Forensic Engineering Investigation of Electrical and Electronic Causes of an Industrial Equipment Failure

This case involved industrial equipment whose repeated, seemingly random failures resulted in the buyer of that equipment suing the seller. The failures had been isolated to a group of several transistors within electro-mechanical modules within the equipment, but the root cause of those transistors failing had not been determined. The equipment seller had more than 1,000 units in the field with no similar failures. And the electro-mechanical module manufacturer had more than 20,000 units in the field with no similar failures. Electrical contractors hired by the buyer had measured power quality, and reported no faults found in the three-phase power at the equipment terminals. This paper presents circuit analyses of the failing electro-mechanical module, basics of electrostatic discharge damage and protection, and the root cause of these failures — an electrical code-violating extraneous neutral-to-ground bond in a secondary power cabinet.

Forensic Engineering Analysis Of Golf Course Cart Club And Ball Accidents

With Over 27.8 Million Golfers And More Than 16,000 Golf Facilities In The United States, Golf Is A Non-Contact Sport With Statistically Low Risk For Injury. However, Research Has Documented Golf Related Injuries Can Be Disproportionally Serious Or Even Fatal. Federal Regulations And Countermeasures To Improve Golf Safety Are Outlined. A Spectrum Of Forensic Engineering Analysis Of Golf-Related Incidents Illustrates The Broad Range Of Resulting Trauma. Categories Of Golf Incidents Include: Cart Collisions With Other Vehicles Resulting From Mixed Use On Automotive Roadways, Cart Solo Incidents Including Ejection With And Without Rollover, Errant Golf Ball Impacts, Inadvertent Golf Club Impacts, Trip And Fall Incidents As Well As Golf Cart Fires.

Computer Fire Modeling and the Law: Application to Forensic Fire Engineering Investigations

Computer fire modeling can be a two-edged tool in forensic fire engineering investigations. Professional standards of care recommend that fire modeling’s primary use is in examining multiple hypotheses for a fire as opposed to determining its origin. This paper covers the current acceptable benefits of computer fire models, historical and pending legal case law, and methods to use modeling results within expert reports and testimony. Particular issues reviewed are the use of animations versus simulations, evidentiary guidelines, and authentication using verification and validation studies.

Ergonomics and Forensic Engineering

In disputes, forensic engineers routinely investigate available hardware and software and may examine other engineering attributes and activities. Human factors and ergonomic (HF&E) aspects may be considered, but these tend to be more limited or overlooked. This paper discusses an HF&E framework for forensic analysis, including its four major subdisciplines (micro-, meso-, macro-, and mega-ergonomics), the role each plays throughout the product life cycle, and examines their relationship to known and foreseeable use and misuse of a product or system. A taxonomy of errors, including distinguishing features of individual user errors versus system use errors, is presented and then used in a diagnostic rubric developed for forensic engineers to help identify HF&E issues as part of a forensic analysis. A health care setting case study is offered to demonstrate rubric use, but the rubric is generalizable to other domains.

Applications of Matchmoving for Forensic Video Analysis of a Fatal Sprint Car Accident: Part II

This paper presents the application of the photogrammetric process known as matchmoving to analyze a racetrack video and reconstruction of a fatal Sprint Car race accident. The use of high-definition 3D laser scanning technology made it possible to accurately perform the matchmoving process on racetrack video footage to determine the path, heading, speed, and acceleration of the involved Sprint Cars. In addition to the accident racetrack, another video of a Sprint Car race on a similar racetrack, taken by a drone, was also analyzed using the same matchmoving method to evaluate the speed and yaw angle of a drifting Sprint Car.

Applications of Matchmoving for Forensic Video Analysis of a Fatal Sprint Car Accident: Part I

The methodology used for the reconstruction of a high-profile Sprint Car accident that was captured by at least three different video recording devices is presented in two parts. Part I discusses a classical method of an accident reconstruction, and Part II discusses matchmoving technique to accurately analyze the video footage of the accident. Accidents captured on video are unlike most simple car collision evaluations and require expert knowledge from experienced professionals. Understanding the race car vehicle dynamics as it relates to recorded video footage allows a proper methodology to be followed in order to gather and process the evidence needed to provide meaningful data to the trier of fact. This paper discusses the classical process to reconstruct the accident as well as the currently acceptable scientific methodologies that were used to collect and interpolate the available scientific evidence. A visualization of the vehicles involved, Sprint Car #13 (SC#13) and Sprint Car #14 (SC#14), is shown in Figure 1.

Forensic Engineering Analysis of Video Screens for a Dispute Over Requirements and Specifications

This case was about LCD video screens intended to become components of medical equipment requiring an ultra-wide viewing angle. The seller was a wholesaler of various types of video screens from multiple manufacturers. The buyer was a distributor of multiple electrical components for various industries. The OEM, not involved in the case, was a manufacturer of medical instruments and equipment. Claiming that multiple units did not meet the requirements specified in the purchase agreement, the OEM refused a shipment of 1,000 LCD video screens. The buyer had already paid the seller, who refused to take back the shipment and issue a refund or credit. As a result, the buyer sued seller, and the author investigated and submitted expert opinions regarding the following questions: Did performance differ between examined samples? Did each sample meet data sheet specification for viewing angle? And was each sample adequate for its intended application as advertised in the datasheet (that is, for industrial settings requiring ultra-wide viewing angle)?

FE Analysis of Communications Systems for Drive-Thru Restaurants in a Business Dispute Over Specifications and Design Process

Forensic analysis in this case involves the design of a communication system intended for use in Quick Service Restaurant (QSR) drive-thru lanes. This paper provides an overview of QSR communication system components and operation and introduces communication systems and channels. This paper provides an overview of non-linear, time-varying system design as contrasted with linear, time-invariant systems and discusses best design practices. It also provides the details of how audio quality was defined and compared for two potentially competing systems. Conclusions include that one of the systems was clearly inferior to the other — mainly due to not following design techniques that were available at the time of the project.

Chemical Incident Analysis Involving Storage of Fertilizer Product

A forensic engineering analyses of a chemical incident is presented that was classified as a self-sustaining decomposition (SSD) event, which occurred in a load of 10,000 tons of NK 21-00-21 fertilizer bulk stored inside a warehouse in the city of São Francisco do Sul in Brazil. The chemical reaction developed within the fertilizer mass and took several days to be controlled, resulting in the evacuation of thousands of residents. The water used to fight against the reaction, after having contact with the load of fertilizer material, promoted changes in adjacent water bodies, causing the death of animals (fish, crustaceans, and amphibians). The smoke from the chemical reaction products damaged the incident’s surrounding vegetation. Large SSD events are rare, with an average worldwide frequency of one every three years. Therefore, in addition to presenting a case study of this type of phenomenon, the main objective of this work is to discuss the causes that led to SSD reaction at this event, evaluate its consequences, and motivate future studies.

State of the Arc (Mapping)

NFPA 921 Guide for Fire and Explosion Investigations considers the technique arc mapping to be one of the methodologies used in isolating a fire’s origin and spread. Provided the technique is used properly and understanding its limitations, it is a tool for investigators. Synthesized here is the latest peer-reviewed research and discussions on the implications of increased use of ground- and arc-fault circuit interrupters on arc mapping analysis. Incorporated are case studies and evaluations of recent legal decisions. The goal is to arm investigators with what’s needed to maximize the arc mapping’s efficacy and best present its use and results.