The Ursa Major (lit. ''Great Bear'') at
Black Thunder Coal Mine, Wyoming, is the largest
dragline excavator
A dragline excavator is a heavy-duty excavator used in civil engineering and surface mining. It was invented in 1904, and presented an immediate challenge to the steam shovel and its diesel and electric powered descendant, the power shovel. M ...
currently in use in North America and the third largest ever built.
It is a
Bucyrus-Erie
Bucyrus-Erie was an American surface and underground mining equipment company. It was founded as Bucyrus Foundry and Manufacturing Company in Bucyrus, Ohio, in 1880. Bucyrus moved its headquarters to South Milwaukee, Wisconsin, in 1893. In 1927, ...
2570WS model and cost US$50 million. The Ursa Major was one of five large walking draglines operated at Black Thunder, with the next two largest in the dragline fleet being Thor, a B-E 1570W - which has a boom and a bucket - and Walking Stick, a B-E 1300W with a boom and a bucket.
Specifications
Its bucket is , and it has a boom. It weighs .
['']Modern Marvels
''Modern Marvels'', formally known under A&E as ''Time Machine'', is a television series first aired by the History Channel in 1995, but previously under A&E starting December 10, 1993. It is the History Channel's first and longest-running prog ...
'': Earthmovers
History
Shortly before the scrapping of
Big Muskie
Big Muskie was a dragline excavator built by Bucyrus-Erie and owned by the Central Ohio Coal Company (formerly a division of American Electric Power), weighing and standing nearly 22 stories tall. It mined coal in the U.S. state of Ohio fr ...
in 1999, the largest dragline ever built, construction of another ultraheavy dragline excavator commenced. Although not as large as the Big Muskie, the Ursa Major was still a large and substantial excavator.
It first began operation around early 2001, the bucket which was newly cast at the time, was delivered at Black Thunder Mine. Operation to deliver the 165,000 pound bucket (82.5 tons) Bucyrus had to obtain special permits for an overweight and oversized load for it to be permissible to be transported. The company also had to check with the power company to make sure it won't hit any power lines on the way to the mine.
See also
*
Dragline excavator
A dragline excavator is a heavy-duty excavator used in civil engineering and surface mining. It was invented in 1904, and presented an immediate challenge to the steam shovel and its diesel and electric powered descendant, the power shovel. M ...
References
{{DEFAULTSORT:Ursa Major (Dragline)
Engineering vehicles
Excavators
Industrial equipment
Draglines
Bucyrus-Erie