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HMS Walmer Castle (K405)
HMS ''Walmer Castle'' was a constructed for the British Royal Navy during the Second World War. Before completion, the ship was transferred to the Royal Canadian Navy and renamed HMCS ''Leaside''. The corvette was used as an ocean convoy escort during the war and was sold for mercantile use following it. The ship was purchased for use as a passenger ship and renamed ''Coquitlam'', then in 1958, ''Glacier Queen''. In 1970 ''Glacier Queen'' was acquired for use as a floating hotel in Alaska. The ship sank in 1978 and was raised and scuttled in Alaskan waters in 1979. Design and description The Castle class were an improved corvette design over their predecessor . The Flower class was not considered acceptable for mid-Atlantic sailing and was only used on Atlantic convoy duty out of need. Though the Admiralty would have preferred s, the inability of many small shipyards to construct the larger ships required them to come up with a smaller vessel. The increased length of the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walmer Castle
Walmer Castle is an artillery fort originally constructed by Henry VIII of England, Henry VIII in Walmer, Kent, between 1539 and 1540. It formed part of the King's Device Forts, Device programme to protect against invasion from France and the Holy Roman Empire, and defended the strategically important The Downs (ship anchorage), Downs anchorage off the English coast. Comprising a keep and four circular bastions, the moated stone castle covered and had 39 firing positions on the upper levels for List of medieval and early modern gunpowder artillery, artillery. It cost the Crown a total of £27,092 to build the three castles of Walmer, Sandown Castle, Kent, Sandown, and Deal Castle, Deal, which lay adjacent to one another along the coast and were connected by earthwork defences. The original invasion threat passed, but during the Second English Civil War of 1648–49, Walmer was seized by pro-Cavalier, Royalist insurgents and was only retaken by Roundheads, Parliamentary forces af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states (Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th parallel, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type 277 Radar
The Type 277 was a surface search and secondary aircraft early warning radar used by the Royal Navy and allies during World War II and the post-war era. It was a major update of the earlier Type 271 radar, offering much more power, better signal processing, new displays, and new antennas with greatly improved performance and much simpler mounting requirements. It allowed a radar with performance formerly found only on cruisers and battleships to be fitted even to the smallest corvettes. It began to replace the 271 in 1943 and was widespread by the end of the year. The Type 271 was one of the first microwave frequency radars to enter service, when microwave electronics design was in its infancy. While it was still being fitted to escort ships during 1941 and 1942, great strides in technique were being made in cavity magnetron, waveguide, antenna design and general electronics. Those upgrades that could be easily combined with the existing systems became the 271 Mark IV mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-frequency Direction Finding
High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is a type of radio direction finder (RDF) introduced in World War II. High frequency (HF) refers to a radio band that can effectively communicate over long distances; for example, between U-boats and their land-based headquarters. HF/DF was primarily used to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid. The basic technique remains in use to this day as one of the fundamental disciplines of signals intelligence, although typically incorporated into a larger suite of radio systems and radars instead of being a stand-alone system. Earlier systems used a mechanically rotated antenna or solenoid and an operator listening for peaks or nulls in the signal, which often took considerable time to determine the bearing on the order of a minute or more. Later systems used a set of antennas to receive the same signal in slightly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASDIC
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extrem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depth Charge
A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive Shock factor, hydraulic shock. Most depth charges use explosive, high explosive charges and a fuze set to detonate the charge, typically at a specific depth. Depth charges can be dropped by ships, patrol aircraft, and helicopters. Depth charges were developed during World War I, and were one of the first viable methods of attacking a submarine underwater. They were widely used in World War I and World War II, and remained part of the anti-submarine arsenals of many navies during the Cold War, during which they were supplemented, and later largely replaced, by anti-submarine homing torpedoes. A depth charge fitted with a nuclear warhead is also known as a "nuclear depth bomb". These were designed to be dropped from a patrol plane or deployed by an anti-submarine missile from a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Numerals
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, each letter with a fixed integer value, modern style uses only these seven: The use of Roman numerals continued long after the decline of the Roman Empire. From the 14th century on, Roman numerals began to be replaced by Arabic numerals; however, this process was gradual, and the use of Roman numerals persists in some applications to this day. One place they are often seen is on clock faces. For instance, on the clock of Big Ben (designed in 1852), the hours from 1 to 12 are written as: The notations and can be read as "one less than five" (4) and "one less than ten" (9), although there is a tradition favouring representation of "4" as "" on Roman numeral clocks. Other common uses include year numbers on monuments and buildings and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Triple Expansion
A compound steam engine unit is a type of steam engine where steam is expanded in two or more stages. A typical arrangement for a compound engine is that the steam is first expanded in a high-pressure ''(HP)'' cylinder, then having given up heat and losing pressure, it exhausts directly into one or more larger-volume low-pressure ''(LP)'' cylinders. Multiple-expansion engines employ additional cylinders, of progressively lower pressure, to extract further energy from the steam. Invented in 1781, this technique was first employed on a Cornish beam engine in 1804. Around 1850, compound engines were first introduced into Lancashire textile mills. Compound systems There are many compound systems and configurations, but there are two basic types, according to how HP and LP piston strokes are phased and hence whether the HP exhaust is able to pass directly from HP to LP ( Woolf compounds) or whether pressure fluctuation necessitates an intermediate "buffer" space in the form of a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-drum Boiler
Three-drum boilers are a class of water-tube boiler used to generate steam, typically to power ships. They are compact and of high evaporative power, factors that encourage this use. Other boiler designs may be more efficient, although bulkier, and so the three-drum pattern was rare as a land-based stationary boiler. The fundamental characteristic of the "three-drum" design is the arrangement of a steam drum above two water drums, in a triangular layout. Water tubes fill in the two sides of this triangle between the drums, and the furnace is in the centre. The whole assembly is then enclosed in a casing, leading to the exhaust flue. Firing can be by either coal or oil. Many coal-fired boilers used multiple firedoors and teams of stokers, often from both ends. Development Development of the three-drum boiler began in the late 19th century, with the demand from naval ships that required high power and a compact boiler. The move to water-tube boilers had already begun, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draft (ship)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water. The more heavily a vessel is loaded, the deeper it sinks into the water, and the greater its draft. After construction, the shipyard creates a table showing how much water the vessel displaces based on its draft and the density of the water (salt or fresh). The draft can also be used to determine the weight of cargo on board by calculating the total displacement of water, accounting for the content of the ship's bunkers, and using Archimedes' principle. The closely related term "trim" is defined as the difference between the forward and aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam (nautical)
The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water. Generally speaking, the wider the beam of a ship (or boat), the more initial stability it has, at the expense of secondary stability in the event of a capsize, where more energy is required to right the vessel from its inverted position. A ship that heels on her ''beam ends'' has her deck beams nearly vertical. Typical values Typical length-to-beam ratios ( aspect ratios) for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells designed for flatwater racing may have length to beam ratios as high as 30:1, while a cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Length Overall
__NOTOC__ Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and is also used for calculating the cost of a marina berth (for example, £2.50 per metre LOA). LOA is usually measured on the hull alone. For sailing ships, this may ''exclude'' the bowsprit and other fittings added to the hull. This is how some racing boats and tall ships use the term LOA. However, other sources may include bowsprits in LOA. Confusingly, LOA has different meanings. "Sparred length", "Total length including bowsprit", "Mooring length" and "LOA including bowsprit" are other expressions that might indicate the full length of a sailing ship. LOD Often used to distinguish between the length of a vessel including projections (e.g. bow sprits, etc.) from the length of the hull itself, the Length on Deck or LOD is often repor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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