Development of Intact Stability Standards for Rigid-Sidehull Surface-Effect Ships

摘要

When a Surface-Effect Ship (SES) is off-cushion, its stability characteristics are similar to those of a displacement ship and its stability requirements can be formulated in the traditional manner. In view of the growing interest in operating SES and other high-performance ships in commercial service in U.S. waters, the United States Coast Guard (USCG) has initiated a program of study to develop stability standards for these ships when operating at high speed. This report summarizes the most recent phase of this work which concerns the stability of the rigid-sidehull SES in normal operation. The USCG objective is to provide guidelines to SES designers that will enable them to determine, during the design stages, whether or not a proposed SES has adequate inherent stability. Care must be taken that the guidelines do not constrain the designer unnecessarily. The types of hazard and types of instability which SES can encounter in normal operation are identified. Corresponding requirements for certification of safe operation are recommended. Results of developing a non-linear, five-degree-of-freedom, mathematical representation of SES response to certain hazards are presented to show the effect of changing normalized stability parameters. Correlation with SES-100B trials results is presented to establish modeling validity.