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Underwater Firearm
An underwater firearm is a firearm designed for use underwater. They are in the arms inventories of many nations. A common feature of underwater firearms or needleguns is that they fire flechettes or spear-like bolts instead of standard bullets. These may be fired by pressurised gas. History Underwater firearms were first developed in the 1960s during the Cold War as a way to arm frogmen. Design Because standard bullet ammunition does not work well underwater, a common feature of underwater firearms is that they fire flechettes instead of standard bullets. The barrels of underwater pistols are typically not rifled. Rather, the fired projectile maintains its ballistic trajectory underwater by hydrodynamic effects. The lack of rifling renders these weapons relatively inaccurate when fired out of water. Underwater rifles are more powerful than underwater pistols and more accurate out of water, but underwater pistols can be manipulated more easily underwater. Among the many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
APS Underwater Rifle REMOV
APS or Aps or aps or similar may refer to: Education * Abbottabad Public School * Adarsh Public School, a public school in New Delhi, India * Alamogordo Public Schools * Albuquerque Public Schools, New Mexico, US school district * Allendale Public Schools * Indian Army Public Schools * Associated Public Schools of Victoria, independent school group, Australia * Atlanta Public Schools * Abbotsford Public School, in Abbotsford, New South Wales Places * Anápolis, Goiás, Brazil, IATA airport code * Apsley railway station, Apsley, England, National Rail code * Alba-la-Romaine, Ardèche, France, known as ''Aps'' until 1904 Science and medicine * Adenosine 5'-phosphosulfate, a metabolic precursor to 3'-phosphoadenosine-5'-phosphosulfate (PAPS) * Advanced Photon Source, a synchrotron X-ray source at Argonne National Laboratory * Algebra of physical space * American Physical Society * American Physiological Society * American Phytopathological Society * Ammonium persulfate, oxidizing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmet
A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United Kingdom) without protective function are sometimes worn. Soldiers wear combat helmets, often made from Kevlar or other lightweight synthetic fibers. The word ''helmet'' is derived from ''helm'', an Old English word for a protective head covering. Helmets are used for recreational activities and sports (e.g., jockeys in horse racing, American football, ice hockey, cricket, baseball, camogie, hurling and rock climbing); dangerous work activities such as construction, mining, riot police, military aviation, and in transportation (e.g. motorcycle helmets and bicycle helmets). Since the 1990s, most helmets are made from resin or plastic, which may be reinforced with fibers such as aramids. Designs Some British gamekeepers during the 18th and 19th centuries wore he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piracy
Piracy is an act of robbery or criminal violence by ship or boat-borne attackers upon another ship or a coastal area, typically with the goal of stealing cargo and other valuable goods. Those who conduct acts of piracy are called pirates, vessels used for piracy are pirate ships. The earliest documented instances of piracy were in the 14th century BC, when the Sea Peoples, a group of ocean raiders, attacked the ships of the Aegean and Mediterranean civilisations. Narrow channels which funnel shipping into predictable routes have long created opportunities for piracy, as well as for privateering and commerce raiding. Historic examples include the waters of Gibraltar, the Strait of Malacca, Madagascar, the Gulf of Aden, and the English Channel, whose geographic structures facilitated pirate attacks. The term ''piracy'' generally refers to maritime piracy, although the term has been generalized to refer to acts committed on land, in the air, on computer networks, and (in scie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially a ''fish''. The term ''torpedo'' originally applied to a variety of devices, most of which would today be called naval mine, mines. From about 1900, ''torpedo'' has been used strictly to designate a self-propelled underwater explosive device. While the 19th-century battleship had evolved primarily with a view to engagements between armored warships with naval artillery, large-caliber guns, the invention and refinement of torpedoes from the 1860s onwards allowed small torpedo boats and other lighter surface combatant , surface vessels, submarines/submersibles, even improvised fishing boats or frogmen, and later light aircraft, to destroy large shi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-submarine Warfare
Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades. Successful ASW operations typically involved a combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel. Typically, sophisticated sonar equipment is used for first detecting, then classifying, locating, and tracking a target submarine. Sensors are therefore a key element of ASW. Common weapons for attacking submarines include torpedoes and naval mines, which can both be launched from an array of air, surface, and underwater platforms. ASW capabilities are often considered of significant strategic importance, particularly following provocative instan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boarding (attack)
Naval boarding action is an offensive tactic used in naval warfare to come up against (or alongside) an enemy marine vessel and attack by inserting combatants aboard that vessel. The goal of boarding is to invade and overrun the enemy personnel on board in order to capture, sabotage or destroy the enemy vessel. While boarding attacks were originally carried out by ordinary sailors who are proficient in hand-to-hand combat, larger warships often deploy specially trained and equipped regular troops such as marines and special forces as boarders. Boarding and close quarters combat had been a primary means to conclude a naval battle since antiquity, until the early modern period when heavy naval guns gained tactical primacy at sea. A cutting out boarding is an attack by small boats, preferably at night and against an unsuspecting, and anchored, target. It became popular in the later 18th century, and was extensively used during the Napoleonic Wars. This heralded the empha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Platform
An oil platform (or oil rig, offshore platform, oil production platform, and similar terms) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms will also have facilities to accommodate the workers, although it is also common to have a separate accommodation platform bridge linked to the production platform. Most commonly, oil platforms engage in activities on the continental shelf, though they can also be used in lakes, inshore waters, and inland seas. Depending on the circumstances, the platform may be fixed Platform, fixed to the ocean floor, consist of an artificial island, or floating oil production system, float. In some arrangements the main facility may have storage facilities for the processed oil. Remote subsea wells may also be connected to a platform by flow lines and by umbilical cable, umbilical connections. These sub-sea facilities may include of one or more subsea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maritime Interdiction
Maritime Interception (or naval interdiction) operations (MIOs) are naval operations, that aim to delay, disrupt, or destroy enemy forces or supplies en route to the battle area before they do any harm against friendly forces, similar to air interdiction. Maritime interdiction took place in both World Wars, the First World War and Second World War during the Battle of the Atlantic campaigns (1914-1918) and (1939-1945). In several other campaigns, such as the Norwegian Campaign and the Battle of the Mediterranean, naval interdiction campaigns took place. Naval interdiction took place in the Persian Gulf, during Operation Southern Watch. They took place between the end of Operation Desert Storm in 1991 and the beginning of the Iraq War in 2003. These operations were conducted to ensure Saddam Hussein was not smuggling his oil out of Iraq, in violation of United Nations sanctions against Iraq. The operations involved the stopping and boarding of any and all ships transiting the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visit, Board, Search, And Seizure
Visit, board, search, and seizure (VBSS) is the term used by United States military and law enforcement agencies for maritime boarding actions and tactics. VBSS teams are designed to capture enemy vessels, combat terrorism, piracy, and smuggling, and to conduct customs, safety and other inspections. United States Navy training The initial training continuum includes three courses, lasting a total of eight weeks (SRF-B, SRF-A, VBSS), with some team members receiving additional follow-on training. Skills taught in VBSS training revolve around Close Quarters Battle (CQB). Training consists of proficiency in hand-to-hand combat tactics, search procedures, tactical team movements, shooting, rappelling, searching, and arrest procedures for compliant and non-compliant combatants. This aspect of the Navy plays a role in maintaining security and freedom of sea lanes worldwide. Some advanced units, known as Helicopter Visit, Board, Search, and Seizure (HVBSS) teams, have been trained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Warfare
Underwater warfare is one of the three operational areas of naval warfare, the others being surface warfare and aerial warfare. It refers to combat conducted underwater such as: *Actions by submarines actions, and anti-submarine warfare, i.e. warfare between submarines, other submarines and surface ships; combat airplanes and helicopters may also be engaged when launching special dive-bombs and torpedo-missiles against submarines; *Underwater special operations, considering: **Military diving sabotage against ships and ports. **Anti-frogman techniques. **Reconnaissance tasks. Name Underwater warfare may also be referred to as undersea warfare or subsurface warfare. History In the 20th century underwater warfare was dominated by the submarine. In the 21st century unmanned underwater vehicles are coming to play a significant part in underwater warfare. Seabed warfare Seabed warfare is defined as “operations to, from and across the ocean floor.” In general the target of sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Operations
Special operations (S.O.) are military activities conducted, according to NATO, by "specially designated, organized, selected, trained, and equipped forces using unconventional techniques and modes of employment". Special operations may include reconnaissance, unconventional warfare, and counter-terrorism actions, and are typically conducted by small groups of highly-trained personnel, emphasizing sufficiency, stealth, speed, and tactical coordination, commonly known as " special forces". History Australia In World War II following advice from the British, Australia began raising special forces. The first units to be formed were independent companies, which began training at Wilson's Promontory in Victoria in early 1941 under the tutelage of British instructors. With an establishment of 17 officers and 256 men, the independent companies were trained as "stay behind" forces, a role that they were later employed in against the Japanese in the South West Pacific Area during 1942 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercavitation
Supercavitation is the use of a cavitation bubble to reduce skin friction drag on a submerged object and enable high speeds. Applications include torpedoes and propellers, but in theory, the technique could be extended to an entire underwater vessel. Physical principle Cavitation is the formation of vapour bubbles in liquid caused by flow around an object. Bubbles form when water accelerates around sharp corners and the pressure drops below the vapour pressure. Pressure increases upon deceleration, and the water generally reabsorbs the vapour; however, vapour bubbles can implode and apply small concentrated impulses that may damage surfaces like ship propellers and pump impellers. The potential for vapour bubbles to form in a liquid is given by the nondimensional cavitation number. It equals local pressure minus vapour pressure, divided by dynamic pressure. At increasing depths (or pressures in piping), the potential for cavitation is lower because the difference between local ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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