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Nab Tower
The Nab Tower was a tower planned for anti-submarine protection in the Solent in World War I. It was sunk over the Nab rocks east of the Isle of Wight to replace a lightship after the war, and is a well-known landmark for sailors as it marks the deep-water eastern entry into the Solent. History During the First World War, the British Admiralty designed eight towers codenamed M-N that were to be built and positioned in the Straits of Dover to protect allied merchant shipping from German U-boats. Designed by civilian Guy Maunsell, the towers were to be linked together with steel nets and armed with two 4-inch guns with the idea of closing the English Channel to enemy ships. However, by the end of the war in 1918 only one such tower had been completed, at the time a cost of one million pounds, and was located at Shoreham Harbour, awaiting deployment. While another part-built tower would eventually be dismantled in 1924, there remained the completed metal cylinder sitting on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isle Of Wight
The Isle of Wight ( ) is a Counties of England, county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the List of islands of England#Largest islands, largest and List of islands of England#Most populous islands, second-most populous island of England. Referred to as 'The Island' by residents, the Isle of Wight has resorts that have been popular holiday destinations since Victorian era, Victorian times. It is known for its mild climate, coastal scenery, and verdant landscape of fields, downland and chines. The island is Historic counties of England, historically part of Hampshire, and is designated a UNESCO Biosphere Reserve. The island has been home to the poets Algernon Charles Swinburne and Alfred, Lord Tennyson. Queen Victoria built her summer residence and final home, Osborne House at East Cowes, on the Isle. It has a maritime and industrial tradition of #Neolithic Isle of Wight, boat-building, sail-making, the manufacture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fifth Order Fresnel Lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens developed by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. It has been called "the invention that saved a million ships." The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. The simpler dioptric (purely refractive) form of the lens was first proposed by Count Buffon and independently reinvented by Fresnel. The ''catadioptric'' form of the lens, entirely invented by Fresnel, has outer elements that use total internal reflection as well as refraction; it can capture more oblique light from a light source and add it to the beam of a lighthouse, making the light visible from greater distances. Description The Fresnel lens reduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass-reinforced Plastic
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinyl ester resin—or a thermoplastic. Cheaper and more flexible than carbon fiber, it is stronger than many metals by weight, non-magnetic, non- conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, orthopedic casts, surfboards, and external door skins. Other common names for fiberglass are glass-reinforced plastic (GRP), glass-fiber reinforced plastic (GFRP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylene Lamp
Acetylene (systematic name: ethyne) is the chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution. Pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities such as divinyl sulfide and phosphine.Compressed Gas Association (1995Material Safety and Data Sheet – Acetylene As an alkyne, acetylene is unsaturated because its two carbon atoms are bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°. Discovery Acetylene was discovered in 1836 by Edmund Davy, who identified it as a "new carburet of hydrogen". It was an accidental discovery while attempting to isolate potassium metal. By heating potassium carbonate with carbon at very high temperatures, he produced a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Pad
A helipad is a landing area or platform for helicopters and powered lift aircraft. While helicopters and powered lift aircraft are able to operate on a variety of relatively flat surfaces, a fabricated helipad provides a clearly marked hard surface away from obstacles where such aircraft can land safely. Larger helipads, intended for use by helicopters and other vertical take-off and landing aircraft (VTOL), may be called ''vertiports.'' An example is Vertiport Chicago, which opened in 2015. Usage Helipads may be located at a heliport or airport where fuel, air traffic control and service facilities for aircraft are available. Most helipads are located remote from populated areas due to sounds, winds, space and cost constraints. However, some skyscrapers maintain a helipad on their roofs in order to accommodate air taxi services. Some basic helipads are built on top of highrise buildings for evacuation in case of a major fire outbreak. Major police departments may use a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bofors 40 Mm Automatic Gun L/60
The Bofors 40 mm Automatic Gun L/60 (often referred to simply as the "Bofors 40 mm gun", the "Bofors gun" and the like, see name) is an anti-aircraft autocannon, designed in the 1930s by the Swedish arms manufacturer AB Bofors. The gun was designed as an intermediate anti-aircraft gun, filling the gap between fast firing close-range small calibre anti-aircraft guns and slower firing long-range high calibre anti-aircraft guns, a role which previously was filled by older outdated guns. The Bofors 40 mm L/60 was for its time perfectly suited for this role and outperformed competing designs in the years leading up to World War II in both effectiveness and reliability. It entered the export market around 1932 and was in service with 18 countries by 1939. Throughout World War II it became one of the most popular and widespread medium-weight anti-aircraft guns. It was used by the majority of the western Allies and some Axis powers such as Nazi Germany and Hungary. In the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, massa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Station
A signal station is a form of Aids to Navigation that is defined by the IHO simply as "A signal station is a place on shore from which signals are made to ships at sea". While this broad definition would include coastal radio stations and fog signal stations, the term is most often used for shore installation that use ''visual'' signals to communicate with ships at sea. History Signal stations were the only practical mean of communicating with passing ships until the development of radio, and played a critical role in both navigation safety and commercial operation of fleets. As they were normally located in high places with extensive fields of view, surviving signal stations are often in scenic locations, and have become local landmarks. Signal stations used a variety of means to communicate shore-to-ship: Chappe Telegraph or other forms of pole-and-arm optical telegraph, flag semaphore Flag semaphore (from the Ancient Greek () 'sign' and - (-) '-bearer') is a semaphore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fog Bell
A fog bell is a navigation mark used as an audible aid to navigation in seafaring, especially in fog and poor visibility. Floating navigation signs with bells are called bell buoys. On ships, the ship's bell is used for sound signals. Due to more suitable sound generators, but also the development and spread of radar, satellite navigation and electronic charting systems, fog bells have lost their importance for maritime navigation. Maritime marks on land Starting in the 18th century, fog signals were given for seafaring in Europe, initially cannons or guns. In 1766, the first bell for this purpose was installed in Nidingen on the Baltic Sea.Thomas Tag''Fog Bells'' United States Lighthouse Society website. Retrieved September 27, 2021. These were initially rung by hand, which was a chore during prolonged fog, others used mechanisms similar to clockwork that had to be wound periodically. Andrew Morse Jr. eventually developed an "perpetual fog bell" that was used in 1839 at Penob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphone
The diaphone is a noisemaking device best known for its use as a foghorn: It can produce deep, powerful tones, able to carry a long distance. Although they have fallen out of favor, diaphones were also used at some fire stations and in other situations where a loud, audible signal was required. History The diaphone horn was based directly on the organ stop of the same name invented by Robert Hope-Jones, creator of the Wurlitzer organ. Hope-Jones' design was based on a piston that was closed only at its bottom end and had slots, perpendicular to its axis, cut through its sides; the slotted piston moved within a similarly slotted cylinder. Outside of the cylinder was a reservoir of high-pressure air. Initially, high-pressure air would be admitted behind the piston, pushing it forward. When the slots of the piston aligned with those of the cylinder, air passed into the piston, making a sound and pushing the piston back to its starting position, whence the cycle would repeat. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Beacon
In navigation, a radio beacon or radiobeacon is a kind of beacon, a device that marks a fixed location and allows direction-finding equipment to find relative bearing. But instead of employing visible light, radio beacons transmit electromagnetic radiation in the radio wave band. They are used for direction-finding systems on ships, aircraft and vehicles. Radio beacons transmit a continuous or periodic radio signal with limited information (for example, its identification or location) on a specified radio frequency. Occasionally, the beacon's transmission includes other information, such as telemetric or meteorological data. Radio beacons have many applications, including air and sea navigation, propagation research, robotic mapping, radio-frequency identification (RFID), near-field communication (NFC) and indoor navigation, as with real-time locating systems (RTLS) like Syledis or simultaneous localization and mapping (SLAM). Types Radio-navigation beacons The mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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