This paper discusses the design and the major components of three (3) Single Anchor Leg Mooring (SALM) terminals which will be used to moor and unload tankers up to 700,000 DWT at the first domestic port capable of accommodating deep draft vessels.
The extensive model tests and basic rationale used for selecting the SALM (vs. the CALM) are discussed as are the design criteria and mooring forces which were determined through model test analysis and supplemental calculations.
The major SALM components are described with emphasis on unique features which were incorporated to improve safety, increase operational efficiency and reduce maintenance requirements.
Special emphasis is placed on the sophisticated equipment incorporated into these SALM systems to allow remote 10aiLinoriitoring and shut-in control of oil flow during the unloading operation and thus provide maximum protection against mooring breakouts and potential environmental damage.
The LOOP SALM terminals will be classified per American Bureau of Shipping's (ABS) "Rules for Building & Classing Single Point Moorings". This paper discusses briefly the involvement and role of ABS in reviewing overall project plans, mooring forces, structural design, and installation plans, and the providing of site inspection doing fabrication and installation.
The Louisiana Offshore Oil Port (LOOP) will be the first domestic facility capable of accommodating deep draft tankers. This facility will greatly improve the efficiency with which crude oil is transported from exporting nations to the United States and will allow full realization of the economics offered by Very Large Crude Carriers (VLCC). These terminals, each designed to safely moor and unload tankers up to 700,000 DWT, will be located approximately 18 miles south of Grand Isle, Louisiana in about 110 feet of water.
The LOOP deepwater port will allow fully loaded VLCC's to unload crude oil directly into underground storage and thence to major pipeline systems and will thus reduce the current requirements for lightering and transshipment. Unloading oil via SPM is ecologically preferable to open ocean lightering because the possibility of spills is greatly reduced. Additionally, the offshore location of the deepwater port provides for environmental safety because it reduces the probability of tanker collision or grounding which are by far the major causes of oil spills.
In its initial stage the LOOP terminal will consist of three (3) SALM-type (Fig. 1) Single Point Mooring (SPM) terminals arranged equidistantly along an 8000 foot radius semi-circle with the pumping platform complex at its center (Fig. 2). Ultimately, expansion plans may add up to three (3) additional SALM's for a total of six (6). A fifty-six (56) inch diameter pipeline will connect each SALM to the central offshore pumping platform and a 48 inch diameter pipeline will connect this pumping facility to a shoreside booster station. From here, the oil will move inland to the underground salt dome storage facility where it will be temporarily stored. Oil will be transferred from storage to the St. James terminal of CAPLINE which feeds refineries in the East and Mid-West, and to other pipelines which supply Louisiana refineries. The LGOP terminal which will initially have an import capacity of 1.4 million barrels per day will ultimately be joined to about twenty-five (25%) percent of the total U. S. refining capacity.