Nine full-scale fire tests were conducted to evaluate the effectiveness of the Ultra Fog high-pressure water mist system in a road tunnel against a Class A fire (made of wood pallets).

The 600 m long test tunnel was longitudinally ventilated via jet fans. Potential fire loads of 30 MW, 50 MW and 100 MW were ignited.

Tenability conditions upstream and downstream were measured along with heat release rate, heat flux and temperatures. Visibility, heat and toxic effects are the primary factors for evaluation of tenability. Efectis used the Fractional Effective Dose (FED) method to determine the toxic effects of the fire products. This method is not only subject to a threshold criterion but also accounts for the exposure time of the evacuating person in the tunnel environment.

The collected valuable data allowed Ultra Fog to optimise and verify their system performance successfully.

Contact: Tomas Rakovec – tomas.rakovec@efectis.com