0.5
0.4
Anasosopo
Aua
Leloaloa
Anua
0.3
0.2
0.1
0.0
Site Location
Figure 15. Wave height amplification factor based on incident wave climate
a. Wave height in berthing areas will not exceed 0.3 m (1 ft) more than
10 percent of the time.
b. Wave height in entrance and access channels and turning basins will not
exceed 0.6 m (2 ft) more than 10 percent of the time.
Standard criteria for wind waves and swell in deep draft harbors, such as
Pago Pago Harbor, are not so well established and are more dependent on vessel
size, mooring configuration, and wave period. However, the criteria for shallow
draft harbors can provide a useful basis for comparing alternative sites at Tutuila.
The 0.3-m (1-ft) criterion has applicability to small moored vessels. Larger deep-
draft vessels are typically more tolerant of waves, and the 0.6-m (2-ft) criterion
provides a more relaxed metric for operational suitability of potential dock areas.
However, some deep-draft operations can be quite sensitive to wave motions.
Experience with the Alaska ferry system (vessel lengths up to 90 m (300 ft))
suggests that the USACE 0.3-m (1-ft) criterion in berthing areas is a meaningful
threshold for that application (personal communication from Harvey Smith,
Department of Transportation and Public Facilities, State of Alaska, 2002).
Another, perhaps more valuable criterion for evaluating proposed new pier
areas is to compare with the existing piers. Many years of practical experience
can then be approximately transferred to new site considerations.
Wave heights for assessing the USACE criteria were computed by combining
the incident wave time-history developed to represent the hindcast wave informa-
tion with numerical model results to create a time-history of wave heights along
24
Chapter 4 Harbor Response to Wind Waves and Swell
Previous Page
