Committee V.5: Special Vessels
Authors: Truelock Darren , Lavroff Jason , Pearson Dustin , Czaban Zbigniew (Jan) , Luo Hanbing , Wang Fuhua , Catipovic Ivan , Begovic Ermina , Takaoka Yukichi , Loureiro Claudia , Song Chang Yong , Garcia Esther , Egorov Alexander , Souppez Jean-Baptiste , Sensharma Pradeep , Nicholls-Lee Rachel 
Published: April 2023

Committee Mandate
Concern for structural challenges of non-conventional, special surface vessels, including uncertainties in established design methods and modelling techniques. Particular attention shall be given to mega yachts, naval craft, offshore service vessels and work boats, which can be characterized by particular structural configurations and materials (wide openings, large unsupported structures, unconventionally shaped superstructures, etc.) and/or are to sustain specific loading conditions (harsh environment, severe cyclic loads or extreme operational ones).

Introduction
This Specialist Committee report for the ISSC 2022 proceedings covers a range of marine vessels particularly “Special” by nature of their structural configurations. In the ISSC 2018 V.5 Special Craft report (Truelock et al., 2018) the Committee’s focus was broad and largely on highlighting “Special” craft through market segments. This report is a continuation of this Special Vessel Committee, the intent is to further discuss those markets and drill down into specific and unique structural configurations. The ISSC 2022 Special Vessel Committee has included the additional year (i.e., originally ISSC 2021) delay due to the COVID-19 global pandemic to gather further research and investigate additional topics for the report. A benchmark has been undertaken by the Committee investigating various calculation and analysis methods on window glazing as a structural material and a discussion on this study is in the Appendix. Additionally, during the Committee’s research, a few of the Committee members were able to present a paper at the 2020 High Speed Marine Vessel (HSMV) Conference, Comparative Assessment of Rule-Based Design on the Pressures and Resulting Scantlings of High Speed Powercraft (Souppez et al., 2020), which was well received by the high-speed vessel community. Finally, new markets are emerging in both commercial and government sectors, so the Committee has also included a Chapter on emerging trends to cast a light on structural uncertainties in new technologies and categories of Special Vessels.
1.1 ISSC 2018 special craft recommendations and official discusser feedback
A discussion in Volume III of the ISSC 2018 V.5 Special Craft report outlines a few areas and recommendations that the 2018 Official Discusser touched on for the follow-on Committee and audience of the Committees presentation at the Congress provided, those we have addressed in this report are as follows:
- The Committee name change to Special Vessels in lieu of Special Craft due to certain expectations that the word “Craft” carries.
- A discussion on cyclic loading on composite structures in Chapter 2, which is a special topic relating to higher speed vessels.
- The Committee focus on green, emission reducing vessels, Chapter 4, as a new emerging trend in the category of Special structural configurations.
- A discussion and analysis on glazing as a structural material in Appendix A.
These topics, along with a few others can be found within the report contents to address and further investigate some of these exciting topics.
1.2 Special vessels addressed
The Committee Report is a consolidation of references that reflects recent research and development and topics of discussion in the areas of structural arrangements, loading, analysis technique and uncertainties in Special Vessels. Our Chapters have been categorised into types or markets of Special Vessels, Table 1.