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This paper presents a careful assessment of fire conditions in a long enclosure, open only at one end, which contained a regularly spaced timber crib fire load and is dominated by under-ventilated combustion. Though the geometrical arrangement, with fully enclosed side walls, differs from many more recent “travelling fire” tests, the essential fire behaviour shows a very clear progression of the main burning zone, driven by a combination of fire spread, ventilation and fuel burn out. By contrast many other travelling fire tests have been designed to be fuel-controlled, in much more open structures. Moreover, due to the enclosed nature of the test, it was observed to result in very high temperatures in the protected and unprotected steel beam members, especially during the phase when the fire travelled back from the opening to the ignition location at the rear of the compartment. The investigated test in this paper is Test number 2, which is one of nine tests carried out at the BRE Cardington laboratory in the UK, led by British Steel Technical (BST) and hosted by the Fire Research Station (FRS).CFD modelling, with NIST’s Fire Dynamics Simulator (FDS), is invoked to assist in exploration and interpretation of the test results, and to evaluate model capabilities for this complex fire scenario. For simplicity, instead of modelling the complex pyrolysis and combustion of timber on a stick-by-stick basis, the entire wood cribs are represented in the FDS model as single objects. Thus ignition and burning are represented in a simplified manner at the scale of the individual crib faces, with idealised mass loss curves derived from measurements in selected rows. Though tied to empirical mass loss, the model is stretched in representing heavily under-ventilated conditions occurring in certain domains. Despite these simplifications and challenges the model does prove capable of representing the qualitative behaviours to a satisfactory level. In particular, with appropriate parameter choice for reaction-to-fire properties, the FDS models are able to represent the fire spread rates for the two distinct stages of the fire: the fire travelling from rear to the front of the compartment in search of oxygen; and the fire travelling back from the opening to the rear as fuel is consumed. The results suggest the potential value of such simplified representations of cribs in FDS for travelling fire scenarios.In the calibrated model, the magnitude of the thermocouple (TC) temperatures at three locations (ignition location, centre location, and opening location) shows generally good agreement between the FDS model and the test at the stage when the fire travels to the opening. However, significantly higher discrepancy appears at the stage when the fire travels back. In addition to the highly simplified representation of crib burning, another likely reason for the latter may be the malfunction of the mass loss measurement in several wood cribs at this stage, which led to significant uncertainties in prescribed burning rates. Another large source of uncertainty relates to residual heat in compartment boundaries and fuel embers, the latter not being easy to represent in CFD models. These results suggest avenues to explore in future model development.

Several attempts have been made in the past to develop a European harmonized testing and assessment method for façades before the European commission decided to publish a call for tender on the topic. A project consortium from five countries (Sweden, UK, France, Germany and Hungary) applied to the call for tender and was contracted to develop a European approach to assess the fire performance of façades. 24 sub-contractors and 14 stakeholder entities were part of the project.

The objective of the European project was to address a request from the Standing Committee of Construction (SCC) to provide EC Member States regulators with a means to regulate the fire performance of façade systems based on a European approach agreed by SCC. In addressing this objective, the project team was asked to consider a number of issues which are presented and discussed.

The initial stages of this project were focused on:

• establishing a register of the regulatory requirements in all Member States in relation to the fire performance of façade systems, and
• to identify those Member States who have regulatory requirements for the fire performance façade systems which go beyond the current EN 13501 (reaction to fire and fire resistance) classification systems and to collate the details of these additional requirements. [6]

After having confirmed the regulatory needs the following steps were discussed:

• a testing and classification methodology based on BS 8414 - Fire performance of external cladding systems series and DIN 4102-20 - Fire behaviour of building materials and building components - Part 20: Complementary verification for the assessment of the fire behaviour of external wall claddings to address the identified key performance and classification characteristics [4] [5]
• a verification and validation proposal, in the form of a round robin programme to support the development of the proposed testing and classification methodologies.
• an alternative test method which was developed on the basis of the comments from stakeholders during the project

Several hundreds of comments were received during the project and were implemented in the development.

This paper is a short overview of results the two-year development work, which Final Report published by the European Commission in 2018 [1].

The present paper investigates a travelling fire scenario in an elongated structure (Length 18 m x width 6 m x height 3 m) with a controlled fire source of six pans filled with diesel (width 4 m x length 0.5 m). The fire spread is controlled manually by initiating fires subsequently in the pools. Fire Dynamics Simulator (FDS) is used to a-priori investigate variations in geometry, material data and fire load whereas simulations using the final design were performed after the test. The input to the model beside fire source and geometry are thermal material data. The FDS simulation were used to determine the appropriate size of the downstands (2 m from the ceiling in the final design) on the side to create a sufficiently one-dimensional fire spread. The post test simulations indicate that although there are a lot of variations not included in the model similar results were obtained as in the test.

A new more insulated and faster responding plate thermometer (PT) is introduced,which has been developed for measurements particularly in air at ambient temperature.It is a cheaper and more practical alternative to water‐cooled heat flux meters(HFMs). The theory and use of PTs measuring incident radiation heat flux and adiabaticsurface temperature are presented. Comparisons of measurements with PTsand HFMs are made. Finally, it is concluded that incident radiation in ambient aircan be measured with HFMs as well as with the new insulated type of PT. In hot gasesand flames, however, only PTs can be recommended. At elevated gas temperatures,convection makes measurements with HFMs difficult to interpret and use for calculations.However, they can be used in standard or well‐defined configurations forcomparisons.

The impact of different passive protective measures against external vertical firespread was investigated using the numerical tool Fire Dynamics Simulator (FDS).The numerical study was divided into a validation study and a comparative analysis.The validation study was performed to evaluate FDS as a calculation tool for modellingexternal vertical fire spread and was conducted using experimental results from alarge‐scale fire test done on a SP FIRE 105 test rig at SP, Sweden. It was concludedthat FDS 6.2.0 could reproduce the experimental results with a reasonable level ofdetail. In the comparative analysis, the impact on the external fire from a smallerapartment was studied in FDS with different configurations of horizontal projectionsand spandrels in the building exterior. Also, the effects of an upper and lower facadeset‐back configuration were studied. The results show that facade solutions based ona horizontal projection or an upper facade set‐back configuration result in comparableor better protection compared with a defined spandrel height. The results also showthat a spandrel height of at least 1.2 m can be replaced by a 60‐cm‐deep horizontalprojection, given that the balcony is wider than the underlying opening.

The objective of this project was to address a request from the Standing Committee of Construction (SCC) to provide EC Member States regulators with a means to regulate the fire performance of façade systems based on a European approach agreed by SCC.

A comparison between full‐scale façade fire tests where SP Fire 105 and BS 8414‐1 were used regarding repeatability and the use of modeling to discern changes in the setups is presented. Two test series according to BS 8414‐1 were repeated outside using the same façade systems on 2 different days, whereas for the SP Fire 105 a set of common façade systems in Sweden were tested indoors. In particular, the results show that the wind around the test setup may have a significant impact on the tests and that the heat exposure to the façade surface will depend on the thickness of the test specimen where an increased temperature in front of the façade, and a decreased temperature on the façade 2.1 m above the fire room, is observed experimentally. The heat exposure to the test specimen varies to a more limited extent when an uncontrollable free burning fire source is used (in this study heptane and wood, respectively) and that this variation increases when wind is present.

Changes of buildings regulations regarding the allowable height of mass timber structures in North America have been proposed. The proposed changes are to a significant extent based on real scale fire experiments of compartments that have been performed in laboratories in which the influence of wind is negligible. It has, however, been questioned whether the proposed regulations are relevant for realistic scenarios with external wind loads acting on the building during a compartment fire.

The study discussed in this report involves a review of previous literature, analysis of available test results and single zone modeling to study potential effects of external wind on the internal and external exposure of fires in compartments with exposed CLT.

In this paper a coarse graining process is used to subsequently model large wildland fires, starting from a model of a single tree. The models are created using Wildland Urban Interface Fire dynamics Simulator (WFDS), and it is here found that reasonable fire spread in small forests can be obtained although the results are quite dependent on grid resolution as well as moisture content. In most realistic scenarios the computational volume is rather large yielding massive amounts of data. In using WFDS a rather small grid size is needed to appropriately model the fire spread this will be a severely limiting factor in creating large models.