Water Mist Introduction

by John Robertson

The main item on our training agenda on 21st June was member’s first practical experience of the Scorpion water mist system. This enables TM51 (or 52) to do everything that the I-Zone truck can do while simultaneously retaining their complete conventional bush firefighting capabilities and having much greater water tank capacity. The objective of water mist is to ensure that almost all the water going onto a fire turns to steam and thus removes far more heat than if it remains as water. Then the rising steam depletes the oxygen above the fire and thus extinguishes the flames there. Water use is 8 litres per minute so 51 can do over 3 hours continuous firefighting on a tank and 52 can do 4 hours.


In the Council yard each member had a go with the water mist and extinguished a real but small fire with it. In each case extinguishing the fire took only seconds and used 2 or 3 litres of water. Water feed was from 52.

At the debrief afterwards there were many really good suggestions on how to improve the set up. The lance trigger had been taped ON and this tape was removed as it disabled a safety feature. Neville suggested that the Scorpion could take its water inlet feed by gravity from the tank at the bottom of the sight tube. Shane suggested that the high-pressure hose (which will be 100 metres long) should be looped over supports on the side of the truck. Rory suggested that for $30 each we could get helmet earpieces which let one ear listen to the radio while the other hears what is going on around. This would be of high value quite apart from its use with the Scorpion.

Posted in Training