Abstract: A pile driving apparatus for jack-in piling system according to the invention utilises two hydraulic cylinder barrels moving along two vertical support structures. An uppermost horizontal member is employed to maintain a working space in between the two vertical support structures. The actuating rods are fixed to the uppermost horizontal member. The cylinder barrels are free in guided movement, exerting a force on a working pile with the assistance of two drive heads. In a first stroke of piling action, the upper drive head is employed to drive half of the working pile into the ground. In a second stroke, the lower drive head is employed to drive the rest of the pile into the ground.