White Rock Steps Up Capacity With World’s Largest Aggregate Dragline

White Rock Steps Up Capacity With World’s Largest Aggregate Dragline
(1st/2nd Quarter 2006)

White Rock Quarries, the second-largest quarry in the U.S., unveiled its latest high-capacity production tool to hundreds of business and community guests earlier this year — the world’s largest aggregate dragline, a Marion 8200 with a 105-cu. yd. bucket.

The bucket is large enough to hold 130 tons of blasted rock. With an average mining cycle of 75 seconds, the machine can yield 24 million tons of limestone per year.

Guests got to see the dragline up-close and in action. They donned hard hats, shuttled to an active pit and boarded the dragline to experience several digging cycles, then toured the aggregate plant before returning to a tented, catered luncheon.

Also enjoying the occasion were executives from North American Mining, which owns and operates the dragline under a mining agreement with White Rock.

Just getting the dragline to White Rock’s Miami location was a monumental task. After disassembly, it was shipped from its previous location in New Mexico aboard 175 semi-trucks — some with up to 13 axles and 50 wheels — for reassembly in Miami.

Thirty-five technicians worked 10-hour shifts, seven days a week to finish the task in a year. The completed unit weighs 6,750,000 lbs. and has a boom length of 275 feet.

Up and running since September 2005, the dragline makes its way around White Rock by “walking” seven feet at a time on “shoes” that measure 12-ft. wide by 60-ft. long.

The mammoth machine, which runs on electricity, requires its own nearby, dedicated power substation.

A python-thick extension cord stretches alongside the quarry’s haul roads to feed the dragline’s 14 motors, which generate up to 14,500 horsepower to drag, hoist and swing the bucket, and to propel the unit as it makes its way around the pit.

Return to top