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Panama Canal Locks
The Panama Canal locks () are a Canal lock, lock system that lifts ships up to the main elevation of the Panama Canal and lowers them down again. The original canal had a total of six steps (three up, three down) for a ship's passage. The total length of the lock structures, including the approach walls, is over . The locks were one of the greatest engineering works ever to be undertaken when they opened in 1914. No other concrete construction of comparable size was undertaken until the Hoover Dam, in the 1930s. There are two independent transit lanes, since each lock is built double. The size of the original locks limits the maximum size of ships that can transit the canal; this size is known as Panamax. Construction on the Panama Canal expansion project, which included a third set of locks, began in September 2007, finished by May 2016 and began commercial operation on June 26, 2016. The new locks allow transit of larger, New Panamax ships, which have a greater cargo capacity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panama Canal
The Panama Canal () is an artificial waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a Channel (geography), conduit for maritime trade between the Atlantic and Pacific Oceans. Lock (water navigation), Locks at each end lift ships up to Gatun Lake, an artificial fresh water lake Above mean sea level, above sea level, created by damming the Chagres River and Lake Alajuela to reduce the amount of excavation work required for the canal. Locks then lower the ships at the other end. An average of of fresh water is used in a single passing of a ship. The canal is threatened by low water levels during droughts. The Panama Canal shortcut greatly reduces the time for ships to travel between the Atlantic and Pacific oceans, enabling them to avoid the lengthy, hazardous route around the southernmost tip of South America via the Drake Passage, the Strait of Magellan or the Beagle Channel. Its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross Section Of Lock Chambers And Walls Of Locks, PC Hbk 1913 E
A cross is a religious symbol consisting of two intersecting lines, usually perpendicular to each other. The lines usually run vertically and horizontally. A cross of oblique lines, in the shape of the Latin letter X, is termed a saltire in heraldic terminology. The cross shape has been widely officially recognized as an absolute and exclusive religious symbol of Christianity from an early period in that religion's history.''Christianity: an introduction'' by Alister E. McGrath 2006 pages 321-323 Before then, it was used as a religious or cultural symbol throughout , in |
Grade (slope)
The grade (US) or gradient (UK) (also called stepth, slope, incline, mainfall, pitch or rise) of a physical feature, landform or constructed line is either the elevation angle of that surface to the horizontal plane, horizontal or its tangent. It is a special case of the slope, where zero indicates horizontal plane, horizontality. A larger number indicates higher or steeper degree of "tilt". Often slope is calculated as a ratio of "rise" to "run", or as a fraction ("rise over run") in which ''run'' is the horizontal distance (not the distance along the slope) and ''rise'' is the vertical distance. Slopes of existing physical features such as canyons and hillsides, bank (geography), stream and river banks, and stream bed, beds are often described as grades, but typically the word "grade" is used for human-made surfaces such as roads, landscape grading, roof pitches, rail tracks, railroads, aqueduct (watercourse), aqueducts, and pedestrian or bicycle routes. The grade may refer to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winch
A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension (physics), tension of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form, it consists of a Bobbin, spool (or drum) attached to a hand crank (mechanism), crank. Traditionally, winches on ships accumulated wire or rope on the drum; those that do not accumulate, and instead pass on the wire/rope (see yacht photo above), are called Capstan_(nautical), capstans. Despite this, sailboat capstans are most often referred to as winches. Winches are the basis of such machines as tow trucks, steam shovels and elevators. More complex designs have gear assemblies and can be powered by electric, hydraulic, pneumatic or internal combustion drives. It might include a solenoid brake and/or a Mechanical brake stretch wrapper, mechanical brake or ratchet (device), ratchet and pawl which prevents it unwinding unless the pawl is retracted. The rope may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conduit Current Collection
Conduit current collection is an obsolete system that was used by some electric tramways to pass current to streetcars via a "conduit", a small tunnel under the roadway. Modern systems fall under the term ground-level power supply. The system is primarily composed of a channel, or conduit, excavated under the roadway; the conduit is positioned either between the running rails, much in the same fashion as the cable for cable cars, or underneath one of the rails; a car is connected to a "plow" or "plough" that runs through the conduit and delivers power from two electric rails at the sides of the conduit to the car's electric motor. Plows were manually attached and detached from cars as they switched rail lines. Conduit current collection systems were implemented as early as 1881 with the Gross-Lichterfelde Tramway. It proved to be much more expensive, complicated, and trouble-prone than overhead wires. When electric street railways became ubiquitous, conduits were only used in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rack And Pinion
rack and pinion is a type of linear actuator that comprises a circular gear (the '' pinion'') engaging a linear gear (the ''rack''). Together, they convert between rotational motion and linear motion: rotating the pinion causes the rack to be driven in a line. Conversely, moving the rack linearly will cause the pinion to rotate. The rack and pinion mechanism is used in rack railways, where the pinion mounted on a locomotive or a railroad car engages a rack usually placed between the rails, and helps to move the train up a steep gradient. It is also used in arbor presses and drill presses, where the pinion is connected to a lever and displaces a vertical rack (the ram). In pipelines and other industrial piping systems, a rack displaced by a linear actuator turns a pinion to open or close a valve. Stairlifts, lock gates, electric gates, and the mechanical steering mechanism of cars are other notable applications. The term "rack and pinion" may be used also when the rac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rack Railway
A rack railway (also rack-and-pinion railway, cog railway, or cogwheel railway) is a steep grade railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail. This allows the trains to operate on steep gradients of 100% (45 degrees) or more, well above the 10% maximum for friction-based rail. The rack and pinion mechanism also provides more controlled braking and reduces the effects of snow or ice on the rails. Most rack railways are mountain railways, although a few are transit railways or tramways built to overcome a steep gradient in an urban environment. The first cog railway was the Middleton Railway between Middleton and Leeds in West Yorkshire, England, United Kingdom, where the first commercially successful steam locomotive, ''Salamanca'', ran in 1812. This used a rack and pinion system designed and patented in 1811 by John Blenkinsop. The first mountain cog railw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broad Gauge
A broad-gauge railway is a railway with a track gauge (the distance between the rails) broader than the used by standard-gauge railways. Broad gauge of , more known as Russian gauge, is the dominant track gauge in former Soviet Union countries (CIS states, Baltic states, Rail transport in Georgia (country), Georgia, Ukraine) and Rail transport in Mongolia, Mongolia. Broad gauge of , commonly known as five foot gauge, is mainly used in Rail transport in Finland, Finland. Broad gauge of , commonly known as Irish gauge, is the dominant track gauge in Ireland, the Australian state of Rail transport in Victoria, Victoria and Railways in Adelaide, Adelaide in South Australia and Rail transport in Brazil, passenger trains of Brazil. Broad gauge of , commonly known as Iberian gauge, is the dominant track gauge in Spain and Portugal. Broad gauge of , commonly known as Indian gauge, is the dominant track gauge in Indian Railways, India, Pakistan Railways, Pakistan, Bangladesh, Sri Lanka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mule
The mule is a domestic equine hybrid between a donkey, and a horse. It is the offspring of a male donkey (a jack) and a female horse (a mare). The horse and the donkey are different species, with different numbers of chromosomes; of the two possible first-generation hybrids between them, the mule is easier to obtain and more common than the hinny, which is the offspring of a male horse (a stallion) and a female donkey (a jenny). Mules vary widely in size, and may be of any color seen in horses or donkeys. They are more patient, hardier and longer-lived than horses, and are perceived as less obstinate and more intelligent than donkeys. Terminology A female mule is often called a "molly" or "Molly mule," though the correct term is "mare mule." A male mule is called a "john" or "John mule," though the correct term is "horse mule." A young male mule is called a "mule colt," and a young female is called a "mule filly." The donkey used to produce mules is called a "mule ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Google Books
Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google that searches the full text of books and magazines that Google has scanned, converted to text using optical character recognition (OCR), and stored in its digital database.The basic Google book link is found at: https://books.google.com/ . The "advanced" interface allowing more specific searches is found at: https://books.google.com/advanced_book_search Books are provided either by publishers and authors through the Google Books Partner Program, or by Google's library partners through the Library Project. Additionally, Google has partnered with a number of magazine publishers to digitize their archives. The Publisher Program was first known as Google Print when it was introduced at the Frankfurt Book Fair in October 2004. The Google Books Library Project, which scans works in the collections of library partners and adds them to the digital inventory, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gate Operating Machine, PC Hbk 1913 I
A gate or gateway is a point of entry to or from a space enclosed by walls. The word is derived from Proto-Germanic ''*gatan'', meaning an opening or passageway. Synonyms include yett (which comes from the same root word) and portal. The concept originally referred to the gap or hole in the wall or fence, rather than a barrier which closed it. Gates may prevent or control the entry or exit of individuals, or they may be merely decorative. The moving part or parts of a gateway may be considered "doors", as they are fixed at one side whilst opening and closing like one. A gate may have a latch that can be raised and lowered to both open a gate or prevent it from swinging. Gate operation can be either automated or manual. Locks are also used on gates to increase security. Larger gates can be used for a whole building, such as a castle or fortified town. Doors can also be considered gates when they are used to block entry as prevalent within a gatehouse. Purpose-specific types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
