IV 



CONTRIBUTION OF SHIP THEORY TO THE 

 SEAWORTHINESS PROBLEM 



Georg P. Weinblum 

 Institut fur Schiffbau der Universitdr Hamburg 



CONTENTS 



Introduction 



Page 



I. The investigation of ship behavior in a seaway 63 



1 . The seaway concept 63 



2. Preliminary survey 64 



3. More detailed survey 66 



3.1. Dimensionless parameters 67 



3.2. Added masses 67 



3.3. Damping 69 



3.4. Simplified theory of heave and pitch 71 



3.5. Investigations on exciting forces 71 



3.6. Coupling of motions and equations of motion 74 



4. Hydrodynamic impacts 76 



5. Full scale experiments 77 



6. Seaworthiness of the hydrodynamic class of vessels 78 



II. The significance of research results for design 79 



1 . General remarks 79 



2. Transverse stability and roll 81 



3. Heave and pitch 81 



3.1. Basic consideration 82 



3.2. Influence of form variations 86 



3.3. Wetness 90 



4. Hydrodynamic Impacts 90 



5. Conclusions 91 



III. Future research 93 



1 . Facilities 93 



Introduction 



In an earlier survey [11 on the behavior of ships in a seaway we quoted A. 

 Krylov's opinion on his famous memoir presented to the INA [2] and later published 

 in the Enzyklopaedie der Mathematischen Wissenschaften, . . . "it is evident that these 



61 



