Big Muskie The World's Largest Dragline Excavator

The Big Muskie was a monumental feat of engineering, a dragline excavator built by the Bucyrus-Erie company and owned by the Central Ohio Coal Company. Standing 22 stories tall and weighing 13,500 short tons, it was designed to uncover vast quantities of coal in the state of Ohio from 1969 to 1991.

Design and Specifications

As a model 4250-W dragline, Big Muskie was the only one of its kind ever produced. It featured a massive 220-cubic-yard bucket, making it the largest single-bucket digging machine ever created. To put its size into perspective, the bucket alone could hold two Greyhound buses side by side.

The construction of Big Muskie took over 200,000 man-hours and cost approximately $25 million in 1969 (roughly $219 million today). It was powered by 13,800 volts of electricity supplied via a trailing cable, utilizing eighteen 1,000-horsepower and ten 625-horsepower DC electric motors.

Operational Power and Movement

The energy requirements for Big Muskie were staggering. While operating, it consumed power equivalent to that of 27,500 homes, costing tens of thousands of dollars per hour. Because of this, the machine often worked around the clock, with a heavy emphasis on night work to take advantage of cheaper electricity rates.

To move, Big Muskie used massive hydraulic walker feet. However, due to its immense weight, it traveled at a very slow pace—approximately 1.76 inches per second (0.1 mph). It required a carefully graded travelway with a roadbed of heavy wooden beams to prevent it from sinking into the soil.

Service History and Impact

Over its 22 years of service, Big Muskie removed more than 608 million cubic yards of overburden, which is twice the amount of earth moved during the construction of the Panama Canal. This effort uncovered over 20 million short tons of Ohio brown coal.

Retirement and Dismantling

Several factors led to the retirement of Big Muskie in 1991, including increased EPA scrutiny, a drop in demand for high-sulfur coal following the 1977 Clean Air Act, and rising electricity costs. By the time it was retired, smaller, more efficient machines had replaced the giant draglines.

After sitting idle for eight years, the machine was dismantled in 1999 to comply with the Surface Mining Control and Reclamation Act. Despite calls to preserve it as a museum, it was scrapped for $700,000 worth of recycled metal.