Some Aspects of Very Large Offshore Structures 



ar seas and we did not consider the drift force in irregulars seas, 

 which is much more difficult, as you know. There are some methods, 

 approximative methods, to calculate the drift force in irregular seas, 

 but I think there is still a lot of work to be done on this subject. 



DISCUSSION 



E. J. Plate 



University of Karlsruhe 

 Karlsruhe, Germany 



I should like to congratulate the author on an excellent paper. 

 May I ask the author to tell us what computer was used for the work, 

 and how much time it takes to get one of these calculations perform- 

 ed ? 



REPLY TO DISCUSSION 



G. van Oortmerssen 



Netherlands Ship Model Basin 

 Wageningen* Netherlands 



I should like to thank you, Professor Plate, for your kind 

 words. Our calculations were performed on a CDC computer of the 

 3, 000 series, and that is a medium sized computer. For the calcu- 

 lation of the square structure of which I showed some results we used 

 about 100 sources, which is quite a lot, and the computations requir- 

 ed about 45 minutes per wave condition for that structure. 



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