Los Angeles and Long Beach Harbors Model Study: Report 3. Analyses of Wave and Ship Motion Data.
Abstract
This report describes the procedures and presents the results of analyses of prototype ship motion and wave data collected in the Los Angeles and Long Beach Harbors during a 1-yr data acquisition program. In the ship motion analyses, observations of ship characteristics, movement, and mooring line configurations/characteristics are statistically analyzed for various time distributions and concurrences of movement. For various ships and mooring configurations in the East Channel of Los Angeles Harbor, a numerical analysis of moored ship response to wave excitation is conducted to define the periods or frequency ranges of maximum surge response. In the analysis of wave data, estimates of wave energy for wave periods ranging from 15 sec to 3 hr are calculated from the prototype wave data by spectral analyses. Time-dependent spectral estimates are calculated for 10 time periods during which concurrences of medium and/or heavy ship movement occurred. From such spectral techniques, frequency bands containing significant energy levels are identified for 15 wave gage locations in the two harbors. In addition to identifying characteristic frequency bands of wave energy for each gage, the time variation of energy levels within each frequency band and the distribution and/or penetration of swell throughout the harbors are estimated. Observations of adverse ship motion are correlated with time variations of energy levels in characteristic frequency bands. Subjective analyses of analog wave records are conducted to provide indications of frequency of occurrence and wave-height distributions for previously identified wave periods having maximum energy (wave heights).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1976
- Accession Number
- ADA029646
Entities
People
- Donald L. Durham
- Douglas G. Outlaw
- Jack K. Thompson
- Leroy G. Crosby