Analysis of the impact of deploying thermal protective immersion suits on evacuation time for passenger ships operating in polar waters

For passenger vessels operating in polar waters, the Polar Code requires that in case of possibility of immersion in polar waters, thermal protective immersion suits (TPIS) should be available for all passengers. Thus, international standards require that TPIS can be donned within 2 min and that walking speeds are reduced by no more than 25%. Clearlythese requirements are arbitrary and do not reflect their potential impact on evacuation performance. Other IMO requirements specify the maximum time permitted for assembly and abandonment times for passenger ships, which can be assessed using agent-based evacuation modelling (ABEM). However, these requirements currently ignore the impact of TPIS and employ a safety factor of 25% to represent all factors ignored when modelling evacuation. Here we explore the impact of TPIS on both the assembly and abandonment times of a hypothetical vessel using ABEM. The results demonstrate that requiring the donning of a TPIS can increase assembly times by as much as 65% and negatively impacts the abandonment process. It is thus essential that additional requirements associated with evacuation of vessels in polar waters are reflected within the IMO passenger ship evacuation certification guidelines. The paper suggests several ways in which this can be achieved

BBN Model with Quantitative Inputs for Risk Analysis of Uncontrolled Fire in Machinery Space

The past decades has witnessed a significant increase in the number and volume of international trade through the sea. Thousands of ships are sailing in the coastal and international waters all over the world. Accident in the sea transport not only results loss of property for the owners of vessels and traders of cargo, but also threatens the environment and the humans who are directly or indirectly associated with the marine industry. One of the most dangerous accidents in ships is fire and statistics has shown more than 50% of the fires in the ships has happened in the aft area of the ship (MEPC 2008). Engine room of the ships by nature is susceptible to fire due to enclosing numbers of ignition sources connected to the pipes and storage tanks containing flammable liquids. In light of the increasing demand for higher level of safety in maritime transport international regulation concerning safety has been upgraded. Frameworks, procedures and regulations concerning fire safety in ships reflected in SOLAS chapter II-2. The accident reports shows that despite of the innovation and preventive regulations and measures, still the risk/frequency of fire is not low enough to be negligible. The critic to the regulation enforced by IMO through chapter II-2 SOLAS is that the rules are achieved largely based on past experiences and assessment of finite set of serious accident scenarios (Mermiris, et al. 2012). Literature review showed there is lack of literature in developing a risk model that can incorporate all the human, organizational and technical factors associated with risk of fire in engine room, which can be used for further analysis and revision of procedures and regulation concerning fire in machinery space. This report reviewed the statistical reports in the literature about source and frequency of fire in the ships with focus on engine room fire. The influencing factors associated with the risk of uncontrolled fire in engine room identified. The main source of uncontrolled fire presented to be combustion of released hydrocarbons in contact with the ignition sources. Sources of leakage in engine rom classified to two main separated compartments of Purifier Room and Engine Room area. Engine room area includes Main Engine, Diesel Generators, Boiler, Incinerator, and other piping and electrical sources. The probability/frequency of all of the risk influencing factors determined using the relevant literatures. BBN model developed for uncontrolled fire in engine room. Influence of different factors on each other discussed and the most appropriate probabilities/frequencies selected for the model. As a part of the further work (in order to determine weights for factors in the model) a pairwise comparison method introduce which needs a degree of expert judgment. For the final step, a semi mechanistic approach introduced for developing the conditional probability tables. Sensitivity analysis recommended for identification of the most critical factors that their change might have the highest influence on outcome of the model. The advantage of the BBN model in this report is that the model includes the most significant technical, human and organizational factors, which are standard in most of the ships. This property of the suggested model makes is applicable for analysis of fire in engine room of any type of ship in any part of the world. The suggested method for quantification of the network, instead of just relying on either expert judgment or statistical data, introduced an approach, which uses combination of both method and gives result that is more realistic

Factors influencing the time required to don thermal protective immersion suits correctly

The cold environment in polar regions introduces additional challenges when abandoning passenger vessels and offshore facilities. The International Maritime Organization Polar Code requires vessels operating in polar regions to be equipped with approved thermal protective immersion suits (TPIS) that can be donned unassisted within 120 s. As time is critical during an evacuation, quantifying the Net Donning Time (NDT) is important as this may need to be factored into passenger ship evacuation analysis. Furthermore, an incorrectly donned TPIS may be ineffective in providing the required thermal protection, so in addition to NDT, it is important to understand the factors that impact donning correctness. In this study, we present the results of a series of trials that quantified participants' performance while donning a TPIS with integrated buoyancy. Analysis of data from 108 participants revealed that NDT ranged from 65 to 341 s, with over 90 % requiring a total donning time of greater than 120 s. The mean NDT was dependent on a complex relationship between, age (increases by 6.6 % for each 10 years), gender (increases by 33 % if female), experience (decreases by 17 % with experience), method of instruction (increases by 21 % with video instruction) and failure to remove shoes (increases by 26 %). Furthermore, the method of instruction significantly impacted the number of donning errors, with instruction by video producing an average of 1.5 errors while written instruction producing 2.3. Finally, a donning time distribution is suggested for use in evacuation modelling analysis

An experimental analysis of the impact of thermal protective immersion suit and angle of heel on individual walking speeds

The cold environment of Polar Regions introduces additional challenges to maritime safety in situations where it becomes necessary to abandon a vessel. The Polar Code requires all vessels operating in Polar Regions to be equipped with approved thermal protective clothing suitable for immersion in polar waters (thermal protective immersion suit (TPIS)) for all passengers and crew. However, in addition to assessing thermal protection offered by TPIS, given the criticality of time in emergencies, it is essential to understand their impact on walking performance during evacuation and how this may be impacted by adverse vessel orientation. The ARCEVAC (ARCtic EVACuation) project examines the impact of two different types of TPIS (Suit-1 and Suit-2) on walking speed at 0°,10°,15° and 20° angles of heel. A test facility representing a 36 m long ship’s corridor was developed and 210 volunteers recruited to participate in the trials. Project findings reveal that male performed considerably better than female counterparts and increases in age, weight and heel angle had significant adverse impact on walking speed while increase in height resulted in significant increase in walking speed. Furthermore, the specific nature of the TPIS had an impact on walking speed, with the most severe reduction in walking speeds being 38% for Suit-2 and 29% for Suit-1 at 20° of heel. Reductions in walking speed of this magnitude can have a profound impact on evacuation and so cannot be ignored from evacuation analysis

An experimental analysis of the impact of thermal protective immersion suit and angle of heel on individual walking speeds

The cold environment of Polar Regions introduces additional challenges to maritime safety in situations where it becomes necessary to abandon a vessel. The Polar Code requires all vessels operating in Polar Regions to be equipped with approved thermal protective clothing suitable for immersion in polar waters (thermal protective immersion suit (TPIS)) for all passengers and crew. However, in addition to assessing thermal protection offered by TPIS, given the criticality of time in emergencies, it is essential to understand their impact on walking performance during evacuation and how this may be impacted by adverse vessel orientation. The ARCEVAC (ARCtic EVACuation) project examines the impact of two different types of TPIS (Suit-1 and Suit-2) on walking speed at 0°, 10°, 15° and 20° angles of heel. A test facility representing a 36 m long ship’s corridor was developed and 210 volunteers recruited to participate in the trials. Project findings reveal that male performed considerably better than female counterparts and increases in age, weight and heel angle had significant adverse impact on walking speed while increase in height resulted in significant increase in walking speed. Furthermore, the specific nature of the TPIS had an impact on walking speed, with the most severe reduction in walking speeds being 38% for Suit-2 and 29% for Suit-1 at 20° of heel. Reductions in walking speed of this magnitude can have a profound impact on evacuation and so cannot be ignored from evacuation analysis