Hydraulic impact hammer

A hydraulic impact hammer comprising an outer protective casing, a first guide member defining a first cylindrical bore, a first attenuating element supporting the first guide member inside the casing in a manner allowing the first guide member to move radially and axially relative to the casing, a piston fitted slidably in the first cylindrical bore, a second guide member defining a second cylindrical bore, an impact member fitted slidably in the second cylindrical bore, and a second attenuating element supporting the second guide member inside the casing in a manner allowing the second guide member to move radially and axially relative to the casing independently of the first guide member and without allowing direct contact between the second guide member and the protective casing, said first and second attenuating elements biasing the first and second guide members to respective positions such that the first guide member is spaced from the second guide member and the second bore is substantially coaxial with the first bore, and the hammer being such that upon displacing the piston in the direction toward the impact member, the piston can enter the second bore and strike the impact member directly.