Steel pilings are universally used as foundations for large buildings. These are often driven into the ground by hammer blows from a "pile driver." In certain soils (sandy, muddy) the piles can be "shaken" into the ground by attaching a "vibratory driver" which imparts a vertical, dynamic shaking force at or near the natural frequency of the pile-earth system. The pile can literally be made to "fall into the ground" under optimal conditions. Design a fourbar linkage-based pile shaker mechanism which, when its ground link is finnly attached to the top of a piling (supported from a crane hook), will impart a dynamic shaking force that is predominantly directed along the piling long, vertical axis. Operating speed should be in the vicinity of the natural frequency of the pile-earth system.