2.2 INSTALLATION INSTRUCTIONS
2.2.1 GENERAL. General installation procedures for the typical three-legged riser
mooring system are presented below. The procedures are preceded by a description
of the main parts of the mooring system which should be assembled before offshore
2.2.2 RISER-TYPE MOORING SYSTEM. Installation of this mooring system shall
generally follow the procedure set forth below.
Preinstallation Assembly. A three-legged riser-type mooring system is
normally assembled in three parts:
Part I. This part is the first anchor chain subassembly with a sinker
Part Il. This part includes the buoy, the riser chain subassembly from
t h e buoy to the ground ring, and the second anchor chain
subassembly with a sinker and anchor (see Figure 2-4).
Part III. This part is the third anchor chain subassembly with a sinker
Installation Procedures. The marker buoys will be placed in their desired
locations. The center marker buoy will be placed in the desired position
of the mooring buoy. The ring marker buoys will be installed 25 feet past
the point that the anchors will be lowered to the bottom and released.
Predicted drag distance of the anchor is needed to determine this point.
Appendix E provides tables of predicted drag distances. The desired final
location of the anchors should be indicated on the design drawing.
provided by the mooring designer. After pulling the anchor to set it and
test its capacity, (see 22.214.171.124) the final position of the anchor must be
within a 40 foot by 20 foot box with the desired location at the center of
the box (see Appendix E, Figure E-2). The range marker buoys should be