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Moveable Bridges
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] |
Madison Street Bridge
Madison Street Bridge may refer to: *Madison Street Bridge (Chicago), a crossing of the Chicago River *Madison Street Bridge (Portland, Oregon), the name of two former bridges over the Willamette River {{Disambiguation ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Bridge
A jet bridge is an enclosed connector which most commonly extends from an airport terminal gate to an airplane, and in some instances from a port to a boat or ship, allowing passengers to board and disembark without heading outside and being exposed to harsh weather. Depending on building design, sill heights, fueling positions, and operational requirements, a jet bridge may be fixed or movable, swinging radially, or extending in length. The jetway was invented by Frank Der Yuen. Similar devices are used for astronauts to enter spacecraft, which are installed at the appropriate height of the launch tower. History Before the introduction of jet bridges, passengers normally boarded an aircraft by walking along the ground-level ramp and climbing a set of movable stairs, or airstairs on aircraft so equipped. Mobile staircases or "ramp stairs" are employed at many airports around the world, particularly smaller airports and terminals supporting low cost carriers. United Ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferry
A ferry is a boat or ship that transports passengers, and occasionally vehicles and cargo, across a body of water. A small passenger ferry with multiple stops, like those in Venice, Italy, is sometimes referred to as a water taxi or water bus. Ferries form a part of the public transport systems of many waterside cities and islands, allowing direct transit between points at a capital cost much lower than bridges or tunnels. Ship connections of much larger distances (such as over long distances in water bodies like the Baltic Sea) may also be called ferry services, and many carry vehicles. History The profession of the ferryman is embodied in Greek mythology in Charon, the boatman who transported souls across the River Styx to the Underworld. Speculation that a pair of oxen propelled a ship having a water wheel can be found in 4th century Roman literature "''Anonymus De Rebus Bellicis''". Though impractical, there is no reason why it could not work and such a ferry, mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transporter Bridge
A transporter bridge, also known as a ferry bridge or aerial transfer bridge, is a type of movable bridge that carries a segment of roadway across a river. The gondola is slung from a tall span by wires or a metal frame. The design has been used to cross navigable rivers or other bodies of water, where there is a requirement for ship traffic to be able to pass. This has been a rare type of bridge, with fewer than two dozen built. There are just twelve that continue to be used today. History The concept of the transporter bridge was invented in 1873 by Charles Smith (1844–1882), the manager of an engine works in Hartlepool, England. He called it a "bridge ferry" and unsuccessfully presented his ideas to councils in Hartlepool, Middlesbrough, and Glasgow. The first transporter bridge, Vizcaya Bridge was built between Las Arenas and Portugalete, Spain, in 1893. The design from Alberto Palacio inspired others to attempt similar structures. The idea came about in locations wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swing Bridge
A swing bridge (or swing span bridge) is a movable bridge that can be rotated horizontally around a vertical axis. It has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the swing span (turning span) can then pivot horizontally as shown in the animated illustration to the right. In its closed position, a swing bridge carrying a road or railway over a river or canal, for example, allows traffic to cross. When a water vessel needs to pass the bridge, road traffic is stopped (usually by traffic signals and barriers), and then motors rotate the bridge horizontally about its pivot point. The typical swing bridge will rotate approximately 90 degrees, or one-quarter turn; however, a bridge which intersects the navigation channel at an oblique angle may be built to rotate only 45 degrees, or one-eighth turn, in order to clear the channel. Small swing bridges as found over narrow canals may be pivo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tilt Bridge
A tilt bridge is a type of moveable bridge which rotates about fixed endpoints rather than lifting or bending, as with a drawbridge. The tilting Gateshead Millennium Bridge spanning the River Tyne between Gateshead on the south bank and Newcastle upon Tyne, England, on the north is a pedestrian bridge with two large hydraulic rams at each side that tilt the structure back allowing small watercraft to pass under. The pedestrian and cycle pathway is an almost-horizontal curve, suspended above the river from a just-beyond-the-vertical parabolic arch. To raise the bridge, this whole assembly rotates as a single, rigid structure. As the arch tilts lower, the pathway rises, each counterbalancing the other so that a minimum of energy is needed. The resultant appearance in motion leads to it sometimes being called the "eyelid bridge", since its shape is akin to the blinking of an eye if seen from along the river. Two further tilt bridges are known to exist in Belgium, both constructed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 vessels 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 Draft, the draft, or draught may refer to: Watercraft dimens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retractable Bridge
A retractable bridge is a type of moveable bridge in which the deck can be rolled or slid backwards to open a gap while traffic crosses, usually a ship on a waterway. This type is sometimes referred to as a thrust bridge. Retractable bridges date back to medieval times. Due to the large dedicated area required for this type of bridge, this design is not common. A retractable design may be considered when the maximum horizontal clearance is required (for example, over a canal). Two remaining examples exist in New York City: the Carroll Street Bridge (built 1889) in Brooklyn, and the Borden Avenue Bridge in Queens. A recent example can be found at Queen Alexandra Dock in Cardiff, Wales, where the bridge is jacked upwards before being rolled on wheels. Helix Bridge at Paddington Basin in London is a more unusual example of the type, consisting of a glass shell supported in a helical steel frame, which rotates as it retracts. The Summer Street Bridge over Fort Point Channel i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Bridge
A table bridge is a moveable bridge in which the deck moves vertically. Two or four hydraulic pillars under the bridge, one or two at each end, raise the bridge deck to allow boat 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 retractable 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical-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. Most vertical-lift bridges use towers, each equipped with counterweights. An example of this kind was built in Portland, Oregon, U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merchant Square Footbridge
The Merchant Square Footbridge (also known as The Fan Bridge) is a moveable pedestrian bridge spanning a canal in Paddington, London. It is composed of five side-by side sections of varying lengths, with offset pivots to accommodate the varying lengths. When opened, the segments are brought to varying angles of elevation. The visual effect when opened has been likened to that of a Japanese fan. Not to be confused with the Fan Bridge which crosses Holland Brook (formerly known as the Holland River) between Little Clacton and Great Holland in Essex (UK) (OS Grid Ref: TM 19710 18667 / Latitude 51°49'24"N Longitude 1°11'12"E). This was the lowest crossing-point until the Gunfleet estuary was reclaimed in the 1700s. See also * List of bridges in London * Moveable bridges 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 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
