Patent Publication Number: US-4096704-A

Title: Offshore product loading terminal

Description:
This invention relates to an offshore product loading terminal. 
     According to this invention there is provided an offshore product loading terminal comprising a support intended to rest directly or indirectly on the sea bed, a pipe swivel carried by the support and to which a product pipe from a product source is intended to be connected, the output and the input of the swivel being capable of relative rotation about a vertical axis. 
     Preferably the support is intended to be secured to an anchor secured by gravity or otherwise to the sea bed. 
     Preferably the support also carries a turntable permitting relative rotation about the said vertical axis and intended to carry a buoy intended to carry a mooring point for a ship. 
     In use the buoy is permitted rotation about the vertical axis by the turntable. 
     Preferably the buoy is carried by the turntable through a universal coupling which permits pivoting of the buoy about two orthogonal horizontal axes. 
    
    
     An embodiment of this invention will now be described, by way of example only, with reference to the accompanying drawings of which: 
     FIG. 1 is a schematic side view of a loading terminal in accordance with this invention; 
     FIG. 2 is a more detailed plan view of a support and swivel; and 
     FIGS. 3 and 4 are sectional elevations along the lines A--A and B--B respectively of FIG. 2. 
    
    
     Referring to the drawings two slurry flow lines 1 from a product source on the sea bed 2 lead to a steel mooring frame 3 resting on a gravity anchor 4. The gravity anchor 4 has a fitted structural steel skirt 5 which transmits the applied horizontal loadings from the anchor 4 to the sea bed 2. 
     The mooring frame 3 carries a turntable 6 which carries a conical structure 7 which supports a vertically extending steel buoy 8 through a universal coupling 9 which permits rotation about two orthogonal horizontal axes. 
     The two lines 1 are joined to a swivel unit 10 and referring to FIGS. 1, 2, 3 and 4 it will be seen that two horizontal pipes 11 connected to the lines 1 are connected to a Y-shaped pipe unit 12 which is coupled to another Y-shaped pipe unit 13 through a swivel 14 which permits relative rotation of the two Y-shaped pipe units 12 and 13 about a vertical axis 15 which is also the axis of the turntable 6. The Y-shaped pipe unit 13 has its outlets 16 connected to a pair of flexible hose lines 17. The pipes 11 and lines 17 do of course, extend away from the swivel unit 10 in opposite directions. 
     The buoy 8 is a mooring tower of cylindrical steel fabrication which is ring tiffened and stiffened into several compartments individually sealed. 
     The upper end of the buoy carries fenders 18 and a mooring line assembly 19 as well as a navigational marker at the end of a pole 20. 
     In use, the flexible hose lines are of course connected at their outer ends to a moored ship and have their initial sections stiffened and unbuoyed so that they remain below the sea surface whereas the final sections of the flexible hose lines are of the self buoyant type. The sections of buoyant hose have marker lights attached to them. 
     The mooring line is designed for use with a bow grapple system. 
     The product may be iron ore or any other mineral. 
     The product lines are independent of the mooring arrangements and could be used without the buoy 8, the coupling 9, and the mooring line 19. Obviously the size of the mooring buoy 8 could be changed. 
     The compartments of the buoy 8 may be individually replaceable.