Expertly Speaking

Swimming Pool

Hotel Pool Channel Proves Dangerous

Tom Griffiths, Ed.D., Aquatic Safety Expert

Several years ago, hotels began constructing indoor/outdoor pools with a connecting “swim-through” channel so that guests could swim from the indoor pool, through a channel into the outdoor pool. While this concept was unique, interesting, and attractive, it had several significant design flaws. Most important to this case, when built in the northern climates above the Mason-Dixon line, during the winter months the cold water in the outdoor pool would infiltrate and chill the water in the indoor pool through the channel. Because both pools were connected, and on the same circulation system, one pool could not be drained without draining the other.

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Rock Climbing Expert Witness

The Humpty-Dumpty Effect

Thomas Cocchiola, P.E., CSP, Mechanical Engineer

Case Synopsis: A school purchased a portable rock-climbing wall for summer camp sessions. For safety purposes, a belay rope is typically used to prevent climbers from slipping and falling. Most rock walls require a partner to hold a belay rope for each climber, but the manufacturer equipped the subject rock wall with an automatic belay fall protection system that eliminated the need for climbing partners.

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Autonomous Vehicles

Waymo Technology Safer than Human Drivers?

Justin P. Schorr, Ph.D., Principal Collision Reconstruction Engineer

Waymo internally develops, funds, conducts, publishes, and peer-reviews its own internal study which shockingly reaffirms their long and deeply held belief that their technology is safer than human drivers.

Waymo, LLC. published a March 8, 2021 paper titled Waymo Simulated Driving Behavior in Reconstructed Fatal Crashes within an Autonomous Vehicle Operating Domain.  The paper was authored by six employees of Waymo, LLC.  As a company, Waymo has boasted about their safety record for years and, more recently, has been developing creative ways to showcase what they believe to be dominance of their self-driving systems over us humans.

The paper is pointless.  The study is designed such that achievement of the expected outcome was obvious and inevitable.  Briefly, the study collected police data for 117 fatal collisions occurring over a 10-year period in Arizona.  Admittedly, limited data was available to reconstruct the details of how these collisions occurred.  Of these 117 collisions, only 72 were included in the data set used for analysis.  Researchers identified 91 “vehicle actors” in the 72 collisions – 52 initiators and 39 responders (initiators being when the assumed actions of a human driver initiated the collision sequence and responders being the assumed actions, or inactions, of a human driver in responding to the actions of an initiator).  The human driver was then “replaced” with the Waymo self-driving technology in a simulation framework and the scenario was “re-run” with the tech in control.  The outcomes were recorded and voila Waymo proved their technology is better than human drivers!

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cell phone technology ruling

Mobile Application Privacy: Apple Reveals User Data Collected

Timothy R. Primrose, Mobile Forensic Analyst

Apple has provided users with a simple way to review data retained when particular applications are utilized. The recent release of iOS 14.3 allows users to access privacy information from respective application privacy pages on the App Store. In addition to descriptions, pictures, and reviews, some transparency as to what user information is gathered during app-use is now available.

Many popular applications retain an alarming amount of information that is either linked to the user or used to track the user. For example, Facebook’s product page on the App Store has a long list of the data they collect from app users, broken down by purpose. If data is collected for third-party advertising, there is a specific list of what datatypes are collected for this purpose. There are 12 categories of datatypes that Facebook collects for third-party advertising. These lists can look rather long; however, some of these datatypes, such as financial information, are collected once and distributed to multiple purposes.

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Airbag Deploy

To Deploy or Not to Deploy – That is the Dilemma

Robert T. Lynch, P.E., Principal Collision Reconstruction Engineer

The purpose of an airbag in a vehicle is to offer an increased level of protection to occupants in a crash. To be able to do this the airbag needs to deploy in crashes where added protection is needed, but not to deploy in crashes when the risk to the occupant would outweigh the benefit. Generally frontal airbags will deploy if the Delta-V, or change in velocity of the vehicle, exceeds 8-14 miles-per-hour (MPH). However, there are scenarios when airbags have deployed in collisions where the Delta-V was less than 8 MPH, or airbags did not deploy in collisions where the Delta-V was above 14 MPH. In these latter instances, a claim for failure to deploy is often made by an injured party.

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Dealer or Buyer: Who Controls the Used Vehicle?

R. Scott King, BSME, CFEI, Principal Automotive/Mechanical Engineer

Are you in the market for a used vehicle? If so, and if you’re thinking of financing that purchase, you may want to continue reading. What you learn here could stop you in your tracks.

In lecturing and authoring on the topic of onboard crash data recording technology for over twenty years, I have come to learn that many people simply do not welcome the concept of their vehicle recording and storing data describing their driving habits and actions – the “Big Brother Bristle,” I have come to call it. However, more recent vehicle technologies do nothing to assuage those concerns. This is because most new vehicles can now facilitate two-way, remote communications between the vehicle and, frankly, anyone that’s listening.

Telematics: In very broad terms relates to the ability for onboard vehicle technologies to send and receive data anywhere, anytime. First used routinely by trucking companies to assist with GPS routing, load procurement, and driver communications, telematics provided improved efficiencies, safety, and customer satisfaction. Although originally installed as after-market solutions, truck chassis manufacturers soon incorporated telematics into their original build configurations, providing new opportunities for real-time vehicle diagnostics, crash data transmission, and more. Since then, the use of telematics has expanded into the passenger vehicle segment, providing similar capabilities, among the most remarkable of them is the ability to control a vehicle remotely.

GM’s OnStar system provided the first mass-produced “telematically controlled” vehicle. To be precise, the potential control that the OnStar system had on a vehicle was limited. Specifically, the system could limit a vehicle’s speed by taking control of its computerized fuel and ignition systems. The benefit here was for law enforcement, assisting with stolen vehicle investigations and child abductions. Most recently, however, used vehicle finance companies have begun using telematic technology to help combat payment delinquency and loan defaults. Here is how it works:

A used vehicle is purchased and financed, typically by subprime lender. As part of the finance agreement, the purchaser consents to the installation of a telematic device that can not only track and pinpoint the vehicle’s location but can disable its starter as well. Systems vary on functionality. For example, most vehicles provide warnings of varying duration, and the scope and resolution of GPS data collected can vary. However, those are the essentials: default on a loan and the car will not start. Where and when a planned disablement occurs is not certain nor is the workmanship involved in the system’s installation. Deficiencies in either could lead to unintended consequences and unique forensic investigative strategies can be deployed to evaluate their potential relevance to a specific circumstance.

R. Scott King, BSME, CFEI, Principal Automotive/Mechanical Engineer with DJS Associates, Inc., can be reached via email at or via phone at 215-659-2010.

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