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Refueling And Complex Overhaul
In the United States Navy, Refueling and Overhaul (ROH) refers to a lengthy Refit, refitting process or procedure performed on Nuclear marine propulsion, nuclear-powered naval ships, which involves replacement of expended nuclear fuel with new fuel and a general maintenance fix-up, renovation, and often modernization of the entire ship. In theory, such process could simply involve only refueling or only an overhaul, but in practice, nuclear refueling is always combined with an overhaul. An ROH usually takes one to two years for submarines and up to almost three years for an aircraft carrier, performed at a naval shipyard. Time periods between ROHs on a ship have varied historically from about 5–20 years (for submarines) to up to 25 years (for s). For modern submarines and aircraft carriers, ROHs are typically carried out about midway through their operating lifespan. There are also shorter maintenance fix-ups called ''availabilities'' for ships periodically at shipyards. A par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 million tons in 2021. It has the world's largest aircraft carrier fleet, with List of aircraft carriers in service, eleven in service, one undergoing trials, two new carriers under construction, and six other carriers planned as of 2024. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the U.S. Navy is the third largest of the United States military service branches in terms of personnel. It has 299 deployable combat vessels and about 4,012 operational aircraft as of 18 July 2023. The U.S. Navy is one of six United States Armed Forces, armed forces of the United States and one of eight uniformed services of the United States. The United States Navy traces its origins to the Continental Navy, which was established during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fission Products
Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release of heat energy (kinetic energy of the nuclei), and gamma rays. The two smaller nuclei are the ''fission products''. (See also Fission products (by element)). About 0.2% to 0.4% of fissions are ternary fissions, producing a third light nucleus such as helium-4 (90%) or tritium (7%). The fission products themselves are usually unstable and therefore radioactive. Due to being relatively neutron-rich for their atomic number, many of them quickly undergo beta decay. This releases additional energy in the form of beta particles, antineutrinos, and gamma rays. Thus, fission events normally result in beta and additional gamma radiation that begins immediately after, even though this radiation is not produced directly by the fission event itse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welding
Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and #Solid-state welding, solid-state welding processes which bond without melting, such as pressure, cold welding, and diffusion bonding. Metal welding is distinct from lower temperature bonding techniques such as brazing and soldering, which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds. In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that can be stronger than the base material. Welding also requires a form of shield to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Radiography
Industrial radiography is a modality of non-destructive testing that uses ionizing radiation to inspect materials and components with the objective of locating and quantifying defects and degradation in material properties that would lead to the failure of engineering structures. It plays an important role in the science and technology needed to ensure product quality and reliability. In Australia, industrial radiographic non-destructive testing is colloquially referred to as "bombing" a component with a "bomb". Industrial Radiography uses either X-rays, produced with X-ray generators, or gamma rays generated by the natural radioactivity of sealed radionuclide sources. Neutrons can also be used. After crossing the specimen, photons are captured by a X-ray detector, detector, such as a silver halide film, a Photostimulated luminescence, phosphor plate, flat panel detector or CdTe detector. The examination can be performed in static 2D (named radiography), in real time 2D (fluorosc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomahawk Cruise Missile
The BGM-109 Tomahawk () Land Attack Missile (TLAM) is an American long-range, all-weather, jet-powered, subsonic cruise missile that is primarily used by the United States Navy and Royal Navy in ship and submarine-based land-attack operations. Developed at the Applied Physics Laboratory of Johns Hopkins University under James H. Walker near Laurel, Maryland, the Tomahawk emerged in the 1970s as a modular cruise missile first manufactured by General Dynamics. The Tomahawk aimed to fulfill the need for a medium- to long-range, low-altitude missile with diverse capabilities. Its modular design allows for compatibility with a range of warheads, including high-explosive, submunitions, and bunker-busters. The Tomahawk can use a variety of guidance systems, including GPS, inertial navigation, and terrain contour matching. Over a dozen variants and upgraded versions have been developed since the original design, including air-, sub-, and ground-launched configurations with both conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistic Missile
A ballistic missile is a type of missile that uses projectile motion to deliver warheads on a target. These weapons are powered only during relatively brief periods—most of the flight is unpowered. Short-range ballistic missiles (SRBM) typically stay within the Earth's atmosphere, while most larger missiles travel outside the atmosphere. The type of ballistic missile with the greatest range is an intercontinental ballistic missile (ICBM). The largest ICBMs are capable of full orbital flight. These missiles are in a distinct category from cruise missiles, which are aerodynamically guided in powered flight and thus restricted to the atmosphere. History One modern pioneer ballistic missile was the A-4, commonly known as the V-2, developed by Nazi Germany in the 1930s and 1940s under the direction of Wernher von Braun. The first successful launch of a V-2 was on October 3, 1942, and it began operation on September 6, 1944, against Paris, followed by an attack on London two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guided Missile Submarine
A cruise missile submarine is a submarine that carries and launches cruise missiles ( SLCMs consisting of land-attack cruise missiles and anti-ship missiles) as its primary armament. Missiles greatly enhance a warship's ability to attack surface combatants and strike land targets; although torpedoes are a more discreet option for submerged submarines, missiles give a much longer stand-off range, shorter time to impact the target, as well as the ability to engage multiple targets on different headings at the same time. Many cruise missile submarines retain the capability to deploy nuclear warheads on their missiles, but they are considered distinct from ballistic missile submarines due to the substantial differences between the two weapons systems' flight characteristics; cruise missiles fly aerodynamically using flight surfaces like wings or fins, while a ballistic missile uses its engine power alone as it may exit the atmosphere. The United States Navy's hull classification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fleet Ballistic Missile Submarine
A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. These submarines became a major weapon system in the Cold War because of their nuclear deterrence capability. They can fire missiles thousands of kilometers from their targets, and acoustic quieting makes them difficult to detect (see acoustic signature), thus making them a survivable deterrent in the event of a first strike and a key element of the mutual assured destruction policy of nuclear deterrence. The deployment of ballistic missile submarines is dominated by the United States, Russia (following the collapse of the Soviet Union) and China. In fact, 70% of nuclear warheads in the USA are carried by ballistic missile submarines.Rafal, A. S. (2021). THE FUTURE OF SUBMARINE WARFARE: NUCLEAR POWERED SUBMARINES ARE THE BEDROCK OF NAVAL WARFARE, OR MAYBE NOT. MS Thesis. Joint Forces Staff College-NDU, Joint Advanced Warfighting School]. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineer
Engineers, as practitioners of engineering, are professionals who Invention, invent, design, build, maintain and test machines, complex systems, structures, gadgets and materials. They aim to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. "Science is knowledge based on our observed facts and tested truths arranged in an orderly system that can be validated and communicated to other people. Engineering is the creative application of scientific principles used to plan, build, direct, guide, manage, or work on systems to maintain and improve our daily lives." The word ''engineer'' (Latin , the origin of the Ir. in the title of engineer in countries like Belgium, The Netherlands, and Indonesia) is derived from the Latin words ("to contrive, devise") and ("cleverness"). The foundational qualifications of a licensed professional engineer typically include a four-year Bachelor of Engineering, bache ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Electronics
Digital electronics is a field of electronics involving the study of digital signals and the engineering of devices that use or produce them. It deals with the relationship between Binary number, binary inputs and outputs by passing electrical signals through Logic gate, logical gates, Resistor, resistors, Capacitor, capacitors, Amplifier, amplifiers, and other Electronic component, electrical components. The field of digital electronics is in contrast to analog electronics which work primarily with analog signals (signals with varying degrees of intensity as opposed to on/off two state binary signals). Despite the name, digital electronics designs include important analog design considerations. Large assemblies of logic gates, used to represent more complex ideas, are often packaged into integrated circuits. Complex devices may have simple electronic representations of Boolean logic#Digital electronic circuit design, Boolean logic functions. History The binary number system was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Electronics
Analogue electronics () are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term ''analogue'' describes the proportional relationship between a signal and a voltage or current that represents the signal. The word ''analogue'' is derived from the Greek word meaning ''proportional''. Analogue signals An analogue signal uses some attribute of the medium to convey the signal's information. For example, an aneroid barometer uses the angular position of a needle on top of a contracting and expanding box as the signal to convey the information of changes in atmospheric pressure. Electrical signals may represent information by changing their voltage, current, frequency, or total charge. Information is converted from some other physical form (such as sound, light, temperature, pressure, position) to an electrical signal by a transducer which converts one type of energy into another (e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
