| Summary: | Source: https://erdc-library.erdc.dren.mil/jspui/ A 1:75-scale three-dimensional hydraulic model was used to investigate the design of a proposed breakwater extension at St . Paul Harbor, St. Paul Island, Alaska, with respect to wave and shoaling conditions. The model r eproduced approximately 13,500 ft of the island shoreline and included the existing harbor (located in Village Cove) and sufficient offshore area in the Bering Sea to permit generation of the required test waves. Improvement plans consisted of extensions to the existing breakwater and the installation of breakwater spurs and a new secondary breakwater structure. A 60-ft-long unidirectional, spectral wave generator, an automated data acquisition and control system, and a crushed coal tracer material were utilized in model operation. It was concluded from test results that: (a.) Existing conditions are characterized by very rough and turbulent wave conditions (wave heights in excess of 10 ft) along the vertical-walled dock during periods of storm wave attack. (b.) The originally proposed breakwater extension with the 1,000-ft-long vertical walled dock (Plan 1) resulted in excessive wave heights (6.8 ft) along the proposed dock. Modifications to this plan, which consisted of the installation of spurs and/or a secondary breakwater, resulted in wave heights in excess of the established wave height criterion of 2.5 ft at the dock. (c.) Of the improvement plans tested with the 750-ft-long vertical-walled dock (Plans 9-43), several met the established 2.5-ft wave height criterion at the dock. These improvement plans were not optimal, however, regarding navigation through the proposed entrance configurations. (d.) Of the improvement plans tested considering a pile-supported dock system (Plans 44- 59), several met the 2.5-ft wave height criterion in the new mooring area situated in the lee of the secondary breakwater. (e.) Of all the improvement plans tested (Plans 1-59), Plan 47 was determined optimum considering wave protection, navigation, harbor ...
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