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USS PC-815
USS ''PC-815'' was a built for the United States Navy during World War II. Its first commander, for about eighty days in 1943, was L. Ron Hubbard, who later became the founder of Scientology. After Hubbard was removed from command for conducting unauthorized gunnery practice in Mexican territorial waters, the ''PC-815'' served as a shore patrol vessel off San Diego, California. In September 1945, the ship was lost along with one of her crew after colliding with the destroyer . ''PC-815''s short career led to the vessel being dubbed the "jinxed sub-chaser". Construction ''PC-815'' was laid down on 10 October 1942, at the Albina Engine and Machinery Works in Portland, Oregon. Her propulsion was two 1,440bhp Hooven-Owens-Rentschler R-99DA diesel engines (Serial No. 6977 and 6978), Westinghouse single reduction gear, two shafts. The ''PC-815'' was fitted out commencing 5 December 1942, and was commissioned on 20 April 1943, with Lieutenant (j.g.) L. Ron Hubbard in command.USS ''P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia River
The Columbia River (Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada. It flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is long, and its largest tributary is the Snake River. Its drainage basin is roughly the size of France and extends into seven US states and a Canadian province. The fourth-largest river in the United States by volume, the Columbia has the greatest flow of any North American river entering the Pacific. The Columbia has the 36th greatest discharge of any river in the world. The Columbia and its tributaries have been central to the region's culture and economy for thousands of years. They have been used for transportation since a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Anomaly Detector
A magnetic anomaly detector (MAD) is an instrument used to detect minute variations in the Earth's magnetic field. The term refers specifically to magnetometers used by military forces to detect submarines (a mass of ferromagnetic material creates a detectable disturbance in the magnetic field); military MAD equipment is a descendant of geomagnetic survey or aeromagnetic survey instruments used to search for minerals by detecting their disturbance of the normal earth-field. History Geoexploration by measuring and studying variations in the Earth's magnetic field has been conducted by scientists since 1843. The first uses of magnetometers were for the location of ore deposits. Thalen's "The Examination of Iron Ore Deposits by Magnetic Measurements", published in 1879, was the first scientific treatise describing this practical use. Magnetic anomaly detectors employed to detect submarines during World War II harnessed the fluxgate magnetometer, an inexpensive and easy to use t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chester W
Chester is a cathedral city and the county town of Cheshire, England. It is located on the River Dee, close to the English–Welsh border. With a population of 79,645 in 2011,"2011 Census results: People and Population Profile: Chester Locality"; downloaded froCheshire West and Chester: Population Profiles, 17 May 2019 it is the most populous settlement of Cheshire West and Chester (a unitary authority which had a population of 329,608 in 2011) and serves as its administrative headquarters. It is also the historic county town of Cheshire and the second-largest settlement in Cheshire after Warrington. Chester was founded in 79 AD as a "castrum" or Roman fort with the name Deva Victrix during the reign of Emperor Vespasian. One of the main army camps in Roman Britain, Deva later became a major civilian settlement. In 689, King Æthelred of Mercia founded the Minster Church of West Mercia, which later became Chester's first cathedral, and the Angles extended and strengthened t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Jack Fletcher
Frank Jack Fletcher (April 29, 1885 – April 25, 1973) was an admiral in the United States Navy during World War II. Fletcher commanded five different task forces through WWII; he was the operational task force commander at the pivotal battles of the Coral Sea and Midway, which collectively resulted in the sinking of six Japanese fleet carriers. In 1914, then Lieutenant Fletcher was awarded the Medal of Honor for his actions in the battle at Veracruz. He was the nephew of Admiral Frank Friday Fletcher, who was also awarded the Medal of Honor for actions at Veracruz. Early life and early Navy career Fletcher was born in Marshalltown, Iowa, on April 29, 1885. Appointed to the US Naval Academy from his native state in 1902, he graduated from Annapolis on February 12, 1906, served two years at sea, then required by law, and commissioned as an Ensign on February 13, 1908. His classmates included Arthur L. Bristol, William L. Calhoun, William A. Glassford, Charles C. Hartigan, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, multi-mission service unique among the United States military branches for having a maritime law enforcement mission with jurisdiction in both domestic and international waters and a federal regulatory agency mission as part of its duties. It is the largest and most powerful coast guard in the world, rivaling the capabilities and size of most navies. The U.S. Coast Guard is a humanitarian and security service. It protects the United States' borders and economic and security interests abroad; and defends its sovereignty by safeguarding sea lines of communication and commerce across vast territorial waters spanning 95,000 miles of coastline and its Exclusive Economic Zone. With national and economic security depending upon open global trade a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K-class Blimp
The ''K''-class blimp was a class of blimps (non-rigid airship) built by the Goodyear Aircraft Company of Akron, Ohio for the United States Navy. These blimps were powered by two Pratt & Whitney ''Wasp'' nine-cylinder radial air-cooled engines, each mounted on twin-strut outriggers, one per side of the control car that hung under the envelope. Before and during World War II, 134 ''K''-class blimps were built and configured for patrol and anti-submarine warfare operations, and were extensively used in the Navy’s anti-submarine efforts in the Atlantic and Pacific Ocean areas. Development In 1937, ''K-2'' was ordered from Goodyear as part of a contract that also bought the ''L-1'', (Goodyear’s standard advertising and passenger blimp). ''K-2'' was the production prototype for future ''K''-class airship purchases. ''K-2'' flew for the first time at Akron, Ohio on December 6, 1938 and was delivered to the Navy at NAS Lakehurst, New Jersey on December 16. The envelope capacit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrophone
A hydrophone ( grc, ὕδωρ + φωνή, , water + sound) is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a sound wave. Some piezoelectric transducers can also serve as a sound projector, but not all have this capability, and some may be destroyed if used in such a manner. A hydrophone can detect airborne sounds, but will be insensitive because it is designed to match the acoustic impedance of water, a denser fluid than air. Sound travels 4.3 times faster in water than in air, and a sound wave in water exerts a pressure 60 times that exerted by a wave of the same amplitude in air. Similarly, a standard microphone can be buried in the ground, or immersed in water if it is put in a waterproof container, but will give poor performance due to the similarly bad acoustic impedance match. History The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extrem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigation, navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Lookout (Oregon)
Cape Lookout is a sharp rocky promontory along the Pacific Ocean coast of northwestern Oregon in the United States. It is located in southwestern Tillamook County, approximately southwest of Tillamook, just south of Netarts Bay. The promontory extends perpendicular to the coast, and is approximately wide at its base, tapering as it extends outward from the coast. Cape Lookout State Park is located on the north side of the promontory, which is part of the Siuslaw National Forest. Cape Lookout Road travels past the base of the cape. Cape Lookout is a member of Tillamook's Three Capes Scenic Drive. The Cape Lookout Trail is a popular hiking trail, extending through Sitka spruce forest to the tip of the promontory. The cliff-top hiking trail offers views of Cape Kiwanda and Cascade Head to the south as well as Cape Meares, Three Arch Rocks, and Neahkahnie Mountain to the north. Migrating whales can also be seen, generally from December through June, as they pass the end of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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