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GHN-45
The GC-45 (''Gun, Canada, 45-calibre'') is a 155 mm howitzer designed by Gerald Bull's Space Research Corporation (SRC) in the 1970s. Versions were produced by a number of companies during the 1980s, notably in Austria and South Africa. The most publicized use of the design was in Iraq, where the GHN-45 variant used by some Iraqi artillery units had a longer range than any coalition cannon systems. This initially caused considerable worry on the part of the allied forces in the Persian Gulf War. Design history The GC-45's general design followed several decades of work by Bull with fin-stabilized artillery shells, starting at the Canadian Armament Research and Development Establishment (CARDE) and later at Project HARP. In these efforts accuracy was not a huge concern, the objective was muzzle velocity, and the test articles were finned darts representing missiles, a low-cost alternative to wind tunnels. Yet with the removal of the rifling and the soft-metal driving band on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerald Bull
Gerald Vincent Bull (March 9, 1928 – March 22, 1990) was a Canadian engineer who developed long-range artillery. He moved from project to project in his quest to economically launch a satellite using a space gun, huge artillery piece, to which end he designed the Project Babylon "Supergun affair, supergun" for Saddam Hussein's government in Iraq. Bull was assassinated outside his apartment in Brussels, Belgium, in March 1990. His assassination is believed to be the work of the Mossad over his work for the Ba'athist Iraq, Iraqi government. No person has ever been charged with his murder. Early life Gerald Vincent Bull was born in North Bay, Ontario, Canada, to George L. Toussaint Bull, a solicitor, and Gertrude Isabelle (née LaBrosse) Bull. George Bull was from a family from the Trenton, Ontario, Trenton area and had moved to North Bay in 1903 to start a law firm. As a Roman Catholic, LaBrosse would have been forbidden from marrying Bull, an Anglican. George converted to Roman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oklahoma
Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northeast, Arkansas to the east, New Mexico to the west, and Colorado to the northwest. Partially in the western extreme of the Upland South, it is the List of U.S. states and territories by area, 20th-most extensive and the List of U.S. states and territories by population, 28th-most populous of the 50 United States. Its residents are known as Oklahomans and its capital and largest city is Oklahoma City. The state's name is derived from the Choctaw language, Choctaw words , 'people' and , which translates as 'red'. Oklahoma is also known informally by its List of U.S. state and territory nicknames, nickname, "The Sooner State", in reference to the Sooners, American pioneer, American settlers who staked their claims in formerly American Indian-o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzzle Velocity
Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/ shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately to in black powder muskets, to more than in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to . Several factors, including the type of firearm, the cartridge, and the barrel length, determine the bullet's muzzle velocity. Projectile velocity For projectiles in unpowered flight, its velocity is highest at leaving the muzzle and drops off steadily because of air resistance. Projectiles traveling less than the speed of sound (about in dry air at sea level) are ''subsonic'', while those traveling faster are ''super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M107 (projectile)
The M107 is a 155 mm high explosive projectile used by many countries. It is a bursting round with fragmentation and blast effects. It used to be the standard 155 mm high explosive projectile for howitzers of the US Army and US Marine Corps, but is being superseded in the US military by the M795. Development The M107 is a development of the M102 155 mm shell that was developed in the 1930s from the French Schneider 155 mm projectile for the Model 1917 Howitzer. Description The body consists of a hollow steel shell containing high explosive (either TNT or Composition B) painted olive drab with yellow markings. A fuze adapter is screwed into the body and brazed in place. An eyebolt lifting plug is screwed into the fuze well to assist in transportation. The plug is removed and replaced with a fuze for firing. The complete projectile weighs , is long and contains 15.8% explosive by weight. It is a separate-loading projectile—propellant bags or modular arti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FH-70
The FH70 (field howitzer for the 1970s) is a towed 155 mm howitzer used by several nations. History In 1963, NATO agreed a NATO Basic Military Requirement 39 for close support artillery, either towed or tracked. Subsequently, Germany and UK started discussions and design studies and in 1968 established agreed operational characteristics for a towed 155 mm close support gun. Italy became a party to the agreement in 1970. Key requirements were: * A detachable auxiliary power unit (APU) * An unassisted range of ; an assisted range of * A burst capability of three rounds in 15–20 seconds, six rounds per minute for a short period and two rounds per minute sustained * The ability to fire all 155 mm munitions in NATO service, plus a new range of ammunition The two national authorities had overall responsibility for R&D, and Vickers Ltd was the co-ordinating design authority. They were also the design authority for the carriage and Rheinmetall GmbH was the authority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probable Error
In statistics, probable error defines the half-range of an interval about a central point for the distribution, such that half of the values from the distribution will lie within the interval and half outside.Dodge, Y. (2006) ''The Oxford Dictionary of Statistical Terms'', OUP. Thus for a symmetric distribution it is equivalent to half the interquartile range, or the median absolute deviation. One such use of the term ''probable error'' in this sense is as the name for the scale parameter of the Cauchy distribution, which does not have a standard deviation. The probable error can also be expressed as a multiple of the standard deviation σ,Zwillinger, D.; Kokosa, S. (2000) ''CRC Standard Probability and Statistics Tables and Formulae'', Chapman & Hall/CRC. (Section 2.2.13) which requires that at least the second statistical moment of the distribution should exist, whereas the other definition does not. For a normal distribution this is \gamma = 0.6745 \times \sigma (see det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzzle Brake
A muzzle brake or recoil compensator is a device connected to, or a feature integral (ported barrel) to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwanted muzzle rise. Barrels with an integral muzzle brake are often said to be ported. The concept of a muzzle brake was first introduced for artillery. It was a common feature on many anti-tank guns, especially those mounted on tanks, in order to reduce the area needed to take up the strokes of recoil and kickback. They have been used in various forms for rifles and pistols to help control recoil and the rising of the barrel that normally occurs after firing. They are used on pistols for practical pistol competitions, and are usually called compensators in this context.STI article o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket
A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, airfoils, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity. Rockets for military and recreational uses date back to at least 13th-century China. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Bleed
Base bleed or base burn (BB) is a system used on some artillery shells to increase range, typically by about 20%–35%. It expels gas into the low-pressure area behind the shell to reduce Drag (physics), base drag (but does not produce thrust, unlike rocket-assisted projectile, rocket-assisted projectiles). Being percentage-based, the range extension is more useful on longer-range artillery where an increase of approximately can be achieved, and it also was found that the reduced turbulence gave the projectiles a more consistent trajectory, resulting in tighter grouping, and efficient shelling more than away. Base bleed technology was developed in Sweden in the mid-1960s but took some time to spread and find its niche between cheaper classical ordnance and even more expensive rocket-assisted projectiles. It is now a fairly common option. Function Most (50–60%) of the drag (physics), drag on an artillery shell derives from the nose portion of the shell. Artillery shells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersonic
Supersonic speed is the speed of an object that exceeds the speed of sound (Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times the speed of sound (Mach 5) are often referred to as hypersonic. Flights during which only some parts of the air surrounding an object, such as the ends of rotor blades, reach supersonic speeds are called transonic. This occurs typically somewhere between Mach 0.8 and Mach 1.2. Sounds are traveling vibrations in the form of pressure waves in an elastic medium. Objects move at supersonic speed when the objects move faster than the speed at which sound propagates through the medium. In gases, sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas, and pressure has little effect. Since air temperature and composition varies significantly with altitude, the speed of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifling
Rifling is the term for helical grooves machined into the internal surface of a firearms's barrel for imparting a spin to a projectile to improve its aerodynamic stability and accuracy. It is also the term (as a verb) for creating such grooves. The opposite of rifling is smoothbore. Rifling is measured in ''twist rate'', the distance the rifling takes to complete one full revolution, expressed as a ratio with 1 as its base (e.g., 1:). A shorter distance/lower ratio indicates a faster twist, generating a higher spin rate (and greater projectile stability). The combination of length, weight, and shape of a projectile determines the twist rate needed to gyroscopically stabilize it: barrels intended for short, large-diameter projectiles such as spherical lead balls require a very low twist rate, such as 1 turn in 48 inches (122 cm). Barrels intended for long, small-diameter projectiles, such as the ultra-low-drag 80-grain 0.223 inch bullets (5.2 g, 5.56&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
