Outlining a provident initial design approach with regard to cruise ship conversions

A conversion describes the process in which a ship undergoes large modifications. For cruise ships, conversions are costly processes that often require drydocking and lengthy off-hire periods. There are many drivers that necessitate such large investments, including technical considerations such as a vessel’s age or operational efficiency, as well as strategic ones such as market competition and revenue. Regardless of the reason, conversions demand large workloads, both in terms of the drydock process and the planning period beforehand. The primary aim of this thesis is to investigate what can be done during a vessel’s initial design stage to reduce the length, planning, and cost of future conversions. Ideally, recommendations should be straightforward, simple to implement, and cost-effective. By identifying potential initial design improvements, a provident approach is established for a ship’s entire lifecycle. In order to develop this outline, current conversion trends are studied at a broad, industry-wide and narrowed vessel level in order to identify today’s conversion drivers and tasks. Using this information, four common conversion cases are selected as the foundation for the initial design solutions. These cases are broad enough to cover all relevant conversion tasks yet narrow enough to yield specific design solutions. A rules-based approach is then adopted to identify the technical challenges and initial design implications of each case, with a focus on SOLAS regulations. The cases are studied with respect to three disciplines, chosen due to their respective impacts on conversion processes. Namely, these are structural fire protection, means of escape and evacuation, and stability. Each discipline carries significant weight both in initial design and conversion engineering and the final recommendations therefore have broad influences. The final list of initial design recommendations covers the three disciplines through arrangement principles and conservative margin allowances. Structural fire protection methods primarily focus on the classification of perimeter bulkhead and deck boundaries. Those for means of escape and evacuation are presented as both arrangement and margin solutions. The dimensioning of escape ways, lifesaving capacity, and evacuation routing are the bases for recommendations within this discipline. Finally, stability concerns are addressed through allowances and planning aimed at both the construction period and entire service life of a ship. The thesis concludes with a case study and a discussion of the results and future implications of the research. The goal of the case study is to illustrate the methods identified and identify the prevalence and impact of the various conversion cases by considering a recently built cruise ship. The emphasis of the case study is on structural fire protection, since it is the most tangible of the three disciplines. The following discussion highlights the limitations and future considerations of both the study itself and the topic as a whole