Dragline excavator

A dragline excavator is a piece of heavy equipment used in civil engineering and surface mining.

Draglines fall into two broad categories: those that are based on standard, lifting cranes, and the heavy units which have to be built on-site. Most crawler cranes, with an added winch drum on the front, can act as a dragline. These units (like other cranes) are designed to be dismantled and transported over the road on flatbed trailers. Draglines used in civil engineering are almost always of this smaller, crane type. These are used for road, port construction, pond and canal dredging, and as pile driving rigs. These types are built by crane manufacturers such as Link-Belt and Hyster.

The much larger type which is built on site is commonly used in strip-mining operations to remove overburden above coal and more recently for oil sands mining. The largest heavy draglines are among the largest mobile land machines ever built. The smallest and most common of the heavy type weigh around 8,000 tons while the largest built weighed around 13,000 tons.

Big Muskie

Big Muskie was a coal mining Bucyrus-Erie dragline owned by the Central Ohio Coal Company (formerly a division of American Electric Power), weighing 12700 tonnes and standing nearly 22 stories tall. It operated in the U.S. state of Ohio from 1969 to 1991.

Design specifications and service

The Big Muskie was a model 4250-W Bucyrus-Erie dragline (the only one ever built). With a 220-cubic-yard (170 m³) bucket, it was the largest single-bucket digging machine ever created and one of the world's largest mobile earth-moving machines alongside the Illinois-based Marion 6360 stripping shovel called The Captain and the German bucket wheel excavators of the Bagger 288 and Bagger 293 family. It cost $25 million in 1969, the equivalent of $161 million today adjusted for inflation. Its bucket could hold two Greyhound buses side by side. It took over 200,000 man hours to construct over a period of about two years.

Big Muskie was powered by electricity supplied at 13,800 volts via a trailing cable, which had its own transporter/coiling units to move it. The electricity powered the main drives, eighteen 1,000 horsepower (750 kW) and ten 625 horsepower (466 kW) DC electric motors. Some systems in Big Muskie were electro-hydraulic, but the main drives were all electric. While working, Big Muskie used the equivalent of the power for 27,500 homes, costing tens of thousands of dollars an hour just in power costs and necessitating special agreements with local Ohio power companies to accommodate the extra load. The machine had a crew of 5, and worked around the clock, with special emphasis on night work since the per kilowatt-hour rate was much cheaper.

Private company limited by shares

A private company limited by shares, usually called a private limited company (Ltd.) (though this can theoretically also refer to a private company limited by guarantee), is the private limited type of company incorporated under the laws of England and Wales, Scotland, that of certain Commonwealth countries and the Republic of Ireland. It has shareholders with limited liability and its shares may not be offered to the general public, unlike those of a public limited company (plc).

"Limited by shares" means that the company has shareholders, and that the liability of the shareholders to creditors of the company is limited to the capital originally invested, i.e. the nominal value of the shares and any premium paid in return for the issue of the shares by the company. A shareholder's personal assets are thereby protected in the event of the company's insolvency, but money invested in the company will be lost.

A limited company may be "private" or "public". A private limited company's disclosure requirements are lighter, but for this reason its shares may not be offered to the general public (and therefore cannot be traded on a public stock exchange). This is the major distinguishing feature between a private limited company and a public limited company. Most companies, particularly small companies, are private.

World

World is a common name for the whole of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth or pertaining to anywhere on Earth.

In a philosophical context it may refer to:

In a theological context, world usually refers to the material or the profane sphere, as opposed to the celestial, spiritual, transcendent or sacred. The "end of the world" refers to scenarios of the final end of human history, often in religious contexts.

World history is commonly understood as spanning the major geopolitical developments of about five millennia, from the first civilizations to the present.

World population is the sum of all human populations at any time; similarly, world economy is the sum of the economies of all societies (all countries), especially in the context of globalization. Terms like world championship, gross world product, world flags etc. also imply the sum or combination of all current-day sovereign states.