Thermal Protection in Inflatable Liferafts – Human and Thermal Manikin Testing to Quantify:Training Issues, Assess Occupant Heat Balance and Develop Performance Criteria

摘要

Inflatable liferafts are used worldwide as a means ofudevacuation and survival from almost all ocean‐going vessels,udregardless of their size, purpose or region of operation.udVessel size ranges from fishing and other commercial vesselsudwith small crews to offshore oil installations and passengerudships with thousands of persons onboard. WhileudInternational Maritime Organisation (IMO) standardsudcurrently require inflatable liferaft components to “provideudinsulation” or “be sufficiently insulated”, no performanceudcriteria accompany these requirements. This paper willudoutline the methodology and results from a three yearudresearch project involving a multidisciplinary team whichudutilised human subjects and a thermally instrumentedudmanikin to investigate the gaps in knowledge for the thermaludperformance of inflatable liferafts in cold environments.udTests were conducted in a controlled laboratory environmentudwith a 16 person SOLAS‐approved liferaft and air and waterudtemperatures as cold as 5°C. The main variables investigatedudwere clothing wetness (wet and dry) and liferaft floorudinsulation (insulated and uninsulated).ududThe project’s four main objectives were to: 1) developudthermal protection criteria for inflatable liferafts assumingudotherwise unprotected occupants, 2) propose an objectiveudmethodology for testing inflatable liferaft thermal protectionudperformance, 3) develop tools for search and rescue plannersudto predict survival times of liferaft occupants and 4) provideudguidance to training authorities and manufacturers.udThe study found that: 1) the thermal insulation of audcombined system of clothing and liferaft using a thermaludmanikin gave good agreement with measurements usingudhumans, as long as proper corrections for differencesudbetween manikin and humans are appropriately applied, 2)udsystem insulation values coupled with a cold exposureudsurvival model can be expected to give search and rescueudplanners reasonable predictions of survival time in liferaftsudwhere hypothermia is the main risk factor and 3) the factorsudsubstantially affecting the survival time of liferaft occupants are: whether any type of thermal protective aid (TPA) is worn,clothing wetness, liferaft floor insulation and liferaft ventilation rate.