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Wrecking Ball
A wrecking ball is a heavy steel ball, usually hung from a crane, that is used for demolishing large buildings. It was most commonly in use during the 1950s and 1960s. Several wrecking companies claim to have invented the wrecking ball. An early documented use was in the breaking up of the in 1888–1889, by Henry Bath and Co, at Rock Ferry on the River Mersey. In 1993, the wrecking ball was described as "one of the most common forms of large-scale coarse demolition." With the invention of hydraulic excavators and other machinery, the wrecking ball has become less common at demolition sites as its working efficiency is less than that of high reach excavators. Construction and design Modern wrecking balls have had a slight re-shaping, with the metal sphere changed into a pear shape with a portion of the top cut off. This shape allows the ball to be more easily pulled back through a roof or concrete slab after it has broken through. Wrecking balls range from about to aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. Formally, a kinetic energy is any term in a system's Lagrangian which includes a derivative with respect to time. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2. In relativistic mechanics, this is a good approximation only when ''v'' is much less than the speed of light. The standard unit of kinetic energy is the joule, while the English unit of kinetic energy is the foot-pound. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tools
A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates back hundreds of millennia, have been observed using tools to make other tools. Early human tools, made of such materials as stone, bone, and wood, were used for preparation of food, hunting, manufacture of weapons, and working of materials to produce clothing and useful artifacts. The development of metalworking made additional types of tools possible. Harnessing energy sources, such as animal power, wind, or steam, allowed increasingly complex tools to produce an even larger range of items, with the Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swing (seat)
A swing is a seat, often found at playgrounds for children, at a circus for acrobats, or on a porch for relaxing, although they may also be items of indoor furniture, such as the Latin American hammock or the Indian oonjal. The seat of a swing may be suspended from chains or ropes. Once a swing is in motion, it continues to oscillate like a pendulum until external interference or drag brings it to a halt. Swing sets are very popular with children. On playgrounds, several swings are often suspended from a shared metal or wooden frame, known as a swing set, allowing more than one child to play at a time. Such swings come in a variety of sizes and shapes. For infants and toddlers, swings with leg holes support the child in an upright position while a parent or sibling pushes the child to get a swinging motion. Some swing sets include play items other than swings, such as a rope ladder or sliding pole. For older children, swings are sometimes made of a flexible canvas seat, of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demolition
Demolition (also known as razing, cartage, and wrecking) is the science and engineering in safely and efficiently tearing down of buildings and other artificial structures. Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for reuse purposes. For small buildings, such as houses, that are only two or three stories high, demolition is a rather simple process. The building is pulled down either manually or mechanically using large hydraulic equipment: elevated work platforms, cranes, excavators or bulldozers. Larger buildings may require the use of a wrecking ball, a heavy weight on a cable that is swung by a crane into the side of the buildings. Wrecking balls are especially effective against masonry, but are less easily controlled and often less efficient than other methods. Newer methods may use rotational hydraulic shears and silenced rock-breakers attached to excavators to cut or break through wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamite
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay), and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, Northern Germany, and patented in 1867. It rapidly gained wide-scale use as a more robust alternative to black powder. History Dynamite was invented by Swedish chemist Alfred Nobel in the 1860s and was the first safely manageable explosive stronger than black powder. Alfred Nobel's father, Immanuel Nobel, was an industrialist, engineer, and inventor. He built bridges and buildings in Stockholm and founded Sweden's first rubber factory. His construction work inspired him to research new methods of blasting rock that were more effective than black powder. After some bad business deals in Sweden, in 1838 Immanuel moved his family to Saint Petersburg, where Alfred and his brothers were educated privately under Swedish and Russian tutors. At age 17, Alfred was sent abroad for two year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excavator
Excavators are heavy construction equipment consisting of a boom, dipper (or stick), bucket and cab on a rotating platform known as the "house". The house sits atop an undercarriage with tracks or wheels. They are a natural progression from the steam shovels and often mistakenly called power shovels. All movement and functions of a hydraulic excavator are accomplished through the use of hydraulic fluid, with hydraulic cylinders and hydraulic motors. Due to the linear actuation of hydraulic cylinders, their mode of operation is fundamentally different from cable-operated excavators which use winches and steel ropes to accomplish the movements. Terminology Excavators are also called diggers, JCBs (a proprietary name, in an example of a generic trademark), mechanical shovels, or 360-degree excavators (sometimes abbreviated simply to "360"). Tracked excavators are sometimes called "trackhoes" by analogy to the backhoe. In the UK and Ireland, wheeled excavators are somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarry
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environmental impact. The word ''quarry'' can also include the underground quarrying for stone, such as Bath stone. Types of rock Types of rock extracted from quarries include: *Chalk * China clay * Cinder *Clay *Coal *Construction aggregate (sand and gravel) *Coquina *Diabase *Gabbro *Granite *Gritstone *Gypsum *Limestone *Marble * Ores *Phosphate rock *Quartz *Sandstone *Slate *Travertine Stone quarry Stone quarry is an outdated term for mining construction rocks (limestone, marble, granite, sandstone, etc.). There are open types (called quarries, or open-pit mines) and closed types ( mines and caves). For thousands of years, only hand tools had been used in quarries. In the 18th century, the use of drilling and blasting operations w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaman K-MAX
The Kaman K-MAX (company designation K-1200) is an American helicopter with intermeshing rotors (synchropter) by Kaman Aircraft. It is optimized for external cargo load operations, and is able to lift a payload of over , which is more than the helicopter's empty weight. An unmanned aerial vehicle version with optional remote control has been developed and evaluated in extended practical service in the war in Afghanistan. After being out of production for more than a decade, in June 2015 Kaman announced it was restarting production of the K-MAX due to it receiving ten commercial orders.Kaman restarts K-Max production on new commercial orders Flightglobal The first flight of a K-MAX from the restarted production took place in Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forging
Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at which it is performed: cold forging (a type of cold working), warm forging, or hot forging (a type of hot working). For the latter two, the metal is heated, usually in a forge. Forged parts can range in weight from less than a kilogram to hundreds of metric tons.Degarmo, p. 389 Forging has been done by smiths for millennia; the traditional products were kitchenware, hardware, hand tools, edged weapons, cymbals, and jewellery. Since the Industrial Revolution, forged parts are widely used in mechanisms and machines wherever a component requires high strength; such forgings usually require further processing (such as machining) to achieve a finished part. Today, forging is a major worldwide industry. History Forging is one of the oldest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Reach Excavator
A long reach excavator is a type of excavator where the arm has been extended to reach farther than a normal excavator would. It is often used in demolition of buildings, but it can also be used in other applications. History The term ''long reach excavator'' was probably first coined by Richard Melhuish, the Chairman of Land & Water. During the 1970s Land & Water operated the UK's first hire fleet of these new and innovative long reach hydraulic excavators. In fact they still operate the largest fleet of long-reaches in the UK. Land & Water's first long reach excavator was the Hymac 580 BT All Hydraulic 360 “Waterway” machine, designed for work on waterways. These early machines from Hymac came to be widely preferred to the more traditional drag lines designs. Around the same time Priestman (and later Ruston Bucyrus) VC (Variable Counterweight) excavators started to become more popular. However, the work VC machines could achieve was slightly constrained by design limitati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
