Oerlikon 20 mm cannon
The Oerlikon 20 mm cannon is a series of autocannons, based on an original German 20 mm Becker design that appeared early in World War I. It was produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II, many versions still in use today. During World War I, the German industrialist Reinhold Becker developed a 20 mm caliber cannon, known now as the 20 mm Becker using the Advanced Primer Ignition blowback method of operation; this had a cyclic rate of fire of 300 rpm. It was used on a limited scale as an aircraft gun on Luftstreitkräfte warplanes, an anti-aircraft gun towards the end of that war; because the Treaty of Versailles banned further production of such weapons in Germany, the patents and design works were transferred in 1919 to the Swiss firm SEMAG based near Zürich. SEMAG continued development of the weapon, in 1924 had produced the SEMAG L, a heavier weapon that fired more powerful 20x100RB ammunition at a higher rate of fire, 350 rpm.
In 1924 SEMAG failed. The Oerlikon firm, named after the Zürich suburb of Oerlikon where it was based acquired all rights to the weapon, plus the manufacturing equipment and the employees of SEMAG. In 1927 the Oerlikon S was added to the existing product line; this fired a still larger cartridge to achieve a muzzle velocity of 830 m/s, at the cost of increased weight and a reduced rate of fire. The purpose of this development was to improve the performance of the gun as an anti-tank and anti-aircraft weapon, which required a higher muzzle velocity. An improved version known as the 1S followed in 1930. Three sizes of gun with their different ammunition and barrel length, but similar mechanisms, continued to be developed in parallel. In 1930 Oerlikon reconsidered the application of its gun in aircraft and introduced the AF and AL, designed to be used in flexible mounts, i.e. manually aimed by a gunner. The 15-round box magazine used by earlier versions of the gun was replaced by drum magazine holding 15 or 30 rounds.
In 1935 it made an important step by introducing a series of guns designed to be mounted in or on the wings of fighter aircraft. Designated with FF for Flügelfest meaning "wing-mounted", these weapons were again available in the three sizes, with designations FF, FFL and FFS; the FF fired a larger cartridge than the AF, 20x72RB, but the major improvement in these weapons was a significant increase in rate of fire. The FF weighed 24 kg and achieved a muzzle velocity of 550 to 600 m/s with a rate of fire of 520 rpm; the FFL of 30 kg fired a projectile at a muzzle velocity of 675 m/s with a rate of fire of 500 rpm. And the FFS, which weighed 39 kg, delivered a high muzzle velocity of 830 m/s at a rate of fire of 470 rpm. Apart from changes to the design of the guns for wing-mounting and remote control, larger drums were introduced as it would not be possible to exchange magazines in flight. For the FF series drum sizes of 45, 60, 75 and 100 rounds were available, but most users chose the 60-round drum.
The 1930s were a period of global re-armament, a number of foreign firms took licenses for the Oerlikon family of aircraft cannon. In France, Hispano-Suiza manufactured development of the FFS as the Hispano-Suiza HS.7 and Hispano-Suiza HS.9, for installation between the cylinder banks of its V-12 engines. In Germany, Ikaria further developed the FF gun as firing 20x80RB ammunition, and the Imperial Japanese Navy, after evaluating all three guns, ordered developments of the FF and FFL as the Type 99-1 and Type 99-2. The incorporation of the improvements of the FFS in a new anti-aircraft gun produced, in 1938, the Oerlikon SS. Oerlikon realized further improvements in rate of fire on the 1SS of 1942, the 2SS of 1945 which achieved 650 rpm. However, it was the original SS gun, adopted as anti-aircraft gun, being widely used by Allied navies during World War II; this gun used a 400-grain charge of IMR 4831 smokeless powder to propel a 2,000-grain projectile at 2,800 feet per second. The Oerlikon FF was installed as armament on some fighters of the 1930s, such as the Polish PZL P.24G.
Locally produced derivatives of the Oerlikon cannon were used much more extensively, on aircraft, on ships and on land. In the air, the Ikaria MG FF was used as armament on a number of German aircraft, of which the most famous is the Messerschmitt Bf 109; the Japanese Navy used their copy of the FF, designated the Type 99 Mark One cannon on a number of types including the Mitsubishi A6M Zero. In the war, they equipped fighters including the Zero with the Type 99 Mark Two, a version of the more powerful and faster-firing Oerlikon FFL; the French firm of Hispano-Suiza was a manufacturer of aircraft engines, it marketed the moteur-canon combination of its 12X and 12Y engines with a H. S.7 or H. S.9 cannon installed between the cylinder banks. The gun fired through the hollow propeller hub, this being elevated above the crankcase by the design of the gearing; such armament was installed on the Morane-Saulnier M. S.406 and some other types. Similar German installations of the MG FF were not successful.
The Oerlikon became best known in its naval applications. The Oerlikon was not looked upon favorably by the Royal Navy as a short-range anti-aircraft gun. All through 1937-1938 Lord Louis Mountbatten a Captain in the Royal Navy, waged a lone campaign within the Royal Navy to set up an unprejudiced trial for the Oerlikon 20 mm gun, but it was all in vain, it was not until the Commander-in-Chief of the Home Fleet, Admiral Sir Roger Backhouse, was appointed First Sea Lord tha
Bayonne, New Jersey
Bayonne bay-OWN is a city in Hudson County, New Jersey, United States. Located in the Gateway Region, Bayonne is situated on a peninsula located between Newark Bay to the west, the Kill Van Kull to the south, New York Bay to the east; as of the 2010 United States Census, the city's population was 63,024, reflecting an increase of 1,182 from the 61,842 counted in the 2000 Census, which had in turn increased by 398 from the 61,444 counted in the 1990 Census. Bayonne was formed as a township on April 1, 1861, from portions of Bergen Township. Bayonne was reincorporated as a city by an act of the New Jersey Legislature on March 10, 1869, replacing Bayonne Township, subject to the results of a referendum held nine days later. At the time it was formed, Bayonne included the communities of Bergen Point, Constable Hook, Centreville and Saltersville. Bayonne is east of Newark, the state's largest city, north of Elizabeth in Union County and west of Brooklyn, it shares a land border with Jersey City to the north and is connected to Staten Island by the Bayonne Bridge.
While somewhat diminished, traditional manufacturing and maritime activities remain a driving force of the economy of the city, a portion of the Port of New York and New Jersey is located there. Inhabited by Native Americans, the region presently known as Bayonne was claimed by the Netherlands after Henry Hudson explored the Hudson River, named after him. According to Royden Page Whitcomb's 1904 book, First History of Bayonne, New Jersey, the name Bayonne is speculated to have originated with Bayonne, from which Huguenots settled for a year before the founding of New Amsterdam. However, there is no empirical evidence for this notion, considered apocryphal. Whitcomb gives more credence to the idea that Erastus Randall, E. C. Bramhall and B. F. Woolsey, who bought the land owned by Jasper and William Cadmus for real estate speculation, named it Bayonne for purposes of real estate speculation, because it was located on the shores of two bays and New York. Significant civil unrest arose during the Bayonne refinery strikes of 1915–1916, in which Polish American workers staged labor actions against Standard Oil of New Jersey and Tidewater Petroleum, seeking improved pay and working conditions.
Four striking workers were killed. According to the United States Census Bureau, the city had a total area of 11.082 square miles, including 5.804 square miles of land and 5.278 square miles of water was water. The city is located south of Jersey City on a peninsula earlier known as Bergen Neck surrounded by Upper New York Bay to the east, Newark Bay to the west, Kill Van Kull to the south. Unincorporated communities and place names located or within the city include: Bergen Point, Constable Hook and Port Johnson; as of the 2010 United States Census, there were 63,024 people, 25,237 households, 16,050.732 families residing in the city. The population density was 10,858.3 per square mile. There were 27,799 housing units at an average density of 4,789.4 per square mile. The racial makeup of the city was 69.21% White, 8.86% Black or African American, 0.31% Native American, 7.71% Asian, 0.03% Pacific Islander, 10.00% from other races, 3.88% from two or more races. Hispanic or Latino of any race were 25.79% of the population.
Non-Hispanic Whites were 56.8% of the population. There were 25,237 households out of which 29.5% had children under the age of 18 living with them, 41.1% were married couples living together, 16.8% had a female householder with no husband present, 36.4% were non-families. 31.6% of all households were made up of individuals, 11.8% had someone living alone, 65 years of age or older. The average household size was 2.49 and the average family size was 3.16. In the city, the population was spread out with 22.5% under the age of 18, 8.9% from 18 to 24, 28.1% from 25 to 44, 27.3% from 45 to 64, 13.2% who were 65 years of age or older. The median age was 38.4 years. For every 100 females there were 91.7 males. For every 100 females ages 18 and older there were 87.9 males. The U. S. Census Bureau's 2006-2010 American Community Survey showed that median household income was $53,587 and the median family income was $66,077. Males had a median income of $51,188 versus $42,097 for females; the per capita income for the city was $28,698.
About 9.9% of families and 12.3% of the population were below the poverty line, including 20.5% of those under age 18 and 8.4% of those age 65 or over. As of the 2000 United States Census there were 61,842 people, 25,545 households, 16,016 families residing in the city; the population density was 10,992.2 people per square mile. There were 26,826 housing units at an average density of 4,768.2 per square mile. The racial makeup of the city was 78.8% White, 5.50% African American, 0.2% Native American, 4.1% Asian, 0.05% Pacific Islander, 7.46% from other races, 4.02% from two or more races. Hispanic or Latino of any race were 17.81% of the population. As of the 2000 Census, the most common reported ancestries of Bayonne residents were Italian and Polish. There were 25,545 households out of which 28.3% had children under the age of 18 living with them, 42.8% were married couples living together, 15.1% had a female householder with no husband present, 37.3% were non-families. 32.8% of all households were made up of individuals and 15.0% had someone living alone who wa
Algeria the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. The capital and most populous city is Algiers, located in the far north of the country on the Mediterranean coast. With an area of 2,381,741 square kilometres, Algeria is the tenth-largest country in the world, the world's largest Arab country, the largest in Africa. Algeria is bordered to the northeast by Tunisia, to the east by Libya, to the west by Morocco, to the southwest by the Western Saharan territory and Mali, to the southeast by Niger, to the north by the Mediterranean Sea; the country is a semi-presidential republic consisting of 1,541 communes. It has the highest human development index of all non-island African countries. Ancient Algeria has known many empires and dynasties, including ancient Numidians, Carthaginians, Vandals, Umayyads, Idrisid, Rustamid, Zirid, Almoravids, Spaniards and the French colonial empire. Berbers are the indigenous inhabitants of Algeria. Algeria is a middle power.
It supplies large amounts of natural gas to Europe, energy exports are the backbone of the economy. According to OPEC Algeria has the 16th largest oil reserves in the world and the second largest in Africa, while it has the 9th largest reserves of natural gas. Sonatrach, the national oil company, is the largest company in Africa. Algeria has one of the largest defence budget on the continent. Algeria is a member of the African Union, the Arab League, OPEC, the United Nations and is a founding member of the Arab Maghreb Union. On 2 April 2019, president Abdelaziz Bouteflika resigned after nearly 20 years in power, following pressure from the country’s army after mass protests against Bouteflika's campaign for a fifth term; the country's name derives from the city of Algiers. The city's name in turn derives from the Arabic al-Jazā'ir, a truncated form of the older Jazā'ir Banī Mazghanna, employed by medieval geographers such as al-Idrisi. In the region of Ain Hanech, early remnants of hominid occupation in North Africa were found.
Neanderthal tool makers produced hand axes in the Levalloisian and Mousterian styles similar to those in the Levant. Algeria was the site of the highest state of development of Middle Paleolithic Flake tool techniques. Tools of this era, starting about 30,000 BC, are called Aterian; the earliest blade industries in North Africa are called Iberomaurusian. This industry appears to have spread throughout the coastal regions of the Maghreb between 15,000 and 10,000 BC. Neolithic civilization developed in the Saharan and Mediterranean Maghreb as early as 11,000 BC or as late as between 6000 and 2000 BC; this life, richly depicted in the Tassili n'Ajjer paintings, predominated in Algeria until the classical period. The mixture of peoples of North Africa coalesced into a distinct native population that came to be called Berbers, who are the indigenous peoples of northern Africa. From their principal center of power at Carthage, the Carthaginians expanded and established small settlements along the North African coast.
These settlements served as market towns as well as anchorages. As Carthaginian power grew, its impact on the indigenous population increased dramatically. Berber civilization was at a stage in which agriculture, manufacturing and political organization supported several states. Trade links between Carthage and the Berbers in the interior grew, but territorial expansion resulted in the enslavement or military recruitment of some Berbers and in the extraction of tribute from others. By the early 4th century BC, Berbers formed the single largest element of the Carthaginian army. In the Revolt of the Mercenaries, Berber soldiers rebelled from 241 to 238 BC after being unpaid following the defeat of Carthage in the First Punic War, they succeeded in obtaining control of much of Carthage's North African territory, they minted coins bearing the name Libyan, used in Greek to describe natives of North Africa. The Carthaginian state declined because of successive defeats by the Romans in the Punic Wars.
In 146 BC the city of Carthage was destroyed. As Carthaginian power waned, the influence of Berber leaders in the hinterland grew. By the 2nd century BC, several large but loosely administered Berber kingdoms had emerged. Two of them were established behind the coastal areas controlled by Carthage. West of Numidia lay Mauretania, which extended across the Moulouya River in modern-day Morocco to the Atlantic Ocean; the high point of Berber civilization, unequaled until the coming of the Almohads and Almoravids more than a millennium was reached during the reign of Masinissa in the 2nd century BC. After Masinissa's death in 148 BC, the Berber kingdoms were reunited several times. Masinissa's line survived until 24 AD, when the remaining Berber territory was annexed to the Roman Empire. For several centuries Algeria was ruled by the Romans. Like the rest of No
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
Sardinia is the second-largest island in the Mediterranean Sea. It is located west of the Italian Peninsula and to the immediate south of the French island of Corsica. Sardinia is politically a region of Italy, whose official name is Regione Autonoma della Sardegna / Regione Autònoma de Sardigna, enjoys some degree of domestic autonomy granted by a specific Statute, it is divided into four provinces and a metropolitan city, with Cagliari being the region's capital and its largest city. Sardinia's indigenous language and the other minority languages spoken on the island are recognized by the regional law and enjoy "equal dignity" with Italian. Due to the variety of its ecosystems, which include mountains, plains uninhabited territories, rocky coasts and long sandy beaches, the island has been defined metaphorically as a micro-continent. In the modern era, many travelers and writers have extolled the beauty of its untouched landscape, which houses the vestiges of the Nuragic civilization; the name Sardinia is from the pre-Roman noun *srd- romanised as sardus.
It makes its first appearance on the Nora Stone, where the word Šrdn testifies to the name's existence when the Phoenician merchants first arrived. According to Timaeus, one of Plato's dialogues and its people as well might have been named after a legendary woman going by Sardò, born in Sardis, capital of the ancient Kingdom of Lydia. There has been speculation that identifies the ancient Nuragic Sards with the Sherden, one of the Sea Peoples, it is suggested that the name had a religious connotation from its use as the adjective for the ancient Sardinian mythological hero-god Sardus Pater, as well as being the stem of the adjective "sardonic". In Classical antiquity, Sardinia was called a number of names besides Sardò or Sardinia, like Ichnusa and Argirofleps. Sardinia is the second-largest island in the Mediterranean Sea, with an area of 24,100 square kilometres, it is situated between 8 ° 8' and 9 ° 50' east longitude. To the west of Sardinia is the Sea of Sardinia, a unit of the Mediterranean Sea.
The nearest land masses are the island of Corsica, the Italian Peninsula, Tunisia, the Balearic Islands, Provence. The Tyrrhenian Sea portion of the Mediterranean Sea is directly to the east of Sardinia between the Sardinian east coast and the west coast of the Italian mainland peninsula; the Strait of Bonifacio is directly north of Sardinia and separates Sardinia from the French island of Corsica. The coasts of Sardinia are high and rocky, with long straight stretches of coastline, many outstanding headlands, a few wide, deep bays, many inlets and with various smaller islands off the coast; the island has an ancient geoformation and, unlike Sicily and mainland Italy, is not earthquake-prone. Its rocks date in fact from the Palaeozoic Era. Due to long erosion processes, the island's highlands, formed of granite, trachyte, basalt and dolomite limestone, average at between 300 to 1,000 metres; the highest peak is part of the Gennargentu Ranges in the centre of the island. Other mountain chains are Monte Limbara in the northeast, the Chain of Marghine and Goceano running crosswise for 40 kilometres towards the north, the Monte Albo, the Sette Fratelli Range in the southeast, the Sulcis Mountains and the Monte Linas.
The island's ranges and plateaux are separated by wide alluvial valleys and flatlands, the main ones being the Campidano in the southwest between Oristano and Cagliari and the Nurra in the northwest. Sardinia has few major rivers, the largest being the Tirso, 151 km long, which flows into the Sea of Sardinia, the Coghinas and the Flumendosa. There are 54 artificial dams that supply water and electricity; the main ones are Lake Coghinas. The only natural freshwater lake is Lago di Baratz. A number of large, salt-water lagoons and pools are located along the 1,850 km of the coastline; the climate of the island is variable from area to area, due to several factors including the extension in latitude and the elevation. It can be classified in two different macrobioclimates, one macrobioclimatic variant, called Submediterranean, four classes of continentality, eight thermotypic horizons and seven ombrotypic horizons, resulting in a combination of 43 different isobioclimates. During the year there is a major concentration
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
A torpedo tube is a cylinder shaped device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, deck-mounted units installed aboard surface vessels. Deck-mounted torpedo launchers are designed for a specific type of torpedo, while submarine torpedo tubes are general-purpose launchers, are also capable of deploying mines and cruise missiles. Most modern launchers are standardised on a 12.75-inch diameter for light torpedoes or a 21-inch diameter for heavy torpedoes, although other sizes of torpedo tube have been used: see Torpedo classes and diameters. A submarine torpedo tube is a more complex mechanism than a torpedo tube on a surface ship, because the tube has to accomplish the function of moving the torpedo from the normal atmospheric pressure within the submarine into the sea at the ambient pressure of the water around the submarine, thus a submarine torpedo tube operates on the principle of an airlock. The diagram on the right illustrates the operation of a submarine torpedo tube.
The diagram does show the working of a submarine torpedo launch. A torpedo tube has a considerable number of interlocks for safety reasons. For example, an interlock prevents the breech muzzle door from opening at the same time; the submarine torpedo launch sequence is, in simplified form: Open the breech door in the torpedo room. Load the torpedo into the tube. Hook up the wire-guide connection and the torpedo power cable. Shut and lock the breech door. Turn on power to the torpedo. A minimum amount of time is required for torpedo warmup. Fire control programs are uploaded to the torpedo. Flood the torpedo tube; this may be done manually or automatically, from sea or from tanks, depending on the class of submarine. The tube must be vented during this process to allow for complete filling and eliminate air pockets which could escape to the surface or cause damage when firing. Open the equalizing valve to equalize pressure in the tube with ambient sea pressure. Open the muzzle door. If the tube is set up for Impulse Mode the slide valve will open with the muzzle door.
If Swim Out Mode is selected, the slide valve remains closed. The slide valve allows water from the ejection pump to enter the tube; when the launch command is given and all interlocks are satisfied, the water ram operates, thrusting a large volume of water into the tube at high pressure, which ejects the torpedo from the tube with considerable force. Modern torpedoes have a safety mechanism that prevents activation of the torpedo unless the torpedo senses the required amount of G-force; the power cable is severed at launch. However, if a guidance wire is used, it remains connected through a drum of wire in the tube. Torpedo propulsion systems vary but electric torpedoes swim out of the tube on their own and are of a smaller diameter. 21" weapons with fuel-burning engines start outside the tube. Once outside the tube the torpedo begins its run toward the target as programmed by the fire control system. Attack functions are programmed but with wire guided weapons, certain functions can be controlled from the ship.
For wire-guided torpedoes, the muzzle door must remain open because the guidance wire is still connected to the inside of the breech door to receive commands from the submarine's fire-control system. A wire cutter on the inside of the breech door is activated to release the wire and its protective cable; these are drawn clear of the ship prior to shutting the muzzle door. The drain cycle is a reverse of the flood cycle. Water can be moved as necessary; the tube must be vented to drain the tube since it is by gravity. Open the breech door and remove the remnants of the torpedo power cable and the guidance wire basket; the tube must be wiped dry to prevent a buildup of slime. This process is called "diving the tube" and tradition dictates that "ye who shoots, dives". Shut and lock the breech door. Spare torpedoes are stored behind the tube in racks. Speed is a desirable feature of a torpedo loading system. There are various manual and hydraulic handling systems for loading torpedoes into the tubes. Prior to the Ohio class, US SSBNs utilized manual block and tackle which took about 15 minutes to load a tube.
SSNs prior to the Seawolf class used a hydraulic system, much faster and safer in conditions where the ship needed to maneuver. The German Type 212 submarine uses a new development of the water ram expulsion system, which ejects the torpedo with water pressure to avoid acoustic detection. List of torpedoes by diameter The Fleet Type Submarine Online 21-Inch Submerged Torpedo Tubes United States Navy Restricted Ordnance Pamphlet 1085, June 1944 Torpedo tubes of German U-Boats