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HMCS Algoma
HMCS ''Algoma'' was a that served with the Royal Canadian Navy in the Second World War. Named for the Algoma District of Ontario, it served primarily in the Battle of the Atlantic. After the war it was sold to the Venezuelan Navy and renamed ''Constitución''. Designed as a convoy escort, the vessel was laid down on 18 June 1940, launched on 17 December and commissioned on 11 July 1941. The ship took part in three major convoy battles and Operation Torch escort duties and was decommissioned in 1945. She served with the Venezuelan Navy from 1946 until 1962. Design and description Flower-class corvettes such as ''Algoma'' serving with the Royal Canadian Navy (RCN) in the Second World War were different from earlier and more traditional sail-driven corvettes. The Flower-class corvettes originated from a need that arose in 1938 to expand the Royal Navy following the Munich Crisis. A design request went out for a small escort for coastal convoys. Based on a traditional whaler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algoma District
Algoma District is a district and census division in Northeastern Ontario in the Canadian province of Ontario. The name was created by an American ethnologist, Henry Rowe Schoolcraft (1793-1864), who was appointed Indian agent to the Ojibwe in Sault Ste. Marie region in 1822. "Al" is derived from Algonquin, while "goma" is a variant of gomee, meaning lake or water. Algoma District has shoreline along Lake Superior and Lake Huron. It has an international border crossing to the American state of Michigan, at Sault Ste. Marie. Historically, it was known for its lumber and mining industries. The rugged scenery of the region has inspired works by Canadian artists, particularly the Group of Seven. They rented a boxcar from the Algoma Central Railway to travel on excursions through this region. History Surviving prehistoric remains in Algoma District are concentrated around waterways. These remains date as far back as the Archaic period. There are also sites from the later Woodlan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceremonial Ship Launching
Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back thousands of years, to accompany the physical process with ceremonies which have been observed as public celebration and a solemn blessing, usually but not always, in association with the launch itself. Ship launching imposes stresses on the ship not met during normal operation and, in addition to the size and weight of the vessel, represents a considerable engineering challenge as well as a public spectacle. The process also involves many traditions intended to invite good luck, such as christening by breaking a sacrificial bottle of champagne over the bow (ship), bow as the ship is named aloud and launched. Methods There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching". The oldest, most familiar, and most widel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BL 4-inch Mk IX Naval Gun
The BL 4-inch Mk IX naval gunMk IX = Mark 9. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Mark IX indicates this was the ninth model of BL 4-inch gun. was a British medium-velocity naval gun introduced in 1917 as secondary armament on the battlecruisers and "large light cruisers", but which served most notably as the main armament on s throughout World War II. History World War I The gun was based on the barrel of the QF 4-inch Mk V and the breech mechanism of the BL 4-inch Mk VIII and was first introduced in World War I on capital ships as secondary armament in triple-gun mountings, intended to provide rapid concentrated fire. This turned out to be unworkable in practice. '' Jane's Fighting Ships'' of 1919 commented, "4-inch triples are clumsy and not liked. They are not mounted in one sleeve; have separate breech mechanism, a gun crew of 23 to each triple". Guns were thereafter used in single-gun mountings, typically on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water-tube Boiler
A high pressure watertube boiler (also spelled water-tube and water tube) is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which boils water in the steam-generating tubes. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam. The heated water/steam mixture then rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In some services, the steam passes through tubes in the hot gas path, (a superheater) to become superheated. Superheated steam is defined as steam that is heated above the boiling point at a given pressure. Superheated steam is a dry gas and therefore is typically used to drive turbines, since water droplets can severely damage turbine blades. Saturated water at the bottom of the steam drum returns to the lower drum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at t ... [...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] |
Draft (hull)
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 a ... [...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 In watercraft, a racing shell (also referred to as just a ''fine boat'' (UK) or just ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement (ship)
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed (known as "lightweight tonnage") to its maximum load. Numerous specific terms are used to describe varying levels of load and trim, detailed below. Ship displacement should not be confused with measurements of volume or capacity typically used for commercial vessels and measured by tonnage: net tonnage and gross tonnage. Calculation The process of determining a vessel's displacement begins with measuring its draft.George, 2005. p.5. This is accomplished by means of its "draft marks" (or "load lines"). A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whaling Ship
A whaler or whaling ship is a specialized vessel, designed or adapted for whaling: the catching or processing of whales. Terminology The term ''whaler'' is mostly historic. A handful of nations continue with industrial whaling, and one, Japan, still dedicates a single factory ship for the industry. The vessels used by aboriginal whaling communities are much smaller and are used for various purposes over the course of the year. The ''whale catcher'' was developed during the age of steam, and then driven by diesel engines throughout much of the twentieth century. It was designed with a harpoon gun mounted at its bow and was fast enough to chase and catch rorquals such as the fin whale. At first, whale catchers either brought the whales they killed to a whaling station, a settlement ashore where the carcasses could be processed, or to its factory ship anchored in a sheltered bay or inlet. With the later development of the slipway at the ship's stern, whale catchers were able ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Munich Crisis
The Munich Agreement ( cs, Mnichovská dohoda; sk, Mníchovská dohoda; german: Münchner Abkommen) was an agreement concluded at Munich on 30 September 1938, by Nazi Germany, Germany, the United Kingdom, French Third Republic, France, and Fascist Italy (1922–1943), Italy. It provided "cession to Germany of the Sudeten German territory" of First Czechoslovak Republic, Czechoslovakia, despite the existence of a 1924 alliance agreement and 1925 military pact between France and the Czechoslovak Republic, for which it is also known as the Munich Betrayal (; ). Most of Europe celebrated the Munich agreement, which was presented as a way to prevent a major war on the continent. The four powers agreed to German occupation of Czechoslovakia, the German annexation of the Czechoslovak borderland areas named the Sudetenland, where more than three million people, mainly Sudeten Germans, ethnic Germans, lived. Adolf Hitler announced that it was his last territorial claim in Northern Europ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Kingdom of France, France. The modern Royal Navy traces its origins to the early 16th century; the oldest of the British Armed Forces, UK's armed services, it is consequently known as the Senior Service. From the middle decades of the 17th century, and through the 18th century, the Royal Navy vied with the Dutch Navy and later with the French Navy for maritime supremacy. From the mid 18th century, it was the world's most powerful navy until the World War II, Second World War. The Royal Navy played a key part in establishing and defending the British Empire, and four Imperial fortress colonies and a string of imperial bases and coaling stations secured the Royal Navy's ability to assert naval superiority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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