Operability assessment of high speed passenger ships based on human comfort criteria

Abstract

The growing popularity of passenger cruise lines means continual challenges are faced concerning both a vessel׳s design and its operational ability. Vessel dimensions, service speeds and performance rates are rapidly increasing to keep pace with this expanding interest. It is essential that vessels demonstrate high performances, even in adverse sea and weather conditions, and ensure the comfort of passengers and the safety of cargo. A vessel׳s operability can be defined as the percentage of time in which the vessel is capable of performing her tasks securely. In order to calculate a vessel׳s operability index, many key parameters are required. These include the dynamic responses of the ship to regular waves, the wave climate of the sea around the ship׳s route, and the assigned missions of the vessel. This paper presents a procedure to calculate the operability index of a ship using seakeeping analyses. A discussion of the sensitivity of the results relative to three different employed seakeeping methods is then given. The effect of seasonality on a ship׳s estimated operability is also investigated using wave scatter diagrams. Finally, a high speed catamaran ferry is explored as a case study and its operability is assessed with regards to human comfort criteria.