Brandteknisk riskvärdering av Hangar 92 F4 Östersund

Sammanfattning: This report is the final result of a project in the course Brandteknisk riskvärdering VBR054 at Lunds University, Faculty of engineering, spring term of 2010. The aim has been to practise problem solving and to apply knowledge from previous courses with the purpose of evaluating the public safety in case of a fire, on an existing object. The object is a building on an area previously belonging to the air force base F4 in Östersund. The building, named Hangar 92 is now being converted to civilian activities, and the aim is to create an assembly hall for exhibitions and other public arrangements. The building consists of two parts, one part with hangar halls named hall A-D, and another part with office spaces in three levels. The report has been limited to only comprise the part with the hangar halls, as these are the areas that are of current interest for public use. The halls have a ceiling height of 9 m and a floor area between 292-1940 m2. Three fire scenarios have been constructed and further analyzed with hand calculations and computer programs to estimate how much time is at disposal before the building has to be evacuated. For the smaller halls, the time is about four to five minutes, and for the whole building between five to eight minutes, depending on the scenario and the placement of the fire. Evacuation times were estimated by simulations in the computer program Simulex, and with data from scientific trials and available literature. It will take approximately ten minutes to evacuate the whole building with 1500 people on the premises. The overall assessment was that the building in its current state does not meet the demands regarding public safety at public arrangements. To shorten the evacuation time, a number of fire technical improvements was identified, and also some measures that should be taken to increase the public safety in general. The measures were validated with new calculations and simulations, and also with sensitivity- and uncertainty analysis. The most important measures that must be taken are: • The fire alarm should be deployed and adjusted to the new operations. • The evacuation alarm should be changed so that it is more easily interpreted. • The function of the smoke management is ensured. • Widen doors used for evacuation, install new opening devices and minimize the heights of thresholds. • Interior sliding doors should be exchanged or permanently fix in an open position. • Way leading markers for evacuation should be permanently mounted. • Emergency lights should be installed as complement at power cuts. • Temporary walls and exhibition stalls must not block evacuation routes and doors. • Prohibition on storing large quantities of wrapping, cartons and similar easily flammable materials indoors. If the measures are taken, the writers are of the opinion that Hangar 92 will meet the safety standards for fire safety for public arrangements.