Journal of the National Academy of Forensic Engineers https://journal.nafe.org/ojs/index.php/nafe <p>The JOURNAL OF THE NATIONAL ACADEMY OF FORENSIC ENGINEERS is intended to provide a means for the Associate Members, Members, Senior Members, Fellows and Affiliates of NAFE to present case studies and principled discussion of the application of their specific technologies in the practice of forensic engineering.</p> <p>A concise abstract of 100 to 150 words maximum shall be sent to the Manuscript Editor for initial consideration. Upon approval of the abstract, authors will be scheduled to present their work at one of the semi-yearly NAFE Technical Conferences. A 90% complete draft copy of the manuscript shall be submitted to the assigned Associate Editor for review and approval no later than 60 days before the conference. Presentation slides are due 45 days before the conference.</p> <p>For details about requirements for manuscripts, visit:<br /><a title="NAFE Journal Contents" href="https://www.nafe.org/assets/Journal/JournalContents.pdf">NAFE Journal Contents</a></p> <p>For details on the NAFE Journal peer review process, visit:<br /><a title="NAFE Peer Review Process" href="https://www.nafe.org/assets/Journal/NAFEPeerReviewProcess030719.pdf">NAFE Peer Review Process</a></p> <p>For the NAFE Bylaws content “Responsibilities of, Obligations of and Guidelines for Authors, the Journal Editor, Technical Review Committee Chair, and Technical Reviewers,” visit:<br /><a title="NAFE Author Guidelines" href="https://www.nafe.org/assets/docs/journalguidelines.pdf">NAFE Author Guidelines</a></p> <p>The Journal of the National Academy of Forensic Engineers® contains papers that have been accepted by NAFE. In most cases, papers have been presented at NAFE seminars. Members and Affiliates receive a PDF download of the Journal as part of their annual dues. All Journal papers may be individually downloaded from the NAFE website at www.nafe.org. There is no charge to NAFE Members &amp; Affiliates. A limited supply of Volume 33 and earlier hardcopy Journals (black &amp; white) are available. The costs are as follows: $15.00 for NAFE Members and Affiliates; $30.00 for members of the NSPE not included in NAFE membership; $45.00 for all others. Requests should be sent to Mary Ann Cannon, Executive Secretary, NAFE, 1420 King St., Alexandria, VA 22314-2794.</p> <p>Comments by Readers<br />Comments by readers are invited, and, if deemed appropriate, will be published. Send to: Mary Ann Cannon, Executive Secretary, 1420 King St., Alexandria, VA 22314-2794. Comments can also be sent via email to journal@nafe.org.</p> <p>Material published in this Journal, including all interpretations and conclusions contained in papers, articles, and presentations, are those of the specific author or authors and do not necessarily represent the view of the National Academy of Forensic Engineers® (NAFE) or its members.</p> <p>© 2020 National Academy of Forensic Engineers® (NAFE). ISSN: 2379-3252</p> National Academy of Forensic Engineers en-US Journal of the National Academy of Forensic Engineers 2379-3244 <p>In connection with my efforts as a presenter at any NAFE educational program and/or as an author of a NAFE Journal article, I may have occasion to perform tasks and activities which could be determined to constitute authorship under applicable copyright laws. It is my express intent never to exercise any intellectual property right in any NAFE document or publication, whether in final or draft form. With regard to any intellectual property I provide to NAFE, I hereby warrant that (1) I am the author of such work or that I have secured written consent for use of any portions of the work copyrighted by others and (2) to the best of my knowledge, the work does not violate or infringe the copyright or other personal property rights of others.</p> <p>I hereby acknowledge that my participation in NAFE activities provides me with substantial and valuable benefits, including access to current and revised forensic engineering content, discussion of existing and emerging legal and forensic principles, concepts and trends, and the opportunity to review forensic engineering information prior to its dissemination to the broader engineering community.</p> <p>Accordingly, for and in consideration of the foregoing, I hereby bargain, sell and irrevocably assign to the National Academy of Forensic Engineering (NAFE), all of my right, title and interest, property claim, and demand of every kind and nature whatever in any and all copyrights (including full and exclusive worldwide ownership of the copyright, and all of the rights comprised therein, in print and in all other media), under and by virtue of any acts of Congress, with the rights to any and all profits, benefits and advantage that may arise from printing, publishing or sale of printed copies, electronic versions or other media assigned to the NAFE.</p> FE Evaluation of Hillside Excavation for a Construction Contract Dispute https://journal.nafe.org/ojs/index.php/nafe/article/view/121 <p><em>This paper presents a forensic evaluation of an earthwork grading dispute between a grading contractor (plaintiff) and property owner (defendant) associated with construction of an approach driveway and hill-side cut for a new residential property. The plaintiff’s allegations were that “changed conditions” had been encountered through the presence of a landslide and/or geologic fault. These conditions resulted in schedule delays and increased costs. Finally, the plaintiff alleged breach of contract after being terminated. The allega-tions were investigated through both on-site field reconnaissance and desktop studies. The forensic analyses found no basis for the changed conditions claims. The case was tried in Napa County California Superior Courts via bench trial. The judge’s decision mirrored the findings of the forensic analyses.</em></p> Rune Storesund Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1 Forensic Engineering Analysis of Common Failures and Inspection Procedures for Residential and Commercial Chairs https://journal.nafe.org/ojs/index.php/nafe/article/view/105 <p><em>Chairs have been designed, manufactured, and used by humans for thousands of years. Eventually, all chairs wear out and fail. When someone is injured due to this failure, costly litigation can ensue. Forensic engineers are consulted to investigate the root cause of failure, and whether the mechanism of failure could have been detected prior to the accident to avoid injury. Materials used in chair manufacturing and several examples of failures are discussed in this paper. Industry safety standards and manufacturers’ guidelines are used as a basis for a proposed inspection and maintenance program for chair owners.</em></p> Anthony Sasso Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1 Dynamic Motion Simulation: Applications in Forensic Engineering https://journal.nafe.org/ojs/index.php/nafe/article/view/140 <p><em>A worker was injured when a large sculpture overturned while it was being transferred on a wheeled cart from a delivery truck onto a dock lift. This paper introduces the use of dynamic motion simulation (DMS) soft-ware as a forensic engineering tool for analyzing and simulating motion/contact between multiple interacting physical objects. Important inputs to the software include the mass properties of the objects — in this case, a very irregularly shaped sculpture. For simple shapes, the distribution of mass can easily be approximated by manually discretizing the object into several smaller, simpler shapes. Accurate determination of the mass dis-tribution of an irregular shape (such as a sculpture) can be aided by measurement methods such as the laser scanning process used in this case. The resulting scan data was used to create a 3-D computer model that was processed using conventional mechanical computer-aided design (CAD) and DMS software to determine the mass properties and ultimately to simulate the dynamic motion.</em></p> Mark Webster Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1 Forensic Engineering Investigation into Factors Contributing to Explosion of a Consumer-Grade Tabletop Torch https://journal.nafe.org/ojs/index.php/nafe/article/view/151 <p><em>In early 2013, approximately 3,500 consumer-grade tabletop torches, designed for use with citronella oil to ward off insects, were sold by a retailer. Within six months of their debut, 22 of these products experi-enced sudden explosions, resulting in one fatality and 21 severe burn injuries to consumers. The author was retained as an expert in the fatal explosion case to determine the root cause(s) that led to these explosions. This paper will describe the detailed, experimental-based investigation that was carried out to reveal design, manufacturing, and marketing defects for which the designer of the torch, the manufacturer of the fuel, and the retailer of the final product were responsible. It was determined that the explosions occurred as a result of a “perfect storm” scenario that involved defective product design, defective marketing of the product through the sale of incompatible fuel by the retailer, and deficient warning instructions by the manufacturer.</em></p> Jahan Rasty Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1 Forensic Engineering Analysis of Upper Extremity Nerve Entrapment Injury Mechanisms as Related to Rear-End Collisions https://journal.nafe.org/ojs/index.php/nafe/article/view/142 <p><em>Nerve entrapments of the median nerve, i.e., carpal tunnel syndrome (CTS) and the ulnar nerve, i.e., cu-bital syndrome (CT) are relatively common, reflecting traumatic and atraumatic mechanisms. Claims of such injuries in relation to rear-end collisions (particularly low-velocity or &lt; 10 mph collisions) are often contested by the defense, acknowledging that there is no obvious relationship between the collision and the claimed inju-ries. Of the collision types (frontal, side, rear-end), it is the least clear how a rear-end collision can establish mechanisms for such injuries. Direct blunt trauma to the carpal tunnel region or the cubital tunnel region are unlikely in a rear-end collision. Also, “stretch” injuries due to hypermotion of either the wrist or elbow are unlikely, reflecting occupant kinematics, vehicle interior geometry, and other factors. A case study involving CTS and CT claims as a result of a low-velocity rear-end collision will be presented.</em></p> William Lee Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1 Forensic Engineering Investigation of a Furnace Oil Supply Line Fitting Leak https://journal.nafe.org/ojs/index.php/nafe/article/view/136 <p><em>A basement oil leak was reported to a service company, which immediately replaced a supply line SAE 37° fitting body while leaving the flared copper lines in place. An environmental remediation claim was later made against this service company, alleging improper installation of new supply lines within the prior year. Fuel delivery records and heating degree day records were analyzed, revealing a consumption rate discrep-ancy versus the homeowner’s narrative. An experimental apparatus was designed to evaluate leak rates for flared fittings in tightened and partially loosened states. The modeled expected consumption rate results inferred tampering with the fittings several days prior to the leak report. The experimental technique and consumption rate analysis withstood a Daubert challenge for relevance at the mediation conference.</em></p> Daniel P Couture Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1 Forensic Engineering Analysis of the Alleged Failure of an Emergency Vehicle Traffic Light Preemption System https://journal.nafe.org/ojs/index.php/nafe/article/view/108 <p><em>This case involved a fatal collision between a police vehicle (operated by a police officer) and a non-police vehicle (operated by a civilian). With lights and sirens activated, the officer in pursuit ran a red light and crashed into the civilian’s vehicle in an intersection whose traffic light controller included an emergency vehicle preemption system. The civilian driver was mortally injured, and died the next day. The estate of the deceased driver sued the police officer, municipal police department, and manufacturer of the emergency vehicle preemption system. The author was retained by counsel for the estate of the deceased to assist in the case against the manufacturer of the emergency vehicle preemption system and municipality. The evidence showed that the preemption system was working properly, but that the system’s confirmation lights had been improperly programmed. A maximum speed was calculated at which a preempted green light for emergency drivers would be assured. Event logs in the police vehicle showed that the police officer was driving too fast for the traffic light controller to cycle through its sequence before the officer reached the intersection.</em></p> Robert Peruzzi Copyright (c) 2020 Journal of the National Academy of Forensic Engineers 2020-08-18 2020-08-18 36 1