A swing bridge is a bridge that moves to provide passage for (usually) boats or barges. The advantage of building drawbridges is their lower cost due to the absence of high supports and long approaches. The main disadvantage is that traffic on the bridge is stopped when it opens to allow ships to pass underneath.
1. Gateshead Millennium Bridge, UK
The Millennium Bridge in Gateshead is a pedestrian and bicycle bridge that spans the River Tyne, England. This bridge connects one side of the embankment, on which the Gateshead's Quays arts district is located, with the other side, which is called the Quayside of Newcastle. In general, the bridge resembles two graceful arcs, one of which plays the role of decks for the passage of pedestrians and cyclists, and the second arc is supporting. The arcs resting on two platforms stretch in parallel from one embankment to the other.
When it becomes necessary to allow a ship to pass, the entire bridge rotates as one solid structure. As the supporting arc descends, the deck arc rises, balancing it. This creates free space for ships to pass along the river. 
The parabolic arcs of the deck measure a distance of 105 meters, but pedestrians and cyclists have to travel 120 meters along the deck, since an additional bend of 15 meters is necessary to free up space for ships passing on the river. The unusual sight of the bridge in motion has led to locals sometimes calling it the "Winking Eye", as when viewed from the river, its shape resembles a winking eye. The bridge looks elegant both in a static position and in motion, but while it is moving, it is simply impossible not to admire this stunning spectacle of architectural art. 
The bridge is driven by six hydraulic cylinders with a diameter of 45 centimeters, which are located symmetrically - three on each side. Each of them is powered by a 55 kW electric motor. Small ships and boats, whose height above the water does not exceed 25 meters, can sail under the bridge. The bridge makes a full 40° rotation in about 4.5 minutes, depending on how fast the wind blows. 
The construction of the bridge helped the architectural firm Wilkinson Eyre win the Stirling Prize in 2002, awarded by the Royal Institute of British Architects. In 2003, the bridge was awarded the Gifford IStructE Supreme Award, and in 2005 the International Association for Bridge and Structural Engineering (IABSE) awarded the firm its Outstanding Structural Award. (Outstanding Structure Award) for the construction of the Millennium Bridge.
2. Slauerhoffbrug Bridge, Netherlands
The Slauerhof Bridge is a fully automatic swing bridge (also known as a tail bridge) located in the Dutch city of Leeuwarden. The bridge uses two lifting arms to move a section of road from place to place directly on the road itself.
It is also known as the "flying Slauerhof drawbridge". The drawbridge can be raised or lowered quickly and easily using a single support bracket (instead of hinges). This, in turn, allows ships to pass faster, with only a short delay in traffic on the road. 
The deck size is 15 by 15 meters. It is painted blue and yellow, that is, the colors representing the flag and symbol of Leeuwarden. The Slauerhof Bridge was most likely named after JJ Slauerhoff, a famous Dutch poet who lived in Leeuwarden. 
The supporting bracket is located next to the bridge. The deck of the oblique bridge emphasizes the asymmetrical shape. The support bracket has slots for the ballast block when the bridge is in the open position. 
A reliable support for the lifting arm is hidden in the moving section of the road. There are no cargo or cross beams in the design. The lower part of the bridge deck is flat.
3. Pont Jacques Chaban-Delmas, France
The Jacques Chaban-Delmas Bridge is a vertical lift bridge stretching over the Garonne River in the French city of Bordeaux. It was opened on March 16, 2013 by French President François Hollande and Mayor of Bordeaux Alain Juppé. The length of the main span of the bridge is 110 meters. 
The height of the bridge is approximately 50 meters and it is raised about 120 times a year so that large-capacity ships sail under it, heading to the ports surrounding Bordeaux. 
The bridge's draw span has a symmetrical transverse compartment that supports four lanes of traffic - two roads for vehicles and two pedestrian and bicycle roads. 
As of 2013, this bridge is the longest vertical lift bridge in Europe. It was named after Jacques Chaban-Delmas, former Prime Minister of France and former mayor of Bordeaux.
4. Vizcaya Bridge, Spain
The Vizcaya Bridge is a suspended cabin bridge that links the towns of Portugalete and Las Arenas, part of the municipality of Getxo in the Spanish province of Biscay. The Biscay Bridge crosses the mouth of the Ibaizabal River.
The bridge is commonly referred to by locals and even the official website as "Puente Colgante", which literally means "suspension bridge", although the design of this bridge is quite different from a suspension bridge. 
The Vizcaya Bridge was built to connect the two banks, which are located at the mouth of the Ibaizabal River. It is the oldest suspended cabin bridge in the world. It was built in 1893 according to the design of Alberto Palacio, one of Gustave Eiffel's students. 
The length of the bridge, still in operation, is 164 meters, and its cabin can transport six cars and several dozen passengers from one bank to the other in one and a half minutes. During the daytime, a bridge cabin departs every eight minutes (every hour at night), all year round. During the day and at night, the crossing fee is different. The bridge is part of the Bilbao Metro's Creditrans transport system. 
The structure consists of four 61-meter towers, which are the basis of the bridge and are located on the banks of the river. Two new visitor lifts have been installed in the towers, allowing people to walk along the bridge platform, overlooking the port and Abra Bay.
5. Women's Bridge (Puente de la Mujer), Argentina
"Puente de la Mujer" (meaning "Women's Bridge" in Spanish) is a rotating pedestrian bridge located at Pier 3 in the commercial district of Buenos Aires called Puerto Madero in Argentina. This is a rope suspension bridge, as well as a drawbridge, but it has an unusual, slightly asymmetrical structure.
There is only one lifting mechanism on the bridge, the cables of which support the part of the bridge that rotates 90 degrees to allow ships to pass through the bridge. When the bridge rotates to allow ships to pass, the far end of the rotating platform rests on a special support that balances the platform. 
The pedestrian bridge, which is 170 meters long, weighs 800 tons. The width of the bridge is 6.2 meters and it is divided into three parts: two fixed parts with a length of 25 meters and 32.5 meters and a middle part, the length of which is 102.5 meters. The middle part of the bridge rotates on a white concrete support, allowing ships to cross the bridge section in less than two minutes. 
This central section is supported by a metal "needle" with a concrete core. The height of the “needle” is approximately 34 meters. The cables supporting the central part of the bridge are attached to a “needle” inclined at an angle of 39°. A computer system installed at the eastern end of the bridge activates the turning mechanism when necessary.
6. Drawable footbridge over the River Hull (River Hull Footbridge), UK
The steel movable footbridge over the River Hull (also called the Scale Lane Bridge) is the world's first footbridge that rotates to open for the passage of ships and close while pedestrians are on it. . The stunning prefabricated structure, designed by London-based McDowell+Benedetti, crosses the River Hull in Yorkshire and takes approximately two minutes to fully open or close. The bridge connects the city center (Hull) with the eastern part under construction, playing the role of both an important element of urban infrastructure and a new city landmark. 
The diameter of the pedestrian bridge is approximately 16 meters and it rotates on several wheels that ride on a circular track located under the center of the bridge, allowing it to open and close depending on the intensity of river traffic. 
It takes approximately two minutes to fully open or close, during which time the bridge moves very slowly, at a speed that is lower than the speed of the London Eye. Pedestrians and cyclists can stay on it while it rotates and enjoy views of the river from a whole new perspective.
Swing footbridge over the River Hull at night
The bridge's lighting was designed by Sutton Vane Associates, which placed energy-efficient light bulbs to cast a glow on the water at night, creating the appearance of a beam of light contouring the bridge.
Small points of light highlight the shape of the bridge and appear as the bridge begins to rotate. For added excitement, lamps placed in the niches turn on as the bridge moves, creating a unique light show.
7. Horn Bridge, Germany
The Horn Bridge is a folding bridge located in the city of Kiel, in the region of Schleswig-Holstein, Germany. The bridge spans the end of the Kiel Fjord called the Horn. It was developed by Gerkan, Marg and Partners. This is a sliding sliding bridge, consisting of three segments. The length of its main part is 25.5 meters and folds into the shape of the Latin letter “N”. The bridge was built in 1997 at a cost of $10,501,224. 
The width of the Horn Bridge is five meters. It connects the city center on the western bank of the Hörn with the Gaarden quarter on the eastern bank. This pedestrian bridge is especially important for passengers as it connects the Norwegian Ferry Terminal (Norwegenkai) to the main railway station.
Many residents of the city of Kiel were initially skeptical of the bridge design. At first, there were constant malfunctions in the operation of the mechanism, hence the bridge got its unofficial nickname “non-folding bridge” (Klappt-Nix-Brücke). To provide road crossing for pedestrians and cyclists, a hydraulically operated retractable bridge was built right next to the Horn Bridge as an interim solution. It is still used today during repairs and maintenance of the folding bridge. The Horn Bridge is now considered an engineering masterpiece and has even become a tourist attraction. 
The bridge typically opens once every hour, allowing small and medium-sized ships to sail in and out of the bay. The bridge offers some of the best panoramic views of the city of Kiel. It is also the start and end of the scenic route: the hiking route from Bremervörde to Kieler Förde. The route passes approximately 50 different ferries, bridges, shipping locks, tidal barriers and maritime museums, as well as bridge ferries in the cities of Rendsburg and Osten.
8. Foryd Harbor Bridge, UK
The Foryd Harbor Cycle and Pedestrian Bridge is located in Rhyl, a coastal resort town and community located in Denbighshire, on the north-east coast of Wales, UK. The bridge's lifting wing forms part of the impressive structure and, when raised, provides unobstructed access to the shipping canal. To maintain balance, the second wing of the bridge also rises. Thus, both wings of the bridge are mirror images of each other. 
The double steel mast rises almost 50 meters above the water. It contains a lifting block and lifting ropes extending from it. The mast provides visual confirmation of the presence of the bridge, which can be seen for many kilometers. She is also the main attraction in the harbour.
The mast is supported by a rigging system similar to that seen on many boats. In order for the mast, located in the center, to fit harmoniously into the structure, each of the bridge arms bifurcates at its middle and provides pedestrians with a three-meter wide passage.
9. Submersible Bridges at Corinth Canal, Greece
Flooded bridge at the eastern end of the Corinth Canal
The Corinth Canal in Greece cuts the narrow Isthmus of Corinth and separates the Peloponnesian peninsula from the Greek mainland, connecting the Gulf of Corinth with the Saronic Gulf in the Aegean Sea. 
Built between 1881 and 1893, the Corinth Canal was considered a major technical achievement at the time. Although the canal eliminates the 700-kilometer journey around the Peloponnese peninsula, it is too narrow for modern ocean-going cargo ships, as it can only accommodate ships with a beam of no more than 16.5 meters and a draft of 7.3 meters.
A boat floats over a flooded bridge at the eastern end of the Corinth Canal.
Vessels can only pass through the canal one at a time and on a one-way system. Large vessels have to be towed by tugboats. Today the canal is mainly used by tourist ships. About 11,000 ships use the canal every year.
In 1988, two flood bridges were built along the edges of the Corinth Canal, one at the Isthmus of Corinth and one at Corinth. The deck of the flood bridge is lowered eight meters into the water to allow ships to use the waterway. 
The main advantage of lowering part of the bridge instead of raising it above the level of the bridge itself is that this does not create any height restriction above the shipping canal and, therefore, ships of any height can navigate the canal without hindrance. This is especially true for sailing ships. In addition, the absence of an overhanging structure is considered aesthetically pleasing. However, the presence of part of the flooded bridge under water limits the vessels in terms of draft.
10. El Ferdan Railway Bridge, Egypt
The El Ferdan Railway Swing Bridge, also known as the Al Firdan Bridge, spans the Suez Canal, near the city of Ismailia in the northeastern region of Egypt. 
The bridge connects mainland Egypt with the Sinai Peninsula. The length of the bridge is 335 meters. This is the longest drawbridge in the world. Both sides of the structure rotate on supports when the bridge opens or closes, and thanks to a pair of electric rotary actuators, the bridge takes a total of 30 minutes to fully open. 
Unlike the other bridges on this list, the Ferdan Railway Swing Bridge remains open to ship traffic on the canal, and is closed only to accommodate trains crossing the canal. The bridge was designed and built by a consortium of Belgian, German and Egyptian architects. Construction of the bridge was completed in 2001. The bridge cost $80 million. The bridge was officially opened on November 14, 2001.
Bonus 1: Barton Swing Aqueduct, UK
The Barton Swing Aqueduct is a swiveling, navigable aqueduct located in the area of Barton upon Irwell in Greater Manchester, England. The aqueduct carries water from the Bridgewater Canal through the Manchester Ship Canal.
The rotary aqueduct at Barton in closed position.
The turning motion of the aqueduct allows large ships using the shipping canal to sail under the aqueduct, and smaller, narrower boats to cross the canal on the aqueduct itself.
The rotary aqueduct at Barton in the open position.
The first and only swing aqueduct in the world, it is considered one of the most significant feats of civil engineering of the Victorian era. Designed by Sir Edward Leader Williams and built by Andrew Handyside of Derby, the swing aqueduct opened in 1894 and remains in use today. 
An aqueduct is a kind of swing bridge. When closed it allows small boats to pass through the Bridgewater Canal. When large vessels need to navigate the shipping canal located below the aqueduct, a 1,450-ton, 100-meter iron trough is rotated 90 degrees on an axle rod mounted on an island specially built for the purpose.
Sluices at each end of the trench hold about 800 tons of water. Additional gates on each bank retain water in the adjacent sections of the canal. The aqueduct originally had a built-in path that ran along its entire length, approximately 2.7 meters above the water level of the Bridgewater Canal. These days this path has been removed.
Bonus 2: M60A1 Armored Vehicle Launched Bridge
The M60A1 Tank Bridge Layer (an engineering vehicle in service with the US Army) was designed to install and remove an 18 meter bridge. The M60A1 is used during combat, and is essentially a folding mobile bridge mounted on a tank chassis. The machine, which is powered by a 750 horsepower diesel engine, requires two people to operate. The weight of the bridge and tank chassis is 58 tons. 
The mobile bridge can withstand the passage of an Abrams tank at reduced speeds. The M60A1 tank bridgelayer entered service with the US Marine Corps in the late 1980s. At this time, the M60A1 is planned to continue to be used until 2015. Subsequently, the M60A1 will be replaced by the M104 WOLVERINE engineering vehicle. 
The M60A1 Tank Bridge Layer is an armored engineering vehicle used for installing and removing a folding bridge (also called a scissor bridge). The M60A1 consists of three main parts: the body, the bridge and the launch module. The launch module is built into the tank chassis. When deployed, the bridge is capable of allowing passage across it for tracked and wheeled vehicles not exceeding the load capacity of class 60 according to the NATO classification.
The bridge can be removed from either end. The width of its passage is 3.8 meters. Installation of the bridge takes from two to five minutes, removal about 10 minutes, and most often takes place under the cover of other armored vehicles. When deployed, the bridge covers a distance of 18.3 meters and can withstand a load of 70 tons. The tank bridge layer allows a 70-ton vehicle to travel 15 meters, while a 60-ton vehicle can travel the entire 18 meters.
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Drop-down bridges
Such bridges are characterized by rotational movement of the span relative to the horizontal axis. The single-wing swing bridge is an asymmetrical system (Fig. 9.1). In the closed state, the span rests on the supporting parts (3) and (4); the axis of rotation (2) is unloaded using a special wedging device (6). When opening, the span structure rests on the axis of rotation, and to ensure a stable position of the span structure and reduce the required engine power, the span structure is balanced by a counterweight (5). The design span L is selected depending on the specified width of the under-bridge clearance, taking into account the distance from the centers of support to the edges of the supports, as well as taking into account the incomplete release of the under-bridge clearance when opening (5-10% more than the width of the under-bridge clearance). The location of the seam (1) of the roadway is possible behind the axis of rotation or in front of it. The latter solution has advantages: at any position of the temporary load, it does not cause a negative support reaction on the support on which the end of the wing is located; during opening, no gap is formed in the roadway through which dirt from the drawbridge falls into the support well, and an accidental fall of a person is not excluded. The seam of the roadway above the main beams and in this case must be arranged behind the axis of rotation so that when opening the main beams do not rest against the structure of the roadway.
Rice. 9.1 - Drop-down bridge: L - design span of the bridge
To ensure the balance of the span of a drop-down bridge at any moment of movement, it is necessary that the centers of gravity of the wing, counterweight and axis of rotation lie on the same straight line, and the moments of the weight of the counterweight Q and the weight of the wing G relative to the axis of rotation are equal. If the counterweight is placed in the support well (see Fig. 9.1), it will require a significant width. The width of the support can be reduced if the counterweight is placed between the beams or trusses of the adjacent span (Fig. 9.2, a) with a device in the support of open niches, and a sub-blade is placed at the end of the wing, pulling it down. The width of the support can be reduced by using a device for hinged attachment of the counterweight to the tail of the wing (Fig. 9.2, b). This will increase the depth of the well into which the counterweight is lowered. In addition, if it is possible for the water level to rise above the bottom of the well, it will need to be waterproofed. The counterweight is additionally connected to the support by rod AB to ensure forward motion and prevent it from swinging. To maintain the balance of such a system, it is necessary that the point Oʹ of the counterweight suspension, the axis O of rotation and the center of gravity of the span (together with the tail section) lie on the same straight line, and the figure OOʹBA is a parallelogram (see Fig. 9.2, b).
Rice. 9.2 - Location of the counterweight of the drop-down span
An important issue is the number and location of the main beams of the movable span, taking into account the clearance of the bridge. For a single-track railway bridge, as well as a road bridge with a small passage width, you need to install two beams. With a large passage width, the number of beams can be increased, but it is advisable to take it as even so that the beams can be connected in pairs with ties.
The drop-down system can also have two wings. It is sometimes used for architectural reasons, and it can be economically feasible if the draw span has a significant length (50-70 m). Here, as a rule, there is a saving in the power of propulsion mechanisms and engines, which must be designed for significantly lower loads (although supplied in duplicate). The width of the supports can also be reduced. Particular attention should be paid to the static diagram of the span in the closed state. There are two main options here: connecting the ends of the wings using a longitudinally movable hinge; closing the span into a three-hinged spacer system with the transmission of thrust through the middle hinge (Fig. 9.3). In the first case, the design of the connection is simple, but the rigidity of the span is relatively low; when a load passes, a fracture of the passage profile above the hinge occurs. Therefore, this solution is unacceptable for railway bridges. In the second case, the design becomes more complicated and a thrust is transferred to the supports, which can be significant, since the system turns out to be flat (f/L ≥ 1/15). However, the structure is more rigid. From the span (see Fig. 9.3), the thrust is transmitted to the support through the stop (1), which limits the rotation of the swinging post (2). The span is slightly unbalanced; when closing, the swinging stand, turning, lifts it and unloads the axis of rotation.
Rice. 9.3 - Spacer system
It is possible to connect the ends of the wings with a lock capable of operating at full bending moment. This solution has not been implemented due to the difficulty of providing a sufficiently rigid lock, designed to withstand significant forces, which, moreover, could be quickly closed and opened.
To bring drop-down drawbridges electromechanical or hydraulic drive. The electromechanical drive (Fig. 9.4, a) has a drive gear (1), which rotates from an electric motor with a gearbox and is engaged with a toothed arc (2), fixed to the span. A drive option with a gear on the span and a gear wheel on the support is possible. A drive with a crank mechanism has its advantages (Fig. 9.4, b). Here the drive gear (1) rotates the crank (3), the force is transmitted to the superstructure through the connecting rod (4). The advantage of this drive is the zero speed of rotation of the span at the beginning and end of movement. The hydraulic drive (Fig. 9.4 c) consists of hydraulic cylinders (5) and pumping units. The hydraulic cylinder has a piston (6), the rod of which is pivotally connected to the span (7). The hydraulic cylinder is also pivotally connected to the support. By supplying oil under pressure into the cavity above or below the piston, it is possible to create the force necessary to set the superstructure in motion. Hydraulic cylinders have a diameter of up to 500 mm, an oil pressure of up to 10 MPa and a force of up to 2000 kN.
Rice. 9.4 - Drop axle drive
Sliding-opening bridges
The span structure of such a bridge (Fig. 9 5), when raised, rolls back along a special rolling path (1), resting on it with a rolling circle (2) attached to the span structure, which makes a plane-parallel movement. By turning in a vertical plane and rolling back, it completely clears the opening of the drawbridge, which is an advantage of this system.
Rice. 9.5 - Sliding-dropping bridge
Vertical lift bridges
Superstructure vertical lift bridge(Fig. 9.6) when spread, it moves forward in a vertical plane. For this purpose, towers (4) are used, which are supported on special supports or on adjacent spans. The towers are equipped with pulleys (2) through which the cables (1) pass. Cables connect the lifting span with counterweights (3), which lower down when the bridge opens. The lifting height h p of the span structure is determined as the difference in the heights of the under-bridge clearance in the draw span in the closed h 3 and in the open h p states - and the height h 3 can be approximately taken equal to the height of the under-bridge clearance in fixed navigable spans. When pre-determining the height of the towers, a margin is left A, equal to 3-5 m.
Rice. 9.6 - Vertical lift bridge
When determining the dimensions of the tower, care is taken to ensure its stability against overturning both along and across the bridge. Significant tensile forces in the tower legs are undesirable. Therefore, the length of the base of the tower when located on an adjacent span is usually assigned to about 1/6 H, and when resting on supports - 1/4÷1/5 H; The width of the tower across the bridge is usually at least 1/6 H.
In addition to the main type of vertical lift bridges with the entire span being lifted on special towers, systems were used with a rising roadway structure at a low lift height h p, with a span descending under water, and in other rare cases.
The lifting span structure can have through or continuous main trusses. For railway bridges, as a rule, two main through trusses with a ride on the bottom are used, and for road bridges other types of structures are also used, for example, a span with a ride on top and with several main beams. In this case, powerful transverse beams will be required, at the ends of which the counterweight cables will be attached. A span with through main trusses can have the same design as a typical span of a conventional fixed bridge.
Additionally, only the elements of the support post and the upper chord in the first panel are required. A transverse lifting beam is attached to the upper node they form.
Towers in most cases consist of two longitudinal trusses, including front and rear posts and a lattice, and two bracing trusses located in transverse planes. The link trusses at the bottom are portals to provide passage. At the top, the heads are arranged in the form of a system of beams that absorb the load from the pulleys and transfer it to the towers. The front pillars of the towers are vertical, the rear pillars are usually inclined or outlined in a broken line. The distance between the axes of the front pillars in the transverse direction is, as a rule, equal to the distance between the axes of the main trusses of the lifting span or the one adjacent to the lifting span (if the tower is located on an adjacent span). The width of the tower at the top in the longitudinal direction is taken to be minimal, insufficient for the free movement of the counterweight inside the tower. At the bottom, the tower must have a width sufficient to ensure its stability against tipping over. If small spans adjoin the draw span, then the towers are placed on closely spaced supports. If the spans in adjacent spans are long, then the towers are placed on them (see Fig. 9.6). Sometimes, with a small lifting height and a significant height of adjacent spans, it is possible to do without towers by placing the heads and pulleys on the upper chords of adjacent spans. Lifting cables, thrown over pulleys and connecting the lifting span to the counterweight, are attached to the span using transverse lifting beams.
The tower head (Fig. 9.7) is a beam cage that absorbs the load from the pulleys and transmits it to the tower nodes. The pulleys (1) rest with their axes through bearings (2) on the longitudinal beams (3). Each longitudinal beam is located at one end on the front transverse beam (4), attached to the front posts (5) of the tower, and the other end is connected to the rear transverse beam (6). In places where concentrated forces are transferred to the beams, stiffeners are installed. In order for the longitudinal beams (3) to be stable and well withstand horizontal wind and random loads, their cross section can be made box-shaped or the points of support on the front transverse beam can be strengthened using brackets.
Rice. 9.7 - Tower head design
Vertical lift bridges have significant rigidity. Standard structures with minor modifications can be used as lifting spans. The system is quite economical if the lift height is not too high. The disadvantage is the presence of towers that worsen the appearance of the bridge.
To set vertical lift bridges in motion, as a rule, an electromechanical drive is used. Electric winches set the superstructure in motion using a system of blocks and cables attached to the superstructure and towers. Winches can be placed on the span, then the synchronization of their operation can be easily ensured. A drive is used in which electric motors with gearboxes are placed on towers, and the force from the drive gear is transmitted directly to the ring gear of the pulley. This device is reliable in operation, but requires synchronization of the rotation of the pulleys on both towers, which can be achieved using a special electrical system connecting the drive motors (electric shaft).
Swing bridges
Such drawbridges have spans that rotate around a vertical axis. When opened, the span structure is located along the river, usually opening two identical spans for navigation. One of the varieties can be a swing bridge (Fig. 9.8) with the superstructure supported on rollers (2) using a central drum (4) attached to the superstructure. The rollers roll along a circular track (5) laid on a support (6). To center the span and rollers, a fixed axis (3) is used, which does not carry a vertical load. Wedging devices (1) are installed on the outer supports, taking on part of the constant load in the closed state.
Rice. 9.8 - Rotary span structure
Swing bridges They are relatively simple in design, have sufficient rigidity and, when deployed, do not restrict the height clearance for ships. Their disadvantages are the danger of ships collapsing on the span and, as a consequence, slowing down the passage of ships, as well as the significant width of the central support. When choosing a swing bridge system, you need to keep in mind that when the span is supported on rollers, they also work under operational loads. To prevent rapid wear of the rollers, it is necessary to install quite a lot of them; The diameter of the rolling circle is significant and the dimensions of the central support increase. Rollers are subject to uneven wear, and their replacement involves raising the span. Accurate alignment of the circular path under the rollers is required, otherwise the movement resistance and wear of the rollers increases sharply.
The distance between the main trusses of the span when driving on top is taken to be 2.5-3.5 m, and the number of main trusses depends on the size of the passage on the bridge. In the case of cramped under-bridge clearance, a span with a ride below and two main trusses is used. Main trusses can be through or continuous; As a rule, for spans up to 50 m, solid main trusses have an advantage. The height of the main trusses usually increases towards the central support, where it reaches approximately 1/8-1/15 L; in the middle of the span the height of the main trusses is about 1/10-1/20 L.
To rotate the span, an electromechanical or hydraulic drive can be used, similar to those used for drop-down bridges with the difference that the rotation here occurs relative to the vertical axis.
The given examples do not exhaust the variety of systems and varieties of metal drawbridges. In suitable conditions, drop-down bridges with a counterweight positioned above the roadway (which reduces the size of the support), as well as rocker drop-down bridges, can be used. With a draw span length of more than 50 m, in many cases through trusses are appropriate. When the underbridge space is cramped and closed, a movable span with a ride underneath is appropriate.
An example of a drop-down drawbridge design
The design of the city drawbridge, which allows the passage of sea vessels with an under-bridge clearance of 55 m wide and 60 m high, was developed by Lengiprotransmost. The drawable part is covered by a single-wing drop-down span, which in the closed state has a design span of 60.4 m. The opening angle of 77° provides the under-bridge clearance (Fig. 9.9). The tail sub-blade is not used. In the closed state, the span rests on a fixed supporting part with the end of the wing (1) on a hinged post located on the same vertical with the axis of rotation, and is a simple beam on two supports with a cantilever on which the counterweight is placed. The stable position of the wing in the closed state, as well as the unloading of the axis of rotation, is ensured due to the imbalance of the wing when opening (the moment from unbalanced forces is 6 MN∙m). This solution required an increase in drive power, but simplified the design due to the absence of sub-blade mechanisms.
Rice. 9.9 - Drop-down movable span structure: 1 - outline of the underbridge clearance; 2 - wing in open position; 3 - axis of rotation; 4 - counterweight; 5 - support stand; 6 - wing in closed position
The bridge with a carriageway width of 18.5 m is designed for four-lane traffic. In addition, two sidewalks of 2.25 m each are provided. 9.10). In cross section, the span has four main beams of solid section and an orthotropic slab of the roadway in the form of a horizontal sheet 12 mm thick, reinforced with longitudinal ribs 80x10 mm every 400 mm and transverse beams 500 mm high, placed every 2200 mm. The walls of the main beams have a thickness of 12 mm (in the tail part - 20 mm) and are reinforced with longitudinal and transverse stiffeners. The material of the span is steel classes C-35 and C-40. Two counterweights are located between the main beams. Drive hydraulic cylinders are located on both sides of the pairs of beams. When opened, the counterweights are lowered into the support well, the bottom of which is 3.5 m below the water level in the river. Therefore, special attention is paid to the waterproofing of the well: its lower part is protected from water penetration by a continuous casing made of steel 10 mm thick, reinforced with stiffening ribs. The casing is welded and tested for water resistance before concreting the support.
Rice. 9.10 - Cross section of the counterweights: 1 - main beams; 2 - counterweight; 3 - hydraulic cylinder axis
During deployment and in the expanded state, the wing rests on rotation axes, separate for each main beam (1); double-row self-aligning roller bearings (2) were used (8 pcs. in total), allowing a static load of up to 4.9 MN (Fig. 9.11). The weight of the wing with counterweight is approximately 24 MN.
Rice. 9.11 - Location of main mechanisms
The span structure is driven using a hydraulic drive. The hydraulic cylinders (3) are located vertically in cross section in four planes and create a pair of forces with a shoulder of 3.4 m, so during their operation there is no additional overload of the rotation axis. The hydraulic cylinder rods are hingedly attached to the span, which includes special transverse beams (7) with brackets (8). In the room, inside the support of the adjustable span, there are the main pump installations, which ensure opening in 4 minutes, as well as spare pumping installations operating from an autonomous power plant.
The support posts (9), on which the span rests in the closed state, simultaneously serve as a mechanism for unloading the wing rotation axes (Fig. 9.12). When the wing is open, the pillars are located obliquely, and the span rests on the axis of rotation. During closing, when the wing approaches a horizontal position, the strut is brought to the wing using a special rod and engages with the supporting part attached to the lower chord of the main beam. At this moment, the support strut has a slight inclination to the vertical, and the wing - to the horizontal. With further movement, which is facilitated by the imbalance of the wing, the stand rises to a vertical position. In this case, the wing is raised by approximately 5 mm, the axis of rotation is unloaded, and a gap is formed in the bearing of the rotation axis.
Rice. 9.12 - Support stand: 1 - axis of rotation; 2 - clearance under the bearing; 3 - stand for the axis of rotation; 4 - support post after opening; 5 - thrust; 6 - support post in closed position; 7 - support
To soften the impact when the wing approaches the maximum opening position, buffer devices (6) made of rubber are provided, and to fix the wing in the open position, automatic hydraulic locks (5) are provided in the form of retractable bolts in the recesses at the ends of the main beams (see Fig. 9.11) .
An example of a vertical lift bridge design
The design of the railway bridge span was developed by Lengiprotransmost in 1978. According to navigation conditions, the passage of large ships requires a bridge opening of 40 m and a lifting height of 30 m (Fig. 9.13).
Rice. 9.13 - Vertically lifting movable span structure
A standard span structure (10) with a span of 44.8 m was used as a lifting structure with the addition of elements necessary to lift it to position (9). The lifting span towers are located on adjacent spans and have welded elements with mounting connections on friction bolts (steel 15HSND). The front racks of the towers (6) are vertical, box-shaped. Significant efforts are transferred to them. The inclined rear pillars (1), like the lattice elements of the longitudinal vertical trusses of the towers, have an H-shaped section.
In the transverse planes there are connections (11), and, in addition, in the horizontal planes in each node of the towers there are cross transverse connections. The top of the tower is a beam cage supported on the front (4) and rear (2) transverse beams. The bearings of pulleys (3) having a diameter of 2700 mm rest on the head. Each pulley has a toothed ring on one side, with which a drive gear is engaged, driven by an electric motor through a gearbox. The gears of two pulleys on one tower are located on one common shaft. To synchronize the lifting of both ends of the span, a device called an electric shaft is used, which requires laying cables connecting the drive motors on both towers. In order to avoid laying cables under water, a lightweight cable bridge (8) is used.
The span structure is balanced using counterweights (5), consisting of metal frames with monolithic concrete filling and removable reinforced concrete slabs for precise weight adjustment. Provision is made for hanging counterweights from the head beams using steel belts to unload the ropes during repairs. Suspension cables (7), 10 on each pulley, connect the span and counterweights (cable type 37-G-V-ZhS-O-N-140). The cables are attached to the lifting beam (12), located in node B1 of the span.
The span is equipped with additional devices (Fig. 9.14). Suspension cables are attached to the lifting beam (1) through threaded steel rods screwed into anchor cups (11) and having nuts (3) at the ends to adjust the length of each cable. It can be adjusted using adjustable hydraulic jacks (4) from a special bridge (5). When the cables approach the lifting beam, they are separated on both sides by steel deflection castings (2). To prevent the span from swinging on the cables during lifting, there are guide devices in the form of eight clips with rollers attached to the span. During lifting, the rollers roll along the guide plates of the towers. In the plane of the lower chord, in the support units of one end of the span, clips with three rollers (9) are installed, preventing the movement of the span in both the longitudinal and transverse directions. The remaining support units of the upper and lower chords are equipped with cages with one roller (10), which only prevent transverse movements. This ensures a stable position of the span during lifting and freedom of temperature movements of the support units. Pneumatic buffer devices (8) are attached to the supporting transverse beam of the lifting span to prevent impacts when lowering the span. To accurately fix the span in the transverse direction, a centering device (7) is used, attached to the support, which includes a protrusion with bevels attached to the supporting transverse beam.
Rice. 9.14 - Details of the movable span
The weight of the lifting span is 2.23 MN; it is not completely balanced by counterweights. The span is 40 kN heavier than the counterweights; in addition, the unbalanced part of the cables when the span is lowered is 66 kN, which creates a stable position of the span in the closed state. For additional guarantee against spontaneous lifting of the span, for example from the action of rising wind, span locks are provided. After lowering the span, the lock bolt (6) moves with the help of a mechanical drive (12) in the longitudinal direction and enters the cutouts of the centering device box,
The railway track on the span is built on metal crossbars. For precise alignment of the rail track on the movable and fixed spans, rail locks are provided.
The duration of lifting by the main drive is 2 minutes. In addition to the main one, there is a spare drive with an autonomous power plant (lifting time 17 minutes) and a manual emergency drive (lifting time 150 minutes). The power of the main and synchronizing drives is 45 - 22 = 67 kW.
The utility model relates to the field of bridge construction and can be used in the construction of road cable-stayed drawbridges, usually in cities across wide navigable rivers. The technical objective of the utility model is to reduce material and financial costs for the construction of a cable-stayed drawbridge, as well as to use all the hollow pylon struts in the navigable span simultaneously and as lifting supports for the vertical movement of the drawbridge to the design level. The technical problem is solved due to the fact that a cable-stayed vertical lift bridge, consisting of cable-stayed girder spans, has a vertical lift span and two pylons with four hollow racks in the navigable span, differs in that all pylon racks in the navigable span are used as lifting supports, inside of which there are counterweights, traction winches and rope-pulley systems for moving the span upwards. In this case, all the pylon posts at the top are rigidly connected to each other along the facade and across the bridge by horizontal metal beams, which are used as pedestrian bridges. At the same time, people are lifted onto them by special observation elevators located outside all pylon posts.
The utility model relates to the field of bridge construction and can be used in the construction of road cable-stayed drawbridges, usually in cities across wide navigable rivers.
Various designs of large and extra-class cable-stayed fixed bridges across wide and deep navigable rivers and straits are known (Byte bridges. A.A. Petrovsky and others - M.: Transport, 1985. Metal bridges. N.N. Bychkovsky, A.F. Dankovtsev. In 2 parts. Saratov, 2005. In 2 kN. P.M. Salamakhin and others. - Academy, 2008. Journal of bridge construction. ).
To ensure a navigable height clearance (up to 70 m or more), high supports are built, which requires significant material and financial costs for the bridge itself and for the construction of long overpass structures to them in order to provide the design slopes for vehicle access to the bridge. However, such solutions are not always possible due to the lack of necessary territories, especially in the cramped conditions of urban development on the banks of a water barrier.
The design of a metal cable-stayed single-pylon drawbridge is also known (Patent for utility model 118319 dated July 20, 2012 “Metal cable-stayed single-pylon drawbridge”), in which the part of the cable-stayed beam span (VBPS) above the shipway, adjacent directly to the pylon, is opening by rotating it upward around a horizontal axis using counterweights of a rope-pulley system and traction winches. These elements are placed inside both hollow pylon posts (reinforced concrete or metal).
The main disadvantage of a cable-stayed bridge is the following: during the erection of the bridge, the fixed part of the VBPS is kept from horizontal shift by its cables to the pylon with a special rigid metal stop placed in the bridge abutment. In addition, the fixed part of the VBPS in the open position of the bridge may have (like a cantilever) significant transverse vibrations (amplitudes) when exposed to wind, which will complicate the process of disconnecting and connecting the adjustable and fixed parts of the VBPS. The consequence of this may be the impossibility of raising the bridge in strong winds.
There are also known designs of vertical lift bridges (for example, across the Neva, Northern Dvina, Svir and other rivers), in the navigable spans of which there are beam spans and two lift towers with elements of a rope-pulley system and guides for the vertical movement of the span. buildings [Drawbridges. V.I. Kryzhanovsky - M.: Transport, 1967].
The main disadvantage of the vertical lift bridge adopted as a prototype is the limitation of the navigable clearance in height. When the height of the towers is greater than the width of the navigable span, such bridges become unprofitable due to the high cost of installing lifting towers.
The technical objective of the utility model is to reduce material and financial costs for the construction of a cable-stayed drawbridge, as well as to use all the hollow pylon struts in the navigable span simultaneously and as lifting supports for the vertical movement of the drawbridge to the design level.
The technical problem is solved due to the fact that a cable-stayed vertical lift bridge, consisting of cable-stayed girder spans, has a vertical lift span and two pylons with four hollow racks in the navigable span, differs in that all pylon racks in the navigable span are used as lifting supports, inside of which there are counterweights, traction winches and rope-pulley systems for moving the span upwards. In this case, all the pylon posts at the top are rigidly connected to each other along the facade and across the bridge by horizontal metal beams, which are used as pedestrian bridges. At the same time, people are lifted onto them by special observation elevators located outside all pylon posts.
The utility model is illustrated in the drawing, where in FIG. Figure 1 shows a diagram of a fragment of a cable-stayed bridge with a navigable span, where it is indicated:
a - section of the pylon stand with a counterweight placed in it, a traction winch and a rope-pulley system for lifting the span;
b - general view of the bridge façade of the pylon strut with the cables of the fan system and the observation elevator;
c - cross section of the bridge in the navigable span;
d - top view of the pylon support and parts of the lifting and cable-stayed beam spans;
1 - cable-stayed beam spans;
2 - lifting span;
4 - pylon stands;
5 - stiffening beams;
6 - panoramic elevators;
7 - observation pavilions on the heads of the pylon posts;
8 - counterweight;
9 - traction winch;
10 - support beam;
11 - pulley rollers;
12 - consoles for lifting (jacking) beams of the lifting span;
13 - supporting parts;
14 - pylon support.
Cable-stayed vertical lift bridge is an extended structure consisting of several cable-stayed-beam spans 1 and at least one vertical-lifting span 2 in the navigable span, as well as several pylon supports 14. The cable-stayed-beam spans 1 are supported by cables 3 of the fan system. The pillars of the pylons 4 at the top are rigidly connected to each other along the façade and across the bridge by metal beams.
A cable-stayed vertical lift bridge works as follows. The lifting span 2 moves upward using counterweights 8, traction winches 9, a rope-pulley system consisting of steel ropes (cables), various rollers 11, some of which are fixed on the support beam 10 and on four consoles 12 of the span 2.
In the lower (unraised) position, spans 1 and 2 rest on supporting parts 13 placed on pylon supports 14 of the navigable span.
During the raising of the bridge, pedestrians, as well as maintenance personnel, can move from one part of the bridge to another along stiffening beams 5, on which decking and railings are installed. Lifting people onto the tops of the pylon posts 4 is carried out by panoramic elevators 6, which are attached to the facade surfaces of the posts 4. Pavilions 7 (or canopies) with fences can be mounted on the tops of the posts 4. These pavilions (or canopies) can also be used as observation platforms.
The mass of counterweights, the power of winches, and pulleys are calculated based on data on the length and mass of the lifting span.
The utility model expands the scope of use of pylon struts and simplifies the design of supports in a navigable span.
1. Cable-stayed vertical lift bridge, consisting of cable-stayed girder spans and having a vertical lift span in the navigable span and two pylons with four hollow racks, characterized in that all pylon racks in the navigable span are used as lifting supports, inside which are placed counterweights, traction winches and rope-pulley systems for moving the span upwards.
2. Cable-stayed vertical lift bridge according to claim 1, characterized in that all the pylon racks at the top are rigidly connected to each other along the facade and across the bridge by horizontal metal beams, which are used as pedestrian bridges, while lifting people onto them is carried out by special observation elevators located outside all pylon posts.
The impressive Lower Hatea Crossing (Te Matau a Pohe) bridge was opened on 27 July 2013 by Whangarei MP Phil Heatley in New Zealand.
Lower Hatea Crossing is a 265 meter long and 17 meter wide highway bridge that crosses the Hatea River and connects Pohe Island and Port Road. It consists of nine middle spans of 25m each and two extreme ones of 20m each.
The bridge is two-lane, the width of each lane is 4.1 m, on one side of the bridge there is a pedestrian sidewalk 2.5 m wide, on the other side a bicycle path 3 m wide.
The bridge was built to ease congestion in the city center and improve access to Whangarei Heads and the airport, making it a key bridge on Whangarei's trunk road network. It is expected that it will handle up to 8,000 cars per day. The bridge project belongs to the English consulting company Knight Architects.
Te Matau a Pohe is movable, its 25m central span is raised when ships pass, but this is not done for all ships. Many boats pass freely under the bridge without raising the span. To allow vessels over 7.5m in height to pass, you must send a request via radiogram to raise the span or call. Vessels awaiting this lifting are moored to pontoons on either side of the bridge.
This swing bridge is a swing bridge, the first of its kind in New Zealand. Such bridges are quite rare outside the United States. This system was chosen because the required span opening clearance is achieved faster than in other drawbridges, due to the fact that the span rolls back and rotates at the same time. And such a quick rise reduces the waiting time for tourists on the bridge.
Since access to the bridge site was not easy, due to shallow water and tidal action that prevented the movement of large floating equipment, as well as limited road access to the site, the developers decided to use prefabricated and prefabricated modular elements that could be shipped and installed appropriate mechanisms.
The bridge is formed from precast concrete units, while the lift span consists of two steel structures: J-shaped beams that are mounted on an orthotropic welded steel slab and two cantilever slabs made of aluminum. The lightweight orthotropic slab is unique to New Zealand and reflects the international state of the art.
Thus, counterweights located at the top of the J-shaped beam maintain balance from the weight of the orthotropic slab and minimize the power required to lower the span.
The lifting span is driven by hydraulic cylinders, which have holes of 320mm, rods with a diameter of 280mm, a working stroke of 8380mm and a weight of 8 tons each.
These 400 ton span raising and lowering cylinders were made in Holland by the Eadon Corporation - one of the few factories in the world that can produce cylinders of this size and quality. Power is supplied to the cylinders by four 30 kW hydraulic units driving pumps.
The hydraulic cylinders are based on a support, which is reinforced with prestressed reinforcement extending down on both sides from monolithic V-shaped racks. The supports, in turn, rest on shell piles.
New Zealand is known for its earthquakes, so the bridge uses fixed connections between the bridge slab and the abutments and monolithic abutments, which have the added benefit of increasing stability on each side of the bridge. This design also has the advantage of helping to protect the bridge from the impact loads of ships. Most of the vessels currently used on the river are light, but in the future it is planned to operate 350t barges.
The lift span is designed to operate in stormy wind conditions, but the bridge is still not opened during stormy winds and during rush hours.
There are very few new swing-open bridges in the world, and even fewer that open using hydraulic cylinders. New Zealand has very few swing bridges at all and so this is a real achievement for their infrastructure. And the curved shape of the J-beams also has a cultural context and is interpreted as a “fish hook”, which is widely used in Maori culture. The shape is designed to be recognizable both day and night, providing a precise entrance to the urban water area.
The bridge was built by McConnell Dowell and Transfield.
The cost of the bridge was 32 million New Zealand dollars.
a bridge over the fortress moat, rising in the event of an enemy attack and blocking access to the fortress. (Architecture: An Illustrated Guide, 2005)
View value Drawbridge in other dictionaries
Bridge- m. platform, laying, steel, roll, all kinds of continuous flooring made of boards, logs, beams, for riding and for walking; a continuous building across a river or ravine for crossing;........
Dahl's Explanatory Dictionary
Bridge- bridge (bridge region), about the bridge, on the bridge, pl. bridges, m. 1. A structure connecting two points on the earth’s surface, separated by water, a ditch or some other thing. other obstacle and giver........
Ushakov's Explanatory Dictionary
Lifting— rise, etc. see lift.
Dahl's Explanatory Dictionary
Bridge M.— 1. A structure for crossing, crossing a river, ravine, railway track, etc. // transfer That which connects something is the link between someone or something. 2. Platform,......
Explanatory Dictionary by Efremova
lifting adj.— 1. Correlative in meaning. with noun: a rise associated with it. 2. Characteristic of the rise (1.6), characteristic of it. 3. Constructed so that it can be lifted; rising.
Explanatory Dictionary by Efremova
Lifting- lifting, lifting. 1. An employee for lifting (see lifting in 1 value). tap. Lifting machine. 2. Adj., by value. associated with lifting, lifting something. weight. Lifting work.........
Ushakov's Explanatory Dictionary
Bank-bridge — -
a bank that has received a license to accept assets and liabilities of the bank -
bankrupt.
Economic dictionary
Bridge- -a and -a, sentence. about the bridge, on the bridge; pl. bridges, -ov; m.
1. A structure for crossing, crossing a river, ravine, railway track, etc. Zheleznodorozhny metro station Pontonny........
Kuznetsov's Explanatory Dictionary
Credit bridge — -
short
loan for operating
expenses or to resolve an urgent financial problem.
Economic dictionary
Lifting- oh, oh.
1. to Rise. Pth works. Pth strength of the ship. P. weight. Pth road. P. tap. P. mechanism.
2. Constructed so that it can be lifted. P frame. P. bridge, curtain.
Kuznetsov's Explanatory Dictionary
Interim Loan; Lit. - Loan-bridge— A short-term loan provided in anticipation of medium or long-term financing.
Economic dictionary
Bridge - Bridge- a device that connects two or more physical networks and transmits
packets from one network to another. Used to connect networks using different
........
Economic dictionary
Bridge- A common Slavic word that apparently goes back to the same basis as the verb to throw - “to throw.” Literally, “thrown over something.” According to another etymological........
Krylov's etymological dictionary
Pons- (pons Varolii; S. Varolio, 1543-1575, Italian anatomist) see Bridge.
Large medical dictionary
Adam's Bridge- a chain of shallows and coral islands between the Hindustan Peninsula and Io. Sri Lanka. Length 30 km. According to legend, Adam, expelled from paradise to earth (on the island of Sri Lanka), walked across Adam's Bridge to the mainland.
Pons- (pons of the brain), the upper part of the BRAINSTEM in humans. Contains nerve fibers connecting the two halves of the CEREBELLUM. Being the lower part of the cerebrum, the brainstem........
Bridge- in dentistry - a prosthesis that reproduces part of the teeth, which is secured with hooks on adjacent teeth. Depending on the circumstances, the bridge may be permanent........
Scientific and technical encyclopedic dictionary
Wheatstone Bridge— (measuring bridge), an electrical circuit used to measure resistance; named after Charles WHISTON. Consists of four resistances connected........
Scientific and technical encyclopedic dictionary
Suspension Bridge- a bridge whose deck is suspended by one or more CABLES, usually passing through raised pylons (towers) and firmly fixed at the ends. The cables consist of......
Scientific and technical encyclopedic dictionary
Lifting Magnet- , a powerful ELECTROMAGNET used for lifting and carrying heavy metal objects. Such a magnet is hung on the crane boom.
Scientific and technical encyclopedic dictionary
Cable-stayed Bridge- a suspension bridge in which the main supporting structure - the truss - is made of steel cables (cables).
Large encyclopedic dictionary
Brain Bridge- (pons; PNA, BNA, JNA; synonym pons) part of the brain located between the medulla oblongata and the cerebral peduncles.
Large medical dictionary
Rear Axle- a set of components of self-propelled machines (for example, a car, a tractor), usually transmitting torque from the propeller shaft or gearbox and vertical load to the mover.......
Large encyclopedic dictionary
Measuring Bridge- a device for measuring electrical resistance, capacitance, inductance, etc. by comparison with a standard measure; made according to a bridge circuit with a galvanometer........
Large encyclopedic dictionary
Floating bridge— a bridge on floating supports (pontoons, rafts, barges). It is built on wide and deep rivers, when constructing a bridge on permanent supports is technically difficult and unprofitable.
Large encyclopedic dictionary
Front Axle- (front axle) - a complex of components of wheeled self-propelled vehicles that receives vertical load from the body (frame) through the suspension and transmits it to the steered wheels,......
Large encyclopedic dictionary
Crane— see Load-lifting crane.
Large encyclopedic dictionary
Drawbridge— has a movable span structure (rotary, vertically lifting, drop-down, rocker, sliding), usually constructed for the passage of ships.
