The Effect of Reducing Sail Height on the Performance of a Generic Diesel Submarine

This work assesses the impact of a reduction in sail height on a generic diesel submarine's resistance, maneuverability, and recoverability. A submarine's sail has been called hydro dynamically undesirable as it increases resistance and complicates maneuverability. Sail size is dictated by the equipement it is fairing, and its height is typically determined by the optical periscope. However, the recent availability of optronic periscopes has reduced the requirement for a tall sail, which has sparked interest in the impact of reducing sail height on hydrodynamic perfomrnace. Using generic diesel-electric submarine shapes, semi-empirical estimation methods, and a fast, validated six degree-of-freedom submarine maneuvering simulator, we examinet he impact of reducing sail height on maneuverability and recoverability following sternplane jams. We show that, while turning effectiveness and horizontal plane dynamic stability are reduced, drag is also reduced, and static stability and recoverability are enhanced. This is considered a net benefit for submarine performance.