These systems advanced the current state-of-the-art in fire protection:
- Installed water mist fire suppression systems were optimized using high pressure/ low flow techniques;
- “Smart” valve technology was implemented in fluid piping systems to automatically detect and isolate ruptures, and redirect fluid flow through intact segments; and
- Early warning fire detection systems used multi-criteria sensing elements and associated algorithms to reduce detection time and prevent nuisance alarms.
These systems were activated and responders were directed from a centralized command center, headed by a Damage Control Officer. The systems provide much better capability in isolating the fire/damage incident, but the Damage Control Officer suffered from “information overload." Next, in the third test series, installed systems were more fully automated using a supervisory control system. This system was programmed to automatically track damage via intact sensors, isolate ruptured systems, and activate suppression systems to contain fire damage. A reduced number of personnel
was used to check on the systems and assure that boundary conditions were stable. A relatively small damage control party then made an indirect firefighting attack to ultimately control the major fire in the damaged space.
The concept continues to evolve. The aggressive, personnel-intensive direct firefighting attack will give way in the future to a more measured, preplanned response utilizing sensors, advanced fire suppression systems, and automated isolation and reconfiguration of systems.
For information, contact Frederick W. Williams, telephone: (1) + 202-767-2476, e-mail: fwilliams@ccs.nrl.navy.mil or Joseph L. Scheffey, telephone: (1) + 410-737-8677, e-mail: joe@haifire.com
Ex-Uss Shadwell (LSD 15)
Canadian Research Has Implications for Smoke Detectors in Homes
Working with the Underwriters' Laboratories of Canada, researchers in the Fire Risk Management Program of the National Research Council of Canada's Institute for Research in Construction have demonstrated through full-scale experiments that combined ionization-photoelectric smoke detectors, can be, in some cases, more effective than ionization or photoelectric detectors used alone in homes. This research was part of an ongoing effort in the fire protection community to maximize the benefit of current smoke detector technologies to improve residential fire safety.
Two houses in the now deserted town of Kemano, British Columbia, served as test sites for the experiments: a 900-square-foot one-story house and a 1400-square-foot two-story house. In both dwellings, the researchers installed groupings of three
types of detectors-photoelectric, ionization and combined photoelectric-ionization to determine the response time to various fires set in the structures.
In general, the results of the experiments were not surprising. Combined ionization-photoelectric detectors responded at the same time, or in some cases, sooner in detecting fires than ionization detectors or photoelectric detectors alone. Surprisingly, however, smoke detectors installed in the "dead air space" (the triangular area 10 cm from ceiling and wall joints in each direction) were among the first to detect fires. Theoretically, smoke detectors should not alarm rapidly or work in this space, and Canadian standards for placement of smoke detectors require that this space be avoided.
The new results relative to detection in the “dead air space” deserve further study to determine to what extent, if any, they were influenced by the temperature in the unconditioned houses (the ambient temperature was around 12°C). Kemano Fire Studies—Part 1: Response of Residential Smoke Detectors is available in PDF format at:
http://irc.nrc-cnrc.gc.ca/fulltext/rr108/
Specific questions can be directed to Dr. Joseph Su at (1) + 613-993-9616, fax (1) + 613-954-0483, or e-mail joseph.su@nrc.gc.ca
Installing different technology smoke detectors in house.
Twenty sheets of newspaper transition from smoldering to flaming during tests.