Lake Oswego firefighters regularly practice for all sorts of situations they might encounter when they respond to emergencies, but this month brought the first time many were formally trained to fight fires fueled by flammable liquids and gases.
'We're trying to find things we haven't done before,' Lake Oswego Fire Department Battalion Chief David Morris said.
About 45 people went through the training, which began with classroom sessions and ended with hands-on 'live fire' exercises outside of the Westlake Fire Station.
Natural gas and propane are by far the most common flammable gases and liquids local firefighters encounter, Morris said, noting it's important that firefighters understand how those substances react and what to watch out for when dealing with them.
'This gives us the opportunity to train with live fire on appliances and storage facilities with liquid in them,' he said. Unlike a typical house fire, 'we don't just put the fire out with water. We have to shut off the source of the gas.'
Shutting off the gas requires a strategic approach to reach the valve and stop the flow of fuel.
'We're learning to come in with the hose streams and push the fire back from the valve so we can turn it off,' Morris said.
The exercises ran firefighting teams through scenarios they might encounter with different types of delivery and containment systems.
In each scenario, the approach was largely the same.
'We're pushing the vapors away with a fog pattern on the nozzle,' Morris said. A fire hose nozzle is adjustable the same way a garden hose is, but with a lot more power. 'It creates its own windstorm, basically.'
But different types of valves turn off in different ways. And in the case of a large storage container filled with flammable liquid, such as in one of the scenarios, 'we need to keep the tank cool,' Morris said. 'If it gets to the point where it can't handle the heat and pressure and we get a (boiling liquid expanding vapor explosion), that can become a catastrophic situation.'
The state Department of Public Safety Standards and Training provided the equipment and an instructor to assist with the education and practice sessions in Lake Oswego.
Jamie Mason, DPSST fire training coordinator, reminded the local firefighters they were only dealing with low-pressure systems during the drills.
'The good thing is you can make mistakes on these props and learn,' he said. 'The bad thing is you won't get the '10 times the fire' you'd really have. The problems you have to fix today would be magnified greatly with a high-pressure system.'