— < 0.0038 ft/sec 

 T 



— < 0.0012 m /s 

 T 



(18) 



where H and Tare long wave height and period measured in an adjacent 

 comer. He refers to this as a slope criterion since it was derived from H/L for 

 a shallow- water wave. The H and T combinations for threshold damage are 

 shown in Figure 47. 



1.00 



10.00 



Wave Height, cm 



Figure 47. Wilson's threshold of surge damage for moored ships (from 

 Seabergh and Thomas (1995)) 



2. Seabergh and Thomas (1995) reference unpublished long-wave significant 

 height criteria suggested by Walker and Szwetlot (H slong <5-10 cm for 

 100 percent operational efficiency with man-made fiber mooring lines; 

 H sJong <lO-\5 cm with steel wire mooring lines) and Burke for the 

 Los Angeles Long Beach Harbor complex. Based on these and Wilson's 

 (1967) published criterion, Seabergh and Thomas use the following criteria 

 as indicators of successful operational conditions: 



H 



tjong 



< 5 cm 



for T=A 1-205 sec 



H sjon g < 10 cm for 7=205-1,024 sec 



(19) 



3. The Permanent International Association of Navigation Congresses 



(PIANC) (1995) gives criteria for each degree of freedom of a moored ship 

 (surge, sway, heave, etc.). The criteria for horizontal translational motions 



Chapter 4 Numerical Model 



65 



