Misplaced Pages

#224775

105-601: The John A. Roebling Suspension Bridge (formerly the Cincinnati-Covington Bridge ) is a suspension bridge that spans the Ohio River between Cincinnati , Ohio, and Covington, Kentucky . When opened on December 1, 1866, it was the longest suspension bridge in the world at 1,057 feet (322 m) main span, which was later overtaken by John A. Roebling 's most famous design of the 1883 Brooklyn Bridge at 1,595.5 feet (486.3 m). Pedestrians use

210-430: A centrifugal pump . The fluid enters along the axis or center, is accelerated by the impeller and exits at right angles to the shaft (radially); an example is the centrifugal fan , which is commonly used to implement a vacuum cleaner . Another type of radial-flow pump is a vortex pump. The liquid in them moves in tangential direction around the working wheel. The conversion from the mechanical energy of motor into

315-410: A cable-stayed bridge in which the deck is in compression. Cable-stayed bridges and suspension bridges may appear to be similar, but are quite different in principle and in their construction. In suspension bridges, large main cables (normally two) hang between the towers and are anchored at each end to the ground. The main cables, which are free to move on bearings in the towers, bear the load of

420-422: A freestone finish. Eleven-ton iron anchors were embedded in each block, securing cables with wrought iron chain links of Roebling's patent. The Civil War depleted the work force on the project, hindering speed and efficiency until its end. Work on the bridge proceeded steadily after the end of the war. In September 1865 the first two wire ropes were laid. They were unwound from a spool on a barge, allowed to sink to

525-460: A 200 feet span (also termed Beose Bridge) was constructed near Sagar, India during 1828–1830 by Duncan Presgrave, Mint and Assay Master. The Clifton Suspension Bridge (designed in 1831, completed in 1864 with a 214 m central span), is similar to the Sagar bridge. It is one of the longest of the parabolic arc chain type. The current Marlow suspension bridge was designed by William Tierney Clark and

630-492: A bridge has a tendency to collapse simply because of the gravitational forces acting on the materials of which the bridge is made. Live load refers to traffic that moves across the bridge as well as normal environmental factors such as changes in temperature, precipitation, and winds. Dynamic load refers to environmental factors that go beyond normal weather conditions, factors such as sudden gusts of wind and earthquakes. All three factors must be taken into consideration when building

735-468: A bridge. Silver Bridge (USA) was an eyebar chain highway bridge, built in 1928, that collapsed in late 1967, killing forty-six people. The bridge had a low-redundancy design that was difficult to inspect. The collapse inspired legislation to ensure that older bridges were regularly inspected and maintained. Following the collapse a bridge of similar design was immediately closed and eventually demolished. A second similarly-designed bridge had been built with

840-788: A bridge. The principles of suspension used on a large scale also appear in contexts less dramatic than road or rail bridges. Light cable suspension may prove less expensive and seem more elegant for a cycle or footbridge than strong girder supports. An example of this is the Nescio Bridge in the Netherlands, and the Roebling designed 1904 Riegelsville suspension pedestrian bridge across the Delaware River in Pennsylvania. The longest pedestrian suspension bridge, which spans

945-464: A curved spiral wound around of thickness half x , though in reality it is manufactured in a single casting. This shaft fits inside a heavy-duty rubber sleeve, of wall thickness also typically x . As the shaft rotates, the rotor gradually forces fluid up the rubber sleeve. Such pumps can develop very high pressure at low volumes. Named after the Roots brothers who invented it, this lobe pump displaces

1050-414: A ferry market, and depreciation of property. The Ohio legislature refused the charter of the bridge. In September, Roebling published a 36-page report containing a technical discussion and an analysis of said problems. He attacked steamboat operators for using oversized chimneys, speculated on future commercial interests, and surmised on the importance of spanning western rivers. Roebling also specified that

1155-530: A gentle pumping process ideal for transporting shear-sensitive media. Devised in China as chain pumps over 1000 years ago, these pumps can be made from very simple materials: A rope, a wheel and a pipe are sufficient to make a simple rope pump. Rope pump efficiency has been studied by grassroots organizations and the techniques for making and running them have been continuously improved. Impulse pumps use pressure created by gas (usually air). In some impulse pumps

SECTION 10

#1732775757225

1260-403: A higher margin of safety and remained in service until 1991. The Tacoma Narrows Bridge , (USA), 1940, was vulnerable to structural vibration in sustained and moderately strong winds due to its plate-girder deck structure. Wind caused a phenomenon called aeroelastic fluttering that led to its collapse only months after completion. The collapse was captured on film. There were no human deaths in

1365-425: A higher hydraulic-head and lower flow-rate. The device uses the water hammer effect to develop pressure that lifts a portion of the input water that powers the pump to a point higher than where the water started. The hydraulic ram is sometimes used in remote areas, where there is both a source of low-head hydropower, and a need for pumping water to a destination higher in elevation than the source. In this situation,

1470-404: A much heavier load than was originally demanded. In 1896, the bridge received a second set of main cables, a wider steel deck, and a longer northern approach. The reconstruction significantly altered the appearance of the bridge, but the new 30-ton weight limit extended its usefulness through the 20th century and beyond. In 1901, electric lighting was added to the bridge. In 1918, an extension of

1575-518: A myriad of markets across the world. Triplex pumps with shorter lifetimes are commonplace to the home user. A person who uses a home pressure washer for 10 hours a year may be satisfied with a pump that lasts 100 hours between rebuilds. Industrial-grade or continuous duty triplex pumps on the other end of the quality spectrum may run for as much as 2,080 hours a year. The oil and gas drilling industry uses massive semi-trailer-transported triplex pumps called mud pumps to pump drilling mud , which cools

1680-485: A pedestrian suspension bridge over the Machchhu River in the city of Morbi, Gujarat, India collapsed, leading to the deaths of at least 141 people. Pump#Reciprocating positive-displacement pumps Mechanical pumps serve in a wide range of applications such as pumping water from wells , aquarium filtering , pond filtering and aeration , in the car industry for water-cooling and fuel injection , in

1785-647: A proposal by Robert Stevenson for a bridge over the River Almond near Edinburgh . Roebling's Delaware Aqueduct (begun 1847) consists of three sections supported by cables. The timber structure essentially hides the cables; and from a quick view, it is not immediately apparent that it is even a suspension bridge. The main suspension cables in older bridges were often made from a chain or linked bars, but modern bridge cables are made from multiple strands of wire. This not only adds strength but improves reliability (often called redundancy in engineering terms) because

1890-574: A pulsation damper. The increase in moving parts and crankshaft load is one drawback. Car washes often use these triplex-style plunger pumps (perhaps without pulsation dampers). In 1968, William Bruggeman reduced the size of the triplex pump and increased the lifespan so that car washes could use equipment with smaller footprints. Durable high-pressure seals, low-pressure seals and oil seals, hardened crankshafts, hardened connecting rods, thick ceramic plungers and heavier duty ball and roller bearings improve reliability in triplex pumps. Triplex pumps now are in

1995-477: A return line back to the suction line or supply tank, provides increased safety . A positive-displacement pump can be further classified according to the mechanism used to move the fluid: These pumps move fluid using a rotating mechanism that creates a vacuum that captures and draws in the liquid. Advantages: Rotary pumps are very efficient because they can handle highly viscous fluids with higher flow rates as viscosity increases. Drawbacks: The nature of

2100-541: A sequence generally described as follows. Depending on length and size, construction may take anywhere between a year and a half (construction on the original Tacoma Narrows Bridge took only 19 months) up to as long as a decade (the Akashi-Kaikyō Bridge's construction began in May 1986 and was opened in May 1998 – a total of twelve years). Suspension bridges are typically ranked by the length of their main span. These are

2205-414: A slight increase in internal leakage as the pressure increases prevents a truly constant flow rate. A positive-displacement pump must not operate against a closed valve on the discharge side of the pump, because it has no shutoff head like centrifugal pumps. A positive-displacement pump operating against a closed discharge valve continues to produce flow and the pressure in the discharge line increases until

SECTION 20

#1732775757225

2310-499: A temporary walkway. Poured sockets are used to make a high strength, permanent cable termination. They are created by inserting the suspender wire rope (at the bridge deck supports) into the narrow end of a conical cavity which is oriented in-line with the intended direction of strain. The individual wires are splayed out inside the cone or 'capel', and the cone is then filled with molten lead-antimony-tin (Pb80Sb15Sn5) solder. Most suspension bridges have open truss structures to support

2415-425: Is a more complicated type of rotary pump that uses two or three screws with opposing thread — e.g., one screw turns clockwise and the other counterclockwise. The screws are mounted on parallel shafts that often have gears that mesh so the shafts turn together and everything stays in place. In some cases the driven screw drives the secondary screw, without gears, often using the fluid to limit abrasion. The screws turn on

2520-400: Is a type of positive-displacement pump. It contains fluid within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A number of rollers , shoes , or wipers attached to a rotor compress the flexible tube. As the rotor turns, the part of the tube under compression closes (or occludes ), forcing the fluid through the tube. Additionally, when

2625-425: Is called a multi-stage pump . Terms such as two-stage or double-stage may be used to specifically describe the number of stages. A pump that does not fit this description is simply a single-stage pump in contrast. In biology, many different types of chemical and biomechanical pumps have evolved ; biomimicry is sometimes used in developing new types of mechanical pumps. Mechanical pumps may be submerged in

2730-645: Is considered the last remaining Inca rope bridge and is rebuilt annually. The first iron chain suspension bridge in the Western world was the Jacob's Creek Bridge (1801) in Westmoreland County, Pennsylvania , designed by inventor James Finley . Finley's bridge was the first to incorporate all of the necessary components of a modern suspension bridge, including a suspended deck which hung by trusses. Finley patented his design in 1808, and published it in

2835-414: Is how they operate under closed valve conditions. Positive-displacement pumps physically displace fluid, so closing a valve downstream of a positive-displacement pump produces a continual pressure build up that can cause mechanical failure of pipeline or pump. Dynamic pumps differ in that they can be safely operated under closed valve conditions (for short periods of time). Such a pump is also referred to as

2940-402: Is the simplest form of rotary positive-displacement pumps. It consists of two meshed gears that rotate in a closely fitted casing. The tooth spaces trap fluid and force it around the outer periphery. The fluid does not travel back on the meshed part, because the teeth mesh closely in the center. Gear pumps see wide use in car engine oil pumps and in various hydraulic power packs . A screw pump

3045-655: The Champion No.1 . The homemade pumps displaced forty gallons of mud and clay in each cycle. When the crews reached the compacted gravel bed of the Ohio River, Roebling decided this would be sufficient for the foundation of the Cincinnati tower. Oak timbers were laid, mirroring the foundation of the Covington tower, and within three months, masonry on both towers reached above the waterline (which, at this time,

3150-540: The Civil War began in January 1861. Upon a threatened siege of Cincinnati from Confederate forces, a pontoon bridge was built to span the Ohio River, allowing Union troops to cross and construct defenses. Soon after, once it had become obvious that a permanent structure was vital, money from investors came pouring in. Bonds were sold, and in January 1863 materials began arriving. In the interest of building more quickly,

3255-836: The Mahakam River , located in Kutai Kartanegara Regency , East Kalimantan district on the Indonesia island of Borneo , was built in 1995, completed in 2001 and collapsed in 2011. Dozens of vehicles on the bridge fell into the Mahakam River . As a result of this incident, 24 people died and dozens of others were injured and were treated at the Aji Muhammad Parikesit Regional Hospital. Meanwhile, 12 people were reported missing, 31 people were seriously injured, and 8 people had minor injuries. Research findings indicate that

John A. Roebling Suspension Bridge - Misplaced Pages Continue

3360-519: The deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges , which lack vertical suspenders, have a long history in many mountainous parts of the world. Besides the bridge type most commonly called suspension bridges, covered in this article, there are other types of suspension bridges . The type covered here has cables suspended between towers , with vertical suspender cables that transfer

3465-500: The energy industry for pumping oil and natural gas or for operating cooling towers and other components of heating, ventilation and air conditioning systems. In the medical industry , pumps are used for biochemical processes in developing and manufacturing medicine, and as artificial replacements for body parts, in particular the artificial heart and penile prosthesis . When a pump contains two or more pump mechanisms with fluid being directed to flow through them in series, it

3570-448: The live and dead loads of the deck below, upon which traffic crosses. This arrangement allows the deck to be level or to arc upward for additional clearance. Like other suspension bridge types, this type often is constructed without the use of falsework . The suspension cables must be anchored at each end of the bridge, since any load applied to the bridge is transformed into tension in these main cables. The main cables continue beyond

3675-539: The potential energy of flow comes by means of multiple whirls, which are excited by the impeller in the working channel of the pump. Generally, a radial-flow pump operates at higher pressures and lower flow rates than an axial- or a mixed-flow pump. These are also referred to as all-fluid pumps . The fluid is pushed outward or inward to move fluid axially. They operate at much lower pressures and higher flow rates than radial-flow (centrifugal) pumps. Axial-flow pumps cannot be run up to speed without special precaution. If at

3780-670: The 1950s the US Army Corps of Engineers replaced the outdated system with new non-navigable dams made of concrete and steel. These dams raised the height of the river at Cincinnati to a normal pool of about 26 feet, lowering the clearance of the Roebling Suspension Bridge to around 74 feet. The Covington-Cincinnati Bridge Company—a private company—operated the bridge until the Commonwealth of Kentucky purchased it in 1953 for $ 4.2 million. Soon after this,

3885-473: The Cincinnati side, work was delayed from the start. The construction crews could not pump water out of the excavating pit fast enough. After months of little progress, Roebling decided against buying costly machinery or bigger engines for his pumps and, quite last minute, designed his own square positive displacement pumps from three-inch (76 mm) pine planks. He built them locally in about forty-eight hours and ran them off of one of Amos Shinkles' tugboats ,

3990-777: The Philadelphia journal, The Port Folio , in 1810. Early British chain bridges included the Dryburgh Abbey Bridge (1817) and 137 m Union Bridge (1820), with spans rapidly increasing to 176 m with the Menai Bridge (1826), "the first important modern suspension bridge". The first chain bridge on the German speaking territories was the Chain Bridge in Nuremberg . The Sagar Iron Suspension Bridge with

4095-552: The River Paiva, Arouca Geopark , Portugal, opened in April 2021. The 516 metres bridge hangs 175 meters above the river. Where such a bridge spans a gap between two buildings, there is no need to construct towers, as the buildings can anchor the cables. Cable suspension may also be augmented by the inherent stiffness of a structure that has much in common with a tubular bridge . Typical suspension bridges are constructed using

4200-482: The Roebling Bridge was formally opened on January 1, 1867, the driver of a horse and buggy was charged a toll of 15 cents to cross; the toll for three horses and a carriage was 25 cents. Pedestrians were charged one cent. The bridge was repainted blue in 1894. The original deck of the bridge was built at the lowest possible cost because of Civil War inflation, but the stone towers had been designed to carry

4305-553: The approach was completed to Third Street. Ramps were constructed leading directly from the bridge to the Dixie Terminal building used for streetcars in the late 1920s. These provided Covington– Cincinnati streetcars "with a grade-separated route to the center of downtown, and the terminal building was originally intended to connect, via underground pedestrian passages, with the never-built Fountain Square Station of

John A. Roebling Suspension Bridge - Misplaced Pages Continue

4410-440: The bottom of the river, then raised in unison from the riverbed. Wooden crossbeams were laid at regular intervals from the wire ropes, and a simple footbridge was constructed for the benefit of the workers. With the Ohio River "spanned," there was a final push to complete the project even through floods and freezing temperatures. The cabling of the bridge went at a feverish pace, with about eighty wires placed per day. Hundreds watched

4515-465: The bridge company purchased one million pounds of wire from Richard Johnson at Manchester, England , for the cables that would span the width of the river. Roebling had used Johnson's wire for one of his other bridges. He preferred it over wire made in the United States because it was of better quality and greater tensile strength . Anchorages on both shores were constructed of limestone base and

4620-589: The bridge company traveled to see Roebling, who was in Iowa, and he secured a contract to build the bridge. In September, Roebling arrived in Cincinnati, and much to his disgust, nothing was prepared. Excavation for the foundation of the Covington tower commenced in September 1856 and went smoothly. A foundation was set consisting of 13 layers of oak beams, each layer set perpendicular to the one beneath it, bolted with iron hardware, and finally all cemented into place. On

4725-432: The bridge deck. Before the deck is installed, the cables are under tension from their own weight. Along the main cables smaller cables or rods connect to the bridge deck, which is lifted in sections. As this is done, the tension in the cables increases, as it does with the live load of traffic crossing the bridge. The tension on the main cables is transferred to the ground at the anchorages and by downwards compression on

4830-469: The bridge location. This latter provision would later be regretted by everyone involved. The roads of Cincinnati and Covington were laid collinear with each other, in the hope that a bridge would be built sometime in the future. When the Ohio legislature decided to choose its own location for the bridge, it failed to pick such an obvious spot, hoping to defend Cincinnati's preeminence over Newport and Covington,

4935-455: The bridge reopened in November 2010. The closing of the bridge only affected vehicular traffic, while one pedestrian lane remained open. On January 10, 2013, a large piece of sandstone fell from the north tower causing the bridge to be closed for approximately 4 hours during rush hour. This time was used to remove debris and inspect the tower for further damage. On March 21, 2018, the bridge

5040-538: The bridge to get between the hotels, bars, restaurants, and parking lots in Northern Kentucky . The bar and restaurant district at the foot of the bridge on the Kentucky side is known as Roebling Point . In the mid-19th century, need of a passage over the Ohio River became apparent. Commerce between Ohio and Kentucky had increased to the point that the highly congested steamboat traffic was constricting

5145-527: The bridge was redecked to have a steel deck instead of the previous wooden one. When streetcar service ceased in the 1950s, the ramps onto the Dixie terminal were rebuilt to be used by diesel buses. The state collected tolls until 1963 when the Brent Spence Bridge was opened on Interstate 75 , downstream, approximately 0.6 miles (0.97 km) to the west of The Roebling Suspension Bridge. In

5250-491: The chains are not attached to abutments as is usual, but instead are attached to the main girders, which are thus in compression. Here, the chains are made from flat wrought iron plates, eight inches (203 mm) wide by an inch and a half (38 mm) thick, rivetted together. The first wire-cable suspension bridge was the Spider Bridge at Falls of Schuylkill (1816), a modest and temporary footbridge built following

5355-631: The collapse of James Finley's nearby Chain Bridge at Falls of Schuylkill (1808). The footbridge's span was 124 m, although its deck was only 0.45 m wide. Development of wire-cable suspension bridges dates to the temporary simple suspension bridge at Annonay built by Marc Seguin and his brothers in 1822. It spanned only 18 m. The first permanent wire cable suspension bridge was Guillaume Henri Dufour 's Saint Antoine Bridge in Geneva of 1823, with two 40 m spans. The first with cables assembled in mid-air in

SECTION 50

#1732775757225

5460-529: The collapse was largely caused by the construction failure of the vertical hanging clamp. It was also found that poor maintenance, fatigue in the cable hanger construction materials, material quality, and bridge loads that exceed vehicle capacity, can also have an impact on bridge collapse. In 2013 the Kutai Kartanegara Bridge rebuilt the same location and completed in 2015 with a Through arch bridge design. On 30 October 2022, Jhulto Pul ,

5565-522: The collapse; several drivers escaped their cars on foot and reached the anchorages before the span dropped. Yarmouth suspension bridge (England) was built in 1829 and collapsed in 1845, killing 79 people. Peace River Suspension Bridge (Canada), which was completed in 1943, collapsed when the north anchor's soil support for the suspension bridge failed in October 1957. The entire bridge subsequently collapsed. Kutai Kartanegara Bridge (Indonesia) over

5670-459: The company should make the decision as to the placement of the bridge along the river. Still, no charter was granted. After observing the construction of a suspension bridge upriver , in Wheeling, Virginia (later West Virginia), the legislature relented and passed the charter, mandating excessive dimensions such as a 1,400 feet (430 m) main span and requesting that the legislature determine

5775-686: The desired direction. In order for suction to take place, the pump must first pull the plunger in an outward motion to decrease pressure in the chamber. Once the plunger pushes back, it will increase the chamber pressure and the inward pressure of the plunger will then open the discharge valve and release the fluid into the delivery pipe at constant flow rate and increased pressure. Pumps in this category range from simplex , with one cylinder, to in some cases quad (four) cylinders, or more. Many reciprocating-type pumps are duplex (two) or triplex (three) cylinder. They can be either single-acting with suction during one direction of piston motion and discharge on

5880-444: The discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant through each cycle of operation. Positive-displacement pumps, unlike centrifugal , can theoretically produce the same flow at a given rotational speed no matter what the discharge pressure. Thus, positive-displacement pumps are constant flow machines . However,

5985-478: The drill bit and carries the cuttings back to the surface. Drillers use triplex or even quintuplex pumps to inject water and solvents deep into shale in the extraction process called fracking . Typically run on electricity compressed air, these pumps are relatively inexpensive and can perform a wide variety of duties, from pumping air into an aquarium , to liquids through a filter press . Double-diaphragm pumps can handle viscous fluids and abrasive materials with

6090-420: The early 1900s Congress authorized a system of locks and dams along the Ohio River. In 1929, the canalization project produced 51 wooden wicket dams and lock chambers along its length. This system assured that the depth of river at Cincinnati never fell below 9 feet. During the 1940s, a shift from steam propelled to diesel powered towboats allowed for longer barges than could be accommodated by the existing dams. In

6195-500: The economy. A solution that would not constrict traffic on the river even further was a wire cable suspension bridge of the type developed by French engineers . Several American engineers had begun designing and building suspension bridges. One of these men was John A. Roebling of Saxonburg, Pennsylvania . The Ohio River, however, was much wider than any river that had been bridged in France . The Covington and Cincinnati Bridge Company

6300-526: The failure of a few flawed strands in the hundreds used pose very little threat of failure, whereas a single bad link or eyebar can cause failure of an entire bridge. (The failure of a single eyebar was found to be the cause of the collapse of the Silver Bridge over the Ohio River .) Another reason is that as spans increased, engineers were unable to lift larger chains into position, whereas wire strand cables can be formulated one by one in mid-air from

6405-447: The fall of 1966, the bridges 100th anniversary was celebrated with a parade at Court Street. In 1969, the bridge was repairs. In 1976, in honor of America's bicentennial, the bridge was painted light blue. The bridge was designated a National Historic Landmark in 1975. It was designated a National Historic Civil Engineering Landmark in 1983. Initially called the "Covington-Cincinnati Suspension Bridge" or "Ohio River Bridge", it

SECTION 60

#1732775757225

6510-484: The floor, and check vibration . Wrought iron trusses were added, running the length of the bridge. On December 1, 1866, pedestrians walked upon the bridge, known locally only as "The Suspension Bridge," for the first time. Over 166,000 people walked across in the first two days. Final touches were put on the bridge over the next few months, and construction officially ended in July 1867. Two men died during construction. When

6615-452: The fluid changes by ninety degrees as it flows over an impeller, while in axial flow pumps the direction of flow is unchanged. An electromagnetic pump is a pump that moves liquid metal , molten salt , brine , or other electrically conductive liquid using electromagnetism . A magnetic field is set at right angles to the direction the liquid moves in, and a current is passed through it. This causes an electromagnetic force that moves

6720-418: The fluid they are pumping or be placed external to the fluid. Pumps can be classified by their method of displacement into electromagnetic pumps , positive-displacement pumps , impulse pumps , velocity pumps , gravity pumps , steam pumps and valveless pumps . There are three basic types of pumps: positive-displacement, centrifugal and axial-flow pumps. In centrifugal pumps the direction of flow of

6825-446: The fluid trapped between two long helical rotors, each fitted into the other when perpendicular at 90°, rotating inside a triangular shaped sealing line configuration, both at the point of suction and at the point of discharge. This design produces a continuous flow with equal volume and no vortex. It can work at low pulsation rates, and offers gentle performance that some applications require. Applications include: A peristaltic pump

6930-423: The gas trapped in the liquid (usually water), is released and accumulated somewhere in the pump, creating a pressure that can push part of the liquid upwards. Conventional impulse pumps include: Instead of a gas accumulation and releasing cycle, the pressure can be created by burning of hydrocarbons. Such combustion driven pumps directly transmit the impulse from a combustion event through the actuation membrane to

7035-410: The head of the cylinder. In the suction stroke, the plunger retracts and the suction valves open causing suction of fluid into the cylinder. In the forward stroke, the plunger pushes the liquid out of the discharge valve. Efficiency and common problems: With only one cylinder in plunger pumps, the fluid flow varies between maximum flow when the plunger moves through the middle positions, and zero flow when

7140-432: The highway, which may be supported by suspender cables or their own trusswork . In cases where trusswork supports the spans, there will be very little arc in the outboard main cables. The earliest suspension bridges were ropes slung across a chasm, with a deck possibly at the same level or hung below the ropes such that the rope had a catenary shape. The Tibetan siddha and bridge-builder Thangtong Gyalpo originated

7245-484: The infamous Cincinnati Subway ." At the time the Suspension Bridge was built, the Ohio River was very shallow, often only a few feet deep. A 100-foot vertical clearance was important as steamboats had high stacks to keep sparks as far as possible from the rest of the wooden craft. As more railroads were built and barges replaced steamboat traffic, dams to raise the river and control flooding made sense. In

7350-418: The line bursts, the pump is severely damaged, or both. A relief or safety valve on the discharge side of the positive-displacement pump is therefore necessary. The relief valve can be internal or external. The pump manufacturer normally has the option to supply internal relief or safety valves. The internal valve is usually used only as a safety precaution. An external relief valve in the discharge line, with

7455-409: The liquid. Applications include pumping molten solder in many wave soldering machines, pumping liquid-metal coolant, and magnetohydrodynamic drive . A positive-displacement pump makes a fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe. Some positive-displacement pumps use an expanding cavity on the suction side and a decreasing cavity on

7560-534: The live loads. In an underspanned suspension bridge, also called under-deck cable-stayed bridge, the main cables hang entirely below the bridge deck, but are still anchored into the ground in a similar way to the conventional type. Very few bridges of this nature have been built, as the deck is inherently less stable than when suspended below the cables. Examples include the Pont des Bergues of 1834 designed by Guillaume Henri Dufour ; James Smith's Micklewood Bridge; and

7665-639: The modern method was Joseph Chaley 's Grand Pont Suspendu in Fribourg , in 1834. In the United States, the first major wire-cable suspension bridge was the Wire Bridge at Fairmount in Philadelphia, Pennsylvania. Designed by Charles Ellet Jr. and completed in 1842, it had a span of 109 m. Ellet's Niagara Falls suspension bridge (1847–48) was abandoned before completion. It was used as scaffolding for John A. Roebling 's double decker railroad and carriage bridge (1855). The Otto Beit Bridge (1938–1939)

7770-678: The other, or double-acting with suction and discharge in both directions. The pumps can be powered manually, by air or steam, or by a belt driven by an engine. This type of pump was used extensively in the 19th century—in the early days of steam propulsion—as boiler feed water pumps. Now reciprocating pumps typically pump highly viscous fluids like concrete and heavy oils, and serve in special applications that demand low flow rates against high resistance. Reciprocating hand pumps were widely used to pump water from wells. Common bicycle pumps and foot pumps for inflation use reciprocating action. These positive-displacement pumps have an expanding cavity on

7875-406: The pillars to deck-level supports, and further continue to connections with anchors in the ground. The roadway is supported by vertical suspender cables or rods, called hangers. In some circumstances, the towers may sit on a bluff or canyon edge where the road may proceed directly to the main span. Otherwise, the bridge will typically have two smaller spans, running between either pair of pillars and

7980-480: The plunger is at the end positions. A lot of energy is wasted when the fluid is accelerated in the piping system. Vibration and water hammer may be a serious problem. In general, the problems are compensated for by using two or more cylinders not working in phase with each other. Centrifugal pumps are also susceptible to water hammer. Surge analysis , a specialized study, helps evaluate this risk in such systems. Triplex plunger pumps use three plungers, which reduces

8085-404: The pulsation relative to single reciprocating plunger pumps. Adding a pulsation dampener on the pump outlet can further smooth the pump ripple , or ripple graph of a pump transducer. The dynamic relationship of the high-pressure fluid and plunger generally requires high-quality plunger seals. Plunger pumps with a larger number of plungers have the benefit of increased flow, or smoother flow without

8190-475: The pump fluid. In order to allow this direct transmission, the pump needs to be almost entirely made of an elastomer (e.g. silicone rubber ). Hence, the combustion causes the membrane to expand and thereby pumps the fluid out of the adjacent pumping chamber. The first combustion-driven soft pump was developed by ETH Zurich. A hydraulic ram is a water pump powered by hydropower. It takes in water at relatively low pressure and high flow-rate and outputs water at

8295-469: The pump into the discharge pipe. This conversion of kinetic energy to pressure is explained by the First law of thermodynamics , or more specifically by Bernoulli's principle . Dynamic pumps can be further subdivided according to the means in which the velocity gain is achieved. These types of pumps have a number of characteristics: A practical difference between dynamic and positive-displacement pumps

8400-513: The pump requires very close clearances between the rotating pump and the outer edge, making it rotate at a slow, steady speed. If rotary pumps are operated at high speeds, the fluids cause erosion, which eventually causes enlarged clearances that liquid can pass through, which reduces efficiency. Rotary positive-displacement pumps fall into five main types: Reciprocating pumps move the fluid using one or more oscillating pistons, plungers, or membranes (diaphragms), while valves restrict fluid motion to

8505-413: The railing and the walking layer of Gyalpo's bridges used wires. The stress points that carried the screed were reinforced by the iron chains. Before the use of iron chains it is thought that Gyalpo used ropes from twisted willows or yak skins. He may have also used tightly bound cloth. The Inca used rope bridges , documented as early as 1615. It is not known when they were first made. Queshuachaca

8610-404: The ram is often useful, since it requires no outside source of power other than the kinetic energy of flowing water. Rotodynamic pumps (or dynamic pumps) are a type of velocity pump in which kinetic energy is added to the fluid by increasing the flow velocity. This increase in energy is converted to a gain in potential energy (pressure) when the velocity is reduced prior to or as the flow exits

8715-455: The requirement for the height of the main span was lowered to 100 feet (30 m). Preparations to resume construction were made. Machinery was ordered, and new derricks were built, but a renewed threat of invasion again temporarily halted progress. Finally, in the spring of 1863, work commenced and continued until the end of the year. In the spring of 1864, work resumed again. Although Roebling operated his own wire mill at Trenton, New Jersey ,

8820-531: The rival Kentucky cities. The bridge was actually located almost entirely in Kentucky because the state boundary follows the north bank of the river. It deprived Cincinnati forever of one of "the finest and most magnificent avenues on this continent." In 1854, a small suspension bridge over the Licking River at Newport, Kentucky , collapsed. This event deterred investors, and the bridge company could not raise enough money to start construction. Amos Shinkle

8925-612: The roadbed, particularly owing to the unfavorable effects of using plate girders, discovered from the Tacoma Narrows Bridge (1940) bridge collapse. In the 1960s, developments in bridge aerodynamics allowed the re-introduction of plate structures as shallow box girders , first seen on the Severn bridge , built 1961–1966. In the picture of the Yichang Bridge , note the very sharp entry edge and sloping undergirders in

9030-421: The shafts and drive fluid through the pump. As with other forms of rotary pumps, the clearance between moving parts and the pump's casing is minimal. Widely used for pumping difficult materials, such as sewage sludge contaminated with large particles, a progressing cavity pump consists of a helical rotor, about ten times as long as its width. This can be visualized as a central core of diameter x with, typically,

9135-519: The spider-like process from both shores. And on June 23, 1866, the last wire was taken across, for a total of 10,360 wires. These were subsequently compressed together and wrapped with an outer covering of wire into two cables of 5,180 wires each. Suspenders were hung from the cables by the end of August, and 600,000 feet (180,000 m) of oak lumber was laid as the floor across 300 wrought iron suspended beams. Two tracks for streetcars were laid. Diagonal stays were added to increase load capacity, strengthen

9240-496: The structure. It reopened in late March. However, it closed again for much of 2008 for repainting. On September 11, 2007, the Commonwealth of Kentucky reduced the weight limit to 11 tons to prevent future structural damage following an analysis by the University of Kentucky . The lower weight limit prevents buses from crossing the bridge. The Commonwealth of Kentucky once again closed the bridge on April 7, 2010, for repainting;

9345-469: The suction side and a decreasing cavity on the discharge side. Liquid flows into the pumps as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant given each cycle of operation and the pump's volumetric efficiency can be achieved through routine maintenance and inspection of its valves. Typical reciprocating pumps are: The positive-displacement principle applies in these pumps: This

9450-401: The suspension bridge shown. This enables this type of construction to be used without the danger of vortex shedding and consequent aeroelastic effects, such as those that destroyed the original Tacoma Narrows bridge. Three kinds of forces operate on any bridge: the dead load, the live load, and the dynamic load. Dead load refers to the weight of the bridge itself. Like any other structure,

9555-417: The suspension bridge to all vehicular traffic so additional safeguards could be put in place. The Roebling Bridge reopened on November 13, 2020, with Covington and Cincinnati police monitoring traffic on the bridge. On February 15, 2021, the bridge closed for a nine-month rehabilitation project; it reopened in November 2021. Suspension bridge A suspension bridge is a type of bridge in which

9660-514: The ten bridges with the longest spans, followed by the length of the span and the year the bridge opened for traffic: (Chronological) Broughton Suspension Bridge (England) was an iron chain bridge built in 1826. One of Europe's first suspension bridges, it collapsed in 1831 due to mechanical resonance induced by troops marching in step. As a result of the incident, the British Army issued an order that troops should "break step" when crossing

9765-489: The towers. In cable-stayed bridges, the towers are the primary load-bearing structures that transmit the bridge loads to the ground. A cantilever approach is often used to support the bridge deck near the towers, but lengths further from them are supported by cables running directly to the towers. By design, all static horizontal forces of the cable-stayed bridge are balanced so that the supporting towers do not tend to tilt or slide and so must only resist horizontal forces from

9870-399: The tube opens to its natural state after the passing of the cam it draws ( restitution ) fluid into the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract . Plunger pumps are reciprocating positive-displacement pumps. These consist of a cylinder with a reciprocating plunger. The suction and discharge valves are mounted in

9975-568: The use of iron chains in his version of simple suspension bridges . In 1433, Gyalpo built eight bridges in eastern Bhutan . The last surviving chain-linked bridge of Gyalpo's was the Thangtong Gyalpo Bridge in Duksum en route to Trashi Yangtse , which was finally washed away in 2004. Gyalpo's iron chain bridges did not include a suspended-deck bridge , which is the standard on all modern suspension bridges today. Instead, both

10080-423: The weight of the cables is small compared to the weight of the deck. One can see the shape from the constant increase of the gradient of the cable with linear (deck) distance, this increase in gradient at each connection with the deck providing a net upward support force. Combined with the relatively simple constraints placed upon the actual deck, that makes the suspension bridge much simpler to design and analyze than

10185-403: Was at a record low for the fall). Work halted for the freezing temperatures and increased water level, a practice which continued seasonally until completion of the bridge. At this time, a revised contract was drawn up, stating work was to be completed by December 1858, barring "unavoidable calamities". After a hard winter of 1856–57, and a wet spring, construction resumed in July 1857. Sandstone

10290-661: Was built between 1829 and 1832, replacing a wooden bridge further downstream which collapsed in 1828. It is the only suspension bridge across the non-tidal Thames. The Széchenyi Chain Bridge , (designed in 1840, opened in 1849), spanning the River Danube in Budapest, was also designed by William Clark and it is a larger-scale version of Marlow Bridge. An interesting variation is Thornewill and Warham 's Ferry Bridge in Burton-on-Trent , Staffordshire (1889), where

10395-437: Was closed until April 27 after an automobile accident damaged a steel section of the bridge. On April 17, 2019, another piece of sandstone fell, prompting closure until August 9. On November 11, 2020, the nearby Brent Spence Bridge was closed following a fiery collision. Semitrucks began using the Roebling Bridge as an alternate crossing point, in violation of the bridge's 11-ton weight limit, prompting Covington police to close

10500-423: Was elected to the board of trustees in 1856. He brought with him a much needed boost of energy. Shinkle immediately managed to find new private investors and to procure more support from both the Ohio and Kentucky governments. During this time the bridge charter was revised, and the span of the bridge was reduced to a minimum of 1,000 feet (300 m). By now, Roebling had established a reputation. President Ramson of

10605-477: Was incorporated in February 1846, and the company asked Roebling to plan a bridge. The brief outline of his ideas called for a 1,200-foot (370 m) span with 100 feet (30 m) of clearance at high water to allow steamboats to pass unobstructed, but it included a monumental tower in the middle of the river. Steamboat and ferry interest groups lobbied against this plan. They feared an obstructed waterway, loss of

10710-521: Was renamed in honor of its designer and builder on June 27, 1983. In 1984, at the cost of $ 200,000, the bridge had lighting installed on its cables. They also later restored its sprails at the cost of 10 million. In 1996, the bridge was renovated. The ramps onto the Dixie Terminal were demolished in 1998 when it ceased being used as a bus terminal. The Commonwealth of Kentucky closed the bridge on November 13, 2006, to make extensive repairs to

10815-404: Was the first modern suspension bridge outside the United States built with parallel wire cables. Two towers/pillars, two suspension cables, four suspension cable anchors, multiple suspender cables, the bridge deck. The main cables of a suspension bridge will form a catenary when hanging under their own weight only. When supporting the deck, the cables will instead form a parabola , assuming

10920-401: Was used for the first twenty five vertical feet of each tower base. Limestone encased this sandstone to protect against scour and collision from watercraft. The remaining height of each tower was to be constructed of sandstone, rough cut and with a large draft. Roebling said this gave the towers "a massive look, quite suitable to their function." Working from July to August 1857, the company

11025-466: Was without liquid funds, a problem compounded by the Panic of 1857 . Work halted because of the inability to pay for the project. In July 1858, operations resumed again, albeit with a smaller workforce. Only one tower was worked on at a time. President Ramson of the company died, and no work was done during the years 1859–60. In November 1860, Abraham Lincoln was elected president of the United States, and

#224775