Abstract: A shear key unit for attachment rigidly to the base of a foundation raft for a maritime structure comprises an open ended thin walled cylinder, which when its open end is facing downwardly beneath the raft, acts as a fluid tight chamber of variable volume - the volume being diminished as the cylinder penetrates the seabed strata. The foundation raft can be lowered by controllably allowing sea water to escape from the chamber. A slidable closure may be provided at the distal end of the cylinder to isolate the interior of the cylinder from the seabed. It is a feature of the invention that the cylinder assembly can be installed through an opening extending downwardly through the foundation raft, and can thereafter be fixed in a position projecting beneath the base of the raft.

Abstract: A method of fabricating a maritime assembly comprising the steps of stabilizing a foundation raft alongside a quay, moving at least a part of an erect tower structure from the quay onto the foundation raft, securing the tower structure to the foundation raft, and floating the assembly so formed away from the quayside site. Additionally a particular method for fabricating a tower structure is described, and a particular foundation raft and a method of constructing such foundation raft are outlined. The method of the invention is not limited to particular method for fabricating the tower structure, or the particular foundation raft.

Abstract: A maritime assembly incorporating a foundation raft for founding, or when founded, on a sea bed, and having venting means responsive to the movement of waves whereby pore pressure at at least one point beneath the raft is reduced with respect to the hydro-static pressure appropriate to the external depth of water below the mean level of water in which the raft is (to be) founded.