Ursa Major (excavator)

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Ursa Major (excavator)
Ursa Major in 2009
Class overview
Name2570-WS Ursa Major
BuildersBucyrus-Erie
Operators United States
CostUS$50 million (1999)
In service2001-Present
Planned1
Completed1
Active1
History
United States
NameUrsa Major
BuilderBucyrus-Erie
Laid down1999
Launched2001
Christened2001
Commissioned2001
NotesLargest walking dragline currently in-service
General characteristics
Class and typeModel 2570-WS-series Dragline excavator
Tonnage6,700 tonnes (7,385 short tons)
Length110 m (360 ft) (boom)
Propulsion2x hydraulically driven walker feet
Speed0.16 km/h (0.1 mph)
CapacityBlade capacity: 160 cubic yards (120 m3)
Complement5


The Ursa Major (lit. Great Bear) at Black Thunder Coal Mine, Wyoming, is the largest dragline excavator currently in use in North America and the third largest ever built.[1][2] It is a Bucyrus-Erie 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 97.5-metre (320 ft) boom and a 69-cubic-metre (2,400 cu ft) bucket - and Walking Stick, a B-E 1300W with a 92-metre (302 ft) boom and a 34-cubic-metre (1,200 cu ft) bucket.[1]

Specifications[edit]

Its bucket is 160 cubic yards (120 m3), and it has a 360-foot (110 m) boom. It weighs 14.7 million pounds (6,700 t).[3][4]

History[edit]

Shortly before the scrapping of Big Muskie 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 160-cubic-yard (120 m3) 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.[5]

See also[edit]

References[edit]

  1. ^ a b "Black Thunder Thermal Coal Mine, Wyoming". Mining Technology. Retrieved 11 January 2019.
  2. ^ Orleman, Eric. "Bucyrus Erie 2570WS "Ursa Major"". Stripmine.org. Retrieved 11 January 2019.
  3. ^ "Black Thunder and Coal Creek mines". Engineering News. 7 May 1999. Retrieved 11 January 2019.
  4. ^ Modern Marvels: Earthmovers [full citation needed]
  5. ^ Stephanie Cooper. "Black Thunder to operate world's largest dragline bucket".