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Rocker crane with increasing haen on ropes, vertically or nearly vertically movable, several times at right angles against weight of the divided boom, the part during the drawing-in of the boom parts in succession are rendered ineffective
Rocker crane with increasing haen on ropes, vertically or nearly vertically movable, several times at right angles against weight of the divided boom, the part during the drawing-in of the boom parts in succession are rendered ineffective