Largest dragline excavator

Big Muskie, a walking earthmoving machine weighing 13,200 tonnes (29.1 million lb) was the largest ever dragline excavator and among the largest mobile machines ever made, weighing as much as nearly 10,000 saloon cars.  It stood at Central Ohio Coal Co.'s Muskingham open-cast coal mine in Ohio, USA, but was dismantled in 1999.

Built on site over two years and completed in 1969, Big Muskie was 46 m (151 ft) wide (equivalent to an eight-lane highway) and capable of moving 17,500 tonnes (38,580,850 lb) of earth every hour. It was 'walked' around on site on four 6 x 20 m (20 x 65 ft) hydraulically powered 'shoes'.

Dragline diggers have a giant bucket suspended by cables or draglines from the end of a boom. The bucket is lowered from the boom and then slowly reeled back towards the machine, scooping up large amounts of eath along the way; in Big Muskie's case, 325 tonnes (716,500 lb) of it at a time.

By the early 1990s Big Muskie was becoming too expensive to run and was decommissioned. A popular campaign soon started to preserve the remarkable machine as a museum and tourist attraction, but in January 1999 Central Ohio Coal Co. announced that a scrapping contract had been awarded. However, the massive 168m³ (220yd.³) bucket - weighing 230 tons empty and capable of shifting 325 tons of dirt in one go - has been preserved as a monument to the miners of southeastern Ohio. During its years in operation it moved 3.6 million cubic meters (4.8 million cubic yards) of earth, nearly twice that moved whilst creating the Panama Canal. Big Muskie cost US$25 million in 1969.

Built by Bucyrus Erie. Dismantling in 1999 was to allow the site to be reclaimed in accordance with state and federal mining permit requirements.