Ursa Major (excavator)
Ursa Major in 2009 | |
| Class overview | |
|---|---|
| Name | 2570-WS Ursa Major |
| Builders | Bucyrus-Erie |
| Operators | United States |
| Cost | US$50 million (1999) (equivalent to US$86.01 million in 2023) |
| In service | 2001-Present |
| Planned | 1 |
| Completed | 1 |
| Active | 1 |
| History | |
| United States | |
| Name | Ursa Major |
| Builder | Bucyrus-Erie |
| Laid down | 1999 |
| Launched | 2001 |
| Christened | 2001 |
| Commissioned | 2001 |
| Notes | Largest walking dragline currently in-service |
| General characteristics | |
| Class & type | Model 2570-WS-series Dragline excavator |
| Tonnage | 6,700 tonnes (7,385 short tons) |
| Length | 110 m (360 ft) (boom) |
| Propulsion | 2x hydraulically driven walker feet |
| Speed | 0.16 km/h (0.1 mph) |
| Capacity | Blade capacity: 160 cubic yards (120 m3) |
| Complement | 5 |
![](https://en.wikipedia.org/wiki/File:"Ursa_Major"_dragline_at_Black_Thunder_Coal_Mine_(3911596414).jpg){kind=link}
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. 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.