Electric motor
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of rotation of a shaft. Electric motors can be powered by direct current sources, such as from batteries, motor vehicles or rectifiers, or by alternating current sources, such as a power grid, inverters or electrical generators. An electric generator is mechanically identical to an electric motor, but operates in the reverse direction, converting mechanical energy into electrical energy. Electric motors may be classified by considerations such as power source type, internal construction and type of motion output. In addition to AC versus DC types, motors may be brushed or brushless, may be of various phase, may be either air-cooled or liquid-cooled. General-purpose motors with standard dimensions and characteristics provide convenient mechanical power for industrial use.
The largest electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors are found in industrial fans and pumps, machine tools, household appliances, power tools and disk drives. Small motors may be found in electric watches. In certain applications, such as in regenerative braking with traction motors, electric motors can be used in reverse as generators to recover energy that might otherwise be lost as heat and friction. Electric motors produce linear or rotary force and can be distinguished from devices such as magnetic solenoids and loudspeakers that convert electricity into motion but do not generate usable mechanical force, which are referred to as actuators and transducers; the first electric motors were simple electrostatic devices described in experiments by Scottish monk Andrew Gordon and American experimenter Benjamin Franklin in the 1740s. The theoretical principle behind them, Coulomb's law, was discovered but not published, by Henry Cavendish in 1771.
This law was discovered independently by Charles-Augustin de Coulomb in 1785, who published it so that it is now known with his name. The invention of the electrochemical battery by Alessandro Volta in 1799 made possible the production of persistent electric currents. After the discovery of the interaction between such a current and a magnetic field, namely the electromagnetic interaction by Hans Christian Ørsted in 1820 much progress was soon made, it only took a few weeks for André-Marie Ampère to develop the first formulation of the electromagnetic interaction and present the Ampère's force law, that described the production of mechanical force by the interaction of an electric current and a magnetic field. The first demonstration of the effect with a rotary motion was given by Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury; when a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire.
This motor is demonstrated in physics experiments, substituting brine for mercury. Barlow's wheel was an early refinement to this Faraday demonstration, although these and similar homopolar motors remained unsuited to practical application until late in the century. In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils. After Jedlik solved the technical problems of continuous rotation with the invention of the commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for teaching, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator and commutator; the device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced by the currents flowing through their windings. After many other more or less successful attempts with weak rotating and reciprocating apparatus Prussian Moritz von Jacobi created the first real rotating electric motor in May 1834.
It developed remarkable mechanical output power. His motor set a world record, which Jacobi improved four years in September 1838, his second motor was powerful enough to drive a boat with 14 people across a wide river. It was in 1839/40 that other developers managed to build motors with similar and higher performance; the first commutator DC electric motor capable of turning machinery was invented by British scientist William Sturgeon in 1832. Following Sturgeon's work, a commutator-type direct-current electric motor was built by American inventor Thomas Davenport, which he patented in 1837; the motors ran at up to 600 revolutions per minute, powered machine tools and a printing press. Due to the high cost of primary battery power, the motors were commercially unsuccessful and bankrupted Davenport. Several inventors followed Sturgeon in the development of DC motors, but all encountered the same battery cost issues; as no electricity distribution system was available at the time, no practical commercial market emerged for these motors.
In 1855, Jedlik built a device using similar principles to those used in his electromagnetic self-rotors, capable of useful work. He built a model electric vehicle that same year. A major turning point came in 1864; this featured symmetrically-grouped coils closed upon themselves and connected to the bars of a commutator, the brushes of which delivered non-fluctuating current. The first c
Deck gun
"Deck gun" can mean a type of big water nozzle used for firefighting. A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open; the main deck gun was a dual-purpose weapon used to sink merchant shipping or shell shore targets, or defend the submarine on the surface from enemy aircraft and warships. A crew of three operated the gun, while others were tasked with supplying ammunition. A small locker box held a few'ready-use' rounds. With a well-drilled, experienced crew, the rate of fire of a deck gun could be 15 to 18 aimed shots per minute; some submarines had additional deck guns like auto-cannons and machine guns for anti-aircraft defense. Similar unenclosed guns are found on surface warships as secondary or defensive armament, although the term "deck gun" refers only to submarine-mounted guns. Although technically not a deck gun, USS Holland, the first American submarine, was equipped with a pneumatic dynamite gun built into the bow in 1900.
The deck gun was first used by the Germans in World War I, proved its worth when the U-boat needed to conserve torpedoes or attack enemy vessels straggling behind a convoy. Submarine captains considered the deck gun as their main weapon, using torpedoes only when necessary, since many World War I submarines carried ten or fewer torpedoes and fired several to increase the probability of hitting the target. Lothar von Arnauld de la Perière used a dynamiting team on 171 of his 194 sinkings; the deck gun was introduced in all submarine forces prior to World War I. The three British M-class submarines mounted a single 12 inch /40 caliber naval gun intended to be fired while the submarine was at periscope depth with the muzzle of the gun above water, principally in a shore bombardment role; this World War I design was found unworkable in trials because the submarine was required to surface to reload the gun, problems arose when variable amounts of water entered the barrel prior to firing. The French submarine Surcouf was launched in 1929 with two 203mm/50 Modèle 1924 guns in a turret forward of the conning tower.
These were the second largest guns carried by any submarine after the British HMS M1 during the Second World War. The London Naval Treaty of 1930 restricted submarine guns to a maximum of 155 mm. In early World War II, German submarine commanders favored the deck gun because of the unreliability of torpedoes; the deck gun became less effective as convoys became larger and better equipped, merchant ships were armed. Surfacing became dangerous in the vicinity of a convoy because of improvements in radar and direction finding.. German U-boat deck guns were removed on the order of the supreme commander of the U-boat Arm during World War II, those deck guns that remained were no longer manned. For a few months in 1943, some U-Boats operating in the Bay of Biscay were equipped with enhanced anti-aircraft guns, being known as "U-Flak" boats to be deployed as service escorts for regular U-Boats. After the Royal Air Force modified their anti-submarine tactics which made it too dangerous for a submarine to stay on the surface to right, the U-Flaks were converted back to standard U-boat armament configuration.
Japanese submarine cruisers used 14 cm/40 11th Year Type naval guns to shell California, British Columbia and Oregon during World War II. Two notable deck guns from German U-boats used in World War II were the 8.8 cm SK C/35 and the 10.5 cm SK C/32. The 88 mm had ammunition, of the projectile and cartridge type, it had the same controls on both sides of the gun so that the two crewmen that were in charge of firing it could control the gun from either side. The 105 mm evolved from the 88 mm in the sense that it was more accurate and had more power due to the 51 lb ammunition it fired. In the US Navy, deck guns were used through the end of World War II, with a few still equipped in the early 1950s. Many targets in the Pacific War were other small vessels that were not worth a torpedo; the unreliability of the Mark 14 torpedo through mid-1943 promoted the use of the deck gun. Most US submarines started the war with a single 3-inch /50 caliber deck gun, adopted in the 1930s to discourage commanders from engaging armed escorts.
However, the aging S-boats were equipped with a 4-inch /50 caliber gun, used to re-equip 3-inch-gunned submarines as the S-boats were transferred to training duties beginning in mid-1942. By 1944 most front-line submarines had been refitted with a 5-inch /25 caliber gun, some were equipped with two 5-inch guns; the cruiser submarines USS Argonaut and Nautilus were each fitted with two 6"/53 caliber guns Mark 18 as built in the 1920s, the largest deck gun to be fitted on any United States submarine. In the Royal Navy, the Amphion-class submarine HMS Andrew was the last British submarine to be fitted with a deck gun. HMS Andrew was decommissioned in 1974 and the deck gun is now in the Royal Navy Submarine Museum; the last submarines in service in any navy to mount a deck gun were two of the four Abtao-class submarines of the Peruvian Navy in 1999. Naval artillery List of naval guns Friedman, Norman. U. S. Submarines Through 1945: An Illustrated
Junsen type submarine
The Junsen type submarine was a ship class of submarines of the Imperial Japanese Navy. There were four submarine designs of the Junsen type: J1, a modified J1, J2 and the J3; the Junsen type submarines were divided into four classes: Junsen I Junsen I Mod. Junsen II Junsen III. Four boats were built in 1923-1929. Genealogy of the large-size submarine in the IJN began with U-142. Japan received six U-boats from Germany as reparations of World War I; the IJN copied one of the six, producing the I-21-class minelayer submarine. The IJN could not find an optimal design of fleet submarine, so they and Kawasaki Heavy Industries sent many technical officers to the United Kingdom and Germany and got drawings of advanced submarines; the British L class became the Kaidai I, the K class became the Kaidai II and U-142 become Junsen I. This is a type which added a floatplane to the Junsen I. Project number S32; this is a type. She was built in 1931 under the Maru 1 Programme. Project number S33; these boats combined the good points of the Junsen II and the Kaidai V.
They were built in 1934 under the Maru 2 Programme. Junsen III became a'typeship' for the Type-A, B and C. "Rekishi Gunzō". History of Pacific War Vol.17 I-Gō Submarines, January 1998, ISBN 4-05-601767-0 Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", March 2005, ISBN 4-05-603890-2 Model Art Extra No.537, Drawings of Imperial Japanese Naval Vessels Part-3, Model Art Co. Ltd. May 1999, Book code 08734-5 The Maru Special, Japanese Naval Vessels No.31 Japanese Submarines I, Ushio Shobō, September 1979, Book code 68343-31
Diesel engine
The Diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel, injected into the combustion chamber, is caused by the elevated temperature of the air in the cylinder due to the mechanical compression. Diesel engines work by compressing only the air; this increases the air temperature inside the cylinder to such a high degree that atomised Diesel fuel injected into the combustion chamber ignites spontaneously. With the fuel being injected into the air just before combustion, the dispersion of the fuel is uneven; the process of mixing air and fuel happens entirely during combustion, the oxygen diffuses into the flame, which means that the Diesel engine operates with a diffusion flame. The torque a Diesel engine produces is controlled by manipulating the air ratio; the Diesel engine has the highest thermal efficiency of any practical internal or external combustion engine due to its high expansion ratio and inherent lean burn which enables heat dissipation by the excess air.
A small efficiency loss is avoided compared with two-stroke non-direct-injection gasoline engines since unburned fuel is not present at valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed Diesel engines can reach effective efficiencies of up to 55%. Diesel engines may be designed as either four-stroke cycles, they were used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in ships. Use in locomotives, heavy equipment and electricity generation plants followed later. In the 1930s, they began to be used in a few automobiles. Since the 1970s, the use of Diesel engines in larger on-road and off-road vehicles in the US has increased. According to Konrad Reif, the EU average for Diesel cars accounts for 50% of the total newly registered; the world's largest Diesel engines put in service are 14-cylinder, two-stroke watercraft Diesel engines. In 1878, Rudolf Diesel, a student at the "Polytechnikum" in Munich, attended the lectures of Carl von Linde.
Linde explained that steam engines are capable of converting just 6-10 % of the heat energy into work, but that the Carnot cycle allows conversion of all the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a machine that could work on the Carnot cycle. After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor. Diesel was criticised for his essay, but only few found the mistake that he made. Diesel's idea was to compress the air so that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent #542846 Diesel describes the compression required for his cycle: "pure atmospheric air is compressed, according to curve 1 2, to such a degree that, before ignition or combustion takes place, the highest pressure of the diagram and the highest temperature are obtained-that is to say, the temperature at which the subsequent combustion has to take place, not the burning or igniting point.
To make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. In that case the initial pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres, so on. Into the air thus compressed is gradually introduced from the exterior finely divided fuel, which ignites on introduction, since the air is at a temperature far above the igniting-point of the fuel; the characteristic features of the cycle according to my present invention are therefore, increase of pressure and temperature up to the maximum, not by combustion, but prior to combustion by mechanical compression of air, there upon the subsequent performance of work without increase of pressure and temperature by gradual combustion during a prescribed part of the stroke determined by the cut-oil". By June 1893, Diesel had realised his original cycle would not work and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application.
Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is stated that the compression must be sufficient to trigger ignition. "1. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas. See US patent # 608845 filed 1895 / granted 1898In 1892, Diesel received patents in Germany, the United Kingdom and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various
Displacement (ship)
The displacement or displacement tonnage of a ship is its weight based on the amount of water its hull displaces at varying loads. It is measured indirectly using Archimedes' principle by first calculating the volume of water displaced by the ship converting that value into weight displaced. Traditionally, various measurement rules have been in use. Today, metric tonnes are more used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed to its maximum load. Numerous specific terms are detailed below. Ship displacement should not be confused with measurements of volume or capacity used for commercial vessels, such as net tonnage, gross tonnage, or deadweight tonnage; the process of determining a vessel's displacement begins with measuring its draft This is accomplished by means of its "draft marks". A merchant vessel has three matching sets: one mark each on the port and starboard sides forward and astern; these marks allow a ship's displacement to be determined to an accuracy of 0.5%.
The draft observed at each set of marks is averaged to find a mean draft. The ship's hydrostatic tables show the corresponding volume displaced. To calculate the weight of the displaced water, it is necessary to know its density. Seawater is more dense than fresh water; the density of water varies with temperature. Devices akin to slide rules have been available, it is done today with computers. Displacement is measured in units of tonnes or long tons. There are terms for the displacement of a vessel under specified conditions: Loaded displacement is the weight of the ship including cargo, fuel, stores and such other items necessary for use on a voyage; these bring the ship down to its "load draft", colloquially known as the "waterline". Full load displacement and loaded displacement have identical definitions. Full load is defined as the displacement of a vessel when floating at its greatest allowable draft as established by a classification society. Warships have arbitrary full load condition established.
Deep load condition means stores, with most available fuel capacity used. Light displacement is defined as the weight of the ship excluding cargo, water, stores, crew, but with water in boilers to steaming level. Normal displacement is the ship's displacement "with all outfit, two-thirds supply of stores, etc. on board." Standard displacement known as "Washington displacement", is a specific term defined by the Washington Naval Treaty of 1922. It is the displacement of the ship complete manned and equipped ready for sea, including all armament and ammunition, outfit and fresh water for crew, miscellaneous stores, implements of every description that are intended to be carried in war, but without fuel or reserve boiler feed water on board. Naval architecture Hull Hydrodynamics Tonnage Dear, I. C. B.. Oxford Companion to Ships and the Sea. Oxford: Oxford University Press. ISBN 0-19-920568-X. George, William E.. Stability & Trim for the Ship's Officer. Centreville, Md: Cornell Maritime Press. ISBN 0-87033-564-2.
Hayler, William B.. American Merchant Seaman's Manual. Cambridge, Md: Cornell Maritime Press. ISBN 0-87033-549-9.. Turpin, Edward A.. Merchant Marine Officers' Handbook. Centreville, MD: Cornell Maritime Press. ISBN 0-87033-056-X. Navy Department. "Nomenclature of Naval Vessels". History.navy.mil. United States Navy. Retrieved 2008-03-24. Military Sealift Command. "Definitions and Equivalents". MSC Ship Inventory. United States Navy. Retrieved 2008-03-24. MLCPAC Naval Engineering Division. "Trim and Stability Information for Drydocking Calculations". United States Coast Guard. Retrieved 2008-03-24. United States of America. "Conference on the Limitation of Armament, 1922". Papers Relating to the Foreign Relations of the United States: 1922. 1. Pp. 247–266. United States Naval Institute. Proceedings of the United States Naval Institute. United States Naval Institute. Retrieved 2008-03-24
Type A submarine
The Cruiser submarine Type-A was a class of submarine in the Imperial Japanese Navy, which served during the Second World War. The Type-A submarines were built to take a role of the command ships for submarine squadrons. For this reason they had equipment for better radio facilities and a floatplane; the Type-A submarines were divided into four classes: Type-A Type-A Mod.1 Type-A Mod.2 V21 Type. The 5094th vessel class boats remained only a design. Project number S35Ja, their design was based on the Junsen III. Three boats were built in 1938-42 under Maru 4 Programme. Boats in class Project number S35B. Five boats were planned under the Kai-Maru 5 Programme, they were equipped with less powerful diesel engines. Only one boat, the I-12, was completed to the original design; the I-13 and the boats were converted to a new submarine class, because the number of I-400 class boats was reduced. Boats in class Project number S35C. Four boats were planned under the Kai-Maru 5 Programme. However, four boats were converted to new submarine class, because a number of submarines of the I-400 class were cancelled.
They had a large hangar and were equipped with bulges to be able to operate 2 × special Aichi M6A1 Seiran attack bombers. The headquarters institutions were removed. Boats in class Project number S48. Three boats were planned under the Kai-Maru 5 Programme. However, all boats were cancelled in late 1943, because the IJN turned its attention to the construction of Type E submarine in 1945. Boats in class "Rekishi Gunzō". History of Pacific War Vol.17 "I-Gō Submarines", January 1998, ISBN 4-05-601767-0 Rekishi Gunzō, History of Pacific War Vol.63 "Documents of IJN submarines and USN submarines", January 2008, ISBN 978-4-05-605004-2 Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", March 2005, ISBN 4-05-603890-2 Model Art Extra No.537, Drawings of Imperial Japanese Naval Vessels Part-3, Model Art Co. Ltd. May 1999, Book code 08734-5 The Maru Special, Japanese Naval Vessels No.13, "Japanese submarines I-13 class and I-400 class", Ushio Shobō, July 1977, Book code 8343-7 The Maru Special, Japanese Naval Vessels No.31, "Japanese Submarines I", Ushio Shobō, September 1979, Book code 68343-31 Senshi Sōsho Vol.88 Naval armaments and war preparation, "And after the outbreak of war", Asagumo Simbun, October 1975 Cruiser submarine
Japanese submarine I-10
The Japanese submarine I-10 was a Type A1 submarine built for the Imperial Japanese Navy during the 1930s. The submarines of the A1 type were versions of the preceding J3 class with superior range, improved aircraft installation, were fitted as squadron flagships, they displaced 2,966 tonnes surfaced and 4,195 tonnes submerged. The submarines were 113.7 meters long, had a beam of 9.5 meters and a draft of 5.3 meters. They had a diving depth of 100 meters. For surface running, the boats were powered by two 6,200-brake-horsepower diesel engines, each driving one propeller shaft; when submerged each propeller was driven by a 1,200-horsepower electric motor. They could reach 19 knots on 8.25 knots underwater. On the surface, the A1s had a range of 16,000 nautical miles at 16 knots; the boats were armed with four internal bow 53.3 cm torpedo tubes and carried a total of 18 torpedoes. They were armed with a single 140 mm /40 deck gun and two twin 25 mm Type 96 anti-aircraft guns. Unlike the J3 class, the aircraft hangar faces forward.
On 30 November 1941, I-10, patrolling in the South Sea region in advance of the attack on Pearl Harbor, launched a Yokosuka E14Y floatplane on a night air sortie of Suva Bay in the Fiji Islands. It reported sighting no enemy in the harbor but failed to return to the sub; the I-10 failed to find the scout. I-10 conducted long-range operations in the Indian Ocean and the Pacific, using her seaplane to carry out reconnaissance on the harbours of Durban and Port Elizabeth and other locales, including Madagascar during 1942. On 12 June 1944, I-10 launched her Yokosuka E14Y to reconnoiter Majuro. "Since the American expeditionary force had departed six days earlier, the aviator saw nothing important, his plane, crashing on landing, had to be abandoned."I-10 was sunk on 4 July 1944 by US warships David W Taylor and Riddle while operating in the Pacific east of Saipan, in the Mariana Islands. Bagnasco, Erminio. Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
Boyd, Carl & Yoshida, Akikiko. The Japanese Submarine Force and World War II. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-015-0. Carpenter, Dorr B. & Polmar, Norman. Submarines of the Imperial Japanese Navy 1904–1945. London: Conway Maritime Press. ISBN 0-85177-396-6. Chesneau, Roger, ed.. Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7. Hackett, Bob. "IJN Submarine I-10: Tabular Record of Movement". SENSUIKAN! Stories and Battle Histories of the IJN's Submarines. Combinedfleet.com. Retrieved 18 August 2015. Hashimoto, Mochitsura. Sunk: The Story of the Japanese Submarine Fleet 1942 – 1945. Colegrave, E. H. M.. London: Cassell and Company. ASIN B000QSM3L0. Stille, Mark. Imperial Japanese Navy Submarines 1941-45. New Vanguard. 135. Botley, Oxford, UK: Osprey Publishing. ISBN 978-1-84603-090-1
Imperial Japanese Navy