Summary of Kahului Harbor Plans and Wave Response 



Harbor 

 Plan 



Distinctive Features 



Wind Waves 

 and Swell 



Surge 

 Oscillations 



Remarks 



Figure 



1 



Slip cut in coral stockpile; 

 Concept C for barge pier 



2 



3 



Large oscillations at 

 passenger pier 



3 



2 



Slip cut in coral stockpile; 

 Concept 12 for barge pier 



2 



3 



Large oscillations at 

 passenger pier 



4 



3a 



Notch cut in coral stockpile; 

 No breakwater stub 



2 



2 





5 



3b 



Notch cut in coral stockpile; 

 600-ft breakwater stub 



1 



1 





5 



3c 



Notch cut in coral stockpile; 

 1 ,000-ft breakwater stub 



1 



1 





5 



4a 



Adjacent to coral stockpile; 

 No breakwater stub 



3 



1 



High wind waves and swell 



6 



4b 



Adjacent to coral stockpile; 

 600-ft breakwater stub 



2 



1 





6 



4c 



Adjacent to coral stockpile; 

 1 ,000-ft breakwater stub 



1 



1 





6 



5 



Fill area in SW harbor 



2 



2 



Large oscillations at barge 

 and passenger piers 



7 



6 



Same as 4b but with 38-ft depth 



2 



1 





8 



7 



Fully utilized harbor 

 (combination of 4b and 5) 



2 



2 



Large oscillations at barge 

 and passenger piers 



9 



1 General indicator of plan performance: 1 = equal or better than existing facilities 



2 = somewhat worse than existing facilities 



3 = much worse than existing facilities 



All of the proposed harbor plans have comparable or increased surge (or 

 oscillation) activity relative to the existing harbor. The dredged access areas, 

 straight piers, and corners added in the alternative plans tend to increase surge 

 motions. Changes in the western harbor can potentially worsen surge conditions 

 at the existing commercial piers. 



Ship surge response 



Kahului Harbor experiences natural resonance modes, which cause standing 

 waves in the harbor. These waves are commonly present in the harbor, but their 

 height varies considerably according to incident wave conditions. High standing 

 waves can cause operational difficulties such as excessive ship motion and high 

 mooring line forces. Areas of greatest horizontal motion (nodal areas) are most 

 likely to experience problems. Possible actions to remedy effects of the surge 

 include proper ballasting as ships are offloaded, adjustment to mooring line 

 tensions, and modifications to mooring line configuration. 



