International Research Institute Develops New Fire Standards for Bus Suppression Systems


The SP Technical Research Institute of Sweden announced it has finalized standards in the works since 2005 to evaluate for the first time the performance of fire suppression systems in bus engine compartments. The result, added SP, can lead to improved passenger evacuation, reduced loss of life and property and better identification of substandard fire suppression systems available on the market. 

SP said its new method 4912 fire test standard, developed in conjunction with international fire organizations, vehicle manufacturers and insurrance companies, demonstrates functionality against realistic fires that start in a bus engine compartment. A voluntary “P” mark of certification, tested in accordance to SPCR 183 certifcation rules developed by SP for fire suppression systems in bus and motorcoach engine compartments, in addition to the SP method 4912 fire tests demonstrates to buyers and sellers a high degree of robustness. It shows the certified fire suppression systems were also tested for resistance to harsh environments in internationally accepted vehicle standards.  

SP said quality assurance and control over time is maintained through an independent, approved auditor that reviews factory production control. 

To obtain the P-mark, a fire suppression system must fulfill the requirements in SP method 4912, a repeatable and reproducible test conducted in a test enclosure, where the fire-fighting performance of different suppression systems can be evaluated “in a well-defined and objective way.” SP’s website explains that different petrol-based fires are initiated that challenge the capability of the suppression system being tested. The test method includes realistic airflows and relevant fire scenarios.

The test method also includes testing of re-ignition due to fuel spray of flammable liquid onto hot surfaces. All system components included in the full suppression system such as nozzles, pressure cylinders, piping, detectors, electronic components, control panels, are tested for harsh environments, EMC, change in temperature, corrosion, vibration, humidity extremes etc.

SP explained that the majority of bus fires start in the engine compartment, usually out of sight of the bus driver.

“Once a fire has started it is important to detect, control and ultimately extinguish the fire as early as possible to avoid injuries, loss of lives, costs related to property damages and to secure business continuity,” the organization said in a statement. “Further, an efficient fire detection and suppression system greatly enhances the time available for safe escape in the event of a fire.”

The new standard was proposed last September at the Fires in Vehicles 2012 International Conference in Chicago.