Predicting the equilibrium depth of a body towed by a faired cable

Abstract Comprehensive wind tunnel measurements have been made of the drag coefficients of both the body and the faired cable of a towed system. The drag data has been embodied in theoretical calculations of the depth attained in tow, at speed up to 3 m s −1 (6 knots) with scopes up to 135 m (440 ft). The agreement with sea trial observations is excellent. The work has highlighted the importance of accounting for the variation of faired cable drag with cable angle and has shown that the drag increments due to gaps and misalignments between individual fairing elements cannot be ignored. Methods are derived for estimating these effects for application to other faired cable towed systems.