For Marietta firefighters, using two new types of foam to battle blazes more efficiently and effectively isn't simply a matter of pointing a hose and letting it fly.
"We spent all day in the classroom," John Wyman, an instructor with the Ohio Fire Academy, said Tuesday. "They need to understand chemically what it is, how it works and why it works."
The Marietta Fire Department's tower truck and three pumpers have been retrofitted with foam injection systems, allowing firefighters easier access to substances that Wyman said can reduce the time and amount of water used in extinguishing flames. Starting Tuesday and continuing Nov. 19 and 26, Wyman is training each of the fire department's shifts on how to use the foam.
EVAN BEVINS The Marietta Times
Marietta firefighter Larry Nicholson, second from left, sprays foam at a pile of dirt, rocks and branches Tuesday afternoon at Jackson Hill Park during a training session on the new foam system installed on four of the department’s trucks.
The trucks can access Class A foam, used to fight structure fires, and Class B foam, which is used primarily when liquids like gasoline or oil are burning. Each type of foam must be mixed with the water in different concentrations and cannot be mixed together, Wyman said.
After several hours learning about how the foam and injection system work, interspersed with responses to some emergency calls, the firefighters headed up to Jackson Hill Park to put their knowledge to practical use.
Firefighter Larry Nicholson blasted the foam at a pile of dirt, rocks and branches at the park, using three different types of nozzles as other firefighters operated the system on one of the pumpers. Nicholson said there isn't really a difference in the feel of spraying the foam compared to using water.
Class A - Helps fight normal combustion fires by reducing the surface tension on the water, allowing the burning structure to soak up water more easily and letting the department use less water.
Class B - Helps fight liquid fires by smothering highly combustible vapors; ideal for use at the scene of a car accident to extinguish spilled oil and gasoline.
Source: Marietta Fire Chief C.W. Durham.
"It works a lot better on the fire though," he said.
Wyman said the Class A foam can douse flames in less time and using less water than water alone. Knocking down a fire faster reduces the risk for firefighters as well as the potential for damage to a burning structure, he said.
"The greatest amount of damage typically done in a house fire isn't from the fire, it's from the water," he said. Also with foam, "you get a better preservation of arson evidence."
Marietta Fire Chief C.W. Durham said the foam provides for less chance of reignition. In addition, the Class A foam is biodegradable and safe from an environmental perspective.
"The basic description of it - it's souped-up dish soap," Wyman said.
Most types of Class B foam are not biodegradable, he said, but those would not be used to douse structure fires.
The foam systems were purchased with a $94,950 federal Assistance to Firefighters grant, which required a $4,747 match from the city. The foam itself costs $18 to $20 a gallon and is mixed in with the water in small amounts, firefighter/EMT Greg Doak said. Tuesday's training only expended about a gallon.
Previously, the only way firefighters could utilize foam was by disconnecting a piece of a hose and attaching a portable injection tool that could draw foam from a five-gallon bucket. That often did not allow the substance to be used in the initial attack on the fire, Durham said.
Durham said training will continue the next two Tuesdays, and members of county volunteer fire departments have been invited to attend.