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PREFACE For many years, the Marine Board of the National Research Council has been concerned that the several aspects necessary for designing and operating port and harbor works be coordinated into a set of rational procedures for systematic engineering. An interdisciplinary meeting convened by the Panel on Harbor/Port Entrance Design of the Marine Board reviewed these aspects in 1980 (Marine Board, 1981) and identified the outstanding problems remaining for research and development. Among the problems were several pertinent to dredging and the adequacy of navigational channels. Subsequently, the U.S. Army Corps of Engineers asked the Board to evaluate the technical adequacy of criteria used in the United States to determine the depths of dredged navi Rational channels in major coastal ports. Origin of the Study Acting on the terms of its charter, "to consider questions of the relation of engineering and technology...to navigation and the commerce of the sea and waterways," the Marine Board agreed to the request. A panel of experts in ship maneuverability, channel and port design, dredging operations, and the management of marine operations was appointed to conduct the evaluation under the direction of the Marine Board. Van
V111 Scope of the Study The panel's evaluation encompassed review of the criteria United States, as well as those used in foreign countries developed port technology, and the consensus standards of national organizations; the analytical techniques used to deters ne depths and allowances; and the factors of greatest importance in channel design, such as the physical environment, ship characteristics, sedimentation, and interactive effects. The study addressed only One used in the with highly inter - technical adequacy ot depth criteria: the environmental implications of dredging and the disposal of dredged materials, as well as the economics of dredging and dredging cycles--although important to decisions about dredging--were specif ically excluded. Methods of the Study In advance of undertaking its investigation, the panel searched the literature addressing the depths of navigational channels. The abstracts written and collected in the course of this search are reproduced in Appendix A. With information provided by the U.S. Army Corps of Engineers about the d' mensions of nine major channels of the United States, the panel tested the adequacy of existing channels for representative ships, using a simple computer model of ship behavior in restricted waters (a brief summary of the results is given in Chapter 4 ; the computer model is described in Appendix D). To compare the criteria of the United States with those of other countries and international groups, the panel requested and received detailed information from the responsible ministries of Canada and Japan, from the Permanent International Association of Navigation Congresses (PIANC), and from the International Association of Ports and Harbors (IAPH). The panel met three times--in Houston, Texas, Norfolk, Virginia, and San Diego, California--conducting site visits and hearing briefings in connection with its meetings from the U.S. Coast Guard, representatives of the district offices of the U.S. Army corps of Engineers, ship pilots, and others with an interest in the design of navigational channels for oceangoing ships. In its meetings, the panel reviewed working papers prepared by members, the pertinent literature, the materials provided to the panel, and the results of the computer model. The conclusions and recommendations presented in Chapter 5 represent the panel's consensus.
ix Acknowledgments The panel gratefully acknowledges the generous contributions of time and information of the Water Resources Support Center and Waterways Experiment Station of the U.S. Army Corps of Engineers, and the briefings and site visits provided by district offices of the U.S. Army Corps of Engineers, captains of the port of the U.S. Coast Guard, and representatives of local pilots associations. The cooperation of the Permanent International Association of Navigation Congresses and International Association of Ports and Harbors made the gathering of information from many countries expeditious, and their interest in the panel's work was of material assistance. Ronald K. Watanabe and Chih-Kang Lee of the Department of Ocean Engineering, Texas A&M University, assisted with the search of the literature and compilation of abstracts and with the computer simulation.