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Position Finder
The depression range finder (DRF) was a fire control device used to observe the target's range and bearing to calculate firing solutions when gun laying in coastal artillery. It was the main component of a vertical base rangefinding system. It was necessitated by the introduction of rifled artillery from the mid-19th century onwards, which had much greater ranges than the old smoothbore weapons and were consequently more difficult to aim accurately. The DRF was invented by Captain H.S.S. Watkin of the Royal Artillery in the 1870s and was adopted in 1881. It could provide both range and bearing information on a target. The device's inventor also developed a family of similar devices, among them the position finder, which used two telescopes as a horizontal base rangefinding system, around the same time; some of these were called electric position finders. Some position finders retained a depression range finding capability; some of these were called depression position finders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base End Station
Base end stations were used by the United States Army Coast Artillery Corps as part of fire control systems for locating the positions of attacking ships and controlling the firing of seacoast guns, mortars, or mines to defend against them. A British equivalent was the position finding cell. Types of base end stations A "true" base end station was one of a pair of stations at either end of a precisely measured (surveyed) baseline. Once simultaneous bearings from each base end station to a target were taken, since the distance between the stations (the baseline) was known, the range to the target from either station could be calculated through triangulation. If the target's bearing from each station was sent to a plotting room and input to a plotting board, the position of the target could be estimated and firing coordinates for a gun battery could be calculated. Some base end stations were located in tall fire control towers (FCTs) Sometimes, the terms "base end station" and "f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plotting Room
A plotting room was the co-ordination centre of a fire control system for guns used against enemy ships or aircraft, whether naval guns or coastal artillery. The plotting room received data on ship or aircraft position and motion from fire control instruments or their operators and determined and transmitted the range and bearing (a.k.a. azimuth or deflection) the guns would fire on. Plotting rooms came into use in the early 1900s for coastal artillery and during World War I for warships as gun ranges increased, and were in general use through the 1970s on World War II-era ships (and into the 1990s on the US Navy's s). Warships had plotting rooms for naval fire control for guns from 5-inch to 18-inch calibre, including anti-aircraft use for the smaller guns. On armoured ships such as battleships and cruisers, plotting rooms were located in the armoured citadel, protected by both deck and belt armour. With a few exceptions (mostly in Scandinavia), coastal defence gun installa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depression Position Finder, Dover Castle
Depression may refer to: Mental health * Depression (mood), a state of low mood and aversion to activity * Mood disorders characterized by depression are commonly referred to as simply ''depression'', including: ** Dysthymia, also known as persistent depressive disorder ** Major depressive disorder, also known as clinical depression Economics * Economic depression, a sustained, long-term downturn in economic activity in one or more economies ** Great Depression, a severe economic depression during the 1930s, commonly referred to as simply ''the Depression'' ** Long Depression, an economic depression during 1873–96, known at the time as the ''Great Depression'' Biology * Depression (kinesiology), an anatomical term of motion, refers to downward movement, the opposite of elevation * Depression (physiology), a reduction in a biological variable or the function of an organ * Central nervous system depression, physiological depression of the central nervous system that can resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coastal Defence And Fortification
300px, Castillo San Felipe de Barajas in Cartagena de Indias, Colombia, an example of an Early Modern coastal defense Coastal defence (or defense) and coastal fortification are measures taken to provide protection against military attack at or near a coastline (or other shoreline), for example, fortifications and coastal artillery. Because an invading enemy normally requires a port or harbour to sustain operations, such defences are usually concentrated around such facilities, or places where such facilities could be constructed. Coastal artillery fortifications generally followed the development of land fortifications, usually incorporating land defences; sometimes separate land defence forts were built to protect coastal forts. Through the middle 19th century, coastal forts could be bastion forts, star forts, polygonal forts, or sea forts, the first three types often with detached gun batteries called "water batteries". Coastal defence weapons throughout history were heavy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort Hancock, New Jersey
Fort Hancock is a former United States Army fort at Sandy Hook in Middletown Township New Jersey. The coastal artillery base defended the Atlantic coast and the entrance to New York Harbor, with its first gun batteries operational in 1896. The fort served from then until 1950 as part of the Harbor Defenses of New York and predecessor organizations. Between 1874 and 1919, the adjacent US Army Sandy Hook Proving Ground was operated in conjunction with Fort Hancock. It is now part of Fort Hancock Memorial Park. It was preceded by the Fort at Sandy Hook, built 1857–1867 and demolished beginning in 1885. The Sandy Hook Light, built in 1764 and the oldest working lighthouse in the United States, is located on the grounds of Fort Hancock.Roberts, pp. 516-518 History Fort at Sandy Hook The Sandy Hook area was first fortified as part of the third system of US fortifications. Construction on the Fort at Sandy Hook began in 1857 and ceased in 1867, with the fort serviceable though larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seacoast Defense In The United States
Seacoast defense was a major concern for the United States from its independence until World War II. Before Military aviation, airplanes, many of America's enemies could only reach it from the sea, making coastal forts an economical alternative to Standing army, standing armies or a large navy. After the 1940s, it was recognized that fixed fortifications were obsolete and ineffective against aircraft and missiles. However, in prior eras foreign fleets were a realistic threat, and substantial fortifications were built at key locations, especially protecting major harbors. The defenses heavily depended on fortifications but also included Submarine mines in United States harbor defense, submarine minefields, nets and boom (navigational barrier), booms, ships, and airplanes. Therefore, all of the armed forces participated in seacoast defense, but the United States Army Corps of Engineers, U.S. Army Corps of Engineers played the central role in constructing fixed defenses. Designs evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coast Artillery Fire Control System
In the U.S. Army Coast Artillery Corps, the term fire control system was used to refer to the personnel, facilities, technology and procedures that were used to observe designated targets, estimate their positions, calculate firing data for guns directed to hit those targets, and assess the effectiveness of such fire, making corrections where necessary. Fire control instruments The Coast Artillery's early fire control instruments supported optical rangefinding and position finding, either horizontal base or vertical base, with both systems usually present for each fort. Early horizontal base rangefinding required two azimuth (a.k.a. bearing or deflection) instruments, preferably widely separated, and a communications system to transmit data to a plotting room and then to the guns. The instruments were often in bunkers called base end stations, as they defined the endpoints of a baseline. A base end station might be a two-story structure with a plotting room or other instrument ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plymouth Sound
Plymouth Sound, or locally just The Sound, is a deep inlet or sound in the English Channel near Plymouth in England. Description Its southwest and southeast corners are Penlee Point in Cornwall and Wembury Point in Devon, a distance of about 3 nautical miles (6 km). Its northern limit is Plymouth Hoe giving a north–south distance of nearly 3 nautical miles (6 km). The Sound has three water entrances. The marine entrance is from the English Channel to the south, with a deep-water channel to the west of the Plymouth Breakwater. There are two freshwater inlets: one, from the northwest, is from the River Tamar via the Hamoaze and Devonport Dockyard, the largest naval dockyard in western Europe. The other, at northeast, is from the River Plym disgorging into its narrow estuary, Cattewater harbour between Mount Batten and the Royal Citadel. In the centre of the Sound, midway between Bovisand Bay and Cawsand Bay, is Plymouth Breakwater, which creates a harbour prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plymouth Breakwater
Plymouth Breakwater is a stone breakwater protecting Plymouth Sound and the anchorages near Plymouth, Devon, England. It is wide at the top and the base is . It lies in about of water. Around 4 million tons of rock were used in its construction in 1812 at the then-colossal cost of £1.5 million (equivalent to £ today). History In 1806, as the Napoleonic Wars impended, Lord St. Vincent commissioned John Rennie and Joseph Whidbey to plan a means of making Plymouth Bay a safe anchorage for the Channel Fleet. These plans may have been taken from ones made by George Matcham (1753 – 3 February 1833). In 1811 came the order to begin construction; Whidbey was appointed Acting Superintending Engineer. This task required great engineering, organizational and political skills, as the many strictly technical challenges were complicated by the significant resources devoted to the project, from which various parties evidenced a desire for advantage. Nearly 4,000,000 (four million) ton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort Bovisand
Fort Bovisand is a fort in Devon, England near the beach of Bovisand. It was built as a result of the Royal Commission on the Defence of the United Kingdom which reported in 1860. It is located on the mainland to defend the entrance of Plymouth Sound, at the narrows opposite the east end of Plymouth Breakwater. The fort is beside Bovisand harbour. History In 1816, a stone jetty and slip were built for boats from sailing warships anchored in Plymouth Sound to collect fresh water from the nearby reservoir. In 1845, the first fort at the site, named Staddon Height Battery, was started. It still exists in the upper part of the present fort. Work started on the main part of the fort in 1861. Originally intended to have two stories of casemates like Fort Picklecombe, the design was altered during construction to a single storey of 23 granite casemates with armoured shields. It was designed by Major (later Maj Gen) Whitworth Porter , and was built by George Baker and Company. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plotting Board
A plotting board was a mechanical device used by the U.S. Army Coast Artillery Corps as part of their fire control system to track the observed course of a target (typically a moving ship), project its future position, and derive the uncorrected data on azimuth (or direction) and range needed to direct the fire of the guns of a battery to hit that target. Plotting boards of this sort were first employed by the Coast Artillery around 1905, and were the primary means of calculating firing data until WW2. Towards the end of WW2 these boards were largely replaced by radar and electro-mechanical gun data computers, and were relegated to a back-up role. Although several different types of plotting boards were used by the Coast Artillery over the years, the example described here is the Whistler- Hearn Plotting Board, Model of 1904 which was widely employed by the Coast Artillery between about 1905 and 1925. This description is primarily derived from two manuals of the period, each of w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
War Office
The War Office was a department of the British Government responsible for the administration of the British Army between 1857 and 1964, when its functions were transferred to the new Ministry of Defence (MoD). This article contains text from this source, which is available under th Open Government Licence v3.0 © Crown copyright It was equivalent to the Admiralty, responsible for the Royal Navy (RN), and (much later) the Air Ministry, which oversaw the Royal Air Force (RAF). The name 'War Office' is also given to the former home of the department, located at the junction of Horse Guards Avenue and Whitehall in central London. The landmark building was sold on 1 March 2016 by HM Government for more than £350 million, on a 250 year lease for conversion into a luxury hotel and residential apartments. Prior to 1855, 'War Office' signified the office of the Secretary at War. In the 17th and 18th centuries, a number of independent offices and individuals were re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
