Fire/Arson Investigations : Fire/Arson Investigations
A place to ask questions and add to probative and informative discussions associated with the various aspects of the field of fire investigation. -- FORUM RULES---BE CIVIL AND NO NAME CALLING, NO BELITTLING, NO BERATING, NO DENIGRATING others. Postings in violation of these rules can be removed or editted to remove the offending remarks at the discretion of the moderators and/or site administrator.
Re: 921 Proposal Regarding Evidence of Electrical Arcing
Posted by: Mike Learmonth (IP Logged)
Date: February 25, 2007 08:19PM
Thanks for the feedback John. I shall try resubmitting the proposal without the references to the photographs.
However, I must say that I agree with the adage, "a picture is worth a thousand words" and I note half of the photographs referenced in my original submission are already in the current edition of 921. Regarding the rest of the photographs that I have submitted as illustrations, I wonder what is the test to be passed proving as you say "the submitter KNOWS what caused the artifact"? For example, one of my submitted photographs shows an electrical conduit melted along its length on one side like a zipper. I believe I KNOW that was caused by internal electrical arcing, and I have seen it enough times during investigations and in published photographs of similar evidence (see Kirk's Fire Investigation 6th edition page 403) to make me pretty certain that I KNOW its cause. If on the other hand the hurdle for accepting a photograph for 921 is, that the artifact must have actually been observed being created during a test burn, then I have to object that I find it unlikely that a number of the photos currently in 921 passed that hurdle.
Regarding your comment about the use of the term "hydrocarbon flames" in the original submission, I wasn't trying to suggest that "liquid hydrocarbon accelerant" flames burn hotter than well-ventilated wood fires. Just that intense flames impinging on steel for a prolonged period of time, may in some instances perforate the steel, often by accelerated oxidation and occasionally (perhaps rarely) by actual melting. I shall modify that section as well.
As an aside, I would suggest that your differentiation between hydrocarbon flames and wood fires is imprecise. My understanding is that wood is composed primarily of cellulose which I believe chemically is still a "hydrocarbon". In fact I have often thought that it may be those inherent similarities in elemental composition and molecular structure amongst wood, plastics and common petroleum products that is the underlying reason why their flame temperatures are fairly similar (and quite dissimilar to say burning hydrazine or burning magnesium).
Thank you again for your comments.
Michael A. Learmonth, B.A.Sc., M.B.A., M.Eng., J.D., LL.B, C.F.E.I., P.Eng.
Senior Associate, Giffin Koerth Forensic Engineering and Science
Michael A. Learmonth, B.A.Sc., M.B.A., M.Eng., J.D., LL.B., C.F.E.I., P.Eng.
Senior Associate, Giffin Koerth Forensic Engineering and Science
40 University Avenue, Suite 800
Toronto, Ontario, Canada M5J 1T1
Phone: 416-368-1700 ext. 225
Fax: 416-368-5576
However, I must say that I agree with the adage, "a picture is worth a thousand words" and I note half of the photographs referenced in my original submission are already in the current edition of 921. Regarding the rest of the photographs that I have submitted as illustrations, I wonder what is the test to be passed proving as you say "the submitter KNOWS what caused the artifact"? For example, one of my submitted photographs shows an electrical conduit melted along its length on one side like a zipper. I believe I KNOW that was caused by internal electrical arcing, and I have seen it enough times during investigations and in published photographs of similar evidence (see Kirk's Fire Investigation 6th edition page 403) to make me pretty certain that I KNOW its cause. If on the other hand the hurdle for accepting a photograph for 921 is, that the artifact must have actually been observed being created during a test burn, then I have to object that I find it unlikely that a number of the photos currently in 921 passed that hurdle.
Regarding your comment about the use of the term "hydrocarbon flames" in the original submission, I wasn't trying to suggest that "liquid hydrocarbon accelerant" flames burn hotter than well-ventilated wood fires. Just that intense flames impinging on steel for a prolonged period of time, may in some instances perforate the steel, often by accelerated oxidation and occasionally (perhaps rarely) by actual melting. I shall modify that section as well.
As an aside, I would suggest that your differentiation between hydrocarbon flames and wood fires is imprecise. My understanding is that wood is composed primarily of cellulose which I believe chemically is still a "hydrocarbon". In fact I have often thought that it may be those inherent similarities in elemental composition and molecular structure amongst wood, plastics and common petroleum products that is the underlying reason why their flame temperatures are fairly similar (and quite dissimilar to say burning hydrazine or burning magnesium).
Thank you again for your comments.
Michael A. Learmonth, B.A.Sc., M.B.A., M.Eng., J.D., LL.B, C.F.E.I., P.Eng.
Senior Associate, Giffin Koerth Forensic Engineering and Science
Michael A. Learmonth, B.A.Sc., M.B.A., M.Eng., J.D., LL.B., C.F.E.I., P.Eng.
Senior Associate, Giffin Koerth Forensic Engineering and Science
40 University Avenue, Suite 800
Toronto, Ontario, Canada M5J 1T1
Phone: 416-368-1700 ext. 225
Fax: 416-368-5576
Sorry, only registered users may post in this forum.