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Sledgehammer Lever
A sledgehammer is a tool with a large, flat, often metal head, attached to a long handle. The long handle combined with a heavy head allows the sledgehammer to gather momentum during a swing and apply a large force compared to hammers designed to drive nails. Along with the mallet, it shares the ability to distribute force over a wide area. This is in contrast to other types of hammers, which concentrate force in a relatively small area. Etymology The word sledgehammer is derived from the Anglo Saxon "''slægan''", which, in its first sense, means "to strike violently". The English words "slag", "slay", and "slog" are cognates. Uses The handle can range from to a full long, depending on the mass of the head. The head mass is usually . Modern heavy duty sledgehammers come with heads. Sledgehammers usually require two hands and a swinging motion involving the entire torso, in contrast to smaller hammers used for driving in nails. The combination of a long swinging ran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Tool
A hand tool is any tool that is powered by hand rather than a motor. Categories of hand tools include wrenches, pliers, cutters, files, striking tools, struck or hammered tools, screwdrivers, vises, clamps, snips, hacksaws, drills, and knives. Outdoor tools such as garden forks, pruning shears, and rakes are additional forms of hand tools. Portable power tools are not hand tools. History Hand tools have been used by humans since the Stone Age when stones were used for hammering and cutting. During the Bronze Age tools were made by casting the copper and tin alloys. Bronze tools were sharper and harder than those made of stone. During the Iron Age iron replaced bronze, and tools became even stronger and more durable. The Romans developed tools during this period which are similar to those being produced today. In the period since the industrial revolution, the manufacture of tools has transitioned from being craftsman made to being factory produced. A large collection of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masonry
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building stone such as marble, granite, and limestone, cast stone, concrete blocks, glass blocks, and adobe. Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern in which the units are assembled can substantially affect the durability of the overall masonry construction. A person who constructs masonry is called a mason or bricklayer. These are both classified as construction trades. Applications Masonry is commonly used for walls and buildings. Brick and concrete block are the most common types of masonry in use in industrialized nations and may be either load-bearing or non-load-bearing. Concrete blocks, especially those with hollow cores, offer va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Spike
The golden spike (also known as The Last Spike) is the ceremonial 17.6-karat gold final spike driven by Leland Stanford to join the rails of the first transcontinental railroad across the United States connecting the Central Pacific Railroad from Sacramento and the Union Pacific Railroad from Omaha on May 10, 1869, at Promontory Summit, Utah Territory. The term ''last spike'' has been used to refer to one driven at the usually ceremonial completion of any new railroad construction projects, particularly those in which construction is undertaken from two disparate origins towards a common meeting point. The spike is now displayed in the Cantor Arts Center at Stanford University. History Completing the last link in the transcontinental railroad with a spike of gold was the brainchild of David Hewes, a San Francisco financier and contractor.Bowman, J.N"Driving the Last Spike at Promontory, 1869" ''California Historical Society Quarterly'', Vol. XXXVI, No. 2, June 1957, pp. 9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leland Stanford
Amasa Leland Stanford (March 9, 1824June 21, 1893) was an American industrialist and politician. A member of the Republican Party, he served as the 8th governor of California from 1862 to 1863 and represented California in the United States Senate from 1885 until his death in 1893. He and his wife Jane were also the founders of Stanford University, which they named after their late son. Prior to his political career, Stanford was a successful merchant and wholesaler who built his business empire after migrating to California during the Gold Rush. As president of the Central Pacific Railroad and later the Southern Pacific from 1885 to 1890, he held tremendous power in the region and a lasting impact on California. Early life and career Leland Stanford was born in 1824 in what was then Watervliet, New York (now the Town of Colonie). He was one of eight children of Josiah and Elizabeth Phillips Stanford. Among his siblings were New York State Senator Charles Stanford (1819– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promontory, Utah
Promontory is an area of high ground in Box Elder County, Utah, United States, 32 mi (51 km) west of Brigham City and 66 mi (106 km) northwest of Salt Lake City. Rising to an elevation of 4,902 feet (1,494 m) above sea level, it lies to the north of the Promontory Mountains and the Great Salt Lake. It is notable as the location of Promontory Summit, where the First transcontinental railroad from Sacramento to Omaha in the United States was officially completed on May 10, 1869. The location is sometimes confused with Promontory Point, a location further south along the southern tip of the Promontory Mountains. Both locations are significant to the Overland Route; Promontory Summit is where the original, abandoned alignment crossed the Promontory Mountains while the modern alignment, called the Lucin Cutoff, crosses the mountains at Promontory Point. By the summer of 1868, the Central Pacific (CP) had completed the first rail route through the Sierra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Union Pacific
The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United States after BNSF, with which it shares a duopoly on transcontinental freight rail lines in the Western, Midwestern and Southern United States. Founded in 1862, the original Union Pacific Rail Road was part of the first transcontinental railroad project, later known as the Overland Route. Over the next century, UP absorbed the Missouri Pacific Railroad, the Chicago and North Western Transportation Company, the Western Pacific Railroad, the Missouri–Kansas–Texas Railroad and the Chicago, Rock Island and Pacific Railroad. In 1996, the Union Pacific merged with Southern Pacific Transportation Company, itself a giant system that was absorbed by the Denver and Rio Grande Western Railroad. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railroad Tie
A railroad tie, crosstie (American English), railway tie (Canadian English) or railway sleeper (Australian and British English) is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge. Railroad ties are traditionally made of wood, but prestressed concrete is now also widely used, especially in Europe and Asia. Steel ties are common on secondary lines in the UK; plastic composite ties are also employed, although far less than wood or concrete. As of January 2008, the approximate market share in North America for traditional and wood ties was 91.5%, the remainder being concrete, steel, azobé (red ironwood) and plastic composite. Tie spacing may depend on the type of tie, traffic loads and other requirements, for example 2640 concrete ties per mile on North American mainline railroads to 2112 timber ties per mile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counter Terrorist
Counterterrorism (also spelled counter-terrorism), also known as anti-terrorism, incorporates the practices, military tactics, techniques, and strategies that governments, law enforcement, business, and intelligence agencies use to combat or eliminate terrorism. Counterterrorism strategies are a government's motivation to use the instruments of national power to defeat terrorists, the organizations they maintain, and the networks they contain. If definitions of terrorism are part of a broader insurgency, counterterrorism may employ counterinsurgency measures. The United States Armed Forces uses the term foreign internal defense for programs that support other countries' attempts to suppress insurgency, lawlessness, or subversion, or to reduce the conditions under which threats to national security may develop. History The first counter-terrorism body formed was the Special Irish Branch of the Metropolitan Police, later renamed the Special Branch after it expanded its scope b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Air Service
The Special Air Service (SAS) is a special forces unit of the British Army. It was founded as a regiment in 1941 by David Stirling and in 1950, it was reconstituted as a corps. The unit specialises in a number of roles including counter-terrorism, hostage rescue, direct action and covert reconnaissance. Much of the information about the SAS is highly classified, and the unit is not commented on by either the British government or the Ministry of Defence due to the secrecy and sensitivity of its operations. The corps currently consists of the 22 Special Air Service Regiment, the regular component, as well as the 21 Special Air Service Regiment (Artists) (Reserve) and the 23 Special Air Service Regiment (Reserve), which are reserve units, all under the operational command of United Kingdom Special Forces (UKSF). Its sister unit is the Royal Navy's Special Boat Service which specialises in maritime counter-terrorism. Both units are under the operational control of the Directo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Field
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence of high heat and pressure in the Earth's crust. Petroleum reservoirs are broadly classified as ''conventional'' and '' unconventional'' reservoirs. In conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability, while in unconventional reservoirs, the rocks have high porosity and low permeability, which keeps the hydrocarbons trapped in place, therefore not requiring a cap rock. Reservoirs are found using hydrocarbon exploration methods. Oil field An oil field is an area of accumulation of liquid oil underground in multiple (potentially linked) reservoirs, trapped as it rises by impermeable rock formations. In industrial terms, an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farm
A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used for specialized units such as arable farms, vegetable farms, fruit farms, dairy, pig and poultry farms, and land used for the production of natural fiber, biofuel and other commodities. It includes ranches, feedlots, orchards, plantations and estates, smallholdings and hobby farms, and includes the farmhouse and agricultural buildings as well as the land. In modern times the term has been extended so as to include such industrial operations as wind farms and fish farms, both of which can operate on land or sea. There are about 570 million farms in the world, most of which are small and family-operated. Small farms with a land area of fewer than 2 hectares operate about 1% of the world's agricultural land, and family farms comprise about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
