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Rusalka (ship)
''Rusalka'' (russian: Русалка, ''Mermaid''), was one of two s built for the Imperial Russian Navy in the 1860s. She served for her entire career with the Baltic Fleet. Aside from hitting an uncharted rock not long after she was completed in 1869, she had an uneventful career. ''Rusalka'' sank in a storm in 1893 with the loss of all hands in the Gulf of Finland. In 1902, a Russalka Memorial, memorial was built in Reval (Tallinn) to commemorate her loss. Her wreck was rediscovered in 2003, bow-down in the mud, which has prompted a new theory regarding her loss. Design and description ''Rusalka'' was long at the waterline. She had a Beam (nautical), beam of and a maximum Draft (hull), draft of . The ship was designed to Displacement (ship), displace , but turned out to be overweight and actually displaced . Her crew numbered 13 officers and 171 crewmen in 1877.McLaughlin, p. 156 The ship had two simple horizontal Marine steam engine#Direct acting, direct-acting steam engi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drydock
A dry dock (sometimes drydock or dry-dock) is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Dry docks are used for the construction, maintenance, and repair of ships, boats, and other watercraft. History Greco-Roman world The Greek author Athenaeus of Naucratis (V 204c-d) reports something that may have been a dry dock in Ptolemaic Egypt in the reign of Ptolemy IV Philopator (221-204 BC) on the occasion of the launch of the enormous ''Tessarakonteres'' rowing ship. It has been calculated that a dock for a vessel of such a size might have had a volume of 750,000 gallons of water. In Roman times, a shipyard at Narni, which is still studied, may have served as a dry dock. Medieval China The use of dry docks in China goes at least as far back the 10th century A.D. In 1088, Song Dynasty scientist and statesman Shen Kuo (1031–1095) wrote in his '' Dream Pool Essays'': Renais ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperial Russian Navy
The Imperial Russian Navy () operated as the navy of the Russian Tsardom and later the Russian Empire from 1696 to 1917. Formally established in 1696, it lasted until dissolved in the wake of the February Revolution of 1917. It developed from a smaller force that had existed prior to Tsar Peter the Great's founding of the modern Russian navy during the Second Azov campaign in 1696. It expanded in the second half of the 18th century and reached its peak strength by the early part of the 19th century, behind only the British and French fleets in terms of size. The Imperial Navy drew its officers from the aristocracy of the Empire, who belonged to the state Russian Orthodox Church. Young aristocrats began to be trained for leadership at a national naval school. From 1818 on, only officers of the Imperial Russian Navy were appointed to the position of Chief Manager of the Russian-American Company, based in Russian America (present-day Alaska) for colonization and fur-trade developme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quick-firing Gun
A quick-firing or rapid-firing gun is an artillery piece, typically a gun or howitzer, which has several characteristics which taken together mean the weapon can fire at a fast rate. Quick-firing was introduced worldwide in the 1880s and 1890s and had a marked impact on war both on land and at sea. Characteristics The characteristics of a quick-firing artillery piece are: *A breech-loading weapon with a breech mechanism that allows rapid reloading *Single-part cased ammunition, i.e. a cartridge containing both shell and propellant *Recoil buffers to limit recoil, so the barrel can quickly return to the same position after firing *The use of smokeless powder – nitrocellulose, nitroglycerine, or cordite – which create far less smoke than gunpowder, meaning that gun crews could still see their target These innovations, taken together, meant that the quick-firer could fire aimed shells much more rapidly than an older weapon. For instance, an Elswick Ordnance Company 4.7-inch gun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torpedo Boat
A torpedo boat is a relatively small and fast naval ship designed to carry torpedoes into battle. The first designs were steam-powered craft dedicated to ramming enemy ships with explosive spar torpedoes. Later evolutions launched variants of self-propelled Whitehead torpedoes. These were inshore craft created to counter both the threat of battleships and other slow and heavily armed ships by using speed, agility, and powerful torpedoes, and the overwhelming expense of building a like number of capital ships to counter an enemy's. A swarm of expendable torpedo boats attacking en masse could overwhelm a larger ship's ability to fight them off using its large but cumbersome guns. A fleet of torpedo boats could pose a similar threat to an adversary's capital ships, albeit only in the coastal areas to which their small size and limited fuel load restricted them. The introduction of fast torpedo boats in the late 19th century was a serious concern to the era's naval strategists, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obukhov State Plant
Obukhov State Plant (also known Obukhovski Plant, russian: Государственный Обуховский Завод, Gosudarstvennyy Obukhovskiy Zavod) is a major Russian metallurgy and heavy machine-building plant in St. Petersburg, Russia. History The factory was founded in 1863 to produce naval artillery based on German designs by Krupp. It has since been a major producer of artillery and other military equipment. V. Volodarsky was assassinated when making his way to a meeting relating to industrial unrest in the factory. From 1922 to 1992 it was renamed Bolshevik Plant no. 232. In the late 1920s, it became one of the two main Soviet tank factories (along with the Kharkov Locomotive Factory), and produced the first domestic tank, the T-18. It later became home to the AVO-5 tank design bureau, soon named OKMO, which was responsible for the T-26 infantry tank. In 1932, the tank department of the Bolshevik factory, became the new Factory No. 174 (K.E. Voroshilov). This n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoothbore
A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. History Early firearms had smoothly bored barrels that fired projectiles without significant spin. To minimize inaccuracy-inducing tumbling during flight, their projectiles required an aerodynamically uniform shape, such as a sphere. However, surface imperfections on the projectile and/or the barrel will cause even a sphere to rotate randomly during flight, and the Magnus effect will curve it off the intended trajectory when spinning on any axis not parallel to the direction of travel. Rifling the bore surface with spiral grooves or polygonal valleys imparts a stabilizing gyroscopic spin to a projectile that prevents tumbling in flight. Not only does this more than counter Magnus-induced drift, but it allows a longer, more streamlined round with greater sectional density to be fired from the same caliber barrel, improvin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifling
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the projectile longitudinally by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs. Rifling is characterized by its twist rate, which indicates the distance the rifling takes to complete one full revolution, such as "1 turn in 10 inches" (1:10 inches), "1 turn in 254 mm" ("1:254 mm" or "1:25.4 cm)", or the like. Normally, an experienced shooter can infer the units of measurement from the numbers alone. A shorter distance indicates a faster twist, meaning that for a given velocity the projectile will rotate at a higher spin rate. The combination of length, weight, and shape of a projectile determines the twist rate needed to gyroscopically stabilize it – barrel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Trial
A sea trial is the testing phase of a watercraft (including boats, ships, and submarines). It is also referred to as a " shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on open water, and it can last from a few hours to many days. Sea trials are conducted to measure a vessel's performance and general seaworthiness. Testing of a vessel's speed, maneuverability, equipment and safety features are usually conducted. Usually in attendance are technical representatives from the builder (and from builders of major systems), governing and certification officials, and representatives of the owners. Successful sea trials subsequently lead to a vessel's certification for commissioning and acceptance by its owner. Although sea trials are commonly thought to be conducted only on new-built vessels (referred by shipbuilders as 'builders trials'), they are regularly conducted on commissioned vessels as well. In new vessels, they are used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire-tube Boiler
A fire-tube boiler is a type of boiler in which hot gases pass from a fire through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam. The fire-tube boiler developed as the third of the four major historical types of boilers: low-pressure tank or "haystack" boilers, flued boilers with one or two large flues, fire-tube boilers with many small tubes, and high-pressure water-tube boilers. Their advantage over flued boilers with a single large flue is that the many small tubes offer far greater heating surface area for the same overall boiler volume. The general construction is as a tank of water penetrated by tubes that carry the hot flue gases from the fire. The tank is usually cylindrical for the most part—being the strongest practical shape for a pressurized container—and this cylindrical tank may be either horizontal or vertic ... [...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 mer ... [...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 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] |
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