Firefighters perfect skills at training session

By Martin B. Cassidy
Staff Writer

April 11, 2007

A dozen firefighters practiced using water-based foam, coating a burned-out building and surrounding parking lot with a heavy carpet of snow white bubbles yesterday on North Street.

Career firefighters are brushing up this week on their skills handling AFFF, or aqueous film-forming foam, at the fire training center at North Street School. The substance is sprayed to smother petroleum and other hydrocarbon-fueled fires and spills on the scenes of tanker truck accidents and other flammable liquid leaks, said training Lt. Sean McDonnell.

When mixed with water, the industrial foam is sprayed on a flammable liquid, forming a protective layer that traps vapors and cuts off the oxygen feeding a fire, McDonnell said.

"It suppresses vapors in the air and floats on top of the hydrocarbon fuel," McDonnell said. "If you just used water, the gasoline would float on top of that and still burn."

The foam is rarely called for, but is indispensable for the department, which responds to truck accidents on Interstate 95, fire Lt. Steve Whittaker said.

"There are trucks rolling up and down I-95 all day, and you don't even want to know what is inside of them," Whittaker said.

Firefighters use a special aerated nozzle when spraying the foam, helping control the heavier water pressure needed to push the lather through the hose and aiding in foam expansion, Whittaker said.

Yesterday William Richardson, a firefighter based out of the Cos Cob Fire House, showed his fellow firefighters how to regulate the water flow on that company's truck.

The foam is so dense that it is heavily diluted for use in fires, Richardson said. Each engine in town carries enough foam-concentrate to convert their on-board water tanks into lather, he said.

Later this month, firefighters will undergo their yearly re-certification in confined space and trench rescue techniques, Assistant Fire Chief Peter Siecienski said.