Fire disasters happen every day all over the world. These hazardous events threaten people's lives and force an immediate movement of people wanting to escape from a dangerous area. Evacuation drills are held to encourage people to practise evacuation skills and to ensure they are familiar with the environment. However, these drills cannot accurately represent real emergency situations and, in some cases, people may be injured during practice. Therefore, modelling pedestrian motion and crowd dynamics in evacuation situations has important implications for human safety, building design, and evacuation processes. This thesis focuses on indoor pedestrian evacuation in fire disasters. To understand how humans behave in emergency situations, and to simulate more realistic human behaviour, this thesis studies human behaviour from fire investigation reports, which provide a variety details about the building, fire circumstance, and human behaviour from professional fire investigation teams. A generic agent-based evacuation model is developed based on common human behaviour that indentified in the fire investigation reports studied. A number of human evacuation behaviours are selected and then used to design different types of agents, assigning with various characteristics. In addition, the interactions between various agents and an evacuation timeline are modelled to simulate human behaviour and evacuation phenomena during evacuation. The application developed is validated using three specific real fire cases to evaluate how closely the simulation results reflected reality. The model provides information on the number of casualties, high-risk areas, egress selections, and evacuation time. In addition, changes to the building configuration, number of occupants, and location of fire origin are tested in order to predict potential risk areas, building capacity and evacuation time for different situations. Consequently, the application can be used to inform building designs, evacuation plans, and priority rescue processes.

The Lattice Boltzmann Method (LBM) is a relatively new approach within the field of CFD and offers several advantages over traditional continuum based CFD solvers including a high degree of parallelisation and relatively simple boundary conditions. This makes it an attractive potential solution to simulating aspects of fire behaviour. However, at present it has a major disadvantage. It does not handle large changes of temperature, which often create numerical instability. Application of the LBM to reacting flows is an area of current development in the field, and shows promise with respect to application in fire scenarios, although it has not yet developed enough to be able to model a compartment fire. The aim of this work was to develop a full 3D CFO model based on the LBM that could model an aspect of reacting flows. The development of a thermal explosion, and the effect of natural convection on that development, was selected as the area of study. Whilst fundamental work on thermal explosions was done in the 1930's, there still remains a lot of development to be done; in particular the effect of natural convection on thermal explosions is not sufficiently quantified. This work is novel as very little work has been published using LBM in this area, and the effect of natural convection on the thermal explosion development has been quantified. This was modelled using the Boussinesq approximation to account for buoyancy changes due to temperature and the Frank Kamenetskii theory for thermal explosion development. Both single fireball and two fireballs were examined for Rayleigh numbers in the range Ra = 6.103-6.107, and the effect was quantified by examination of the ratio of the critical Frank Kamenetskii value under natural convection conditions to the same parameter under no convection conditions. It was found that the ratio increased monotonically with increasing Rayleigh number. The separation distance between the centres for two fireballs was also evaluated. For higher separation distances the effect of natural convection was more profound than for closer separation distances.

This research focuses on the career and work identity of watch managers in the Fire and Rescue Service (FRS). Their role is to manage firefighters who are infamously known in political circles to possess grass root cultures that remain resistant to forms of change and modernisation. Watch managers are not only tasked with leading emergency teams at incidents but they are also at the receiving end of a relentless stream of political pressure to achieve change. This research draws on qualitative data collected within two fire services consisting of thirty-nine face-to-face interviews, four focus groups and field observations, which in combination highlight various ways the watch manager becomes an important construct in relation to the momentum of organisational change. Previous FRS research has explored the creation and enactment of masculinities in the watch and 'how' and 'why' the watch sustains highly masculinised images (Salaman 1986, Baigent 2001, Ward and Winstanley 2006). Despite Woodfield (2016) and Perrott's (2016) recent contributions focusing on women inhabiting FRS managerial and leadership roles, there has been limited emphasis in broader FRS research on how managerial work identities develop against watch cultures resistant to change, or in relation to male dominated 'informal' hierarchies in the watch. In order to manage their team successfully, watch managers show themselves to possess differing forms of managerial masculinities, and in so doing, draw on various combinations of charismatic, traditional and rational-legal authority. These phenomena highlight new understandings of the invisible and hidden processes by which watch managers attend to power tensions between them, the watch, and senior management. My findings suggest these power dynamics impact on the shaping of the watch manager's own sense of work identity and in reverse, the ways these tensions are handled also influence the way they are socially constructed as managers by firefighters and senior managers. Particularly revealing are the ways transformations of work identity develop as watch managers move from new to time-served firefighter, then upward to the watch manager role, and how differing identity-enabling resources are drawn from to manage and keep an equilibrium between firefighters and the watch they manage.

Fire statistics from the UK and the USA attribute 60% to 70% of fire fatalities in dwellings to the inhalation of fire toxic smoke. The objective of this project was to provide more toxic yield data from typical compartment fires and in the process develop a methodology for faster generation of such data on bench scale apparatus. The models for overall toxicity assessment (for irritants and asphyxiants) were reviewed and the reported threshold limits for typical smoke toxicants, were collected, categorised and compared for increasing levels of harm. An extensive database was created of yields of toxic species from different materials and under different fire conditions. This highlighted the need for more yield data for under-ventilated fires in compartments. Eight full scale tests were carried out in a room enclosure with ventilation through a corridor to a front access door. Fire loads were wood pallets, cotton linen and towels, typical living room furniture and diesel. The fires were allowed to become fully developed before extinguishment by the local FRS team. Toxic concentrations were monitored in the hot layer and the corridor (through a heated sampling line) using a heated FTIR analyser, calibrated for 65 species. An emissions based model, developed as part of this work, was used to quantify the equivalence ratio and also the toxic species yields, even for the cases where the fuel mass loss rate was unknown. An important finding was the overwhelming contribution of Acrolein and Formaldehyde in most tests, in exceeding the impairment of escape threshold. The modified controlled atmosphere cone calorimeter showed comparable results to the full scale tests for lean burning combustion however it proved difficult at this stage to produce combustion in the rich burning regime and further development of the methodology is needed.

No description available.

United Kingdom fire investigators use ad hoc adsorbents to investigate the suspected use of ignitable liquids and their residues (ILR) at fire scenes. It was unknown whether these materials adsorb all ignitable liquid target compounds specified by ASTM methods, or if they interfered with such analysis and therefore prevented the positive identification of ignitable liquids. This research has ascertained that adsorbents such as clay based cat litter, montmorillonite, limestone, Tampax®, Tenalady®, talc; sand and the use of a squeegee tool cannot adsorb the full range of ASTM target compounds in common ignitable liquid residues by themselves. However, some can adsorb a limited range of target compounds. For example, cat litter can adsorb C3 and C4 alkylbenzenes and other molecules for the identification of petrol, but cannot adsorb heavy alkanes such as those found in diesel fuel. In contrast, limestone can adsorb heavy alkanes but not all aromatic target compounds present in petrol. This study has found that when limestone was mixed with Fuller’s Earth (10:1 w/w) that a range of common ignitable liquids and their associated target compounds could be adsorbed and identified. Furthermore, the instrumentation and separation methods used with an automated thermal desorption-gas chromatography-mass spectrometer (ATD-GC-MS) and Tenax TA® were improved and it is hoped that these would form a basis for a new standard method. Limestone and Fuller’s Earth as well as the limestone/Fuller’s Earth mixture were characterised with Fourier-Transform Infra-Red spectroscopy and X-ray Diffraction. The results showed that mixing the components together did not alter the chemical composition of the adsorbent mixture and that the major phases in the mixture were identified as calcite, quartz and palygorskite. The performance of the adsorbents was assessed using a combination of a standard ASTM method for analysis using GC-MS and an improved oven separation time of six to nine hours. The ATD method was improved for real fire debris samples by setting the split flow valves to 40 mL/min to minimise instrument overloading. The adsorbents were subjected to evaluation in the laboratory using blind tests and also a field blind test at a real fire scene. The laboratory analysis and fire scene evaluation revealed that the limestone/Fuller’s Earth mixture adsorbed all ignitable liquid target compounds from different ignitable liquids and as a result were identified from extracted ion chromatograms. This is the first reported use of this novel mixture as a universal adsorbent for common ignitable liquids.

Firefighters are exposed to a high prevalence of both occupational and traumatic stress, consequently protective factors, such as social support, become highly relevant to the well-being of this population. Accordingly the psychological health of firefighters is maintained, in part, by their family (Regehr, Dimitropoulos, Bright, George, and Henderson, 2005; Beaton, Murphy, Johnson, Pike, and Corneil, 1999). This thesis aimed to inform the published literature by establishing a detailed model of occupational impacts of the firefighting occupation on relatives of firefighters and the resources they use to manage those impacts. This was undertaken using a sequential mixed methods approach through three empirical studies. Findings across the thesis include the development of the firefighter becoming a ‘satellite’ family member in order to protect against unusual working patterns, secondary traumatic reactions and relatives’ perception of danger and harm within the occupation. In addition to this, findings clearly highlight the need for firefighters to share their expertise and job content with their families; facilitating the relatives’ ability to protect their personal resilience and well-being and their firefighter. However if firefighters become disengaged, rather than a ‘satellite’ family member, then their reactions to their job content becomes decontextualised for their relatives. This in turn causes the well-being of relatives to decrease and an increase in secondary trauma of the relative related to their firefighter’s experiences. A prevalence rate of 12% was established for this population of secondary trauma for relatives of firefighters by this thesis. To establish the homogeneity of this population differences were explored based upon rank, length of service of the firefighters, and continent of service, all of which suggest the group is homogenous. Differences of length of time the relative has lived with the firefighter were significant providing further support to the finding that educating relatives about the role of the firefighter is an enabling and protective factor. Implications for theory are discussed, concluding with evidenced-based recommendations to effectively support both firefighters and their families. Practical methods are outlined to develop a positive resource ecology within the fire and rescue service community in order to build collective resilience and protect well-being amongst its membership.

No description available.

In fire, elevated temperatures undermine the resistance of structural materials, which leads to steel-framed buildings being subject to very large deformations. Elevated temperatures also cause the affected members to expand, and subsequent cooling induces contraction and recovery of strength. Because of the irreversible nature of plastic straining this causes extremely complex force combinations in connections. Connections which are traditionally idealized as “pinned” or “rigid” in design actually display considerable semi-rigid behaviour, which may contribute to the structure’s survival during and after an internal fire. It will be necessary in future for structural engineers to understand how joints perform in fire, which has been emphasized by a series of case studies, including the official forensic reports on buildings of the New York World Trade complex which collapsed during the “9/11” events in 2001. Eventually, advances in analysis, testing and design codes must allow engineers to design structures which will survive fires without experiencing disproportionate collapse. This PhD study describes the development of a general component-based connection element, which has been implemented in the Vulcan software in order to enable modelling of the robustness and ductility of the connections in fire scenarios. The component-based method which has been adopted is generally accepted as an efficient intermediate way of treating the behaviour of connections in small-deflection ambient-temperature design of semi-rigid frameworks, which is included in Eurocode 3 Part 1.8. This has been developed in the course of several projects at the University of Sheffield towards high-temperature large-deflection representation of connections in a series of stages, including the characterization of individual components, joint testing and component assembly for some conventional connection types. The RFCS-funded project COMPFIRE, of which this work forms a part, extended the data-set to an innovative connection type, the reverse channel, which offers the prospect of greatly enhanced ductility as a way of improving structural robustness in fire. The new data derives from both structural furnace testing and detailed Finite Element analyses. Used in combination with the “static/dynamic” solver in Vulcan, the use of the general-purpose component-based connection element has been demonstrated in studies of the performance, including progressive collapse, of planar steel frames in fire scenarios. The development should allow engineers to identify local failure of joints, and to predict the subsequent failure of the remaining structure, in analytical design. This will enable vulnerable areas to be identified in the structure and their design details to be amended in order to produce a building which is more robust in fire.

The use of lightweight building systems is very controversial as existing knowledge about their performance is limited. Not enough research has been conducted to determine the suitability of these modern construction technologies and there is an ongoing controversy as to whether they are an appropriate replacement to traditional construction techniques. The prime objective of this study is to present a number of methodologies to assess lightweight external walling systems focusing on thermal efficiency, structure and fire performance, which are currently the main driving forces for this industry. Traditionally, these areas have been studied separately but there is a need to integrate them in order to get comprehensive solutions to the way these systems are designed. The drive to achieve improvements in one of these specific areas could potentially result in reduced effectiveness in the others. That is the reason why an integrative approach is recommended. These techniques are meant to be applied in the design phase of building projects so as to provide early quantitative information about the systems analyzed. The methodologies described herein are then applied to real life light steel building solutions. Within this context, two different wall constructions are examined and conclusions made on their relative performance. The study highlights the importance of having analytical and experimental solutions as a framework for further development. Two different approaches have been considered to assess thermal efficiency, structure and fire performance. On the one hand, a prescriptive approach has been employed to establish regulation compliance. On the other hand, a performance based approach is taken to actually understand and explain how these systems work in real life conditions. The outcome is a comprehensive set of tools to assure both industry and other stake holders.