RISE Research Institutes of Sweden have carried out fire tests to evaluate fire fighting methods in case of a fire involving alternative fuel vehicles (AFV) in a ro-ro space. This report presents how selected fire fighting methods were practically evaluated for their possible to use in ro-ro spaces. The results can be applied for safer and more efficient manual fire fighting operations, which is increasingly important when carrying AFVs.
The fire tests were performed in a large fire test hall at RISE Fire Research in Borås and the fire load was represented by a steel mock-up of a personal vehicle with a propane test rig, creating a fire of 4 MW. Steel walls, representing adjacent vehicles, were fitted with thermocouples to measure the temperature 0.6 m from the mock-up vehicle. Extinguishing media were applied between the mock-up and the steel wall on the left-hand of the vehicle and the temperature reduction was measured. The results present the reduction coefficient achieved by different systems, i.e. the heat blockage effect achieved by the systems. A high reduction coefficient indicates that the system has a high capacity to reduce heat exposure and prevent fire spread to an adjacent vehicle.
For handheld system, the highest reduction coefficient was achieved by the Industrial system and the FRS system (but only with a high water flow rate), providing both a reduction coefficient of 0.64. Reduction coefficient on the opposite side of the vehicle, from where the water was applied, also varied between the different systems. The highest reduction coefficient on this side was achieved by the high pressure 60 system, providing a reduction coefficient of 0.34. For water curtain system the Hose provided the highest capacity to reduce heat exposure on both side of the vehicle.
How different tactical options could optimize the performance of the handheld systems was evaluated primarily by visual observations. After the first part of the test was conducted (measuring blockage effects) the operator was able to oscillate the water spray, both up and down and over the vehicle. The operator also approached the vehicle from the front, at an angel of 45°, in order to observe the effects with respect to cooling or suppression. By varying the technique, it was possible to optimize the cooling effect on both sides of the vehicle, but the operator must be able to adjust cone angle and water spray pattern to maximize the effect. During this part of the tests it was possible to observe that some systems had a limitation in capacity with respect to cooling or suppression, especially if the pressure was low or if it had a low water flow rate. The water curtain systems were not able to affect the other side of the vehicle, which indicates the need of positioning the nozzle or hose on at least two sides of the burning vehicle to be able to efficiently prevent fire spread.
A field test (outdoor) was also conducted to evaluate the practical usability of the tested systems. A simulated ro-ro space was built up on a fire rescue training field where relevant crew tried different tactical options with the different system. It was found that a semi-rigid hose with a small inner diameter is much easier to handle in most cases but must be compared with desired capacity of pressure, water flow rate and throw length. A hose with a larger inner diameter will have greater stiffness which proved to be useful when trying to position water curtain nozzles. The tests showed that it is possible to position water curtain nozzles to prevent fire spread, but the hose most be further developed to be able to use in ro-ro spaces.