In the 1950's the Pierce, South Agnew and Morton mines utilized a Marion 1150 Dragline to strip off the glacial till from above the iron ore body. This stripping bucket was on that Hanna Mining Company dragline. Several of the mining companies took advantage of the large capacity, high productivity and low cost of these enormous machines.- In Partnership with the Cleveland-Cliffs Foundation -
The bucket displayed has a 30 cubic yard capacity (approximately 600-bushel for comparison) and was designed as a 'sludge bucket'. With the large drainage holes in the bucket it was possible to dig muskeg, lake sediment and tailing while leaving behind most of the water.
Draglines work opposite of the traditional wire rope shovels, which predominated on the Mesabi Range for ore production. With a boom the length of a football field the operator was able to swing the bucket forward and drop it to the surface with the open end of the bucket facing towards him. The heavy cable was then rolled on the drum to retrieve the bucket. Then the boom was swung to cast the material off to either side.
Normally the material was just dropped into a hopper that fed onto a moving conveyor, with several transfer points, on it's 2 mile journey to an oscillating feeder for stockpiling.
When the dragline had to move, the 'pontoons' on either side were forced down on the ground lifting the machine very slightly and sliding it forward on it's belly pan. Material, under the weight of the dragline, was compacted to a surface similar to a roadway.