http://www.tmastands.com/recalls.php

http://www.cpsc.gov/cpscpub/prerel/prhtml10/10036.html

http://www.consumerwatch.com/hunting-tree-stands/recall.php

Fire chemistry is the study of chemical process that occur in fires, including changes of state, decomposition, and combustion. Phases changes most relevant in fire are melting and vaporization. There is no change in chemical structure during these phase changes. Thermal decomposition, however, involves irreversible changes in the chemical structure of a material due to the effect of heat. This process is known as pyrolysis and it generally produces gases.

Heat transfer is defined as the transport of heat energy from one point to another caused by a temperature difference between those two points. Unless work is being done on the system by outside forces, heat is naturally transferred from a higher temperature mass to a lower temperature mass. The three heat transfer are conduction, convection, and radiation.

Conduction is a form of heat transfer that takes place within solids when one portion of an object is heated. Energy is transferred from the heated area to the unheated area at a rate dependent on the difference in temperature and the thermal conductivity of the material.

Convection is the transfer of heat energy by the movement of heated liquids or gases from the source of heat to a cooler part of the environment. In the early part of a fire, convection plays a major role in heating the surfaces exposed to gases heated by the fire.

Radiation is the transfer of heat energy from one hot surface or gas, the radiator, to a cooler material by electromagnetic waves without the need of an intervening medium. Radiation explains flashover.

In order for a fire to start and proliferate, there has to be four components all available at the same time. This is known as the fire tetrahedron. Fires can be prevented or suppressed by controlling or removing one or more of the sides of the tetrahedron. A combustion reaction can be characterized by the following four components: Fuel, Heat, Oxidizing agent (usually atmospheric oxygen), and an uninhibited chemical chain reaction.

A fuel is any substance that can undergo combustion. It is generally organic and can be a solid, liquid, or gas. However, fuels can only be consumed in the vapor state. Therefore, combustion of liquid fuels and most solid fuels takes place above the fuel surface in a region of vapors created by heating the fuel surface. Gaseous fuels, however, do not require vaporization or pyrolysis before combustion can occur and only proper mixture with an oxidizer and an ignition source are needed.

Heat can come from ambient conditions, from an ignition source, or from exposure to an existing fire. Heat produces fuel vapors, causes ignition, and promotes fire growth and flame spread by maintaining a continuous cycle of fuel production and ignition. The heat energy must be above the minimum level necessary to release fuel vapors and cause ignition.

The oxidizing agent is generally oxygen found in the earth’s atmosphere, but can be a chemical oxidizer as well, such as ammonium nitrate fertilizer. The fuel to air ratio has an optimum ratio at which combustion will be most efficient.

The oxidation reaction, or burning, must produce enough heat to maintain burning. Combustion is a complex set of chemical reactions that results in the rapid oxidation of a fuel, producing heat, light, and a variety of chemical by-products. If this complex chain reaction is uninhibited, a fire will sustain itself and most likely spread.

On August 1, 2007, in the middle of evening rush hour, over a thousand feet of the Interstate 35-W bridge in Minneapolis, Minnesota’s deck truss collapsed. Part of it fell 108 feet into the Mississippi, killing 13 people and injuring 145. The culprit was determined to be a failed gusset plate, which is a flat heavy piece of steel bolted in pairs to join the end of the steel members that make up the truss. The gusset plates were determined to be about half as thick as they should have been, as a result of a design error made decades before.

A design flaw was clearly the major factor in the disaster, however routine inspections of bridges never required an inspection of gusset plates. Bridge capacity, or load rating, was never considered to be effected by gusset plates until this disaster. It was assumed that gusset plates were properly sized to be stronger than the members they connect. In order to assist with the process of analyzing gusset plate strength, guidance was sought in order to “load rate” gusset plates.

Because there was little information on the failure modes of gusset plates, The Federal Highway Administration (FHWA) along with the National Institution of Standards and Technology (NIST), began building full-scale models of bridge gusset plate joints and pulling them apart using a hydraulic test machine. There was a need to measure how the gusset plates failed, which brought about a technology that has been used forever – Photogrammetry. Through the use of photographic measurement of paint specks, digital images allows engineers to watch the failure of key bridge components in great detail.

There is a lot to gain from correlating the digital image method to the FHWA actual measurement methods. First, it tells the FHWA the normal ranges of stress in which the plates can handle and will spring back into their original shape. Second, the method really shows what happens past the normal stress point – when the plate starts to permanently deform and eventually fails. With this new technology, the FHWA has learned a lot about how to predict what loads will cause gusset plates to fail.

The FHWA is working to translate the findings into a language that can be adopted into the Bridge Design Specification and Manual for Bridge Evaluation, two documents that are used in the US for designing and load rating bridges.

See Article: http://www.asminternational.org/portal/site/www/NewsItem/?vgnextoid=49ab76a8253d4310VgnVCM100000621e010aRCRD

The basic methodology of fire investigations should rely on the use of a systematic approach and attention to all relevant detail. The proper methodology for a fire or explosion investigation is to first determine the point of origin or origins, and investigate the cause of the fire. The cause of the fire is determined by the circumstances, conditions, or agencies that brought the ignition source, fuel, and oxidant together. The point of origin is where the fire starts and usually contains the most damage. Once the point of origin is determined, the cause of fire can be determined.
The origin and cause of the fire should be determined by using the scientific method. Thus, the investigator should recognize the need, define the problem, collect data, analyze the data, develop a hypothesis, test the hypothesis, and most importantly, avoid presumption, expectation bias, and confirmation bias. All investigations should be approached without any presumptions, and investigators should never reach a premature conclusion without having examined or considered all relevant data. Also, the investigator should never try to prove the hypothesis is right, and testing should be done to disprove the hypothesis.

After a fire or explosion incident occurs, the investigator should be notified of what his or her role will be in the investigation. The investigator should prepare for the investigation by estimating which tools, equipment, and personnel will be needed. The actual investigation may include different steps and procedures, which will be determined by the purpose of the assignment. The goal is to arrive at accurate determinations related to origin, cause, fire spread, and responsibility for the incident. Evidence should be documented properly and preserved for testing and courtroom presentation. Once data is collected, it should be analyzed using the scientific method. Conclusions are drawn as a result of testing the hypothesis.

The four causes of fire highlighted by the National Fire Protection Association’s National Fire Code NFPA 921 are natural, accidental, intentional, and undetermined. Often the local fire department has an investigation team who determined the origin and cause of the fire. However, consulting and litigation firms such as RWFE can be hired to investigate the fire as well by insurance companies or the private sector. The ATF comes in for drastic events or where criminal activity may be present.

Fire investigation is inherently a multidisciplinary activity. Therefore, special expertise from different fields would facilitate the investigation to reach a reasonable conclusion with sound evidence. Experts include many types of engineers including electrical engineers, chemical engineers, and mechanical engineers. An electrical engineer understands how electricity can be converted to heat and light and energy. A chemical engineer understands fires involving chemicals in the ignition, cause, or spread of the fire. A mechanical engineer can help investigate machine parts, such as bearing or other sources of friction. Moreover, a forensic scientist understands fire chemistry as well as the elements of arson.

The levels of certainty in a fire investigation are important because they describe how strongly someone holds an opinion or conclusion. These levels are determined by assessing the investigators confidence in the data, analyses of the data, and testing of the hypotheses. The level may determine the practical application of the opinion such as in legal proceedings. The two levels commonly used are “probable” and “possible”. Probable is described when a statement is more likely true than not (>50%), whereas possible is described when a hypothesis is demonstrated to be feasible but not declared probable. If two or more hypotheses are equally likely, then the level of certainty must be “possible”. If the level of certainty is “suspected”, the opinion does not qualify as an expert opinion.

Lastly, there are review procedures for all fire investigation reports. An administrative review is a review that is typically carried out within an organization to ensure that the investigators work product meets the quality assurance requirements. A technical review is a review by someone qualified and familiar with all aspects of proper fire investigation and should, at a minimum, have access to all of the documentation available to the investigator. A peer review is a review by someone who has no interest in the outcome of the review, thus the reviewer should not be a coworker or supervisor. All three types of reviews are important to the report and should be carried out if possible.

We are happy to announce our acquisition of the accident reconstruction software ARAS 360. ARAS 360 is a 3D accident reconstruction and diagramming software that can be used to produce animations and screen shots for court exhibits and demonstrations. Accident animation software is frequently used to demonstrate the opinion of an expert in the court of law and to provide a visual representation of his or her opinions that can been shown to the court and jury. In addition to acquiring the new software, Professor Rasty and Travis Wells both completed a 24-hour training course “ARAS 360 Advanced 3D Computer Diagramming for Crash Reconstruction” in San Angelo, Texas.

If you would like to learn more about our services feel free to CONTACT US TODAY.

Earlier this year, Pacific Gas and Electric Company (PG&E) submitted records for pressure tests or historical operating pressure on more than 90% of its 1,805 miles of natural gas transmission pipelines in high-consequence areas (HCA) to the California Public Utilities Commission (CPUC). PG&E also presented an aggressive inspection and field test plan that raised the bar on standards industry-wide. These actions occurred as a result of the San Bruno pipeline explosion that happened last year, killing 8 people and destroying 38 homes. According to reports, the catastrophic event was caused by a faulty seam weld pinpointed by the National Transportation Safety Board (NTSB).

PG&E’s inspection and field test plan included in-line inspections with “smart pigs” and new camera inspection technologies, as well as pressure testing and pipeline replacement. Recently, PG&E has taken a look inside a three-mile section of the same pipeline that exploded in San Bruno last year. A remote-controlled camera operates inside the 30-inch Line 132, where inspectors are looking for welding problems (incomplete seam welds), corrosion, and other signs of problems. This is part of PG&E’s efforts to test and possibly replace 150 miles worth of pipe similar to the San Bruno line.

The cameras are also being used to locate branding inside the pipe in order to determine who manufactured the pipe in order to validate the pipes’ safety as well as records on the pipes. Line 132 was installed in 1948, and was never examined inside after its placement. After the incident last year, PG&E discovered the pipe had multiple welded seems when records showed that it was “seamless”. Now, 150 miles of pipe with incomplete or faulty records will have to be tested in this same manner and most likely have to be replaced. The cameras being utilized are likely to identify faulty welds and seams.

The Los Angeles Times says the NTSB “findings suggested investigators are focusing on a weld failure as one cause of the disaster. But NTSB investigators declined to elaborate, saying their inquiry is still in the early stages, and a final report will not be completed until late next year.” In response to the NTSB report, PG&E said they’re researching pipe welding standards and practices from when the 30-inch PG&E transmission line was constructed, to better understand the variances found in welding patterns.

Excavation damage such as dents, gouges, and other physical indicators were not found on the pipe that failed, ruling out any kind of damage caused by excavating equipment. Also, it was reported that no signs of corrosion were found. Retired NTSB metallurgist Michael Marx “said most [pipeline] failures were traceable to corrosion or excavation damage…if you didn’t have either one of those, that means you had some kind of a bad manufacture of the pipe”.

Links:

http://articles.sfgate.com/2010-12-23/news/25297130_1_pipeline-safety-trust-pg-e-direct-assessment

http://mailview.custombriefings.com/mailview.aspx?m=2011052501nspe&r=4981106-904d&l=007-d2f&t=c

http://www.latimes.com/news/local/la-me-san-bruno-pipeline-20101215,0,7299885.story

A new crane safety rule that requires signalers to pass a written exam and riggers to be “qualified” has led to over 1,000 phone calls to OSHA with requests for clarification. The new rule is intended to raise standard for safety riggers, but employers are having trouble enforcing the standard because it is difficult to interpret. OSHA is working to help clarify the standard and is currently training field personnel on how to interpret them. Employers should be aware that despite the difficulties in interpretation, OSHA has already issued violations for noncompliance.

Related Links:

http://www.osha.gov/FedReg_osha_pdf/FED20100809.pdf

http://www.osha.gov/cranes-derricks/index.html

http://enr.construction.com/business_management/safety_health/2011/0516-EnforcingtheNewRule.asp

Safety regulators are investigating a fuel tank problem affecting over 2.7 million Ford F-150 pickup trucks. The National Highway Traffic Safety Administration is looking into trucks from the 1997-2001 model years and believes a recall is likely to result. Steel straps holding up the gas tank can rust and rupture leading to a fuel spill and potential fire. For more information see the links listed below.

Related Links:

http://www.insideline.com/ford/f-150/nhtsa-widens-probe-of-1997-2001-ford-f-150-trucks-to-27-million-units.html

http://consumerist.com/2011/05/nhtsa-investigating-27-million-ford-f-150s-for-potential-fuel-tank-problems.html

http://www.csmonitor.com/Business/Latest-News-Wires/2011/0510/Ford-F-150-dangerous-design-may-cause-recall-of-2.7-million-trucks

Video:

http://www.youtube.com/watch?v=95WP1kch604&feature=player_embedded

Hello, and welcome to our new website. We intend this website to grow into a valuable resource for both us and our clients. However, as with any new product we expect that some growing pains will be experienced. Should you notice any problems or experience any difficulties please let us know and we will do our best to address the issue.

We look forward to hearing from you,

-Travis