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Brazilian Monitor Alagoas
The Brazilian monitor ''Alagoas'' was the third ship of the river monitors built for the Imperial Brazilian Navy during the Paraguayan War in the late 1860s. ''Alagoas'' participated in the Passage of Humaitá on 19 February 1868 and provided fire support for the army for the rest of the war. The ship was assigned to the Upper Uruguay ( pt, Alto Uruguai) flotilla after the war. ''Alagoas'' was transferred to Rio de Janeiro in the 1890s and participated in the Navy Revolt of 1893–94. The ship was scrapped in 1900. Design and description The ''Pará''-class monitors were designed to meet the need of the Brazilian Navy for small, shallow-draft armored ships capable of withstanding heavy fire. The monitor configuration was chosen as a turreted design did not have the same problems engaging enemy ships and fortifications as did the casemate ironclads already in Brazilian service. The oblong gun turret sat on a circular platform that had a central pivot. It was rotated by four men ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fortress Of Humaitá
The Fortress of Humaitá (1854–68), known metaphorically as the Gibraltar of South America, was a Paraguayan military installation near the mouth of the River Paraguay. A strategic site without equal in the region, "a fortress the likes of which had never been seen in South America", it was "the key to Paraguay and the upper rivers". It played a crucial role in the deadliest conflict in the continent's history – the Paraguayan War – of which it was the principal theatre of operations. The site was a sharp horseshoe bend in the river; practically all vessels wishing to enter the Republic of Paraguay – and indeed to steam onwards to the Brazilian province of Mato Grosso – were forced to navigate it. The bend was commanded by a line of artillery batteries, at the end of which was a chain boom which, when raised, detained the shipping under the guns. The navigable channel was only 200 yards wide and ran in easy reach of the artillery. The fortress was protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolta Da Armada
The Brazilian Naval Revolts, or the Revoltas da Armada (in Portuguese), were armed mutinies promoted mainly by admirals Custódio José de Melo and Saldanha da Gama and their fleet of rebel Brazilian navy ships against the claimed unconstitutional staying in power of president Floriano Peixoto. First revolt In November 1891, President Marshal Deodoro da Fonseca, amid a political crisis compounded by the effects of an economic crisis, in flagrant violation of the new constitution, decided to "solve" the political crisis by ordering the closure of Congress, supported mainly by Paulista oligarchy. The Navy, still resentful of the circumstances and outcomes of the coup that had put an end to the monarchy in Brazil, under the leadership of admiral Custódio José de Melo, rose up and threatened to bombard the city of Rio de Janeiro, then the capital of Brazil. To avoid a civil war, marshal Deodoro resigned the presidency in 23 November. With the resignation of Deodoro, after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
70-pounder Whitworth Naval Gun
The 70-pounder Whitworth naval gun was designed by Joseph Whitworth during the 1860s. It was a rifled muzzle loader and used his hexagonal, rifled-bore design. Principle The gun used polygonal rifling, a principle invented by Whitworth in 1853. The concept was to use the hexagon to impart a very rapid spin to the projectile. The method of manufacturing the rifling was thus described by the Report of the Armstrong & Whitworth Committee of the British War Office (1866): may be described in general terms as a hexagonal bore with a rapid twist, although, strictly speaking, the bore is not hexagonal, but has 24 surfaces. The gun is, in the first instance, bored out cylindrically; a part of this original bore is left in the centre of each side of the hexagon, making six surfaces, then there are the coming out sides of the hexagon which give six more surfaces, and the going in sides giving also six surfaces, and lastly, the rounding off of the angles, which give six more, making 24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canoas Paraguayas Dando Abordagem Ao Monitor ALAGOAS, Nas Proximidades Das Baterias Do Timbó
Canoas (), which earned city status in 1939, is a municipality in the Brazilian state of Rio Grande do Sul. With more than 340,000 inhabitants, it is part of the Porto Alegre conurbation and has the second highest GDP in the state. It is also the fourth largest city in the state by population. Canoas boasts a strong manufacturing-based economy and is the home to Canoas Air Force Base - ALA3, one of the most important bases of the Brazilian Air Force. According to the IBGE, Brazil's Geography and Statistics Institute, Canoas currently has no rural areas, but it started as a village of large landowners. The first of them was ''conquistador'' Francisco Pinto Bandeira, who received from the Portuguese Crown, in 1740, an area north of the Gravataí River. History has that 1871 was the beginning of the village of Canoas, when the first section of the railway that would link Porto Alegre to São Leopoldo was inaugurated. Canoas was then part of the municipalities of Gravataí and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Steam Engine
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II. Reciprocating steam engines were progressively replaced in marine applications during the 20th century by steam turbines and marine diesel engines. History The first commercially successful steam engine was developed by Thomas Newcomen in 1712. The steam engine improvements brought forth by James Watt in the later half of the 18th century greatly improved steam engine efficiency and allowed more compact engine arrangements. Successful adaptation of the steam engine to marine applications in England would have to wait until almost a century after Newcomen, when Scottish engineer William Symington built the world's "first practical steamboat", the ''Charlotte Dundas'', in 1802. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freeboard (nautical)
In sailing and boating, a vessel's freeboard is the distance from the waterline to the upper deck level, measured at the lowest point of sheer where water can enter the boat or ship. In commercial vessels, the latter criterion measured relative to the ship's load line, regardless of deck arrangements, is the mandated and regulated meaning. In yachts, a low freeboard is often found on racing boats, for increased speed (by reducing weight and therefore drag). A higher freeboard will give more room in the cabin, but will increase weight and drag, compromising speed. A higher freeboard, such as used on ocean liners, also helps weather waves and so reduce the likelihood of being washed over by full water waves. A low-freeboard vessel is susceptible to taking in water in rough seas. Freighter ships and warships use high freeboard designs to increase internal volume, which also allows them to satisfy International Maritime Organization The International Maritime Organizatio ... [...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 d ... [...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 Hull may refer to: Structures * Chassis, of an armored fighting vehicle * Fuselage, of an aircraft * Hull (botany), the outer covering of seeds * Hull (watercraft), the body or frame of a ship * Submarine hull Mathematics * Affine hull, in affi ..., 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 fro ... [...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 repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofouling
Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that cause degradation to the primary purpose of that item. Such accumulation is referred to as '' epibiosis'' when the host surface is another organism and the relationship is not parasitic. Since biofouling can occur almost anywhere water is present, biofouling poses risks to a wide variety of objects such as boat hulls and equipment, medical devices and membranes, as well as to entire industries, such as paper manufacturing, food processing, underwater construction, and desalination plants. Anti-fouling is the ability of specifically designed materials (such as toxic biocide paints, or non-toxic paints) to remove or prevent biofouling. The buildup of biofouling on marine vessels poses a significant problem. In some instances, the hull stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muntz Metal
Muntz metal (also known as yellow metal) is an alpha-beta brass alloy composed of approximately 60% copper, 40% zinc and a trace of iron. It is named after George Fredrick Muntz, a metal-roller of Birmingham, England, who commercialised the alloy following his patent of 1832. The alloy must be worked hot and is used today for corrosion-resistant machine parts. Alpha-beta (also called duplex) metals contain both the α and β phases. The α phase refers to a crystal structure that is face-centered cubic, while the β phase is body-centered cubic. Its original application was as a replacement for copper sheathing on the bottom of boats, as it maintained the anti-fouling abilities of the pure copper at around two thirds of the price. It became the material of choice for this application and Muntz made his fortune. It was found that copper would gradually leach from the alloy in sea water, poisoning any organism that attempted to attach itself to a hull sheathed in the metal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Ram
A ram was a weapon fitted to varied types of ships, dating back to antiquity. The weapon comprised an underwater prolongation of the bow of the ship to form an armoured beak, usually between 2 and 4 meters (6–12 ft) in length. This would be driven into the hull of an enemy ship to puncture, sink or disable it. Ancient rams It was possibly developed in late Bronze age Egypt, but it only became widely used in later Iron age Mediterranean galleys. The ram was a naval weapon in the Greek/ Roman antiquity and was used in such naval battles as Salamis and Actium. Naval warfare in the Mediterranean rarely used sails, and the use of rams specifically required oarsmen rather than sails in order to maneuver with accuracy and speed, and particularly to reverse the movement of a ramming ship to disentangle it from its sinking victim, lest it be pulled down when its victim sank. The Athenians were especially known for their '' diekplous'' and '' periplous'' tactics that disabled enemy shi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
