The journal
Open the journal →The conversation starts in the journal — be the first to post.
About Ursa Major
The Ursa Major 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$38 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 (90 yd3) bucket - and Walking Stick, a B-E 1300W with a 92-metre (302 ft) boom and a 34-cubic-metre (44 yd3) bucket.
Everything about Ursa Major →