The machine consists of a supporting vehicle (1) with a hammer (18) on a carrier frame (17) which can move up or down and is adjustable sideways and for inclination. The frame has a supporting arm (19) for a drive bar (20) designed to make an initial hole for the next post to be inserted. The arm can be moved between a position in which the bar is situated beneath the hammer and a retracted position, and the hammer is equipped with a bell-shaped striker (38) which enables the hole to be made and the post driven in while the vehicle is stationary. The carrier frame (17) is mounted on a side arm (13) and slides transversely on a carriage (12) which itself travels along a column (11) pivoted to a base (4) fixed to the vehicle.
