Shrub fuels are capable of extreme fire behaviour under conditions that are often moderate in other fuels. There is also a narrow range of conditions that determine fire success in these fuels, below which fires may ignite but hardly spread and above which they ignite and develop into fast moving and high intensity fires. This is due to the elevated dead fine fuels that dry rapidly and carry fire. Fire danger rating systems designed for forest and grassland fuels do not predict fire potential in shrub fuels very well. Fire management requires fire danger rating systems to provide accurate and timely information on fire potential for all important fuel types. Studies of fuel moisture, ignition and fire spread were carried out in the field in gorse (Ulex europaeus L.) shrub fuels to predict the moisture content of the elevated dead fuels and to define the conditions that govern fire development. The accuracy of the Fine Fuel Moisture Code (FFMC) of the Canadian Forest Fire Weather Index (FWI) System to predict moisture content of this layer was assessed. A bookkeeping method to predict moisture content was developed based on semi-physical models of equilibrium moisture content, fuel response time and the FFMC. The FFMC predicted moisture content poorly, because the FWI System is based on the litter layer of a mature conifer forest. The gorse elevated dead fuel layer is more aerated and dries faster than this conifer forest litter layer. The bookkeeping method was reliable and allowed adjustment of fuel response time based on weather conditions. Difficulties in modelling meteorological conditions under the gorse canopy limited its accuracy. Separate thresholds determined ignition and fire spread success, with both based on the elevated dead fuel moisture content. Options to improve the shrub fire danger rating system were presented based on these findings. The results are significant because they are based on data collected in the field under real conditions. Validation of these results and extension to other shrub fuels is required before the findings are used to change current models. However, the study has significantly advanced the knowledge of fire behaviour in shrub fuels and will contribute to safe and effective fire management in these fuels.

The current design methods used to determine fire progression and temperature-time development in fire compartments today are being questioned to not give accurate results in large and complex enclosures (larger than 500 m2). The established design methods proposed by Eurocode and used by fire safety engineers today are primarily the standard temperature-time curve and the parametric temperature-time curves. The parametric temperature-time curves are based on the heat and mass balance equations and both methods assume homogenous temperatures and uniform burning. These assumptions are being questioned for use in large enclosures such as open-plan compartments and compartments with multiple floors connected which are typically modern and common building types in today’s society. Today there are no established design methods developed to determine fire progression in large enclosures, but the Improved Travelling Fire Method (iTFM) and the New MT model II are new, alternative design methods which are prospects to become established engineering tools in the future. The iTFM is developed at the University of Edinburgh for travelling fires in large size compartments and the New MT model II is developed by RISE, Research Institutes of Sweden, for large tunnel fires. These two new design methods have been investigated and compared to established methods in a case study. Also localised fires from Eurocode with proposed interpretations by Ulf Wickström has been investigated and compared to the standard temperature-time curve and the parametric temperature-time curves. The new interpretation suggests that the given heat flux boundary conditions in Eurocode are interpreted as adiabatic surface temperatures based on given emissivities and convection heat transfer coefficients according to Eurocode. Through a case study the different methods were compared throughout reference buildings with constant material properties and fire loads, but with varying floor area and height. The result focused on if the new methods have more bearing on reality than the standard fire curve and the parametric temperature-time curves methods when determining fire progression and temperature-time development. Desired benefits with the new methods are to better predict and describe fire development in large enclosures. The referenceIIIbuildings were considered as occupancy class 2 (Vk2) and Br2 buildings with a load bearing fire resistance capacity demand of 30 minutes. This report is an early stage in the process of developing new fire models to improve the fire designing process when working with large compartments. The aim with the new, alternative methods and localised fires with proposed interpretation is to enable them to become engineering tools used by fire safety engineers in the future to create a more efficient and adapted design process. The results differ significantly depending on used method and reference building. The maximum temperatures conducted by the iTFM are in general higher than the standard fire curve and the parametric temperature-time curves. When applying the method to the reference building with high ceiling height and low spread rate the resulting temperatures were lower than the standard fire curve. The fire progression of the New MT model II is highly dependent on opening factor and time until temperature increase starts. In comparison to the parametric fire curves with the same opening factors the New MT model II resulted in considerably faster temperature development and higher temperatures. Localised fires with the new proposed interpretations resulted in adiabatic surface temperatures which were compared to the standard temperature-time curve after 30 minutes of fire and the maximum temperature of the parametric temperature-time curves. The comparison resulted in slightly lower temperatures for the localised fires with the new proposed interpretations compared to the standard temperature-time curve and similar temperatures compared to the parametric temperature-time curves in the case study. The results of the iTFM and the New MT model II differs significantly depending on physical parameters used in the calculation processes. The models are customizable and vary depending on fire scenarios and compartments and could possibly be future alternative methods when designing for fires in large compartments. Further studies and development together with real fire tests would provide the models with better accuracy and continuity. Localised fires with proposed new interpretations are a future prospect to become a future standard method for determination of maximum temperature of member surfaces in fire safety design.

The fire development and flame spread in the railway carriages are investigated by performing a set of simulations using a widely accepted simulation software called &amp / #8216 / Fire Dynamics Simulator&amp / #8217 / . Two different rolling stock models / representing a train made up of physically separated carriages, and a 4-car train with open wide gangways / have been built to examine the effects of train geometry on fire development and smoke spread within the trains. The simulations incorporate two different ignition sources / a small size arson fire, and a severe baggage fire incident. The simulations have been performed incorporating variations of parameters including tunnel geometry, ventilation and evacuation strategies, and combustible material properties. The predictions of flame spread within the rolling stock and values of the peak heat release rates are reported for the simulated incident cases. In addition, for a set of base cases the onboard conditions are discussed and compared against the tenability criteria given by the international standards. The predictions of heat release rate and the onboard conditions from the Fire Dynamics Simulator case studies have been checked against the empirical methods such as Duggan&amp / #8217 / s method and other simulation softwares such as CFAST program.