| 11. |
- Ingason, Haukur, et al.
(författare)
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Large Scale Tunnel Fire Tests with Large Droplet Water-Based Fixed Fire Fighting System
- 2016
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Ingår i: Fire technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 52:5, s. 1539-1558
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the main results of six large scale fixed fire fighting system tests that were carried out in the Runehamar tunnel in September 2013. It describes the background and the performance of the system. The main fire load consisted of 420 standardized wood pallets and a target consisting of a pile of 21 wood pallets placed 5 m from the rear end of the main fire load. The purpose was to investigate possible fire spread. The water spray system is a deluge zone system delivering 10 mm/min in the activated zone. The detection system was simulated with use of thermocouple in the tunnel ceiling. The alarm was registered when the ceiling gas temperature was 141°C. After alarm was obtained the system was activated manually after a given delay time that was varied in the tests. The heat release rates in tests with fire suppression were reduced to 20–45 MW compared to 100 MW estimated for a free-burn test or 75 MW in test 6 with a failure of activation. Fire spread to the target was prevented after fire suppression.
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| 12. |
- Ingason, Haukur
(författare)
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New Challenges in Tunnel Fire Safety
- 2016
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Ingår i: Fire technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 52:5, s. 1445-1447
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Tidskriftsartikel (refereegranskat)
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| 13. |
- Jaldell, Henrik, 1968-
(författare)
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How Important is the Time Factor? Saving Lives Using Fire and Rescue Services
- 2017
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Ingår i: Fire technology. - : Springer Publishing Company. - 0015-2684 .- 1572-8099. ; 53:2, s. 695-708
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Tidskriftsartikel (refereegranskat)abstract
- The shorter the response time of emergency services the more lives aresaved. But, how important in fact is the time factor for saving lives? The objective ofthis study is to analyse the relation between response time and fatalities, to be able tomeasure how many lives could be saved with a shorter response time. The study usesdata from reports from the fire and rescue services in Sweden for 2005–2013 for residentialfires. The time variable used is continuous and the statistical methods are non-linearregression techniques. It is found that the risk of fatality is a non-linear function ofresponse time. For a given change of response time, the increase in risk of fatality islarge for a short response time, then decreases, and eventually seems to approach zero.If it was possible to decrease the median response time by 1 min 0.00035 lives could besaved for every turn-out on average. For all turn-outs to residential homes that meansthat about two lives, or 3%, could be saved per year. The response time is most importantfor blocks of flats, nursing homes and semi-detached/terraced houses. The responsetime is more important for fires due to smoking, children playing or started intentionally(arson). The results can be used to evaluate the performance of local fire and rescueservices. The method is easy to use for other emergency services, such as ambulances.
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| 14. |
- Johansson, Nils, et al.
(författare)
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A Study of Reproducibility of a Full-Scale Multi-Room Compartment Fire Experiment
- 2015
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Ingår i: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 51:3, s. 645-665
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Tidskriftsartikel (refereegranskat)abstract
- A study of 45 pool fire tests is presented in this paper. All tests have been conducted in the same experimental setup but with four different ventilation scenarios. The experimental setup consisted of a three-room compartment connected to a stairway. The tests have been conducted during a 6-year period under slightly different ambient conditions. The purpose of this paper is to study and quantify the reproducibility of these tests with the aim to illustrate the degree of variability that can be expected in this kind of experiment and how the variability is affected by different ventilation scenarios. The 95% confidence interval of the measured temperature rise in the tests covered ±7% to 35% around the mean, depending on place of measurement and studied scenario. The variation in the results is due to both the variation of different weather conditions and other unknown parameters. It has not been possible to statistically distinguish between these two sources of variation. The data set allows to estimate the effect of random variations in experiments of fire behavior and smoke movement across compartments. The fuel of the pool fires is well defined and the mass loss is known, which makes the data of use in validation of multi-room compartment fire models.
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| 15. |
- Johansson, Nils, et al.
(författare)
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Review of the Use of Fire Dynamics Theory in Fire Service Activities
- 2019
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Ingår i: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 55:1, s. 81-103
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Tidskriftsartikel (refereegranskat)abstract
- The work of the fire service has changed during the last decades from being essentially operational to include a larger variety of activities to increase fire safety in society. Also, the theoretical understanding of fire development, fire dynamics in buildings and fire safety engineering have improved. There are several good examples of areas were fire dynamics theories have supported and improved the fire service activities associated with building fire safety during the last decades. Despite such examples the quality of knowledge transfer between theory and research, and the more practical arena, such as fire service activities is sometimes questionable. This paper includes a systematic literature review and an interview study that is used to discuss how fire dynamics is used to support fire service activities today and where the use of fire dynamics theory could or should be increased in the future. It is found in the paper that fire dynamics theories are currently used more in the preventative and investigative areas than in the operational area of fire service activities. The primary reasons for this is that the timeframe is much shorter in the latter and that there are established procedures and tactics that work well for the common operational situations. However, there is a potential to use fire dynamics theories more in the operational area when it comes to events that occurs less frequent and with a longer duration than for example the normal compartment fire. In general, there is room for improvement of the use of fire dynamics in the fire service and a way forward could be a stronger link between theory and practice in education and training.
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| 16. |
- Johansson, Nils, et al.
(författare)
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Variation in Results Due to User Effects in a Simulation with FDS
- 2018
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Ingår i: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 54:1, s. 97-116
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Tidskriftsartikel (refereegranskat)abstract
- The results from a round-robin study in which practicing fire safety engineers simulated the same scenario are presented in this paper. The simulation task included the simulation of an 800 mm heptane pool in a three-room apartment. The participants, representing eight Swedish consultancy firms, simulated the well-specified scenario with FDS 5. The participants received information about the building, the fire mass loss rate and initial conditions. The task was performed a priori, meaning that the participants were not given any experimental or simulation results prior to performing the task. The study shows that there is a variation between the participants in how the input file was specified, the choice of input data and the types of devices used in FDS. The differences in how the fuel and the burner were described were relatively large, which resulted in large differences in mass loss rate and heat release rate. Furthermore, several of the participants made mistakes when the fire was prescribed and this resulted in a variation in the calculated parameters like the temperature increase, which was 300 K in the fire room and 50 K to 150 K in the adjacent rooms. However, the study shows that when the heat release rate and wall boundary conditions were well defined, good temperature predictions could be made.
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| 17. |
- Jonsson, Anders, et al.
(författare)
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Fire-Related Mortality in Sweden : Temporal Trends 1952 to 2013
- 2016
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Ingår i: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 52:6, s. 1697-1707
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Tidskriftsartikel (refereegranskat)abstract
- This study examines temporal trends in deaths due to fire-related accidents in Sweden from 1952 to 2013 based on statistics in the Cause of Death register held by the Swedish National Board of Health and Welfare. Fatalities coded with underlying cause of death associated with fire-related accidents are included and absolute numbers and age-adjusted mortality rates are calculated and statistically analysed for trends using Poisson regression. The results show a significant reduction in both absolute numbers and in the age-adjusted mortality rate with a decline in absolute number of deaths of 34% over the period. However, the elderly population (80+ years) showed a significant increase in absolute numbers. Regarding the age-adjusted mortality rate, a significant reduction of 63% was observed and children aged 0 to 4 years showed the largest decrease (91%). A reduction was seen both in terms of fatalities due to burns and carbon monoxide poisoning, although the reduction was more pronounced with regards to burns (69% compared to 46%). Although an overall decrease was observed in both absolute numbers and in the age-adjusted mortality rate, with an aging population, the absolute numbers of fire-related deaths for the elderly population will most likely increase in the future. Therefore, whilst previously a child-injury issue, fire-related deaths in Sweden is now predominantly an issue of safety for the elderly. In combination with more deaths now being attributed to carbon monoxide poisoning, new preventative strategies may be required.
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| 18. |
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| 19. |
- Lange, David, et al.
(författare)
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The reduced cross section method applied to glulam timber exposed to non-standard fire curves
- 2015
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Ingår i: Fire technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 51:6, s. 1311-1340
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Tidskriftsartikel (refereegranskat)abstract
- Timber is an desired material for structural applications due to its green credentials and attractive external appearance. Fire safety design of timber structures is largely limited to considering the exposure of elements to the standard fire, to which timber demonstrates exceptional resilience. This paper reports on a series of tests which were carried out with the intention of exploring the impact of non-standard fires on timber elements. Because of the natural variation in timber elements, the tests and the resulting analysis of the test results were conceived and designed in such a way that as much information about the statistical distribution of the response of the elements as possible could be obtained. The resulting testing programme comprised four furnace fire tests, each of eight loaded timber beams, with three different temperature time curves: two standard fire tests, one long-cool parametric fire and one short-hot parametric fire. The reduced cross section method for structural calculations is extended in this paper to parametric fire exposures, and the results of the tests are compared with this method. It is shown that the thickness of the zero-strength layer is dependent on the temperature time curve to which the timber is exposed in the furnace and that the 7 mm zero-strength layer prescribed in EN 1995-1-2 may be un-conservative for members in bending. For the cases studied, the zero-strength layer thickness in bending is shown to be around about 15 mm under standard fire exposure and 16 mm under exposure to a long cool parametric fire. Conversely, the zero-strength layer is only 8 mm deep under exposure to a short hot parametric fire. This has implications for the design of timber elements not only for parametric fire exposure in enclosures, but also perhaps for the use of timber elements in large open structures such as halls or arenas where more localised fire exposure or travelling fire exposure may be expected.
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| 20. |
- Lindström, Johan, et al.
(författare)
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Fire Test of Profile Plank for Transformer Pit Fire Protection
- 2016
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Ingår i: Fire technology. - : Springer. - 0015-2684 .- 1572-8099. ; 52:2, s. 309-319
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Tidskriftsartikel (refereegranskat)abstract
- In general it is recommended to fill a transformer pit with rock ballast to extinguish the fire if there is a leakage of burning transformer oil. There is a lack of technology-neutral performance requirements for the design of solutions for fire extinguishment in transformer pit fires. This hampers the introduction of alternatives to the traditional method of filling the pit with rocks. Therefore we have conducted quantitative tests where temperatures and concentrations of CO, CO2, and O2 were measured at different position in a transformer pit subjected to burning oil simulating an accidental rupture and leakage. The tests were conducted to investigate the extinguishing capacity of one specific alternative solution, i.e. a profile plank layer over the pit. Three tests were performed with 90°C and 140°C pre-heated transformer oil. In the second test, a 19 cm water bed was used to examine the impact of rain water in the pit. The result showed that the profile plank extinguished the flames in a few seconds and that the water level did not have any significant effect on the result. The measurements showed that the temperatures peaked at 600–800°C 50 cm above the profile plank in all tests but dropped to under 100°C in 14–16 s. Furthermore the O2-concentration dropped to 3–5 vol% below the plank, which contributed to the rapid extinction of the burning oil.
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