MOORING DYNAMIC MODELS 

 By 

 Dr. B. J. Muga 



INTRODUCTION 



It is particularly appropriate that this seminar is being 

 sponsored by the Civil Engineering Laboratory. As far as is 

 known, this Laboratory was the first (at least in modern times) 

 to begin the systematic study of moored ship behavior. The 

 earliest group of studies consisted of (1) an aircraft carrier 

 moored alongside a conventional pier at Bremmerton, Washington, 



(2) another aircraft carrier anchored off San Nicholas Island 

 in what has come to be known as a single point mooring, and 



(3) an LST moored off a drilling platform in the Gulf of Mexico 

 in what is known as a multipoint mooring or spread mooring or 

 what in the industry is referred to as a sea berth mooring. 



In addition, a study of the motions of the CUSS I vessel as a 

 part of Phase I of Project Mohole was carried out here at this 

 Laboratory . 



All of these studies were, for the most part, data collec- 

 tion efforts having rather specific objectives which were satis- 

 fied by what would be regarded as crude data analysis. In brief, 

 they were field studies of prototypes. It should be remembered 

 that when these studies were initiated over 20 years ago, analyses 

 techniques were not as highly developed and even those there were 

 were not well-known. Computer capability, in terms of what we 

 have available today, was in a stage of infancy. Therefore, it 

 is no wonder that the course of field studies was taken, even . 

 though some model studies were also carried out by outside con- 

 tract. (As a matter of fact, even though field studies are very, 

 very expensive, still they were not as expensive, relatively 

 speaking, as they are today.) 



The important role of these early studies — aside from 

 satisfying the immediate objectives — was in drawing attention 

 to the various deficiencies in understanding moored ship behavior. 



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