Validation of reported events from a vertical chute marine evacuation study

BackgroundThe use of vertical chute marine evacuation systems (MES) is now well established on board marine passenger vessels; this system has yet to be deployed in an emergency situation, however, it has been associated with a fatality and several major injuries during training. Brunel University's Ethics Committee endorsed an initial retrospective cross sectional study (Harwood and Farrow, 2008) and the present quantitative observational study. Harwood and Farrow (2008) found that the physical, physiological and psychological characteristics of potential evacuees increased the likelihood of injury and adversely affected the reliability of the system.PurposeThe validation of factors associated with the adverse outcomes recorded by Harwood and Farrow (2008) during vertical chute MES training, and to assess the hypothesis that evacuee's clothing material will affect the efficiency of the system.DesignObservational data in a marine training establishment providing a triangulation measurement process of evidence from the retrospective study (Harwood and Farrow, 2008). Subjects were three hundred and seventy five representative participants on training courses for evacuation from a ship into inflated life rafts. The main outcome measures were stopping during descent and exiting the chute in an undesirable position.Results6.1% stopped momentarily during descent; 20.3% exited the chute in an undesirable position; on entering the raft 7.7% flipped over and 9.1% had their legs tucked up under their bodies. Independent variables including evacuees' clothing material were statistically significantly associated with adverse outcomes. Participants stopping during descent had an RR of 3.03 (95% CI 1.38, 6.64) for exiting the chute in an undesirable position.ConclusionsThis quantitative observational study broadly supported the results obtained from the retrospective cross sectional study (Harwood and Farrow, 2008). Stopping during descent and evacuee clothing increased the likelihood of undesirable outcomes and impacted on the efficiency of the system.

► Stopping momentarily in the chute was significantly associated with adverse outcomes.
► Clothing fabric worn by evacuees adversely effects chute efficiency.
► High friction clothing, such as rubber can lead to chute blockages.
► Increased injury risk seen on chute exit compared to previous questionnaire answers.