scholarly journals Lessons Learned from a Forensic Engineering Investigation of a Scaffold Support Failure

2021 ◽  
Vol 38 (1) ◽  
Author(s):  
John Schwartzberg
Keyword(s):  
Stress Analysis ◽  
Lessons Learned ◽  
Expert Opinions ◽  
Structural Capacity ◽  
Physical Testing ◽  
Fundamental Cause ◽  
Cause Of Failure ◽  
Forensic Engineering ◽  
Engineering Investigation ◽  
Metallurgical Evaluation

During use, a scaffold support allegedly failed, causing injuries to the user when he fell. The plaintiff’s expert identified a defective weld as the cause of failure and opined that the product was improperly designed. This paper examines methods used to evaluate the circumstances of and claims made regarding the incident. A combination of engineering methodologies, including metallurgical evaluation, stress analysis, and physical testing, was used to examine the plaintiff’s claims of deficiencies in the design and fabrication of the product. The engineering methodologies refute claims made about the structural capacity of the product by the plaintiff’s expert and the fundamental cause of failure. This paper examines themes related to the presence of apparent defects/failure and the necessity of verifying postulated hypotheses. It also examines the efficacy of analysis and testing as part of implementation of the “forensic engineering method” in verifying or rejecting hypotheses en route to offering expert opinions in forensic engineering investigations.

scholarly journals Forensic Engineering Investigation Of Sectional Ladder Treestand Failures

2013 ◽  
Vol 30 (2) ◽  
Author(s):  
Jahan Rasty
Keyword(s):  
Structural Strength ◽  
Standard Requirement ◽  
Root Cause ◽  
Section Modulus ◽  
Minimum Requirements ◽  
Cause Of Failure ◽  
Forensic Engineering ◽  
Trade Names ◽  
Testing Standards ◽  
Engineering Investigation

The Purpose Of This Forensic Engineering Investigation Was To Determine The Root-Cause Of Failure Of Three 15-Foot Sectional Ladder Treestands That Caused Injury To Users. All Three Treestands Were Identical In Design And Manufactured By The Same Company Despite Differences In Trade Names. Within A Reason-Able Degree Of Scientific And Engineering Certainty, It Was Concluded That Failure Of The Treestands Was The Result Of Overstressing The Star-Crimped Area Of The Treestands At Adjoining Ladder Sections. Overstressing Was Caused By A Designed Reduction In Section Modulus Of The Rail At Adjoining Ladder Sections. Further, The Load-Bearing Ability Of The Ladder Treestands Was Evaluated In Accordance With Com-Monly Accepted Engineering Principles For Metal Ladder Design (Ansi A14.2-2007). Analysis Revealed That The Structural Strength Of The Rail Section And Testing Standards For The Treestand Industry Are Lack-Ing When Compared To Portable Metal Ladders Designed For Identical Load Ratings. In Fact, The Treestands Failed To Meet The Standard Requirement For A Portable Metal Ladder Rated At 170-Pounds Even When The Treestand Was Tested At ½ Of Its Spanning Length (2-Sections). Comparisons Between The Treestands And Portable Metal Ladder Standards Indicated That The Treestands Failed To Meet Minimum And Generally Accepted Standards For Ladder Design And Suggested The Treestands Do Not Meet Minimum Requirements For Merchantability.

scholarly journals Forensic Engineering Investigation Of An Alleged Plastic Chair Failure

2010 ◽  
Vol 27 (2) ◽  
Author(s):  
John P. Leffler
Keyword(s):  
Standard Test ◽  
Test Method ◽  
Destructive Testing ◽  
Expert Opinions ◽  
Show Evidence ◽  
Forensic Engineering ◽  
The Subject ◽  
Residential Use ◽  
Engineering Investigation ◽  
The Chairs

Several Identical One-Piece Molded Plastic Chairs Were Purchased By A Mental Hospital For Use In An Outdoor Smoking Area. The Chairs Were Labeled As Being For Residential Use. A Hospital Patient Alleged That While Seated In One Of These Chairs, The Chair Failed And He Fell Backward, Striking His Head And Suffering Injury. The Subject Chair Did Not Show Evidence Of A Failure That Would Correlate To The Plaintiff Allegation. Analysis And Destructive Testing Was Conducted On Several Of The Remaining Chairs, Referencing The Astm Standard Test Method For Residential And Nonresidential Molded Plastic Chairs. Adverse Expert Opinions Were Also Addressed.

scholarly journals Forensic Engineering Investigation Of Failure Of An Oil Pipeline

2012 ◽  
Vol 29 (1) ◽  
Author(s):  
William R. Broz
Keyword(s):  
Contaminated Soil ◽  
Fuel Oil ◽  
Weld Repair ◽  
Butt Weld ◽  
Oil Pipeline ◽  
Weld Joints ◽  
General Contractor ◽  
Forensic Engineering ◽  
Engineering Investigation ◽  
Surrounding Soil

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.

scholarly journals Forensic Engineering Investigation Of Dezincification In A Major Corrosion Litigation

2013 ◽  
Vol 30 (1) ◽  
Author(s):  
Robert N. Anderson
Keyword(s):  
Zinc Content ◽  
Building Code ◽  
Insurance Companies ◽  
Urban Location ◽  
Home Owner ◽  
Plumbing Systems ◽  
Forensic Engineering ◽  
Low Strength ◽  
Engineering Investigation

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.

scholarly journals Forensic Engineering Investigation of Above-Ground Pool Submersion Accidents

2015 ◽  
Vol 32 (2) ◽  
Author(s):  
Richard Ziernicki ◽  
William H. Pierce
Keyword(s):  
United States ◽  
The United States ◽  
Swimming Pool ◽  
Consumer Product Safety Commission ◽  
Adult Supervision ◽  
Forensic Engineering ◽  
Product Defect ◽  
Engineering Investigation ◽  
Alternative Designs

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.

scholarly journals Forensic Engineering Investigation of a Fatal Farm Tractor Incident

2018 ◽  
Vol 35 (2) ◽  
Author(s):  
Daniel P. Couture
Keyword(s):  
Head Injuries ◽  
Field Tests ◽  
Cad Model ◽  
Small Farm ◽  
Sequence Of Events ◽  
Farm Tractor ◽  
Parking Brake ◽  
Forensic Engineering ◽  
Engineering Investigation

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.

scholarly journals A Forensic Engineering Investigation Of a Ladder Failure

2009 ◽  
Vol 26 (2) ◽  
Author(s):  
Nicholas A. Petrucci
Keyword(s):  
Load Capacity ◽  
National Standards ◽  
Shear Load ◽  
Improper Use ◽  
Forensic Engineering ◽  
Left Front ◽  
Engineering Investigation

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.

scholarly journals Forensic Engineering And The Scientific Method

2009 ◽  
Vol 26 (1) ◽  
Author(s):  
Laura L. Liptai
Keyword(s):  
Scientific Method ◽  
Knowledge Engineering ◽  
Analytical Framework ◽  
Education Experience ◽  
Forensic Engineering ◽  
Investigative Technique ◽  
Ultimate Objective ◽  
Definition Of ◽  
Prevention Methods ◽  
Engineering Investigation

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.

scholarly journals Forensic Engineering Investigation Of a Long Span Wooden Truss Failure during Erection

2009 ◽  
Vol 26 (2) ◽  
Author(s):  
Ross Curtis
Keyword(s):  
Shared Responsibility ◽  
Convenience Store ◽  
Long Span ◽  
Forensic Engineering ◽  
Number Of Parties ◽  
Engineering Investigation

With About One Third Of The Long Span Wood Trusses In Place For A 60 By 100 Building Being Constructed As A Convenience Store, The Trusses Already Erected Fell Over Like Dominos Injuring Three Laborers.He Three Workers Sued A Number Of Parties Involved In The Project Including The Crane Rental Companynd The Manufacturer And Supplier Of The Trusses, Claiming That They Shared Responsibility For The Accidentnd That They Should Have Taken Action To Prevent The Collapse. The Author Was Retained As An Expert Witnessor The Crane Rental Company. Investigation And Analysis Of Available Facts Established That The Craneental Company Was Not Responsible And Should Have Had No Liability.

Sign in / Sign up

Export Citation Format

Share Document