Posts Tagged Underwriter’s Lab conducting research

UL tests transitional attack for house fires (more)

Excerpts from Fox6now.com:

A groundbreaking study in Illinois could change the way firefighters attack the hottest and most dangerous fires. The Milwaukee Fire Department is taking part in the study, but a retired New York City battalion chief says the researchers are all wet. It may sound elementary, but scientists in suburban Chicago are studying whether applying water on a fire from the outside should come before search and rescue on the inside.

“It’s an inherently dangerous profession,” says Erich Roden, battalion chief for the Milwaukee Fire Department. “Our ethos and our mission is to get inside that building as quickly as possible to rescue those trapped civilians.”

Roden is on the advisory board for Underwriters Laboratories, which recently invited firefighters from around the world to witness a first-of-its-kind experiment. Not just a controlled burn, but a live fire inside a fully-furnished, 1,200 square foot house, with temperature sensors, oxygen sensors, air flow sensors and video cameras.

“We couldn’t make measurements like this 30, 40 years ago,” said Steve Kerber, director of UL’s Fire Safety Research Institute. “Now we can.”

The tests are being driven, in part, by the way most homes have changed.

“There is a lot more synthetic material in our homes today, which means fires burn hotter and faster than they did 30 or 40 years ago,” says John Drengenberg, a spokesman for UL. “This means you have less time to escape.”

It also means that by the time firefighters get to a burning building, the fire may already be nearing its most dangerous point — a sudden, dramatic combustion event known as flashover.

“It used to take upwards of 20 to 30 minutes for a room to reach flashover stage. Now it’s down to as few as seven or eight minutes,” said Lloyd Bertram with the New Berlin Fire Department.

To prevent firefighters from getting trapped, UL is studying an alternative method of attack.

“A standard attack would involve usually going right through the front door, getting inside and searching for occupants,” Kerber said.

Instead, they’re employing what’s known as a transitional attack that starts outside. In the fire service, they call that “hitting it hard from the yard.”

“The occupants are on the inside, so the firefighters want to get to the inside as quickly as possible. But if the fire isn’t under control, that opening in the door can make the fire larger and now you are in a situation where you could potentially be making things worse for me inside,” Kerber said.

Hartland Fire Chief Dave Dean describes how his crews used transitional attack on a suburban garage fire.

“The fire was extremely hot. A lot of flames. Huge fire ball,” Dean said.  “Before we were able to send anybody into that structure, we were able to cool the fire by a large diameter hose attack line outside… then entering the structure. It worked like clock-work.”

“I don’t fight fires like that,” said John Salka, a retired battalion chief for the New York City Fire Department. “I am not a scientist, but I have done some experiments myself. Like about 30,000 experiments. I’ve been to a lot of fires.”

Salka says experience tells him there’s no time to waste.  In 2012, he wrote an opinion piece for Firehouse magazine titled, “Transitional Attack Is Whack.”

“Any minute that you delay going in to find a victim in a building puts them at greater risk,” he said.

In addition to delaying search and rescue, there’s another concern among old-school firefighters.

“The conventional teaching was that if you put water on a fire before you have had a chance to actually rescue a victim, you are, in essence, steaming that victim,” Bertram said.

“Am I doing what my grandfather taught me 30 years ago?” Kerber asked a room full of firefighters.

He says science is proving that theory wrong.

“It allows temperatures to cool off quickly, heat flux to go down, [and it’s] more survivable for occupants faster. The numbers don’t lie,” Roden said.

Salka is not convinced.

“They set all these beautiful controlled conditions up, do an experiment and then write down with their little pencils the results and say, look what happened.” Salka said. “It certainly is a lot easier and a lot safer to be out there than inside.”

He worries that the new approach is being driven by a desire among firefighters for self-preservation.

Data obtained by FOX6 News from the US Fire Administration shows civilian fire deaths have steadily declined over the past 40 years, but firefighter deaths have remained the roughly the same.

“So this research is focused on how to keep firefighters safe,” Drengenberg said.

“I’m fairly certain that it is designed to assist and protect firefighters, rather than civilians,” Salka said.

Milwaukee’s Erich Roden says they’re trying to do both.

“What we are learning here is a much more rapid application of water is going to allow us to get in there and rescue occupants much quicker and it is safer for the victim and for ourselves,” he said.

For some, the retired FDNY chief represents the stubborn old guard of the fire service.

“We’re very attached to the way we have always done things,” Roden said.

But the director of UL’s research says it’s not their place to tell firefighters how to do their jobs. “What we are going for is informing them,” Kerber said.

When the right approach is a matter of life and death, they just want to put the data behind the decision. The tests conducted by UL back in March are part of a three-year study that’s expected to be published later this year (2016). Fire departments can then use that information to determine the best approach for protecting their own personnel as well as victims who may be trapped inside a burning building.

thanks Dan

Tags: , , , , , , , , ,

UL tests transitional attack for house fires

Excerpts from the ChicagoTribune.com:

About 100 firefighters from the U.S. and Canada assembled at Northbrook‘s Underwriters Laboratories on March 18 to find out if they have more, and safer, choices than they might think as they pull up to a residential fire.

Steve Kerber, director of UL’s Firefighter Safety Research Institute, said the traditional way to extinguish a house fire has been to immediately carry hoses in and aggressively attack from room to room, forcing the fire against the outside walls with water. The accepted wisdom finds that attacking through windows from the outside can essentially push the fire into other rooms, and the water, becoming superheated, can “steam the occupants” to death, he said.

A combination method, however, involves attacking quickly through windows before moving to the inside. The transitional attack – still shunned in many departments, Kerber said, because it involves exterior firefighting — was demonstrated in a test house at UL, festooned with hundreds of sensors.

“We’re not trying to tell you how to fight a fire,” Kerber said. “We’re trying to give you more choices.”

Underwriters has tested the transitional method about two dozen times in the past month as part of a three-year study of transitional attack, funded by a $3.5 million U.S. Department of Homeland Security grant, which will culminate in a report next year, Kerber said.

On March 18, a crew of about ten UL-hired firefighters attacked through two windows where separate rooms were on fire, flames extending from the windows. They sprayed water up, not horizontally, to avoid pushing the fire, then sprayed in a circle to hit as many surfaces as possible without letting more air into the room.

The flames were gone in each room in about 15 seconds, and temperatures quickly dropped from around 1,800 degrees to 250 degrees. When firefighters headed in to put out any fire that remained, all they found was one little spot on a chair, Kerber said.

But the transitional method has limitations.

“The windows were open,” said Northbrook firefighter Lt. Ryan Lee. . “What happens if the windows are closed, and all the fire is bottled in?” Breaking a window, he said, would introduce air into a fire, making it easier for it to flame through an interior wall.

Kerber said in that situation, based on current data, arriving firefighters should go inside if they have enough personnel on scene to protect each other. If not, he said: “Break a window.”

One of the key features of transitional firefighting is that it reduces the time a firefighter is inside a structure while it’s ablaze, proponents say. For firefighters, that’s important.

One of the visitors was Winnipeg (Manitoba) Fire Paramedic Service senior firefighter Lionel Crowther, who was burned over 70 percent of his body in a 2007 fire. He said two fire captains died in that fire, including one he was unable to push out a second-story window before he himself dived through it.

Though transitional firefighting has been studied for years, this is the first time it’s been done with so much electronic data collection, and with a component of the effect on human skin, according to UL representatives.

UL has been joined in the study by the University of Illinois Fire Service Institute, which is testing how much heat trapped people are exposed to as transitional attack is practiced. Kerber said they’re testing with carcasses of young hogs, which have skin similar to humans, and by exposing rats to similar levels of heat as produced in Northbrook.

Results are still being studied, but Gavin Horn, the Institute’s research director, said it’s a myth that spraying water on fire dramatically increases the steaming effect on trapped people. “We’ve been surprised by the amount of moisture created just by the fire itself,” he said.

Observers watched the fire on screens featuring footage from eight cameras in and outside of the house.

A fire was started with a dropped match and allowed to burn for several minutes before firefighters were given the “go” sign. Kerber said that “flashover,” the point when everything in a room catches fire, usually occurs within four minutes.

Fire Chief Brad Shull, of the Jefferson Twp., Ohio, fire department, said many fire departments don’t even reach a scene before seven minutes have passed, indicating departments may be playing catch-up more often that they thought.

Kerber said the use of the hoses in the transitional method can keep air from fueling the fire, but McCulloch said later that the demonstration model didn’t replicate many of the situations fire departments find in America’s wealthier suburbs.

“A three-bedroom ranch isn’t a 5,000 square-foot McMansion, where you’ve got a lot of air to feed a fire,” he said. In such houses, he said, there may be no choice but to start firefighting from within.

He said one of the best ways to cut down the oxygen fuel of a fire is up to the residents of the home where the fire has started. “When they leave the house,” he said, “they should close the door.”

Tags: , , , , , , , , ,

Fire Behavior Study at UL

The Fire Safety Engineering area at Underwriter’ Laboratories was conducting research last week in Northbrook.

Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Program, UL examined fire service ventilation practices as well as the impact of changes in modern house geometries.  There has been a steady change in the residential fire environment over the past several decades.

This series of experiments examine this change in fire behavior and the impact on firefighter ventilation tactics.  This fire research project developed the empirical data that is needed to quantify the fire behavior associated with these scenarios and result in immediately developing the necessary firefighting ventilation practices to reduce firefighter death and injury.

Two houses were constructed in the large fire facility of UL in Northbrook, IL.

A summary of the testing along with the complete report can be accessed HERE.

Tim Olk was on hand during some of the burning and submitted some images.

Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction

One of the houses that was built for the testing inside the Northbrook facility of UL. Tim Olk photo

Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction

Firefighters apply water into a window during one of the burns. Tim Olk photo

Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction

A firefighter stands by as the fire rages in one of the test structures. Tim Olk photo

Tim has more images from the testing HERE.

Tags: , , ,