Bofors 40 mm gun
The Bofors 40 mm gun, often referred to simply as the Bofors gun, is an anti-aircraft/multi-purpose autocannon designed in the 1930s by the Swedish arms manufacturer AB Bofors. It was one of the most popular medium-weight anti-aircraft systems during World War II, a small number of these weapons remain in service to this day, and saw action as late as the Gulf War. In the post-war era the original design was not suitable for action against jet powered aircraft, so Bofors introduced a new model of more power. In spite of sharing almost nothing with the design other than the calibre and the distinctive conical flash hider. Although not as popular as the original L/60 model, the L/70 remains in service to this day, especially as a weapon for light armored vehicles. Bofors itself has been part of BAE Systems AB since March 2005, the Swedish Navy purchased a number of 2 pounder Pom-Poms from Vickers as anti-aircraft guns in 1922. The Navy approached Bofors about the development of a capable replacement.
Bofors signed a contract in late 1928, Bofors produced a gun that was a smaller version of a 57 mm semi-automatic gun developed as an anti-torpedo boat weapon in the late 19th century by Finspong. Their first test gun was a re-barreled Nordenfelt version of the Finspong gun, testing of this gun in 1929 demonstrated that a problem existed feeding the weapon in order to maintain a reasonable rate of fire. A mechanism that was enough to handle the stresses of moving the large round was too heavy to move quickly enough to fire rapidly. One attempt to solve this problem used zinc shell cases that burned up when fired and this proved to leave heavy zinc deposits in the barrel, and had to be abandoned. This seemed to be the solution they needed, improving firing rates to a level. During this period Krupp purchased a share of Bofors. Krupp engineers started the process of updating the Bofors factories to use equipment and metallurgy. The prototype was completed and fired in November 1931, and by the middle of the month it was firing strings of two and three rounds.
Changes to the mechanism were all that remained, and by the end of the year it was operating at 130 rounds per minute. Continued development was needed to turn it into a suitable for production. Since acceptance trials had been passed the year before, this known as the 40 mm akan M/32
Polly Woodside is a Belfast-built, three-masted, iron-hulled barque, preserved in Melbourne and forming the central feature of the South Wharf precinct. The ship was built in Belfast by William J. Woodside and was launched in 1885. Polly Woodside is typical of thousands of smaller iron barques built in the last days of sail, intended for deep water trade around the world and designed to be operated as economically as possible. Polly Woodside was built at the shipbuilding yard of Workman, Clark and Co, Queens Island, Belfast during 1885, for William J. Woodside. She was launched on 7 November 1885, the performed by the owners wife, Mrs Marian Woodside. In sixteen voyages between December 1885 and August 1903 she made a number of arduous passages around Cape Horn, the Polly Woodsides operating crew, including master and mate was generally less than 20. In 1904 Polly Woodside was sold to A. H. Turnbull of New Zealand and renamed Rona after Miss Rona Monro, valued in 1906 at £4,300, Rona generally operated on the New Zealand–Australian run, carrying timber, cement and coal.
The ship changed hands in 1911 for £3000 to Captain Harrison Douglas, of New Zealand, because of the heavy loss of shipping in the 1914–1918 war, Rona traded between New Zealand ports and San Francisco, carrying case oil and copra. Two mishaps occurred in the last years of the ships sailing career, in March 1920 the schooner W. J. Pirie, under tow in San Francisco harbour, collided with Rona at anchor, carrying away her headgear. Then in June 1921 the Rona, carrying a cargo of coal, grounded on Steeple Rock, the shingle bottom caused little damage and she was able to be towed into Wellington harbour. However, some slight stress fractures to the hull plating could still be seen when the ship was dry-docked in 1974, maritime historian Georg Kåhre has described the early 1920s as the final abandonment of sail by most of the worlds maritime nations. In the hectic economic climate of the war there had been no question of scrap prices. However, by 1922 this had changed, World freight rates were sliding in the post war slump, what had been marginal before was now uneconomic.
A few larger sailing ships defied this trend, but not the relatively small Rona, in September 1921 the ship was laid up, sold to Adelaide Steamship Company for service as a coal hulk in Australia. She arrived in Sydney on 8 October 1922, and by early 1923 had been stripped down, in March 1925 the Lammeroo towed Rona to Melbourne for this purpose. She spent the next 40 years quite unremarkably, bunkering coal-burning ships in the Port of Melbourne, an exception was her war service, during the Second World War. In 1943 she was requisitioned as a lighter by the Royal Australian Navy for service with other hulks in New Guinea waters. She was taken under tow of ST Tooronga on 28 October 1943 and she was taken in tow by ST Wato and towed to Milne Bay in New Guinea waters
Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, spacecraft, guided missiles, motor vehicles, weather formations, Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the objects location and speed. Radar was developed secretly for military use by several nations in the period before, the term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging or RAdio Direction And Ranging. The term radar has since entered English and other languages as a common noun, high tech radar systems are associated with digital signal processing, machine learning and are capable of extracting useful information from very high noise levels. Other systems similar to make use of other parts of the electromagnetic spectrum. One example is lidar, which uses ultraviolet, visible, or near infrared light from lasers rather than radio waves, as early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects.
In 1895, Alexander Popov, an instructor at the Imperial Russian Navy school in Kronstadt. The next year, he added a spark-gap transmitter, in 1897, while testing this equipment for communicating between two ships in the Baltic Sea, he took note of an interference beat caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon might be used for detecting objects, the German inventor Christian Hülsmeyer was the first to use radio waves to detect the presence of distant metallic objects. In 1904, he demonstrated the feasibility of detecting a ship in dense fog and he obtained a patent for his detection device in April 1904 and a patent for a related amendment for estimating the distance to the ship. He got a British patent on September 23,1904 for a radar system. It operated on a 50 cm wavelength and the radar signal was created via a spark-gap. In 1915, Robert Watson-Watt used radio technology to advance warning to airmen. Watson-Watt became an expert on the use of direction finding as part of his lightning experiments.
As part of ongoing experiments, he asked the new boy, Arnold Frederic Wilkins, Wilkins made an extensive study of available units before selecting a receiver model from the General Post Office. Its instruction manual noted that there was fading when aircraft flew by, in 1922, A. Hoyt Taylor and Leo C. Taylor submitted a report, suggesting that this might be used to detect the presence of ships in low visibility, eight years later, Lawrence A. Australia, New Zealand, and South Africa followed prewar Great Britain, and Hungary had similar developments during the war. Hugon, began developing a radio apparatus, a part of which was installed on the liner Normandie in 1935
Fram is a ship that was used in expeditions of the Arctic and Antarctic regions by the Norwegian explorers Fridtjof Nansen, Otto Sverdrup, Oscar Wisting, and Roald Amundsen between 1893 and 1912. Fram is said to have sailed north and farther south than any other wooden ship. Fram is preserved at the Fram Museum in Oslo, nansens ambition was to explore the Arctic farther north than anyone else. To do that, he would have to deal with a problem that many sailing on the ocean had encountered before him. Fram is a schooner with a total length of 39 meters. The ship is both wide and unusually shallow in order to better withstand the forces of pressing ice. Nansen commissioned the shipwright Colin Archer from Larvik to construct a vessel with these characteristics, Fram was built with an outer layer of greenheart wood to withstand the ice and with almost no keel to handle the shallow waters Nansen expected to encounter. The rudder and propeller were designed to be retracted, the ship was carefully insulated to allow the crew to live on board for up to five years.
The ship included a windmill, which ran a generator to provide power for lighting by electric arc lamps. Initially, Fram was fitted with a steam engine, prior to Amundsens expedition to the South Pole in 1910, the engine was replaced with a diesel engine, a first for polar exploration vessels. Nansen had Fram built in order to explore this theory and he undertook an expedition that came to last three years. When Nansen realised that Fram would not reach the North Pole directly by the force of the current, he, after reaching 86°14 north, he had to turn back to spend the winter at Franz Joseph Land. Nansen and Johansen survived on walrus and polar bear meat and blubber, finally meeting British explorers, the Jackson-Harmsworth Expedition, they arrived back in Norway only days before the Fram returned there. The ship had spent nearly three years trapped in the ice, reaching 85°57 N, in 1898, Otto Sverdrup, who had brought Fram back on the first Arctic voyage, led a scientific expedition to the Canadian Arctic Archipelago.
Fram was slightly modified for this journey, its freeboard being increased, Fram left harbour on 24 June 1898, with 17 men on board. Their aim was to chart the lands of the Arctic Islands, the expeditions lasted till 1902, leading to charts covering 260,000 km2, more than any other Arctic expedition. Fram was used by Roald Amundsen in his polar expedition from 1910 to 1912. The ship was left to decay in storage from 1912 until the late 1920s, in 1935 the ship was installed in the Fram Museum, where she now stands
Falls of Clyde (ship)
Falls of Clyde is the last surviving iron-hulled, four-masted full-rigged ship, and the only remaining sail-driven oil tanker. Designated a U. S. National Historic Landmark in 1989, she is now a museum ship in Honolulu and she is currently not open to the public. In September 2008, ownership was transferred to a new organization, the Friends of Falls of Clyde. Efforts to raise $1.5 million to get the ship into drydock have not succeeded as of 2015, an additional $30 million may be needed to fully restore the ship. In August,2016, the Harbors Division of the State of Hawaii impounded the ship, efforts are underway to convince the Governor to preserve the ship, including an online petition. Falls of Clyde was built in 1878 by Russell and Company in Port Glasgow, Scotland, launched as the first of nine iron-hulled four-masted ships for Wright and Breakenridges Falls Line. She was named after the Falls of Clyde, a group of waterfalls on the River Clyde and her maiden voyage took her to Karachi, now in Pakistan, and her first six years were spent engaged in the India trade.
She became a tramp pursuing general cargo such as lumber, jute and wheat from ports in Australia, India, New Zealand, and the British Isles. To economize on crew, Matson rigged Falls of Clyde down as a barque, at the same time, he added a deckhouse and rearranged the after quarters to accommodate paying passengers. From 1899 to 1907, she made over sixty voyages between Hilo and San Francisco, carrying general merchandise west, sugar east and she developed a reputation as a handy and commodious vessel, averaging 17 days each way on her voyages. In 1907, the Associated Oil Company bought Falls of Clyde, ten large steel tanks were built into her hull, and a pump room and generator fitted forward of an oil-tight bulkhead. In this configuration she brought kerosene to Hawaii and returned to California with molasses for cattle feed, in 1927, she was sold to the General Petroleum Company, her masts cut down, and converted into a floating fuel depot in Alaska. In 1959 she was purchased by William Mitchell, who towed her to Seattle, Washington, in 1963, the bank holding the mortgage on Falls of Clyde decided to sell her to be sunk as part of a breakwater at Vancouver, British Columbia.
Kortum and Klebingat aroused interest in the ship in Hawaii, at the end of October 1963, Falls of Clyde was taken under tow bound for Honolulu. Falls of Clyde was given to the Bishop Museum and opened to the public in 1968, in 1970 the grandson of original 19th century designer William Lithgow was engaged to assist in her restoration as a full-rigged ship. Support came from Sir William Lithgow, the shipbuilder and industrialist, whose Port Glasgow shipyard donated new steel masts, in 1973 the ship was entered into the National Register of Historic Places, and declared a U. S. National Historic Landmark in 1989. The ship is now in poor condition, causes of the deterioration of the ship are multiple. The ship has not been dry docked for a long time, preventive maintenance was not performed, although it would have been relatively inexpensive
A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, Naval mines can be used offensively—to hamper enemy shipping movements or lock vessels into a harbour, or defensively—to protect friendly vessels and create safe zones. Mines can be laid in many ways, by purpose-built minelayers, refitted ships and their flexibility and cost-effectiveness make mines attractive to the less powerful belligerent in asymmetric warfare. The cost of producing and laying a mine is usually anywhere from 0. 5% to 10% of the cost of removing it, parts of some World War II naval minefields still exist because they are too extensive and expensive to clear. It is possible for some of these 1940s-era mines to remain dangerous for many years to come, Mines have been employed as offensive or defensive weapons in rivers, estuaries and oceans, but they can be used as tools of psychological warfare.
Offensive mines are placed in enemy waters, outside harbours and across important shipping routes with the aim of sinking both merchant and military vessels. Defensive minefields safeguard key stretches of coast from enemy ships and submarines, forcing them into more easily defended areas, minefields designed for psychological effect are usually placed on trade routes and are used to stop shipping from reaching an enemy nation. They are often spread thinly, to create an impression of minefields existing across large areas, a single mine inserted strategically on a shipping route can stop maritime movements for days while the entire area is swept. International law requires nations to declare when they mine an area, the warnings do not have to be specific, for example, during World War II, Britain declared simply that it had mined the English Channel, North Sea, and French coast. Chinese records tell of naval explosives in the 16th century, used to fight against Japanese pirates and this kind of naval mine was loaded in a wooden box, sealed with putty.
General Qi Jiguang made several timed, drifting explosives, to harass Japanese pirate ships, although this is the rotating steel wheellocks first use in naval mines, Jiao Yu had described their use for land mines back in the 14th century. The first plan for a sea mine in the West was by Ralph Rabbards, the Dutch inventor Cornelius Drebbel was employed in the Office of Ordnance by King Charles I of England to make weapons, including a floating petard which proved a failure. Weapons of this type were apparently tried by the English at the Siege of La Rochelle in 1627, American David Bushnell developed the first American naval mine for use against the British in the American War of Independence. It was a watertight keg filled with gunpowder that was floated toward the enemy and it was used on the Delaware River as a drift mine. In 1812 Russian engineer Pavel Shilling exploded a mine using an electrical circuit. Russian naval specialists set more than 1500 naval mines, or infernal machines, designed by Moritz von Jacobi and by Immanuel Nobel, the mining of Vulcan led to the worlds first minesweeping operation.
During the next 72 hours,33 mines were swept, the Jacobi mine was designed by German born, Russian engineer Jacobi, in 1853. The mine was tied to the sea bottom by an anchor, a cable connected it to a cell which powered it from the shore
Star of India (ship)
Star of India was built in 1863 at Ramsey in the Isle of Man as Euterpe, a full-rigged iron windjammer ship. After a full career sailing from Great Britain to India and New Zealand, retired in 1926, she was not restored until 1962–63 and is now a seaworthy museum ship home-ported at the Maritime Museum of San Diego in San Diego, California. She is the oldest ship still sailing regularly and the oldest iron-hulled merchant ship still floating, the ship is both a California Historical Landmark and United States National Historic Landmark. She was launched on 14 November 1863, and assigned British Registration No.47617, euterpes career had a rough beginning. She sailed for Calcutta from Liverpool on 9 January 1864, under the command of Captain William John Storry, a collision with an unlit Spanish brig off the coast of Wales carried away the jib-boom and damaged other rigging. The crew became mutinous, refusing to continue, and she returned to Anglesey to repair,17 of the crew were confined to the Beaumaris Jail at hard labor.
Then, in 1865, Euterpe was forced to cut away her masts in a gale in the Bay of Bengal off Madras and limped to Trincomalee, Captain Storry died during the return voyage to England and was buried at sea. In late 1871 she began twenty-five years of carrying passengers and freight in the New Zealand emigrant trade, the fastest of her 21 passages to New Zealand took 100 days, the longest 143 days. She made ports of call in Australia, California, a baby was born on one of those trips en route to New Zealand, and was given the middle name Euterpe. Another child, John William Philips Palmer, was born on the 1873 journey to Dunedin, New Zealand and she was registered in the United States on 30 October 1900. In 1906, the Association changed her name to be consistent with the rest of their fleet and she was laid up in 1923 after 22 Alaskan voyages, by that time, steam ruled the seas. In 1926, Star of India was sold to the Zoological Society of San Diego, the Great Depression and World War II caused that plan to be canceled, and it was not until 1957 that restoration began.
Alan Villiers, a captain and author, came to San Diego on a lecture tour. Seeing Star of India decaying in the harbor, he publicized the situation, progress was still slow, but in 1976, Star of India finally put to sea again. She houses exhibits for the Maritime Museum of San Diego, is kept fully seaworthy, unlike many preserved or restored vessels, her hull and equipment are nearly 100% original. This location is slightly west of downtown San Diego, the other ships belonging to the Maritime Museum are always docked to the north of Star of India. Her nearest neighbor – since 2007 – is HMS Surprise, a replica of a British frigate, when she sails, Star of India often remains within sight of the coast of San Diego County, and usually returns to her dock within a day. She is sailed by a volunteer crew of Maritime Museum members
Estonian Maritime Museum
The Estonian Maritime Museum is located in the Fat Margaret tower in the old town of Tallinn. The museum presents history of ships and navigation in Estonia and related to Estonia, other parts of the Maritime Museum are the mine museum and the Seaplane Harbour where museum ships are presented. Fat Margaret was built in the early 16th century during the reconstruction of the city gate system. Apart from being a fortification against would-be invaders to the port of the town, the tower is a defensive structure at the end of Pikk tänav. Together with the Suur Rannavärav, an arch flanked by two towers, it served to defend the harbour of Tallinn. Suur Tõll - a steamer-icebreaker built in 1914 Estonian Navy EML Olev EML Vaindlo Media related to Estonian Maritime Museum at Wikimedia Commons Estonian Maritime Museum
SS Great Britain
SS Great Britain is a museum ship and former passenger steamship, which was advanced for her time. She was the longest passenger ship in the world from 1845 to 1854 and she was designed by Isambard Kingdom Brunel for the Great Western Steamship Companys transatlantic service between Bristol and New York. While other ships had been built of iron or equipped with a screw propeller and she was the first iron steamer to cross the Atlantic, which she did in 1845, in the time of 14 days. The ship is 322 ft in length and has a 3 and she was powered by two inclined 2 cylinder engines of the direct-acting type, with twin 88 in bore, 6-foot stroke cylinders. She was provided with secondary sail power, the four decks provided accommodation for a crew of 120, plus 360 passengers who were provided with cabins and promenade saloons. When launched in 1843, Great Britain was by far the largest vessel afloat, in 1852 she was sold for salvage and repaired. Great Britain carried thousands of immigrants to Australia from 1852 until converted to sail in 1881, three years later, she was retired to the Falkland Islands where she was used as a warehouse, quarantine ship and coal hulk until scuttled in 1937.
In 1970, following a donation by Sir Jack Hayward that paid for the vessel to be towed back to the UK. Now listed as part of the National Historic Fleet, she is a visitor attraction and museum ship in Bristol Harbour. After the initial success of its first liner, SS Great Western of 1838, the same engineering team that had collaborated so successfully on Great Western—Isambard Brunel, Thomas Guppy, Christopher Claxton and William Patterson—was again assembled. This time however, whose reputation was at its height, construction was carried out in a specially adapted dry dock in Bristol, England. Two chance encounters were to affect the design of Great Britain. In late 1838, John Lairds 213-foot English Channel packet ship Rainbow—the largest iron-hulled ship in service—made a stop at Bristol, Brunel despatched his associates Christopher Claxton and William Patterson to make a return voyage to Antwerp on Rainbow to assess the utility of the new building material. Both men returned as converts to iron-hulled technology, and Brunel scrapped his plans to build a wooden ship, Great Britains builders recognised a number of advantages of iron over the traditional wooden hull.
Wood was becoming more expensive, while iron was getting cheaper, Iron hulls were not subject to dry rot or woodworm, and they were lighter in weight and less bulky. The chief advantage of the hull was its much greater structural strength. The practical limit on the length of a ship is about 300 feet. Iron hulls are far less subject to hogging, so that the size of an iron-hulled ship is much greater
The Estonian Navy, is the name of the unified naval forces among the Estonia Defence Forces. There are about four commissioned ships in the Estonian Navy, including three ships, the displacement of the navy is under 10,000 tonnes making it one of the smallest navies in the world. The Estonian Navy has participated numerous times in NATO´s naval joint-exercises, the “Merevägi” was founded on November 21,1918. The foundation and development of the Estonian Navy relies greatly on the British Navy which operated in the Gulf of Finland as an ally to Estonia during the Estonian War of Independence. The first Estonian navy ships, minecruisers Lennuk and Wambola, were gifts from the British Royal Navy after they had captured from the Russian Baltic Fleet in 1919. The Meredessantpataljon, was a short lived marine infantry - Naval landing battalion of the Estonian Defence Forces subject to the Estonian Navy, the battalion was created from the crews of the Estonian surface warships and was based in Tallinn.
Since the end of the 19th century the Russian Empire began to build coastal fortresses, Tallinn having been historically an important trading center between the East and the West became one of the main naval bases of the Imperial Russian Baltic fleet. A systematic coastal defence network and naval gun installations were ordered, during the Estonian War of Independence and after the Treaty of Tartu the Estonian Navy began to rebuild and develop the coastal defence network. From 1918 to 1940 Estonia invested millions of kroons into the renovation, by 1939 the coastal batteries presented a considerable naval force and were considered among the Estonian Navy elite forces. During World War II and the Soviet occupation of Estonia, little has remained of the coastal defence lines. Today some buildings and firing positions can be seen at places of which the best preserved ones are located on the island of Aegna. In 1998 the Baltic Naval Squadron BALTRON was inaugurated, the main responsibility of BALTRON is to improve the co-operation between the Baltic States in the areas of naval defence and security.
Constant readiness to contribute units to NATO-led operations is assured through BALTRON, each Baltic state appoints one or two ships to BALTRON for certain periods and staff members for one year. Service in BALTRON provides both, the crews and staff officers, with an excellent opportunity to serve in an international environment, Estonia provides BALTRON with on-shore facilities for the staff. Since 1995 Estonian Navy ships have participated in most of the major international exercises, ENS Admiral Pitka was the first vessel from the Baltic navies to be part of the force. SNMCMG1 is one of the Estonian Navys main NATO partners, the Estonian Navy uses a small number of different vessels and weapon-systems. Since the restoration of the Estonian Defence Forces on 3 September 1991, then-Commander Estonian Naval Defence Forces, Commodore Roland Leit, was interviewed by Janes Defence Weekly on 9 July 1994. When the Soviet Navy left the Tallinn Naval Base, they sabotaged the facilities and they broke all the windows, all the heating, and all the electricity equipment
Charles W. Morgan (ship)
Charles W. Morgan is an American whaling ship built in 1841 whose active service period was during the 19th and early 20th centuries. Ships of this type were used to harvest the blubber of whales for whale oil. The ship has served as a ship since the 1940s. She is the worlds oldest surviving merchant vessel, and the surviving wooden whaling ship from the 19th century American merchant fleet. She was designated a National Historic Landmark in 1966, Charles Waln Morgan chose Jethro and Zachariah Hillmans shipyard in New Bedford, Massachusetts to construct a new ship. Charles W. Morgans live oak keel was laid down in February 1841, the bow and stern pieces of live oak were secured to the keel by an apron piece. The sturdy stern post was strengthened with hemlock root and white oak, yellow pine shipped from North Carolina was used for the ships beams and hemlock or hackmatack was used for the hanging knees. Construction of Charles W. Morgan proceeded until April 19,1841, the strike gathered support until it encompassed the shipyard, the oil refineries, and the cooper shops, Morgan was appointed chairman of the employers and given the task of resolving the strike.
Morgan opposed their demands, and a meeting with four master mechanics ended in failure, on May 6, an agreement was reached when the workers accepted a ten-and-a-half-hour workday. Work resumed on the ship without incident and she was launched on July 21,1841, the ship was registered as a caravel of 106 1⁄2 feet in length,27 feet 2 1⁄2 inches inches in breadth, and 13 feet 7 1⁄4 inches in depth. The ship was outfitted at Rotchs Wharf for the two months while preparations were made for its first voyage. The eponymous name, Charles W. Morgan, was rejected by her namesake builder before being used. Captain Thomas Norton sailed Charles W. Morgan into the Atlantic alongside Adeline Gibbs, a stop was made at Porto Pim on Faial Island to gather supplies before crossing the Atlantic. The ship passed Cape Horn, charted a course to the north, on December 13, the men launched in their whaling boats and took their first whale and killing it with the thrust of a lance under the side fin. Charles W. Morgan entered the port of Callau in early February, in 1844, the ship sailed to the Kodiak Grounds before sailing for home on August 18.
Charles W. Morgan returned to her port in New Bedford on January 2,1845.56. In her 80 years of service from her port of New Bedford, Massachusetts. Charles W. Morgan, in total, brought home 54,483 barrels of sperm and she sailed in the Indian and South Atlantic Oceans, surviving ice and snow storms
A minesweeper is a small naval warship designed to engage in minesweeping. Using various mechanisms intended to counter the threat posed by naval mines, although naval warfare has a long history, the earliest known usage of the naval mine dates to the Ming dynasty. Dedicated minesweepers, only appear in the record several centuries later, to the Crimean War. In the Crimean War, minesweepers consisted of British rowboats trailing grapnels to snag the mines, despite the use of mines in the American Civil War, there are no records of effective minesweeping being used. Officials in the Union Army attempted to create the first minesweeper but were plagued by flawed designs, minesweeping technology picked up in the Russo-Japanese War, using aging torpedo boats as minesweepers. In Britain, naval leaders recognized before the outbreak of World War I that the development of sea mines was a threat to the nations shipping, sir Arthur Wilson noted the real threat of the time was blockade aided by mines and not invasion.
A Trawler Section of the Royal Navy Reserve became the predecessor of the mine sweeping forces with specially designed ships and these reserve Trawler Section fishermen and their trawlers were activated, supplied with mine gear, rifles and pay as the first minesweepers. The dedicated, purpose-built minesweeper first appeared during World War I with the Flower-class minesweeping sloop, by the end of the War, naval mine technology had grown beyond the ability of minesweepers to detect and remove. Minesweeping made significant advancements during World War II, combatant nations quickly adapted ships to the task of minesweeping, including Australias 35 civilian ships that became Auxiliary Minesweepers. Both Allied and Axis countries made heavy use of minesweepers throughout the war, historian Gordon Williamson wrote that Germanys minesweepers alone formed a massive proportion of its total strength, and are very much the unsung heroes of the Kriegsmarine. Naval mines remained a threat even after the war ended, after the Second World War, allied countries worked on new classes of minesweepers ranging from 120-ton designs for clearing estuaries to 735-ton oceangoing vessels.
The United States Navy even used specialized Mechanized Landing Craft to sweep shallow harbors in, as of June 2012, the U. S. Navy had four minesweepers deployed to the Persian Gulf to address regional instabilities. Minesweepers are equipped with mechanical or electrical devices, known as sweeps, mechanical sweeps are devices designed to cut the anchoring cables of moored mines, and preferably attach a tag to help the subsequent localization and neutralization. They are towed behind the minesweeper, and use a body to maintain the sweep at the desired depth. Influence sweeps are equipment, often towed, that emulate a particular ship signature, the most common such sweeps are magnetic and acoustic generators. There are two modes of operating an influence sweep, MSM and TSM, MSM sweeping is founded on intelligence on a given type of mine, and produces the output required for detonation of this mine. If such intelligence is unavailable, the TSM sweeping instead reproduces the influence of the ship that is about to transit through the area. TSM sweeping thus clears mines directed at this ship without knowledge of the mines, mines directed at other ships might remain