0.2 



0.8 



0.4 0.6 



Frequency (sec" ) 



Figure B-16. Heave response of FORDS in regular waves of small amplitude. 



The axial forces imparted in the string for test condition 1 are 

 particularly significant; they are comparable to what can be expected in a 

 ship of around 13,000 tons displacement. For a ship heading directly into a 

 sea state 6, the dynamic forces are 1 7% of the static forces; for a sea state 4 

 the same heading will result in dynamic stress 10% of the static. The latter 

 is more realistic. 



134 



