Passenger Comfort Assessment Method for High Speed Craft Design

Importance of passenger comfort is rapidly increasing in the design of modern passenger ships. Especially, in the case of high speed craft (HSC) comfort level has a significant influence on the earning capability of the vessel. The passenger comfort should be assessed already in the early design phase when only the basic ship parameters are known and it is still possible to make changes in the design. This paper presents a method developed at VTT for assessing passenger and crew comfort in terms of motion sickness and safety of footing. This study was a part in an EU-funded research project Safety at Speed launched to develop a formalised design methodology for the safety and comfort of HSC by using state-of-the-art techniques and tools. The comfort assessment method is applied for long-term and short-term evaluation of comfort levels of HSC SuperSeaCat MDV 1200 by Finncantieri. The required input data of the craft for motion sickness and safety of footing calculations is described both in long-term and short-term cases. The basic principles of the simplified seakeeping calculation method used to generate the RAOs’ of the main ship motion components are reviewed. The parameters of irregular sea needed in the calculations are presented. The analysis is made for a typical sea area where this kind of fast passenger craft operates. All input data is easily available already in the very beginning of the design project. The long-term evaluation results are given in terms of the overall passenger and crew comfort levels during one year of operation in a given sea area. Short-term evaluation results are presented as the comfort levels for a short period of time (typically 2 hours) in one sea state and one angle of wave incidence. The effect of different sea states, velocities and wave encounter angles are studied. The definitions of different comfort and safety of footing levels are discussed and tentative acceptable motion sickness and safety of footing limits are proposed.