Abstract All three ship design, ship approval and ship oper- ation determine the safety of a vessel in rough con- ditions。 Now while designing as much seaworthiness as economically possible into a ship from the start provides the best basis for safe operation, it alone is not enough。 Experience from ship operation shows, that the safety of a vessel and its crew relies strongly on the ability of the crew to judge the vessels perfor- mance and its limits。 This paper summarizes devel- opments within the German BMBF-funded project SinSee where one goal is to more closely link numer- ical assessments, model tests and real environmental data。81339

Keywords Safety, seakeeping, motion simulation, deterministic wave groups, wave radar, decision support

Introduction In today’s highly competitive environment ship de- signs change very rapidly。 Especially in areas where the design process is supported by advanced de- sign and analysis tools which are available for ap- plication worldwide today, e。g。 CFD-optimization or FEM-Analysis used either by the yards themselves or being accessed through subsuppliers。 Consequently also the seakeeping characteristics of modern vessels change and thus it is increasingly difficult for the crew to identify and judge possibly dangerous en- vironmental conditions correctly。 Typical problems are large container ships being susceptible to para- metric rolling and/or pure loss of stability, Ferries and Cruise ships suffering from very short roll pe- riods and/or high accelerations and the like。 Still, sea keeping assessments and characteristics are usu-

ally not included in the building contract and de- velopments to introduce more suitable assessments of ship dynamics in rules and regulations will take some more years。

Available means to investigate the sea keeping per- formance of vessels are numerical simulations and/or model tests。 Many examples show, that today’s tools and procedures in these areas are well suited to inves- tigate accidents [3], [6]。 With respect to design opti- mization it can furthermore be demonstrated that the consequent application of numerical investiga- tions in the early design phase allows to efficiently improved in the design performance with respect to intact safety [2]。 But what is lacking are standards with respect to such evaluations。

With respect to ship operation – obviously valuable data is available or can be generated, which can be used as a basis to compile information for decision making in ship operation。 But ways need to be de- veloped of how to present these information in the most pragmatic and useful way。 And again stan- dards defining minimum requirements with respect to significance and reliability are lacking。 Further- more it is well known that seaway parameters such as the significant wave height and the peak period are difficult to impossible to estimate visually from on board a ship。 But especially the peak period is the basic information needed to identify possibly danger- ous combinations of ship speed and encounter angle with respect to any roll resonance problems。

Within the project SinSee, funded by the German BMBF, a full-scale measurement system is developed and tested which will allow a simultaneous measure- ment of ship reactions and the belonging environ- mental conditions。 Basis for the measurement of the seaway is the sea-clutter data from a standard X- band marine radar。  The Wave  Monitoring   System

WaMoS was developed to determine the directional wave spectrum and all derived sea state parameters in real time from these radar images。

While in SinSee the  focus  is  on  the development of a full-scale measurement system, with the data to be used for validation purposes and the system being available for future long-term measurements, components could also be used as a basis for the de- velopment of decision support systems。