Structural analysis of HSC hull design for JFD swimmer delivery system

Abstract: Fiber composites are widely used for small high-speed crafts due to their high strength to weight ratio. James Fisher Defense (JFD) has developed a high-speed swimmer delivery system called SEAL Carrier which is built upon a carbon fiber structure. The SEAL Carrier structure is designed according to Det Norske Veritas (DNV) rules for classification from 2011. Since the merge between DNV and Germanischer Lloyd (GL), a harmonization of the rule sets was per-formed and in 2016 a new set of rules were adopted. The analysis carried out in this thesis aims to give an understanding for JFD how their hull structure relates to the new set of rules. A number of weak structural members was identified, which raised questions about the effects of the changes in the rule sets. For some panel fields the lateral deflection differed up to 500%and it was also shown that the criteria for maximum stress differs up to 42%. This analysis will be used as support in the further development of new series of SEAL Carrier which might be classified by DNV-GL. The author proposes material tests to avoid uncertainties discussed in the report, together with higher level of detail in the structural arrangement to decrease the margin of error.