New Righting Test Method for Lifejackets Using Buoyancy Material Considering Clothing Influence

Abstract

In 2016, an accident in the United Kingdom in which people wearing lifejackets were found in face-down positions in water led to an investigation into the influence of clothing on the righting performance of lifejackets on board ships. The results showed that the righting performance is reduced when lifejackets are worn over clothing. In addition, the reproducibility of the righting test was poor when the subject was wearing clothing. Therefore, developing a highly reproducible righting test method for lifejackets considering the influence of clothing is required.

In this study, we present a reproducible righting test method for lifejackets using almost impermeable buoyancy material instead of clothing. The purpose of using buoyancy material is to simulate the observed effect where clothing diminishes the righting performance of the lifejacket. The size and arrangement of the buoyancy material in this study were determined using a numerical evaluation method for the righting performance of the lifejacket, considering the influence of clothing, as proposed by the authors. The accuracy and reproducibility of the proposed righting test method were confirmed by comparing the results of the lifejacket righting tests performed by human test subjects wearing clothing and buoyancy materials.