ping' echo to return to the attacking ship from the target submarine became too short to allow the human operator to distinguish the returning audible echo from that of the initial sound pulse emitted by the sonar – the so-called "instantaneous echo", where the output sound pulse and returning echo merge; this "blind spot" allowed the submarine to make evasive manoeuvres undetected while the ship was out of range for depth charge attack. Hence, the submarine was invisible to the sonar as the ship came within the sonar's minimum range; the solution was a weapon mounted on the foredeck that discharged the projectiles up and over that carrying ship's bow, to land in the water some distance in front of the ship while the submarine was still outside the sonar's minimum range.
The Hedgehog entered service in 1942. Carrying a Torpex charge weighing 16 kg, each mortar had a diameter of 18 cm and weighed about 29.5 kg. The projectiles were angled so they would land in a circular shape with a diameter of 40 m about 180 m ahead of a stationary ship; the projectiles would sink at about 7 m/s. They would reach a submerged U-boat, for example at 200 ft in under 9 seconds. Sympathetic detonation of projectiles near those contacting hard surfaces was a possibility, but the number of explosions counted was fewer than the number of projectiles launched; the prototype launcher was tested aboard HMS Westcott in 1941, but there were no submarine kills until November 1942, after it had been installed aboard one hundred ships. Initial success rates – of about 5% – were only better than depth charges. Swells and spray covered the launcher during heavy North Atlantic weather, subsequent attempts to launch revealed firing circuit problems launching an incomplete pattern; the disappointment of a quiet miss discouraged crews who might otherwise assume depth charge explosions had damaged their target or at least frightened the enemy.
The Royal Navy launched Hedgehog so in early 1943 that a directive was issued ordering captains of ships equipped with Hedgehog to report why they had not used Hedgehog on an underwater contact. The results were blamed on low confidence in the weapon. However, after an officer from the DMWD was sent to Londonderry Port, where the convoy crews were based, with better training and shipwide talks on examples of successful Hedgehog attacks, the kill rate improved considerably. By the end of the war, statistics showed that on average, one in every five attacks made by Hedgehog resulted in a kill. In response to this new deadly threat to its U-boats, the Kriegsmarine brought forward its programme of acoustic torpedoes in 1943, beginning with the Falke; these new "homing" torpedoes could be employed without the use of a periscope, providing submarines a better chance to remain undetected and evade counterattack. In the Pacific Theater, USS England sank six Japanese submarines in a matter of days with Hedgehog in May 1944.
In 1946, USS Solar was destroyed after a crewman accidentally dropped a Hedgehog charge near one of her main turret am