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Trunnion
A trunnion (from Old French "''trognon''", trunk) is a cylindrical protrusion used as a mounting or pivoting point. First associated with cannons, they are an important military development. Alternatively, a trunnion is a shaft that positions and supports a tilting plate. This is a misnomer, as in reality it is a cradle for the true trunnion. In mechanical engineering (see the 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. As they allowed the muzzle to be raised and lowered easily, the integral casting of trunnions is seen by military historians as one of the most important advances in early field artillery. With the creation of larger and more powerful siege guns in the early 15th century, a n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunnion
A trunnion (from Old French "''trognon''", trunk) is a cylindrical protrusion used as a mounting or pivoting point. First associated with cannons, they are an important military development. Alternatively, a trunnion is a shaft that positions and supports a tilting plate. This is a misnomer, as in reality it is a cradle for the true trunnion. In mechanical engineering (see the 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. As they allowed the muzzle to be raised and lowered easily, the integral casting of trunnions is seen by military historians as one of the most important advances in early field artillery. With the creation of larger and more powerful siege guns in the early 15th century, a n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tainter Gate
The Tainter gate is a type of radial arm floodgate used in dams and canal locks to control water flow. It is named for Wisconsin structural engineer Jeremiah Burnham Tainter. A side view of a Tainter gate resembles a slice of pie with the curved part of the piece facing the source or upper pool of water and the tip pointing toward the destination or lower pool. The curved face or skinplate of the gate takes the form of a wedge section of cylinder. The straight sides of the pie shape, the trunnion arms, extend back from each end of the cylinder section and meet at a trunnion which serves as a pivot point when the gate rotates. Pressure forces on a submerged body act perpendicular to the body's surface. The design of the Tainter gate results in every pressure force acting through the centre of the imaginary circle of which the gate is a section, so that all resulting pressure force acts through the pivot point of the gate, making construction and design easier. When a Tain ... [...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, effective range, mobility, rate of fire, 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''. In the modern era, the term ''cannon'' has fallen into decline, replaced by ''guns'' or ''artillery'', if not a more specific term such as howitzer or mortar, except for high-caliber automatic weapons firing bigger rounds than machine guns, called autocannons. The earliest known depict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gun Carriage
A gun carriage is a frame and 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. 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 developed, with the result that the barrel could be held in two recesses in the carriage and secured with an iro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bombard (weapon)
The bombard is a type of cannon or mortar which was used throughout the 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 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 long weighing up to 20 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Artillery
Field artillery is a category of mobile artillery used to support armies in the field. These weapons are specialized for mobility, tactical proficiency, short range, long range, and extremely long range target engagement. Until the early 20th century, field artillery were also known as foot artillery, for while the guns were pulled by beasts of burden (often horses), the gun crews would usually march on foot, thus providing fire support mainly to the infantry. This was in contrast to horse artillery, whose emphasis on speed while supporting cavalry units necessitated lighter guns and crews riding on horseback. Whereas horse artillery has been superseded by self-propelled artillery, field artillery has survived to this day both in name and mission, albeit with motor vehicles towing the guns (this towed artillery arrangement is often called mobile artillery), carrying the crews and transporting the ammunition. Modern artillery has also advanced to rapidly deployable wheeled a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floodgate
Floodgates, also called stop gates, are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge system. Since most of these devices operate by controlling the water surface elevation being stored or routed, they are also known as crest gates. In the case of flood bypass systems, floodgates sometimes are also used to lower the water levels in a main river or canal channels by allowing more water to flow into a flood bypass or detention basin when the main river or canal is approaching a flood stage. Types Valves Valves used in floodgate applications have a variety of design requirements and are usually located at the base of dams. Often, the most important requirement (besides regulating flow) is energy dissipation. Since water is very he ... [...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 bastion fort, 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 armour, 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 (Nubia), 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, Maiden Castle, Dorset were high. Medieval fortifications Glacis, also call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bastion
A bastion or bulwark 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habsburg Monarchy
The Habsburg monarchy (german: Habsburgermonarchie, ), also known as the Danubian monarchy (german: Donaumonarchie, ), or Habsburg Empire (german: Habsburgerreich, ), was the collection of empires, kingdoms, duchies, counties and other polities that were ruled by the House of Habsburg, especially the dynasty's Austrian branch. The history of the Habsburg monarchy can be traced back to the election of Rudolf I as King of Germany in 1273 and his acquisition of the Duchy of Austria for the Habsburg in 1282. In 1482, Maximilian I acquired the Netherlands through marriage. Both realms passed to his grandson and successor, Charles V, who also inherited the Spanish throne and its colonial possessions, and thus came to rule the Habsburg empire at its greatest territorial extent. The abdication of Charles V in 1556 led to a division within the dynasty between his son Philip II of Spain and his brother Ferdinand I, who had served as his lieutenant and the elected king of Hungary and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canal Lock
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself (usually then called a caisson) that rises and falls. Locks are used to make a river more easily navigable, or to allow a canal to cross land that is not level. Later canals used more and larger locks to allow a more direct route to be taken. Pound lock A ''pound lock'' is most commonly used on canals and rivers today. A pound lock has a chamber with gates at both ends that control the level of water in the pound. In contrast, an earlier design with a single gate was known as a flash lock. Pound locks were first used in China during the Song Dynasty (960–1279 AD), having been pioneered by the Song politician and naval en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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