Experimental comparison of Q-fog and residential sprinklers in a residential fire scenario

In this report, the effectiveness of a detector-activated water mist system, Q-fog, has been compared to traditional residential sprinklers. In total, eight tests were performed with a realistic fuel (bed with pillow and duvet) based on the test procedure described in LPS 1655. The bed was placed at different locations in the room and was ignited at the pillow and below the bed, also according to LPS 1655. Temperatures were measured using six thermocouples at different locations and heights. Also, near field heat flux was measured using plate thermometers.The results show that the detector-activated water mist system seems to be superior when the fuel package is located in front of the suppression system, and the fire starts on top of the bed. If the fire starts below the bed or if the bed is located in a less favorable location, the performance is similar to traditional sprinklers. Finally, if the fuel package is both located in an unfavorable location and ignition occurs below the bed, the traditional sprinkler is superior. However, few fatal fires start below the bed and therefore, the overall effectiveness can be expected to be higher for the detector-activated water mist compared to the bulb-activated sprinklers

Relationship between safety culture aspects - A work process to enable interpretation

Knowledge about the existing safety culture in a maritime organization such as in shipping companies or on board ships can enable the formulation of effective interventions to maintain and improve safety culture and safety in the organization. When assessing the safety culture, questionnaires developed for this purpose are often used. This paper proposes a work process that facilitates the analysis and interpretation of the relationships between safety culture aspects using questionnaire data. The work process includes the use of variable cluster analysis where the cluster solutions are presented in dendrograms. These were found to be an excellent way to visualize complex relationships in the quantitative data and to facilitate the understanding of the safety culture concept. Results are presented from applying the statistical process to safety culture data from six Swedish ships in international traffic. The visualized safety culture results can enable group discussions about safety on different organizational levels and can constitute an important input to the continuous improvement processes for safety and safety culture

Fatal Residential Fires : Prevention and Response

Fatal fires in residential occupancies show a decreasing trend over time, but are still responsible for takingapproximately 90 lives in Sweden each year. Much is known about the victims, but less is known about how thesedeaths can be prevented. There is research on the effectiveness of different measures, but generally they are populationaverageeffectiveness and, since different groups are known to be subject to quite different scenarios, this effectivenessis not necessarily representative of the effectiveness for any specific group. Therefore, group-specific effectiveness isderived in this thesis. The results indicate that smoke alarms are effective for most groups, but additional measures areneeded for some groups. This is particularly true for older adults, for whom synthetic clothes and detector-activatedsprinklers are highly effective.Also, responses to potentially fatal fires in residential occupancies are almost missing from the literature and weretherefore analysed in the thesis. The conclusion was that fire services saved 51 lives during the studied year (2017),which indicates that the number of fatalities in residential occupancies would have increased by 58% in that yearwithout fire service responses. Response time was found to be important, but also what the crew could perform onarrival at each scene, because many were developed fires that required breathing apparatus to perform the rescue. Inanother study, responses by other actors were also included for older adults (65+), indicating that, in addition to thefire service, neighbours are very important, but for the oldest individuals home care also played an important role

Measuring the Capabilities of the Swedish Fire Service to Save Lives in Residential Fires

The ability of the fire service to save lives in building fires has a profound impact on planning. However, very little empirical data are available on how different factors affect this capability—or even how many that are rescued annually. The current paper aims to partly fill this gap with an assessment of all rescues performed by the fire departments in Sweden during 2017. A combination of incident reports and a large number of post-event interviews yielded a total of 51 rescues (to be compared to 88 fatalities) during that year, which show that the fire service has a great potential to reduce the number of fire fatalities. In these cases, the call to the dispatcher most frequently came from a neighbor (55%) or the victim (26%). The rescue was in 71% of the cases performed with interior attack with a breathing apparatus. The cases were also compared with fatal fires revealing that the odds of successful rescue increased, for example, if the fire occurred in an apartment building or if the response time was short. The joint data set of rescues and fatal fires was used to develop a methodology to calculate the probability of successful rescue depending on the capability of the fire service. This methodology provides the first fully empirical method for organizing the fire service in relation to saving lives in fires. A similar approach should be pursued for other accident types and consolidated for an evidence based assessment of the capability of the fire service

The Influence of Sociodemographic Factors on the Theoretical Effectiveness of Fire Prevention Interventions on Fatal Residential Fires

The risk of fatal residential fires is known to be differentiated by sociodemographic factors. However, often prevention measures are introduced generally in a population, thereby perhaps affecting the effectiveness of these interventions. By using a 20-year high-quality register over fatal fires in Sweden and a previously validated Boolean expressions regarding the effectiveness for specific interventions, this study investigates the theoretical effectiveness of fire interventions in relation to different sociodemographic variables and fatal residential fires. The results show that the effectiveness of different fire-related prevention measures varies considerably in relation to different sociodemographic variables such as age, sex, municipal characteristics and living conditions. As such, the paper highlights the importance of matching the correct fire prevention measure to each individual depending upon sociodemographic risk factors in order to achieve maximal effectiveness

Recruitment, retention and resignation among Non-Career Firefighters

The purpose of this paper is to provide a review of literature about recruitment, retention and resignation among non-career firefighters. Design/methodology/approach: A systematic review was conducted to identify factors associated with the recruitment, retention and resignation of non-career firefighters. The authors divided the results into three topics and four levels for further analysis. Findings: 27 articles are included in the review. Most research addresses retention at an organizational level and indicates a link between job satisfaction and factors such as supervisor support, recognition and close relationships within the workgroup. Further, a recurring reason that contributes to resignations seems to be family related (e.g. partner disapproval). Research limitations/implications: There is a lack of European and Asian research into non-career firefighters. The included research papers generally have low response rates and the sample is often mostly male and Caucasians from a limited area. Practical implications: The identified factors offer deeper understanding and can help practitioners in their pursuit of the sustainable retention of non-career firefighters. Originality/value: Because securing adequate numbers of non-career firefighters is important, there is a need to synthesize current evidence to identify and further understand which factors contribute to retention. To the authors' knowledge, this is the first systematic review to synthesize such evidence about non-career firefighters

Parameterstudie av ventilationsbehov för vätgasinstallationer

Vätgas har en tendens att i läcka ut i små mängder i kopplingar samt även diffusera igenom de flesta material. Detta innebär, tillsammans med vätgasens utmanande förbränningsegenskaper, att normalventilation av utrymmen där vätgas hanteras är mycket viktig.I denna rapport presenteras kortfattat en ny metod för dimensionering av normalventilation baserad på multizon‐konceptet där utrymmet delas in i olika celler där flödet mellan dessa sedan beräknas.Metoden har fördelen gentemot CFD‐simuleringar att den är mycket snabbare och möjliggör därmedoptimering av ventilationsarean/‐flödet med rimliga simuleringstider.Modellen används i denna rapport för att undersöka hur parametrar kopplade till såväl utrymmet (längd, bredd och höjd), utsläppet (hålstorlek, lagringstryck och utsläppets höjd) som omgivningen (temperaturen) påverkar behovet av normalventilation – både för naturlig och mekanisk ventilation. Syftet är att studien ska utgöra ett underlag i en pågående revidering av MSB:s föreskrift ombrandfarliga gaser (MSBFS 2020:1) med avseende på vätgashantering.Slutsatsen var att utrymmets storlek (som är grunden för dagens krav) har ett förhållandevis svagt samband med behovet av ventilation där en fördubbling innebar ca 20% högre flöden och större area. Ett betydligt starkare samband finns med läckagets storlek och därför kan en koppling mellan erforderlig ventilationsarea (eller ventilationsflöde) och rördimensioner i utrymmet stämma bättre överens med de underliggande fysikaliska fenomenen.OBS! Modellen är fortfarande under pågående validering vilket gör att resultaten ska tolkas med viss försiktighe