Vytenis Babrauskas, Ph.D
Arc mapping was first introduced in the 2001 edition of NFPA 921 and was subsequently expanded so that in the recent editions it constitutes one of the four main methods for determining the origin of a fire. Careful consideration of engineering principles and large-scale experimental studies on the subject indicates that the relevance and prominence of arc mapping as a leading indicator of fire origin is greatly overstated. The technique is valid and applicable only in some very limited scenarios. Yet it has seen very extensive use in recent years by investigators preparing fire reports. In many cases, such attempted use of arc mapping is based on incorrect and invalid hypotheses, which are often implicitly assumed to be true instead of being explicitly stated. The following are myths: (i) An abundance of arc beads at a given locale means that fire originated in that area, while a paucity of arc beads indicates that it did not. (ii) When multiple arcs are present on a circuit, the direction of arcing will necessarily proceed upstream towards the power source. (iii) If an appliance is the victim of a fire, internal arcing will be primarily near the exterior of the unit, while arcing deep inside indicates a fire origin at that place. NFPA is urged to revise NFPA 921 to eliminate arc mapping as one of the four main methods for establishing fire origin, and to subsume it under the more general category of “fire patterns.” In addition, it is important that NFPA 921 reduce the implied general utility of the method and provide more explicit information on its interpretation and its limitations and on the circumstances under which it may be a valid method for assisting in the determination of the fire origin.
Vytenis Babrauskas, Ph.D.
Short circuits to building wiring can happen due to electrical mishaps, or as a result of fire impinging on the wiring. In either case, this may cause arcing. It is sometimes erroneously assumed that this must produce signs of ‘electrical activity,’ which is a term often used by fire investigators to mean discernable arc marks or arc beads. While such artifacts may indeed be produced, it is shown that it does not necessarily happen in every case. Shorting and arcing (whether due to fire or due to an accident) may occur without leaving physical evidence that is discernable as an arc bead. Ejecta also may, but do not have to be produced. Some variables have been identified which can influence the size of arc beads, when arc beads are produced. But stochastic aspects dominate, and no predictive correlations can be expected. It is also shown that there are no prediction methods available to establish if an arc locale will result in severing or welding together of conductors.
From Out of the Abyss...
This week’s article from the past is titled Incendiary Fires Can Be Spotted and was written by Benjamin Horton, CPCU, who was President of the National Adjuster Traing School in Louisville, Kentucky.. It is taken from the Decembe 1968 Vol. XVI No.5 issue.
Incendiary Fires Can Be Spotted
In the new issue of NFPA Journal®, President Jim Shannon said the Association will focus on the leading causes of home fires, including cooking. "We also need to continue to push hard for home fire sprinklers. That's still a large priority for NFPA, and we plan to work very aggressively in 2014 on our residential sprinkler initiative," he said.
From: The Desk of Scotty Baker
To: The CCAI Training Committee
Over the last several training seminars, even as an old hand, I have learned new information concerning fires and how they do what they do.
Get started today
The focus will be on Interviewing, Report Writing and Fundamentals
Register now online or Fill out the registration form and email, mail or fax it
This is not a recall (yet).
An Alaska Airlines passenger's phone burst into flames on a flight en route to Hawaii, and the airline and the FAA say they are investigating.
See the news video and full article here.
This recall involves 14 ounce, white ceramic coffee mugs with “Love Today” printed in gold metallic on the outside of mug. “Microwave Safe” and “Illume” are printed on a removable label on the bottom of the mug.
Read all the details at CPSC
Toshiba has issued a recall for Li-Ion battery packs sold with certain models of its laptops and notebooks due a risk of the device catching fire.
Click here to read the article
Suzuki Motor of America, Inc. (Suzuki) is recalling certain model year 2013 Suzuki SFV650 motorcycles manufactured March 23, 2013, to April 8, 2013, 2014 Suzuki SFV650 motorcycles manufactured October 24, 2013, to November 26, 2013 and 2015 Suzuki SFV650 motorcycles manufactured August 9, 2014, to September 12, 2014. During assembly of the motorcycle, the fuel tank breather hose may have not been positioned properly and may become kinked.
If the fuel tank breather hose is kinked, pressure may build inside the fuel tank and cause the tank to crack, resulting in a fuel leak, increasing the risk of a fire.
Go to NHTSA for more details
Save the Dates – – –
CCAI will be presenting another in its series of “BURN TO LEARN” training seminars on March 7 through 9, 2016 in San Luis Obispo. Don’t miss out!
Live burns and various tests will expand your knowledge on a variety of burn patterns so that you may confidently explain them in the courtroom.
Whether you’re just starting to build your CV or just keeping it polished, you need to attend this conference!
In order to get the discounted conference room rate, you MUST make your hotel reservation by the 25th of February.
Call Embassy Suites at 805-547-6417 or 805-549-0800 to make yours TODAY.
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