A New Methodology for the Evaluation of the Maneuvering Characteristics of Surface Ship Models

An Arc Second Indoor Global Positioning System (IGPS) has been applied in the evaluation of the maneuvering characteristics of surface ships. The system consists of a series of laser transmitters located around the Maneuvering and Seakeeping (MASK) Basin at the David Taylor Model Basin (DTMB) in West Bethesda, Maryland. Receivers for the location of the model within the MASK are installed on a free-running surface ship model. Since the system provides position of the model within the basin as a function of time, velocity is also computed from finite differences of position and time. The system has been effective in providing velocity calibration data versus propeller shaft speed in straight-line runs. The characteristics of circle maneuvers have also been determined from the system such as the steady turn radius as a function of approach velocity and rudder angle, velocity in a turn, and the drift angle. Quantitative results are provided for a surface ship model in circle maneuvers and velocity calibration from straight-line runs. The typical Froude number range for a test is typically 0.1 < Fr < 0.4 with an uncertainty of ±0.0048 at the 95% confidence level.