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Trunnion
A trunnion () is a cylinder, cylindrical Boss (engineering), protrusion used as a mounting or pivoting point. First associated with cannons, they are an important military development. In mechanical engineering (see the Trunnion#Trunnion bearings, trunnion bearing section below), it is one part of a rotating joint where a shaft (the trunnion) is inserted into (and turns inside) a full or partial cylinder. Medieval history In a cannon, the trunnions are two projections cast just forward of the center of mass of the cannon and fixed to a two-wheeled movable gun carriage. With the creation of larger and more powerful siege guns in the early 15th century, a new way of mounting them became necessary. Stouter gun carriages were created with reinforced wheels, axles, and “trails” which extended behind the gun. Guns were now as long as in length and they were capable of shooting iron projectiles weighing from . When discharged, these wrought iron balls were comparable in range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gun Carriage
A gun carriage is a frame or a mount that supports the gun barrel of an artillery piece, allowing it to be maneuvered and fired. These platforms often had wheels so that the artillery pieces could be moved more easily. Gun carriages are also used on ships to facilitate the movement and aiming of large cannons and guns. These are also used in the funeral procession of any higher authority of any state and country. Early guns The earliest guns were laid directly onto the ground, with earth being piled up under the muzzle end of the barrel to increase the elevation. As the size of guns increased, they began to be attached to heavy wooden frames or beds that were held down by stakes. These began to be replaced by wheeled carriages in the early 16th century. Smoothbore gun carriages From the 16th to the mid-19th century, the main form of artillery remained the smoothbore cannon. By this time, the trunnion (a short axle protruding from either side of the gun barrel) had been devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walking Beam
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II. Reciprocating steam engines were progressively replaced in marine applications during the 20th century by steam turbines and marine diesel engines. History The first commercially successful steam engine was developed by Thomas Newcomen in 1712. The steam engine improvements brought forth by James Watt in the later half of the 18th century greatly improved steam engine efficiency and allowed more compact engine arrangements. Successful adaptation of the steam engine to marine applications in England would have to wait until almost a century after Newcomen, when Scottish engineer William Symington built the world's "first practical steamboat", the '' Charlotte Dundas'', in 1802. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannon
A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge (firearms), gauge, effective range, mobility (military), mobility, rate of fire, elevation (ballistics), angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. The earliest known depiction of cannons may have appeared in Science and technology of the Song dynasty#Gunpowder warfare, Song dynasty China as early as the 12th century; however, solid archaeological and documentary evidence of cannons do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bombard (weapon)
The bombard is a type of cannon or mortar which was used throughout the Late Middle Ages and the early modern period. Bombards were mainly large calibre, muzzle-loading artillery pieces used during sieges to shoot round stone projectiles at the walls of enemy fortifications, enabling troops to break in. Most bombards were made of iron and used gunpowder to launch the projectiles. There are many examples of bombards, including Mons Meg, the Basilic, the Dardanelles Gun, and the handheld bombard. The weapon provided the name to the Royal Artillery rank of bombardier and the word 'bombardment'. Terminology The term "bombard" was first used to describe guns of any kind from the early to mid-14th century, but it was later applied primarily to large cannons during the 14th to 15th centuries. Despite its strong association with large cannons, there is no standard size for bombards, and the term has been applied to cannons only a meter in length as well as cannons several meters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacis
A glacis (, ) in military engineering is an artificial slope as part of a medieval castle or in early modern fortresses. They may be constructed of earth as a temporary structure or of stone in more permanent structure. More generally, a glacis is any slope, natural or artificial, which fulfils the above requirements. The etymology of this French word suggests a slope made dangerous with ice, hence the relationship with ''glacier''. A ''glacis plate'' is the sloped front-most section of the hull of a tank or other armoured fighting vehicle. Ancient fortifications A glacis could also appear in ancient fortresses, such as the one the ancient Egyptians built at Semna in Nubia. Here it was used by them to prevent enemy siege engines from weakening defensive walls. Hillforts in Britain started to incorporate glacis around 350 BC. Those at Maiden Castle, Dorset were high. Medieval fortifications Glacises, also called taluses, were incorporated into medieval fortifications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bastion
A bastion is a structure projecting outward from the curtain wall of a fortification, most commonly angular in shape and positioned at the corners of the fort. The fully developed bastion consists of two faces and two flanks, with fire from the flanks being able to protect the curtain wall and the adjacent bastions. Compared with the medieval fortified towers they replaced, bastion fortifications offered a greater degree of passive resistance and more scope for ranged defence in the age of gunpowder artillery. As military architecture, the bastion is one element in the style of fortification dominant from the mid 16th to mid 19th centuries. Evolution By the middle of the 15th century, artillery pieces had become powerful enough to make the traditional medieval round tower and curtain wall obsolete. This was exemplified by the campaigns of Charles VII of France who reduced the towns and castles held by the English during the latter stages of the Hundred Years War, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habsburg Monarchy
The Habsburg monarchy, also known as Habsburg Empire, or Habsburg Realm (), was the collection of empires, kingdoms, duchies, counties and other polities (composite monarchy) that were ruled by the House of Habsburg. From the 18th century it is also referred to as the Austrian monarchy, the Austrian Empire () or the Danubian monarchy. The history of the Habsburg monarchy can be traced back to the election of Rudolf I of Germany, Rudolf I as King of the Romans, King of Germany in 1273 and his acquisition of the Duchy of Austria for the Habsburgs in 1282. In 1482, Maximilian I, Holy Roman Emperor, Maximilian I acquired the Habsburg Netherlands, Netherlands through marriage. Both realms passed to his grandson and successor, Charles V, Holy Roman Emperor, Charles V, who also inherited the Monarchy of Spain, Spanish throne and Spanish Empire, its colonial possessions, and thus came to rule the Habsburg empire at its greatest territorial extent. The abdication of Charles V in 1556 led ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grease (lubricant)
Grease is a solid or semisolid lubricant formed as a dispersion of thickening agents in a liquid lubricant. Grease generally consists of a soap emulsified with mineral or vegetable oil. A common feature of greases is that they possess high initial viscosities, which upon the application of shear, drop to give the effect of an oil-lubricated bearing of approximately the same viscosity as the base oil used in the grease. This change in viscosity is called shear thinning. Grease is sometimes used to describe lubricating materials that are simply soft solids or high viscosity liquids, but these materials do not exhibit the shear-thinning properties characteristic of the classical grease. For example, petroleum jellies such as Vaseline are not generally classified as greases. Greases are applied to mechanisms that can be lubricated only infrequently and where a lubricating oil would not stay in position. They also act as sealants to prevent the ingress of water and incompressible ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Motors
American Motors Corporation (AMC; commonly referred to as American Motors) was an American automobile manufacturing company formed by the mergers and acquisitions, merger of Nash-Kelvinator Corporation and Hudson Motor Car Company on May 1, 1954. At the time, it was the largest corporate merger in U.S. history. American Motors' most similar competitors were those automakers that held similar annual sales levels, such as Studebaker, Packard, Kaiser Motors, and Willys-Overland. Their largest competitors were the Big Three (automobile manufacturers), Big Three—Ford Motor Company, Ford, General Motors, and Chrysler. American Motors' production line included Compact car, small cars—the Rambler American, which began as the Nash Rambler in 1950, AMC Hornet, Hornet, AMC Gremlin, Gremlin, and AMC Pacer, Pacer; intermediate car, intermediate and full-size car, full-sized cars, including the AMC Ambassador, Ambassador, Rambler Classic, AMC Rebel, Rebel, and AMC Matador, Matador; musc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Ravenna (1512)
The Battle of Ravenna, fought on 11 April 1512, was a major battle of the War of the League of Cambrai. It pitted forces of the Holy League against France and their Ferrarese allies. Although the French and Ferrarese eliminated the Papal–Spanish forces as a serious threat, their triumph was overshadowed by the loss of their young general Gaston of Foix. The victory therefore did not help them secure northern Italy. The French withdrew entirely from Italy in the summer of 1512, as Swiss mercenaries hired by Pope Julius II and Imperial troops under Emperor Maximilian I arrived in Lombardy. The Sforza were restored to power in Milan. Monster of Ravenna A month before the battle, multiple sources reported a monstrous birth which became known as the Monster of Ravenna. This child's terrifying features included a horn on its forehead, wings, an eye on its knee, and a clawed foot, according to Florentine chronicler Luca Landucci. Its appearance was a cause for alarm, and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
