GEM of Egypt

1950-B "GEM of Egypt"
GEM of Egypt
TypeElectric power shovel
ManufacturerBucyrus-Erie
Production1967
Length70 m (229 ft)
Width18 m (59 ft)
Height67 m (220 ft)
Weight7,000 t (15,400,000 lb)
Propulsion8 x caterpillar tracks
Gross power13,500 hp or 10.1 megawatts
Speed0.25 mph or 0.4 km/h
Blade capacity130 cubic yards (99.4 m3) or 35.1 short tons (31.8 t)

The GEM of Egypt was a power shovel built by Bucyrus-Erie in 1966. The shovel was designed for strip mining at the Egypt Valley coalfield near Barnesville, Ohio. GEM is an acronym for “Giant Earth Mover” or “Giant Excavating Machine”. It was one of only two Bucyrus-Erie 1950-B shovels built (the other being The Silver Spade) and one of two to use the knee-action crowd licensed from Marion Power Shovel in exchange for Marion's use of Bucyrus-Erie's cable crowd patent.

In a power shovel, "crowding" is pushing the bucket at the end of a "handle" ("dipper" or "dipper stick") in or out to control the depth of cut or to position for dumping. With knee action, the handle is connected to a moveable pivot point rather than being supported directly by the boom. Knee-action design made possible the largest shovel ever built, increased digging power, allowed the bucket to move horizontally into the cut and improved swing efficiency, distance, and radius.