Cost Effectiveness Study of Wastewater Management Systems for Selected U.S. Coast Guard Vessels. Volume VI. Mission Profiles of Selected U.S. Coast Guard Vessels.

摘要

The operations of six U.S. Coast Guard vessels within and beyond restricted waters (within 3 miles from shore or on inland bodies of water) were analyzed in order to determine parameters which affect the design and operating costs of shipboard wastewater management systems. The maximum holding time (i.e., the longest continuous time within restricted waters) is a design parameter which affects equipment sizing. The system utilization factor and number of mode changeover cycles (from primary to overboard or pierside) affect operating costs. The latter two parameters were derived respectively from an analysis of the fraction of time the vessel is within restricted waters and the number of crossings of the three-mile limit as well as the number of shore dockings. Data for the analysis was obtained from visits to the vessels and examination of the logs. From a study of the recorded vessel operations and activities (buoys tended, fisheries patrol, search and rescue, shore dockings, etc.), reference to navigation maps and the assistance of vessel personnel, every sortie was analyzed in terms of its relevant characteristics namely, holding times, times beyond restricted waters, number of 3-mile crossings, and shore dockings. The lists of sortie holding times and times beyond restricted waters constituted basic data which was subjected to further computer-aided statistical analyses, including confidence limits on the maximum holding time for each vessel. Prior to data collection and analysis, pertinent guidelines and assumptions which have a significant effect on the analysis were established.