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Submersible Bridge
A submersible bridge is a type of movable bridge that lowers the bridge deck below the water level to permit waterborne traffic to use the waterway. This differs from a lift bridge or table bridge, which operate by raising the roadway. Two submersible bridges exist across the Corinth Canal in Greece, one at each end, in Isthmia and Corinth. They lower the centre span to 8 metres below water level when they give way to ships crossing the channel. The submersible bridge's primary advantage over the similar lift bridge is that there is no structure above the shipping channel and thus no height limitation on ship traffic. This is particularly important for sailing vessels. Additionally, the lack of an above-deck structure is considered aesthetically pleasing, a similarity shared with the Chicago-style bascule bridge and the table bridge. However, the presence of the submerged bridge structure limits the draft of vessels in the waterway. The term ''submersible bridge'' is also somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift Bridge
A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck. The vertical lift offers several benefits over other movable bridges such as the bascule and swing-span bridges. Generally speaking, they cost less to build for longer moveable spans. The counterweights in a vertical lift are only required to be equal to the weight of the deck, whereas bascule bridge counterweights must weigh several times as much as the span being lifted. As a result, heavier materials can be used in the deck, and so this type of bridge is especially suited for heavy railroad use. The biggest disadvantage to the vertical-lift bridge (in comparison with many other designs) is the height restriction for vessels passing under it, due to the deck remaining suspended above the passageway. Although most vertical-lift bridges use towers, each equipped with counterweights, some use hydraulic jacks located below the deck. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draft (hull)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water. The more heavily a vessel is loaded, the deeper it sinks into the water, and the greater its draft. After construction, the shipyard creates a table showing how much water the vessel displaces based on its draft and the density of the water (salt or fresh). The draft can also be used to determine the weight of cargo on board by calculating the total displacement of water, accounting for the content of the ship's bunkers, and using Archimedes' principle. The closely related term "trim" is defined as the difference between the forward and aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridges
A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, and the material used to make it, and the funds available to build it. The earliest bridges were likely made with fallen trees and stepping stones. The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge (dating from the 13th century BC, in the Peloponnese) is one of the oldest arch bridges still in existence and use. Etymology The ''Oxford English Dictionary'' traces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Bridge
__NOTOC__ An underwater bridge is a military structure that was employed during World War II and the Korean War. Underwater bridges, typically constructed of logs, sand and dirt just beneath the surface of the water in a river or similar narrow body of water, allow heavier vehicles to cross the river driving through only shallow water. Air reconnaissance finds such "bridges" difficult to spot; even if seen, air strikes have difficulty in destroying them as the water insulates the structure from blasts. Soviet troops, notably Georgy Zhukov, used the concept during the Khalkhin Gol campaign (1939) and in World War II (1941-1945). North Korean troops also used such structures during the Korean War (1950-1953), particularly to cross the Naktong River during the Battle of Pusan Perimeter of August-September 1950. In the Vietnam War the Ho Chi Minh trail used such bridges. See also *Low water crossing *Ford Ford commonly refers to: * Ford Motor Company, an automobile manufacturer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Bridge
A table bridge is a moveable bridge in which the deck moves along the vertical axis. Four hydraulic pillars under the bridge, two at each end, raise the bridge deck to allow barge traffic to pass beneath it. In contrast to a lift bridge, where the deck is pulled upwards along towers, the deck of a table bridge is pushed upwards by otherwise hidden pillars. The name originates from the fact that when open it resembles a table. The total space required by a table bridge is hardly larger than the bridge deck, which is not the case with a thrust bridge. Unlike a lift bridge this type has only slight visual impact upon its surroundings when closed for use by road traffic. This is very well demonstrated by the '' Pont levant Notre Dame'' at Tournai in Belgium. Examples of table bridges Several rivers and waterways are home to multiple examples of table bridges. These include but are not limited to: :* Erie Canal in New York between Lockport and the Genesee River is home to one o ... [...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-cam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Water Crossing
A low-water crossing (also known as an Irish bridge or Irish Crossing, causeway in Australia, low-level crossing or low-water bridge) provides a bridge when water flow is low. Under high-flow conditions, water runs over the roadway and precludes vehicular traffic. This approach is cheaper than building a bridge to raise the level of the road above the highest flood stage of a river, particularly in developing countries or in semi-arid areas with rare high-volume rain. Low-water crossings can be dangerous when flooded. Construction The low-water crossing was developed from the traditional ford. A ford permits vehicular traffic to cross a waterway with wet wheels. In some countries the term “low-water crossing” implies that the crossing is usually dry, while “ford” implies that the crossing is usually wet. The simplest type of low water crossing is called an ''unvented ford'' or ''drift''. This type of low water crossing is used mainly for shallow waterways or dry stream ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corinth
Corinth ( ; el, Κόρινθος, Kórinthos, ) is the successor to an ancient city, and is a former municipality in Corinthia, Peloponnese, which is located in south-central Greece. Since the 2011 local government reform, it has been part of the municipality of Corinth, of which it is the seat and a municipal unit. It is the capital of Corinthia. It was founded as Nea Korinthos (), or New Corinth, in 1858 after an earthquake destroyed the existing settlement of Corinth, which had developed in and around the site of ancient Corinth. Geography Located about west of Athens, Corinth is surrounded by the coastal townlets of (clockwise) Lechaio, Isthmia, Kechries, and the inland townlets of Examilia and the archaeological site and village of ancient Corinth. Natural features around the city include the narrow coastal plain of Vocha, the Corinthian Gulf, the Isthmus of Corinth cut by its canal, the Saronic Gulf, the Oneia Mountains, and the monolithic rock of Acrocorinth ... [...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 the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isthmia, Corinthia
Isthmia ( el, Ισθμία) is a Greek village and community 7.5 km southeast of Corinth. It is located in the south entry of Corinth Canal. The community spreads in the place where the Isthmian Games were held in antiquity. So, near the village important ruins of the archaeological site are kept including the Temple of Poseidon, the ancient stadium and the ancient theatre. Administravely, Isthmia belongs to Loutraki-Perachora-Agioi Theodoroi municipality and Loutraki-Perachora municipal unit. Description Isthmia is located in an area where the Isthmian Games were held. The Isthmian Games started in 582 BC and finished during 5th century AD. In modern times, Isthmia was a small village. But after the digging of Corinth Canal between 1880 and 1893 the village developed. Today it is a community, including five settlements Isthmia, Kyras Vrysi, Kalamaki, Paradeisos, Agios Charalampos and Kavos. The population of the village Isthmia is 1,134 inhabitants and the population of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to the northeast. The Aegean Sea lies to the east of the Geography of Greece, mainland, the Ionian Sea to the west, and the Sea of Crete and the Mediterranean Sea to the south. Greece has the longest coastline on the Mediterranean Basin, featuring List of islands of Greece, thousands of islands. The country consists of nine Geographic regions of Greece, traditional geographic regions, and has a population of approximately 10.4 million. Athens is the nation's capital and List of cities and towns in Greece, largest city, followed by Thessaloniki and Patras. Greece is considered the cradle of Western culture, Western civilization, being the birthplace of Athenian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
