|
Drawbridge
A drawbridge or draw-bridge is a type of moveable bridge typically at the entrance to a castle or tower surrounded by a moat. In some forms of English, including American English, the word ''drawbridge'' commonly refers to all types of moveable bridges, such as bascule bridges, vertical-lift bridges and swing bridges, but this article concerns the narrower historical definition of the term where the bridge is used in a defensive structure. As used in castles or defensive structures, drawbridges provide access across defensive structures when lowered, but can quickly be raised from within to deny entry to an enemy force. Castle drawbridges Medieval castles were usually defended by a ditch or moat, crossed by a wooden bridge. In early castles the bridge might be designed to be destroyed or removed in the event of an attack, but drawbridges became very common. A typical arrangement would have the drawbridge immediately outside a gatehouse, consisting of a wooden deck wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drawbridge
A drawbridge or draw-bridge is a type of moveable bridge typically at the entrance to a castle or tower surrounded by a moat. In some forms of English, including American English, the word ''drawbridge'' commonly refers to all types of moveable bridges, such as bascule bridges, vertical-lift bridges and swing bridges, but this article concerns the narrower historical definition of the term where the bridge is used in a defensive structure. As used in castles or defensive structures, drawbridges provide access across defensive structures when lowered, but can quickly be raised from within to deny entry to an enemy force. Castle drawbridges Medieval castles were usually defended by a ditch or moat, crossed by a wooden bridge. In early castles the bridge might be designed to be destroyed or removed in the event of an attack, but drawbridges became very common. A typical arrangement would have the drawbridge immediately outside a gatehouse, consisting of a wooden deck wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drawbridge Mentality
A drawbridge mentality is the attitude of people who have migrated to a more exclusive or more "unspoiled" community and then campaign to preserve the tranquility of that community by opposing further inward migration by people or businesses and, possibly, any development or refurbishment, including plans put forward by those already located there. The term can imply a selfish attitude and can be taken as an insult by people who have strong affection for their home locality and wish to protect it from any changes. It is closely related to the NIMBY attitude. There are many factors that can lead to a person developing a drawbridge mentality, and two of the factors are quality of place and migration. When new people migrate into an already populated area, they often bring with them new ideas and practices. Sometimes, the original population is upset with this change and wants to keep things how they were. These individuals “reject change and work to preserve the status quo, adopting a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double-beam Drawbridge
A double-beam drawbridge, seesaw or folding bridge is a movable bridge . It opens by rotation about a horizontal axis parallel to the water. Historically, the double-beam drawbridge has emerged from the drawbridge. Unlike a drawbridge, a double-beam drawbridge has counterweights, so that opening requires much less energy. Unlike the bascule bridge, the simple drawbridge and the "oorgat" (earhole) bridge, the double-beam drawbridge has two hinges. The road surface is connected to the bottom hinge. Above the hinge is a portal, the hamei gate. A rotating arm, the balance, is attached to this hamei gate. On one side of the balance hangs the counterweight, the balance box, on the other side, the arm is connected to the tip of the bridge deck. So when the bridge goes up, the balance and the bridge deck turn parallel. The drawback of a traditional double-beam drawbridge is that it has a limited clearance height. That is why the balance box sometimes does not hang between the two arms, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moveable Bridge
A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. In American English, the term is synonymous with , and the latter is the common term, but drawbridge can be limited to the narrower, historical definition used in some other forms of English, in which ''drawbridge'' refers to only a specific type of moveable bridge often found in castles . An advantage of making bridges moveable is the lower cost, due to the absence of high piers and long approaches. The principal disadvantage is that the traffic on the bridge must be halted when it is opened for passage of traffic on the waterway. For seldom-used railroad bridges over busy channels, the bridge may be left open and then closed for train passages. For small bridges, bridge movement may be enabled without the need for an engine. Some bridges are operated by the users, especially those with a boat, others by a bridgeman (or bridge tender); a few are remotely controlled using video-ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linkspan
A linkspan or link-span is a type of drawbridge used mainly in the operation of moving vehicles on and off a roll-on/roll-off (RO-RO) vessel or ferry, particularly to allow for tidal changes in water level. Linkspans are usually found at ferry terminals where a vessel uses a combination of ramps either at the stern, bow or side to load or unload cars, vans, trucks and buses onto the shore, or alternately at the stern and/or the bow to load or unload railroad cars. History The first linkspans appeared at the end of the 19th century when train ferries came into operation. Each rail ferry berth has to be specifically designed to make sure that it fitted one class of ship. In most of these vessels it was also possible to carry some road vehicles. By the mid 20th century with the rise of road transport, general purpose Ro Ro ferries started to come into service. Most could use the rail ferry berths but generally they were fitted with stern ramps that had the dual function o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Château Du Plessis-Bourré
Château du Plessis-Bourré is a château in the Loire Valley in France, situated in the commune of Écuillé in the Maine-et-Loire department. Built in less than 5 years from 1468 to 1472 by Finance Minister Jean Bourré, the principal advisor to King Louis XI. The château has not been modified externally since its construction and still has a fully working drawbridge. It was classified as a in 1931. The château was purchased in 1911 by Henry Vaïsse who, when he died in 1956, bequeathed it to his nephew, François Reille-Soult, Duke of Dalmatie, descendant of the marshals of the French empire < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmingham Hall
Helmingham Hall is a moated manor house in Helmingham, Suffolk, England. It was begun by John Tollemache in 1480 and has been owned by the Tollemache family ever since. The house is built around a courtyard in typical late medieval/Tudor style. The house is listed Grade I on the National Heritage List for England, and its park and formal gardens are also Grade I listed on the Register of Historic Parks and Gardens. History The present Helmingham Hall may have been initially constructed in 1510 on the site of an earlier house called Creke Hall. The exterior was altered between 1745 and 1760, again in 1800 by John Nash, and in 1840. The original half-timbered walls have been concealed by brick and tiles. The house is surrounded by a moat 60 feet wide, over which it is reached only by two working drawbridges, which have been pulled up every night since 1510. These were originally operated with a windlass but in recent years this has been replaced by an electric motor. In addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bascule Bridge
A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- or double-leafed. The name comes from the French term for balance scale, which employs the same principle. Bascule bridges are the most common type of movable span because they open quickly and require relatively little energy to operate, while providing the possibility for unlimited vertical clearance for marine traffic. History Bascule bridges have been in use since ancient times, but until the adoption of steam power in the 1850s, very long, heavy spans could not be moved quickly enough for practical application. Types There are three types of bascule bridge and the counterweights to the span may be located above or below the bridge deck. The fixed- trunnion (sometimes a "Chicago" bascule) rotates around a large axle that raises th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bascule Bridge
A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- or double-leafed. The name comes from the French term for balance scale, which employs the same principle. Bascule bridges are the most common type of movable span because they open quickly and require relatively little energy to operate, while providing the possibility for unlimited vertical clearance for marine traffic. History Bascule bridges have been in use since ancient times, but until the adoption of steam power in the 1850s, very long, heavy spans could not be moved quickly enough for practical application. Types There are three types of bascule bridge and the counterweights to the span may be located above or below the bridge deck. The fixed- trunnion (sometimes a "Chicago" bascule) rotates around a large axle that raises th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guthrie Rolling Bridge
A Guthrie rolling bridge was a kind of retractable bridge, an 18th-century version of the drawbridge. It was commonly installed as the access across the narrow steep sided ditches characteristic of the polygonal forts of this era. Rolling bridges were unhinged, and remained horizontal as they were retracted within the gates of a fortification, similar in operation to a modern thrust bridge. Running the bridge out Running the bridge out is effected by pushing it along its rails until the outer two wheels are at the edge of the granite sill of the ditch. When the bridge is pushed beyond this point the two outer wheels do not descend the slopes of the granite slabs but instead the bridge remains in a horizontal position. This is due to the centre axle being offset from the centre of the girders causing the bridge to run on its inner two wheels. The middle two wheels follow along the trays. When the bridge is just less than halfway out, the ends of the centre axle then engage in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, and the modern period. The medieval period is itself subdivided into the Early, High, and Late Middle Ages. Population decline, counterurbanisation, the collapse of centralized authority, invasions, and mass migrations of tribes, which had begun in late antiquity, continued into the Early Middle Ages. The large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the 7th century, North Africa and the Middle East—most recently part of the Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gatehouse
A gatehouse is a type of fortified gateway, an entry control point building, enclosing or accompanying a gateway for a town, religious house, castle, manor house, or other fortification building of importance. Gatehouses are typically the most heavily armed section of a fortification, to compensate for being structurally the weakest and the most probable attack point by an enemy. There are numerous surviving examples in France, Austria, Germany, England and Japan. History Gatehouses made their first appearance in the early antiquity when it became necessary to protect the main entrance to a castle or town. Over time, they evolved into very complicated structures with many lines of defence. Strongly fortified gatehouses would normally include a drawbridge, one or more portcullises, machicolations, arrow loops and possibly even murder-holes where stones would be dropped on attackers. In some castles, the gatehouse was so strongly fortified it took on the function of a keep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Helmingham Hall")
.jpg "Click for more on -> Gatehouse")