Ursa Major has the distinction of being one of the largest operating draglines in the world. Now it will have one of the largest buckets.

On Monday, a 175-cubic-yard bucket will be delivered to the Black Thunder Mine south of Wright. The bucket will be the largest operating dragline bucket in the world.

In fact, in order to move the 165,000-pound bucket, special permits for an overweight and oversized load had to be obtained. 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.

The second largest operating dragline bucket is in Australia, measuring in at 143 cubic yards.

"We knew we had the biggest operating dragline," said Greg Schaefer, Arch Coal's director of external affairs for western operations.

The biggest dragline in the world is the Big Muskie in the East but the dragline and its 225-cubic-yard bucket were mothballed and has since been taken down piece by piece, Schaefer said.

Schaefer believes the larger bucket will be more efficient.

"You are using the same equipment and getting more production for the same price. It's increasing efficiency," Schaefer said. "It will clear overburden at a faster pace.

"In the mining industry, everybody is looking at the small incremental increase, looking for seconds -- anything that will give you just that little bit more."

The new bucket was constructed in Gillette by Minserco, a subsidiary of Bucyrus International Inc., and took six people about 10 weeks to build.

The bucket could easily hold two full-sized sports utility vehicles, or four SUVs if they were stacked on top of each other, said Cal Willey, Minserco's regional manager.

Mike Schranz, business development manager, said the size of the bucket was determined by the dragline rating, which takes into account the weight of the material being moved, how heavy the bucket is and the weight of all the different chains hanging off the boom.

"This is an inside hoist trunion, which means the rigging weight can be lighter so the bucket can be larger," Willey said.

It may be awe-inspiring to some to know that biggest dragline bucket in the world is going to be at work in the Powder River Basin, but to the guys at Minserco, it's just part of the job.

"It's every day work for us," Schranz said.

In fact, last year the company built the 172-cubic-yard bucket for Ursa Major that the new bucket will replace.

Ursa Major is one of four draglines used at Black Thunder that removes overburden, the dirt that covers the coal. The others are: Walking Stick, a 45-cubic-yard bucket; Thor, a 85-cubic-yard bucket; and Raisin' Thunder, a 130-cubic-yard bucket.

Raisin' Thunder is the newest dragline at the mine. It has only been operating about a year.

-- By STEPHANIE COOPER, News-Record Writer

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