Abstract: A double-acting hydraulic impact hammer includes a drop weight and an inner hydraulic piston. The drop weight is arranged to be driven in an upward and downward direction and the drop weight acts on a pile during its downward motion. The piston has a voided internal area defining a piston volume which is arranged to receive a piston rod and along which the piston extends and retracts axially. The piston volume is in sealed hydraulic communication with the hollow rod volume to form a first volume which changes size as the piston moves along the piston rod whereby the application of hydraulic pressure to the first volume biases the piston towards its extended position. The hammer includes a bore and a collar. The collar forms an outer piston having a working surface which when exposed to hydraulic fluid has sufficient surface area to lift the piston and the drop weight.

Abstract: A method of forming a sheet pile wall comprising cold reforming a Z-shape pile or a U-shape pile and connecting a plurality of reformed steel piles so as to form a sheet pile wall having at least one engagement section, the engagement section when viewed in a cross section being a recess that has a narrowed neck portion.

Abstract: A method of forming a structure comprising at least one locking bar and at least one structural member, at least one flange of the structural member being formed with alternating first and second flange portions. The first flange portions are deformed out of the plane of the flange. The locking bar has arms which between them define a slot configured to receive the flange of the structural member. The method includes deforming one arm of the locking bar into at least some of the gaps between the said first flange portions.

Abstract: A hammer for driving piles comprises an anvil adapted to rest on top of a pile to be driven and a weight arranged to travel through a stroke between an upper position and a lower position. At least one flexible member interconnects the anvil and weight in such a way that when the weight travels to its lower position the flexible member is in tension and prevents the weight striking the anvil. The tension in the flexible member transfers the energy of the weight in a progressive fashion to the anvil.