Flammability of wooden decks to be tested by fire-breathing 'Dragon'
By Ben Coxworth
September 29, 2011
Thousands of people were left homeless this May, when over 40 percent of the town of Slave Lake, Alberta, Canada was destroyed by a wildfire that started in the adjacent forest. This is just one example of the devastation that can result when fires occur in what is known as the wildland-urban interface. While some buildings are destroyed when the wildfire itself reaches them, others can catch fire due to wind-borne embers from that fire. In an effort to test how well wooden decks are able to resist such embers, America's National Institute of Standards and Technology (NIST) created something known as the Dragon - it's a device that sucks in tree mulch, and "breathes" it out as firebrands.
The NIST Dragon (more formally known as the Firebrand Generator) was designed by mechanical engineer Samuel Manzello. The goose neck-shaped apparatus sits two meters (6.6 feet) tall, uses two propane burners to ignite the mulch, and a blower to expel it. The rate at which it does so can be controlled by the user.
Instead of the traditional cave, this dragon dwells in Japan's Building Research Institute. There, it is used in a wind tunnel that was designed specifically to study how wind affects fire. NIST has been collaborating with the Institute since 2005, on researching ways of minimizing the risk posed by flying embers.
The deck experiments are scheduled to take place early next year, with hopes that the results could be used to revise codes and standards for decks built in areas that are subject to wildfires.
The video below briefly shows the NIST Dragon in action.