MARINE MONOMOORING TERMINAL

1446367 Marine monomooring terminals INGECO SpA 11 Jan 1974 1404/74 Heading B7S [Also in Division B8] A marine monomooring terminal comprises a base structure piled into the sea bed, a head located above the surface and supported by a jacket which is constructed so as to yield should a vessel collide with the terminal and thereby prevent the head and base structure from being damaged. It is stated that the head may be supported by a single vertical column, but in the preferred embodiment it is supported by a plurality of columns 19 whose lower ends are stepped in respective housing parts 4 and 7 of the base structure 3 pinned to the sea bed by piles 1. The head comprises an inner space frame 9 which is rotatable on a bearing 8 about a vertical axis and an outer annular space frame 11 suspended from the frame 9 by metal rods, chains or cables 10, connected to the frames 9, 11 by spherical or cardan joints. Fenders 12 are located around the periphery of the frame 11 and stacks of rubber elements 13 or other known spring elements are provided between the frames 9 and 11 and are interconnected by horizontal tie rods 21. Loading or unloading pipes 17 are connected to piping 15 leading to a rotatable coupling 14 and vertical pipe 18 rising from the sea bed. In the event of a collision, the impact will initially be absorbed by sideways movement of the outer frame 11 which causes rods 10 to swing about their pivots and finally upward rising movement of the frame 11. During these movements the impact forces are absorbed by the movement of the frame 11 itself and the elements 13, but if these forces are not fully absorbed, then the jacket flexes to exert a damping resistance to the impact forces. Where a very heavy impact occurs, the tubes 19 flex until they fracture at a predetermined weakened zone above the base structure 3, whilst the head and base structure 3 will remain comparatively undamaged. The terminal is consequently repaired by unstepping the damaged pipes 19 from their housing parts 4, 7 and replacing them.