Aids to Navigation Principal Findings Report on the Ship Variables Experiment: The Effect of Ship Characteristics and Related Variables on Piloting Performance

摘要

This experiment is one of a series done for the U.S. Coast Guard to quantify the relationship between variables related to aids to navigation and piloting performance in narrow channels and, potentially, safety in such channels. This is one of several experiments restricted to visual piloting, and further to buoys only. It was done on a simulator built for the U.S. Coast Guard at Eclectech Associates in North Stonington, Connecticut. The variables evaluated were: Ship Characteristics: an 80,000 dwt tanker with a rear bridge and an 80-foot height of eye versus a 30,000 dwt tanker with a midship bridge and a 45-foot height of eye; Size and Complexity of Bow Image: larger and smaller bow image for the 30,000 dwt tanker; Speed of transit: 6 knots versus 10 knots; buoy density: a three-buoy turn and short (5/8 nm) spaced, gated buoys versus a one-buoy turn and long (1-1/4 nm) spaced, staggered buoys; and Underkeel clearance: 1 foot versus 600 feet. Only selected combinations of these variables were included as scenarios in the experiment. Tasks and wind and current effects were varied within the scenarios. The findings are presented as the means and standard deviations of crosstrack position of transits under each condition. Observed differences in their inherent controllability parameters to provide a methodology for extrapolating the findings to a variety of ships not included in the experiment.