3D Firefighting
The Fire Risk Management Program at National Research Council (NRC) of Canada has initiated a study to review current firefighting technologies in an effort to improve the safety and effectiveness of firefighting teams. The initial research efforts have resulted in the research report on Grimwood's three dimensional (3D) Water Fog Technique. In the report, current research and applications of this technique for firefighting services worldwide have been reviewed, and future studies on this technique have been identified and recommended in order to provide more insights into the technique.

'Compared to traditional straight stream or narrow fog techniques, both experimental and analytical results show that proper use of the 3D water fog technique can have a better cooling effectiveness, generate less steam and lead to less disruption of the thermal balance in the smoke layer by using short discharges, fine droplets and wide spray angle'.

 We would appreciate it if you would review the research report (download below) and provide your feedback and comments on the report. Further, we would also appreciate it if you would indicate other firefighting technologies or research areas that would be of interest to you. 

Interior structure firefighting is now becoming more challenging and dangerous than in the past. Many new buildings, such as commercial centers, galleries, exhibition halls and warehouses, are becoming bigger and more complex. These buildings have big open indoor areas containing extensive volumes of combustion gas once a fire occurs. Also, the extensive use of new materials for building construction and contents can result in increasing smoke productions and more rapid flame development once they ignite. The use of new construction technologies, such as the widespread installation of double-glazed, energy-efficient windows, that allow hot smoke to be contained in the room for an extended period, also adds to the challenges for firefighting.

The 3D water fog technique is not designed to replace the direct fire attack but rather to complement existing forms of fire attack in an effort to increase the safety and effectiveness of firefighting teams. Over the last two decades, several fire authorities in Sweden, UK, Australia, Spain and the US Navy (for firefighting onboard surface ships) have officially adopted the 3D water fog techniques for firefighting. This approach is also under review in the USA, Holland, Germany and France

For the obstructed fire scenarios, the 3D water fog technique had advantages over the traditional stream attack in controlling the fire threat. Several bursts (2-3 s in duration) of water fog were sufficient to attack and control the overhead fires. The smoke temperature was quickly reduced by 200-250oC and then continued to cool. With the straight stream tactic, the overhead temperatures were reduced initially but quickly returned to their original level. The steam generated with the 3D water fog technique was less than that produced using a straight stream or narrow angle fog. It was a moist, "sweaty" type of steam, resulting in no burns to the participants, rather than a hot, penetrating steam. A straight stream or narrow angle fog directed into the smoke layer, however, resulted in excessive amounts of hot, penetrating steam, which caused burns to the hands, wrists, face, neck and backs of the firefighters. Heat flux data indicated that there was no significant disturbance in the thermal balance in the room with the 3D water fog technique, while the thermal balance was disturbed in several tests with the traditional straight stream attack.

For non-obstructed fire scenarios, full-scale tests showed that neither the 3D water fog technique nor the traditional straight stream had a clear advantage. The tenability and extinguishment benefits provided by using the 3D water fog technique were offset by the ability to mitigate the threat quickly by applying water directly to the fire using the straight stream approach.

For the low visibility scenario, only one test was conducted using each approach. As such, the performance of the two approaches could not be compared but it was observed there was no disadvantage in using the 3D water fog technique in this scenario.

NRC Report into 3D Firefighting Tactics

For more information on our study, please contact with Dr. Zhigang Liu at Tel: 1-613-990-5075, Fax: 1-613-954-0483, e-mail: zhigang.liu@nrc.ca  , or Dr. Ahmed Kashef at Tel: 1-613-, Fax 1-613-954-04883, email: ahmed.kashef@nrc.ca