scholarly journals Forensic Engineering Investigation of a Pipe Joint Tester Explosion

Author(s):  
William Keefe

A construction laborer was killed while operating a pipe joint tester, which was used to test joints between sections of newly installed sewer pipe. The joint tester contained a donut-shaped rubber bladder, which was inflated with compressed air to seal against the inside of the pipe joint during the test. During a pipe joint test, the pipe joint tester bladder exploded without warning. The joint tester operator was fatally injured when he was struck by pipe joint tester components and the air blast. A forensic engineering investigation was conducted to determine the role of the design and construction of the pipe joint tester in the cause of the incident.

Author(s):  
Richard Ziernicki ◽  
William H. Pierce

In the United States, approximately 35 children under the age of five years old drown each year after access-ing above-ground pools via pool ladders. Consumer Product Safety Commission (CPSC) data also shows that approximately 486 additional children sustain submersion-related injuries after accessing above-ground pools via pool ladders. In many cases, these events occurred during brief lapses of adult supervision. This paper fo-cuses on potential product defect issues related to child submersion accidents, including the role of user manuals, alternative designs, warnings, instructions, and child behavior testing. The authors examine the issues related to the investigation of above-ground swimming pool submersion accidents. In addition, procedures and steps are outlined that may be useful in analyzing whether the swimming pool is defective and unreasonably dangerous.


Author(s):  
William R. Broz

A Below-Grade, Nps 12 Pipeline Serving A Major Commercial Marine Terminal Failed At A Flanged Joint, Causing A Major Leak And Contamination Of The Surrounding Soil. The Gasket At The Failed Joint Showed Evidence Of Localized, Radial Through-Leakage. At The Terminal, The Initial Excavation Of Contaminated Soil Caused Minor Damage To Several Non-Leaking Segments Of Pipe And The Author Was First Tasked To Oversee The Related Inspection, Weld Repair And Corrosion Protection Work. The Author Subsequently Performed A Forensic Pipe Stress Analysis Of The Affected Portion Of The Fuel Oil System Per The Governing Pressure Piping Code. The Results Indicated That The Leaking Joint Failed With Respect To The Code Criterion Of Equivalent Pressure. Further Investigation Revealed That The System As Originally Designed Was Entirely Of Butt Weld Construction With No Flanged Joints, And Would Have Complied With All Code Requirements. The Investigation Determined That The General Contractor Had Made An Unauthorized Substitution Of Flanged Joints For Butt Weld Joints, Without Informing The Owner Or Design Engineer Of Record.


Author(s):  
Robert N. Anderson

Zinc-Rich Brasses With The Zinc Content Above 30% Can Be Involved In Corrosion Processes With Catastrophic Results. The Dezincification Results In A Low Strength Copper With A Porous Sponge Like Structure. The Case, Where Dezincification Occurred With Massive Impact, Involved 34,000 New Homes In An Urban Location In Nevada. These Homes Were Constructed Using Building Code Approved Plastic Pex Tubing For Plumbing With Brass Fittings. Leaks Developed In The Home Plumbing Systems After Approximately 3-6 Years. This Failure Resulted In Lawsuits Involving Home Owner Associations, Insurance Companies, Contractors, Plumbers, Architects, Manufacturers, And Suppliers.


Author(s):  
Richard M. Ziernicki

This paper outlines the legal system in the United States, the different types of courts, the differences between criminal and civil law, and the role of forensic engineering experts involved in civil lawsuits. After providing a summary of relevant procedures employed by civil and criminal courts, the paper describes the basic principles and requirements for the selection and work of a forensic engineering expert in both the state and federal court system. This paper outlines the role and function of forensic experts (specifically forensic engineers), in the United States court system. It is not a treatise on the legal system but on the role of experts. The paper presents the requirements typically used in today’s legal system to qualify a forensic engineer as an expert witness and to accept his or her work and opinions. Furthermore, this paper discusses who can be an expert witness, the expert’s report, applicable standards, conducted research, engineering opinions, and final testimony in court — and how those elements fit into the legal system. Lastly, the paper describes the concept of spoliation of evidence.


Author(s):  
Daniel P. Couture

A farm owner was found unresponsive with crushing head injuries on his property in rural Ontario. His small farm tractor was found 60 meters away down a small incline with the engine running and transmission in neutral. The owner’s son alleged that when the parking brake was engaged (with the engine running and transmission in neutral), this tractor’s parking brake would “pop out,” allowing the tractor to move. Field tests were conducted on the tractor to attempt to duplicate the scenario and to determine if the alleged sequence of events was plausible. Components of the parking brake and one exemplar were assessed with specialized metrology to determine whether they were within the manufacturing specifications on the blueprint. A 3-D CAD model of fit was created, and several variances were identified between the parts and the factory drawing. The results of the analysis concurred with the scenario that these variances led to the disengagement of the parking brake and operator fatality.


Author(s):  
Nicholas A. Petrucci

A Worker (Plaintiff) Fell From A Step-Ladder And Was Injured. The Purpose Of The Forensic Engineering Investigation Was To Determine The Cause(S) Of The Incident, And In Particular, If The Incident Was Caused By A Ladder Defect. The Incident Ladder And A Representative Incident Scene Were Inspected. Various Discovery Documents And The Applicable American National Standards Institute (Ansi) Standard Were Reviewed. A Critique From The Opposing (Defendant) Expert Is Presented And Addressed. The Cause Of The Plaintiff Fall From The Ladder Was Determined To Be Its Sudden Instability Due To The Failure Of A Rivet That Secured The Top Cap To The Left-Front Rail. The Failed Rivet Was Not Recovered. Further Analysis Indicated That The Cause Of The Rivet Failure Was Its Defective Design Coupled With Its Reduction In Shear Load Capacity From Normal And Improper Use Of The Ladder. The Determination Of The Defective Design Of The Rivet Was Confirmed By Subsequent Design Improvements Of The Ladder. The Relevance Of The Analysis Performed Is Discussed. Various Noteworthy Points Are Presented For Consideration For Forensic Engineers Of Various Technical Disciplines.


Author(s):  
Laura L. Liptai

The Scientific Method Is Utilized In Order To Understand The Relationship Among Observations Of Physical Phenomena, While Minimizing The Influence Of Human Bias And Maximizing Objectivity. Specific Procedures For The Application Of The Scientific Method Vary From One Field Of Science To Another, But The Investigative Technique Universally Provides For An Analytical Framework To Acquire, Collect And/Or Integrate Knowledge. Engineering Forensics Involves The Analysis Of The Parameters Or Cause(S) Of Incidents Or Failures And/Or Hypothetical Prevention Methods. Engineering Analysis Of Forensic Problems Is A Multifaceted, Multidisciplinary Pursuit That Is Often Wide In Scope. Forensic Engineering Generally Applies Existing Science In Conjunction With The Knowledge, Education, Experience, Training And Skill Of The Practitioner To Seek Solution(S). The Scientific Method, Including Definition Of A Null Hypothesis, Is Rarely Utilized In Forensics As New Science Is Rarely Required. A Forensic Engineering Investigation Typically Involves The Application Of Long Established Science (Newtons Laws, For Example). Forensic Engineering Encompasses The Systematic Search For Knowledge Necessitating The Observation And Definition Of A Problem; The Collection Of Data Through Observation, Research, Experimentation And/Or Calculation; The Analysis Of Data; And The Development And Evaluation Of Findings And Opinions. The Ultimate Objective Of A Forensic Engineering Investigation Is Uncompromised Data Collection And Systematically Considered, Iteratively Derived And Objectively Balanced Conclusions.


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