Design Margin of Composite Structures of Korean Fishing Vessel and Assessment of Its Environmental Impact

Small vessels of GT (gross ton) 30 or below account for 90 percent of all registered vessels in Korea, most of which are built from composite materials. Recently several efforts have been made to reduce the amount of greenhouse gas emitted from such small vessels; however, they are mainly ineffective as they are not compulsory like the emission regulations from IMO MARPOL. This study aims to evaluate design margins of Korean composite fishing vessels by comparing the Korean rules on small composite vessel designs to other related international rules. This study also aims to quantitatively show how reducing the design margins can help make small composite vessels more environmentally friendly. This study showed that the Korean rules were not taking into account the fiber weight fraction of composite laminated plate, which determines physical properties of the plate. The Korean rules also failed to consider the effect of hull shape and structural layout on the design load of a vessel. As a result, design margins in Korean rules were slightly larger than that of other international regulations. This difference in design margins was proven to contribute to the global warming and the depletion of ozone layers. © 2020, Editorial Office of Ship Building of China. All right reserved.