A Hot Assignment: Set Fire to Cocoa, Concrete and Sludge
Burgeoning Field of Testers Keeps Materials Safer By Incinerating Them
By THEO FRANCIS and ALEX FRANGOS Staff Reporters, The Wall Street Journal
WEST GLOCESTER, R.I. - Dennis Waters and Tom Lawson have set fire to power-turbine housings, burned up a big stack of toilet paper and incinerated municipal-waste sludge. They have set applesauce ablaze and torched teddy bears stacked by the hundreds in cartons.
"You name it, we've probably burned it," says Mr. Lawson, head of research and testing for FM Global, an insurance company in Johnston, R.I., a suburb of Providence. Mr. Waters runs the company's burn laboratory.
It's their job to burn things down, not just for FM Global's insurance clients but also for building-supply manufacturers. They study how materials burn and help develop ways to minimize losses from fires.
The field is hotter than ever, with new materials being introduced every day. Terrorism fears have also spurred business, as large-scale testing of building materials and industrial equipment takes on a new urgency. Today, another crew of engineers, at Underwriters Laboratories Inc. in Northbrook, Ill., will ignite a 17-foot replica of a section of the World Trade Center's flooring to see what role it may have played in the buildings' collapse.
The slab of concrete, supported by steel trusses, will be heated in a gas furnace to 1,100 degrees Fahrenheit. Shyam Sunder, the lead investigator for the National Institute of Standards and Technology, in Gaithersburg, Md., decided a year ago to conduct the live fire test at UL. While it's long been known that fire contributed to the collapse, its precise role still isn't clear.
It has taken nearly a year to fabricate the trusses and pour and cure concrete to the requisite hardness. "Too much water in the concrete and it would affect the result," Mr. Sunder says. Sprayed with the fireproofing material used in the original building, the floor unit will be scorched until it shows signs of damage.
Last week, engineers did a preliminary test at a UL lab near Toronto. A 35-foot truss, almost identical to those that held the World Trade Center's floors, was burned until it showed signs of weakening. Mr. Sunder, who witnessed the test, says, "All I will say is it was enlightening to see the results," which were, he says, "counterintuitive to conventional wisdom."
FM Global recently built a new 1,600-acre testing complex on its wooded compound in West Glocester. The company uses the site to simulate full-size fires, test roofs against hurricane-force winds and study how electrical equipment stands up to explosions. The Bureau of Alcohol, Tobacco, Firearms and Explosives -- part of the Justice Department -- last year opened a new $106 million facility, which includes a forensic fire research laboratory, in Ammendale, Md. It regularly burns mock living rooms and small buildings to assist in arson investigations. This month it agreed to burn merchandise for the U.S. Consumer Product Safety Commission.
The FM Global lab features a concrete outdoor bunker where testers study the combustibility of dust. Fine powder of almost any sort will explode violently under the right circumstances. The lab has burned cocoa powder, which smells like hot chocolate, and dried municipal waste sludge, which smells as you would expect.
In a test last Thursday, a 10-pound cloud of plastic powder was ignited, sending a 20-foot fireball into the sky with a Hollywood-style bang. An eight-year-old boy named Kyle Bodine was there to see it, watching wide-eyed from behind a transparent safety partition. "It's pretty amazing you can do all this stuff without getting hurt," he said. Kyle was on a tour with his father, Craig, a member of the Association of Governmental Risk Pools, visiting from Prague, Okla.
That day Mr. Waters was in his office showing off film footage of a transformer fire that a friend of his had sent him. A dozen sprinkler heads line the desk of his colleague Dennis Anderson, one dating to 1896. His computer wallpaper shows a nearly out-of-control lab test, dubbed "the mother of all fire tests," in which a stream of industrial lubricant was set aflame. His FM Global mouse pad shows a tower of flame and the sales slogan "Don't play with fire. Let us do it for you."
In a test two years ago, FM Global ignited wooden pallets stacked high with 8,000 tiny plastic bottles of heptane, an industrial solvent standing in for perfume or nail-polish remover. The question at hand: Would a large number of small bottles necessitate fewer fire sprinklers than a small number of large containers filled with the same flammable liquid? Soon, one box exploded, then another. Mr. Waters shouted for water as fireballs erupted. He got his answer: Packed together, tiny bottles are little Molotov cocktails, and they should be stored like gasoline, with sprinklers not just in the ceiling but in the storage racks themselves. "It took them an hour to get it out," Mr. Anderson says. "That was a very dandy fire."
At the nonprofit Southwest Research Institute in San Antonio, engineers have ignited pallet-loads of swimming-pool chemicals ("high order of flammability") and watermelons ("low order of flammability"). Once they sent about 2,400 pounds of pecans up in smoke.
The Institute tests new materials for industry and the military. A few years ago, it set fires in garbage cans lined with high-tech garbage bags designed to shrink-wrap in the heat and smother flames. "It was the most amazing thing to watch," says James R. Griffith, manager of the department of fire technology. "It's like a Venus flytrap." The bags have yet to be marketed.
Another hot area of testing: plastic gas tanks, which have replaced metal tanks in most cars because they can be molded to fit into cramped underbodies. Mr. Griffith and his colleagues pour gasoline on the pavement beneath cars and let it rip to see whether tanks can withstand the heat.
Plastics -- "solid gasoline," as some engineers call them -- and other petrochemicals are increasingly turning up in building and packaging roles once dominated by wood, paper or metal, which engineers already understand well. Now, 100-gallon tanks used to store flammable liquids often are plastic. Where wooden pallets once reigned in shipping and in warehouses, plastic pallets have become common, says Bob Zalosh, a professor of fire protection and engineering at Worcester Polytechnic Institute in Worcester, Mass. Just how these materials will behave in bulk, and in combination, requires real-world testing.
Burning buildings shed light on construction practices as well. Crews raised pieces of two mock houses at the National Institute of Standards and Technology, mimicking small-lot subdivisions springing up around the country. Although the houses are commonly just six feet apart, codes don't require exterior fire-cladding. Safety experts worry that flames could sweep through whole blocks, says David D. Evans, a manager of the institute's fire research program.
Mr. Evans, who admits he "enjoys looking at a big fire," had his crew light a sofa on fire in the den of one house. In three minutes, the fire broke the window. In five minutes, the flames jumped to the neighboring house.
Mr. Evans used high-tech calorimeters during the test to gather data that will eventually feed into a computer model. He'll use that model to spark a virtual fire that engulfs an entire neighborhood on a windy day, a concern following last year's devastating southern California brush fires.
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