A PRACTICAL TECHNIQUE FOR ASSESSING THE LIKELIHOOD OF SURF-RIDING OF A HIGH-SPEED CRAFT IN FOLLOWING AND QUARTERING SEAS

摘要

For safe design and operation of high-speed craft, it is essential to develop a methodology for assessing the criticalrnconditions for surf-riding. This is because surf-riding of high-speed craft could result in broaching or bow-diving inrnfollowing waves. However, this is still an unsolved problem in the framework of the IMO High-Speed Craft Code. Inrnparticular, for high-speed craft the higher limit of operational speed resulting in surf-riding is important, while the lowerrnlimits have already been investigated for conventional ships. Considering this, a significant effort has gone intorndeveloping a numerical simulation to investigate the critical speed for surf-riding to occur in the past. However, this isrntoo complex to apply on a routine basis for commercial high-speed craft. Therefore, for more practical applications, anrnanalytical method has been developed for calculating the upper threshold, the boundary between overtaking waves andrnsurf-riding, and this is verified with the numerical simulation and validated with results from free running modelrnexperiments. The results can be used for ensuring the safe design and operation of high-speed marine vessels withoutrnnumerical integration.