A driver based on the principle of delivering vertical vibrations to the head of a pile in alternating up and down cycles at a rate of 100 Hz. These vibrations set up highamplitude waves of tension and compression in the pile, producing alternate expansion and contraction in minute amounts. The elongation of the pile in expansion displaces the soil at the pile tip, and the weight of the pile, hammer, and added loads shoves the pile into the miniscule void. Since this action is occurring at the rate of 100 Hz, the individual movements need not be of great magnitude to produce rapid penetration of the pile.