Ship design with the human factor: evacuation and normal operations modelling in the ship design process

This thesis addresses the modelling of human factors and how they can impact ship design. Two different but related applications areas are considered; passenger ship evacuation analysis and naval vessel normal operations and evacuation analysis. In the first instance, this thesis investigates the impact of the current regulatory specified passenger response time distributions upon evacuation analysis and then recommends a more realistic passenger response time distribution which should be implemented when performing an evacuation analysis of a passenger RO-RO vessel. This realistic passenger response time distribution is based upon the results of sea trials. The results of this analysis have been adopted by the IMO and form part of the new guideline document, IMO MSC 1238. In addition, this thesis addresses the analysis of the human factors’ performance of a naval vessel. Naval vessels are built primarily for undertaking assigned missions in times of war and conflict. While the safety of those on board is important, the ability of the vessel to function and complete its assigned mission is of paramount importance. This thesis utilises an evacuation model, maritimeEXODUS, which was extended to incorporate the functionality of modelling non-evacuation scenarios, to assess the human factors’ performance of a naval vessel during both normal operations and evacuation scenarios. This thesis develops a methodology for simultaneously assessing the human factors’ performance of both a range of normal operation scenarios and evacuation scenario on board a naval vessel. The methodology, called the Human Performance Metric (HPM), is discriminating, diagnostic, systematic, transparent and reproducible in nature. This thesis then implements the HPM methodology into the early stages of the design cycle for a new naval vessel. The thesis presents the software modifications required to implement the methodology in to the design cycle as well as presenting a demonstration of the new system

Computational Fluid Dynamics Methods Used in the Development of the Space Launch System Liftoff and Transition Lineloads Databases

The objective of this paper is to document the reasoning and trade studies that supported the selection of appropriate tools for constructing aerodynamic lineload databases for the Liftoff and Transition phases of flight for launch vehicles. These decisions were made amid the maturation of an evolving workflow for generating databases on variants of the Space Launch System launch vehicle, with most being based on results from brief developmental studies performed in response to specific, unforeseen challenges that were encountered in analyzing a given configuration. This report is intended to provide a summary of the results and the decision-making processes chronologically over the design cycles of various configurations, starting with isolated free-air bodies for the Block 1 Crew, then the Block 1B Crew and Cargo configurations, and most recently the Block 1B Crew configuration in proximity to the launch tower. The results from these analyses led to the selection of the CREATE-AV Kestrel flowsolver for simulating these problems. The need to accurately capture the expected leeward-wake flow field characteristics required the use of Delayed Detached Eddy Simulation (DDES) method, for which the vorticity magnitude was employed as the solution Adaptive Mesh Refinement (AMR) function over the off-body Cartesian grid region. In addition, the Spalart-Allmaras (SA) model is used to account for the flow turbulence effects

Oceanographic drivers of deep-sea coral species distribution and community assembly on seamounts, islands, atolls, and reefs within the Phoenix Islands Protected Area

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Auscavitch, S. R., Deere, M. C., Keller, A. G., Rotjan, R. D., Shank, T. M., & Cordes, E. E. Oceanographic drivers of deep-sea coral species distribution and community assembly on seamounts, islands, atolls, and reefs within the Phoenix Islands Protected Area. Frontiers in Marine Science, 7, (2020): 42, doi:10.3389/fmars.2020.00042.The Phoenix Islands Protected Area, in the central Pacific waters of the Republic of Kiribati, is a model for large marine protected area (MPA) development and maintenance, but baseline records of the protected biodiversity in its largest environment, the deep sea (>200 m), have not yet been determined. In general, the equatorial central Pacific lacks biogeographic perspective on deep-sea benthic communities compared to more well-studied regions of the North and South Pacific Ocean. In 2017, explorations by the NOAA ship Okeanos Explorer and R/V Falkor were among the first to document the diversity and distribution of deep-water benthic megafauna on numerous seamounts, islands, shallow coral reef banks, and atolls in the region. Here, we present baseline deep-sea coral species distribution and community assembly patterns within the Scleractinia, Octocorallia, Antipatharia, and Zoantharia with respect to different seafloor features and abiotic environmental variables across bathyal depths (200–2500 m). Remotely operated vehicle (ROV) transects were performed on 17 features throughout the Phoenix Islands and Tokelau Ridge Seamounts resulting in the observation of 12,828 deep-water corals and 167 identifiable morphospecies. Anthozoan assemblages were largely octocoral-dominated consisting of 78% of all observations with seamounts having a greater number of observed morphospecies compared to other feature types. Overlying water masses were observed to have significant effects on community assembly across bathyal depths. Revised species inventories further suggest that the protected area it is an area of biogeographic overlap for Pacific deep-water corals, containing species observed across bathyal provinces in the North Pacific, Southwest Pacific, and Western Pacific. These results underscore significant geographic and environmental complexity associated with deep-sea coral communities that remain in under-characterized in the equatorial central Pacific, but also highlight the additional efforts that need to be brought forth to effectively establish baseline ecological metrics in data deficient bathyal provinces.Funding for this work was provided by NOAA Office of Ocean Exploration and Research (Grant No. NA17OAR0110083) to RR, EC, TS, and David Gruber

A validation data-set and suggested validation protocol for ship evacuation models

An evacuation model validation data-set collected as part of the EU FP7 project SAFEGUARD is presented. The data was collected from a cruise ship operated by Royal Caribbean International (CS). The trial was a semi-unannounced assembly trial conducted at sea and involved some 2500 passengers. The trial took place at an unspecified time however, passengers were aware that on their voyage an assembly exercise would take place. The validation data-set consists of passenger; response times, starting locations, end locations and arrival times in the assembly stations. The validation data were collected using a novel data acquisition system consisting of ship-mounted beacons, each emitting unique Infra-Red (IR) signals and IR data logging tags worn by each passenger. The results from blind simulations using maritimeEXODUS for the assembly trial are presented and compared with the measured data. Three objective measures are proposed to assess the goodness of fit between the predicted model data and the measured data

Investigating the impact of culture on evacuation response behaviour

The aim of this work was to investigate whether social culture impacts how people respond to an evacuation alarm. As part of this work four unannounced library evacuations were conducted in the Czech Republic, Turkey, Poland and the UK. In an attempt to isolate social culture as the primary independent variable across the trials, the key parameters that are known to influence Response Phase behaviour and performance e.g. population demographics, type of structure, alarm system, etc were controlled across the trials. Response Phase behaviour was determined for a total of 477 individuals, 192 from Poland, 51 from Turkey, 70 from the Czech Republic and 104 from the UK. The results suggest that there are significant differences in the nature of the population behaviour during the Response Phase across the four trials. On average, the population with the quickest to the slowest response times are: Turkey, Poland, UK and Czech Republic. When applied to a simulated evacuation, the observed differences in response time distribution for the national groups resulted in significantly different evacuation performance

Recommendations on the nature of the passenger response time distribution to be used in the MSC 1033 assembly time analysis based on data derived from sea trials

The passenger response time distributions adopted by the International Maritime Organisation (IMO)in their assessment of the assembly time for passanger ships involves two key assumptions. The first is that the response time distribution assumes the form of a uniform random distribution and the second concerns the actual response times. These two assumptions are core to the validity of the IMO analysis but are not based on real data, being the recommendations of an IMO committee. In this paper, response time data collected from assembly trials conducted at sea on a real passanger vessel using actual passangers are presented and discussed. Unlike the IMO specified response time distributions, the data collected from these trials displays a log-normal distribution, similar to that found in land based environments. Based on this data, response time distributions for use in the IMO assesmbly for the day and night scenarios are suggeste

Assessing the suitability of ship design for human factors issues associated with evacuation and normal operations

Evaluating ship layout for human factors (HF) issues using simulation software such as maritimeEXODUS can be a long and complex process. The analysis requires the identification of relevant evaluation scenarios; encompassing evacuation and normal operations; the development of appropriate measures which can be used to gauge the performance of crew and vessel and finally; the interpretation of considerable simulation data. In this paper we present a systematic and transparent methodology for assessing the HF performance of ship design which is both discriminating and diagnostic. The methodology is demonstrated using two variants of a hypothetical naval ship

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

The use of confidence intervals to determine convergence of the total evacuation time for stochastic evacuation models

International guidelines (IMO MSC.Circ 1533) specify that evacuation models used to certify evacuation performance of passenger ships must demonstrate that the calculated representative evacuation time, the sample 95th percentile time τS, is lower than a prescribed Pass/Fail Criterion Time (PFCT). In this paper a Confidence Interval Convergence Test (CICT) method is presented that minimises the computational burden required to demonstrate that a model design has passed/failed by calculating a CI for the population 95th percentile time, τP, rather than simply relying on τS determined from an arbitrary sample of 500 simulations as specified in the current guidelines. The CICT has comparable pass/fail accuracy to using 500 simulations whilst significantly reducing the number of simulations required when the PFCT is far from the τP. In addition, the proposed method has superior accuracy to the convergent method described in the IMO guidelines. Furthermore, the methodology described in the guidelines fails to identify situations where there may be uncertainty in the pass/fail status due to proximity of τP to PFCT. The CICT identifies these situations and provides a means of resolving the uncertainty. The CICT can be applied to any stochastic evacuation model to determine parameter convergence

Repair strategies for assistive technology in low resource settings

PURPOSE: To investigate the practices of repair that exist for users of mobility assistive products in low resource settings, as well as the psychosocial impact that the repair, or non-repair, of these devices has on users' lives. MATERIALS AND METHODS: This article collates data on repair practices and the responses from participants on the topic of repair from studies conducted by the authors across four different low resource settings in Kenya, Uganda, Sierra Leone, and Indonesia. This data was then analyzed to identify the common themes found across geographies. RESULTS: Three major models of repair practice emerged from the data: "Individual or Informal Repair in the Community"; "Local Initiatives"; and "Specialist AT Workshop Repair". Additionally, the wider impact on the participants' lives of "Problems & Concerns with Repair"; "Experiences of Breakages & Frequencies of Repair" and the "Impact of Broken Devices" are explored. CONCLUSIONS: The results of this analysis demonstrate the paramount importance of community-based repair of devices, and how despite this importance, repair is often overlooked in the planning and design of assistive products and services. There is a need to further incorporate and support these informal contributions as part of the formal provision systems of assistive device.IMPLICATIONS FOR REHABILITATIONA lack of available specialist repair services in low resource settings hinders the potential impact of assistive technology provision systems.Community-based repair is the major route by which assistive devices are repaired in low resource settings.Appropriate community-based repair strategies should be incorporated into and supported by the formal assistive technology provision models in order to optimise outcomes.A lack of data on outcomes across the lifecycle of assistive products hinders progress on improving focus on follow-up services - in particular repair & maintenance.By supporting community-based repair, repairs that are inappropriate for that approach could be better directed to specialist repair services