Forensic Engineers and Consultants

Tag Archive: The Warren Group

  1. Staying Connected on the Loop: Two by Two’s Mobile Internet Setup

    Leave a Comment

    After completing the sit-stand workstation in the guest stateroom of our 47’ Nova Scotia pilothouse trawler, Two by Two, that I reported in a previous blog, I found I needed an internet connection with reasonable speed and reliability.  While almost every marina will give you a password for their WiFi, the quality of most marina connections is unreliable and too slow to effectively work as a forensic engineering consultant. When I tried to download a simple photograph through any type of remote connection to the Irmo, SC office, I could go make a cup of coffee and come back before the download finished.  To upload a group of photographs from my camera to the server back in the office was simply not practicable. The same was true for transferring large documents.

    At first, I purchased a Verizon MiFi Mobile Hotspot with an unlimited data plan. The MiFi had two problems: once the battery was charged, a message on the MiFi recommended that you unplug the charger. The MiFi ran well unplugged, but later I would realize I had no internet connection because the MiFi battery needed a recharge. After 24 GB of data usage, the Verizon Unlimited Plan throttled to a speed so slow that no significant activity could be performed until the beginning of the next month.

    To solve these problems, I began researching how to stay connected. I became a member of the RV Mobile Internet Resource Center and signed up for their Mobile Internet Interactive Video Course.  It cost $65 to become a member and $129 to take the online video course. I found their course and published information very informative. The discounts they had arranged with the supplier of the router and cellular antenna I ultimately purchased almost paid for the course.

    Because of my work with The Warren Group, I consider myself a serious mobile worker. I concluded that cellular was the most cost effective and reliable way to stay connected. I need to transfer file materials between the boat and the office. After I perform an accident scene site inspection, I upload photographs to The Warren Group’s server where they are stored and backed up. I also download large quantities of documents that clients send through Dropbox or similar services. I connect to the server to record my time, obtain documents from our company library and work with other engineers and our administrative coordinator to prepare and submit reports to clients. Finally, I need to send and receive emails.

    In the boating world, we also download updated navigation charts and update software for our Garmin navigation equipment and our Coastal Explorer computer software. We also stream TV through our internet connection.

    The Pepwave MAX Transit DUO Modem LTE-Advance Mobile Router. I hardwired the power supply to the router and also connected a LAN cable directly from the router to my docking station at the sit-stand desk in the guest stateroom.

    Having decided on cellular, I ordered and installed a Pepwave MAX Transit DUO Dual Modem LTE-Advance Mobile Router. The Transit DUO has a dual modem configuration allowing for two simultaneous cellular connections. The unit can connect with AT&T, Verizon, Sprint, and T-Mobile. With simultaneous dual band WiFi, I can setup multiple networks for 2GHz (range) and 5GHz (speed) within the boat to optimize and load balance connected devices based on need. Thanks to automatic failover switching and multiple SIM card slots with multi-carrier support, this device allows me to always connect if cellular coverage is available. This router will allow 1 to 100 devices to connect to it. With two embedded modems we can utilize two cellular connections at the same time with immediate failover from one provider to another as well as the additional 2 SIM cards. With 4 SIM card slots total and two routers, I can load the router with SIM cards from multiple carriers and select which SIM/carrier is used. The signal from the cellular connection is re-broadcast wirelessly inside the boat using the unit’s high powered multiple-input/multiple-output (MIMO) antennas. I also can connect my laptop docking station with the wired ethernet port.

    Two By Two Internet set-up

    To extend cellular reception and performance, and provide excellent range to use a marina’s WiFi with the router’s WiFi-as-WAN feature, I installed an OMNI-296 Dual Band WiFi antenna on a 4 ft Shakespeare Style 4008-4 extension mast mounted to a dual axis ratchet mount on the pilothouse roof.

    A view of the MIMO antenna. The OMNI-296 Dual Band WiFi antenna mounted on a 4 ft. Shakespeare extension and a dual axis ratchet mount.

    I purchased an AT&T unlimited data plan ($249.00 for the first month, $140/month thereafter) and installed the SIM card in Slot 1. This AT&T unlimited plan includes 1000 GB limit before bandwidth throttling will occur. This proved more than adequate for our usage. I put the MiFi  SIM card in slot 2. As programmed, the router will use the AT&T plan first and only go to the Verizon card if the AT&T signal is poor. Should I need additional coverage I still have slots for two additional SIM cards from other carriers.

    With the addition of the AT&T data plan, router, and antenna I have greatly improved access and reliability to internet access on my boat.  While I enjoy cruising the waterways and taking in spectacular views with my wife, I welcome the opportunity to consult with you about your cases involving mechanical engineering, machine design, machine safeguarding, risk assessment or safety. Please give me a call.

    Jeffery H. Warren, PhD, PE, CSP, is the chief engineer and CEO at Warren specializing in mechanical, machine design and safety.  His deep expertise in machine design and safety analysis makes him a frequent presenter, trainer and expert witness. In addition to investigating more than 2000 claims involving property damage and injuries related to machinery and equipment since 1987, Jeff has an undergraduate degree in Mechanical Engineering from UNC Charlotte as well as a Master of Science and a Doctorate in Mechanical Engineering from Virginia Polytechnic Institute and State University — both with machine design emphasis.

  2. P&ID’s, If You Please – Piping and Instrumentation Diagrams Explained

    Leave a Comment

    When investigating an industrial incident, one piece of information I always ask for is the relevant P&ID’s for the process.  P&ID stands for Piping and Instrumentation Diagram and is defined as “A schematic diagram of the relationship between instruments, controllers, piping, and system equipment.” A set of P&ID’s for an entire facility allows you to trace the entire manufacturing process from raw material unloading to finished product loadout, including utilities like steam, water, fuel, and air. That’s great information to have, but isn’t especially useful in an incident investigation. However, the information from the P&ID’s covering the vessel or vessels involved in an incident can be very useful.

    In a previous blog, I wrote about the distributed control systems (DCS) that manufacturers use to monitor and store process data such as temperatures, pressures and flow rates, etc.  The P&ID for those processes will show where these measurements are taken. Not physically, as in, “the flow meter is located on the northwest corner of the third floor”, but relative to the rest of the process, “the flowmeter is located downstream of the discharge pump and upstream of the split between Vessel A and Vessel B.”

    The symbology and abbreviations used on P&ID’s typically come from one of two standards: “ANSI/ISA-5.1 Instrumentation Symbols and Identification” or “PIP PIC001 Piping and Instrumentation Diagram Documentation Criteria.” These are both real page-turners!  Actually, they are jam-packed with useful information that is, by definition, pretty dry.  They lay the groundwork for how to read the instrument identifications (tag numbers) on the drawings.  Part of the symbology shows whether a measurement point is being tracked by the DCS, and therefore, useful in investigations.

    P&ID with marked tag numbers

    P&ID’s also let you see the control loops in a process.  A control loop is a collection of equipment that will control a part of a process.  Let’s say you have six identical reactors, then TIC-100 could be a temperature indicating controller on Reactor 1, TIC-200 on Reactor 2.  The P&ID will show that the temperature controller for each reactor works by opening or closing the valve in the steam supply to the reactor’s heater.  The math behind how the controllers determine when and how much to move the valve opening is emotionally scarring, by the way.

    In another example, let’s look at a tank that has a level controller. It controlled the tank level by sending a signal to a flow controller in the discharge line.  This signal adjusted the setpoint of the flow controller. To keep the level at 50% required an outflow of 100 lb/min of material which normally required the flow control valve to be 35% open.  Over time, the flow stayed the same to control the level, but the valve opening went from 35% up to 100%, indicating something was impeding flow from the tank.  Subsequently, the valve in the discharge line stayed at 100% but the flow started dropping off from the 100 lb/min needed to keep the level at 50%, so the level started to rise.  If this was a tank overflow incident I was investigating, then the P&ID’s would show me the tags for which I would request process data from the DCS.  That data would tell the story written above.

    An example of a control loop and tag numbers

    In addition to providing information about control loops, P&IDs are incredibly useful when authoring a Lockout/Tagout or Confined Space Entry procedures.  When I was in manufacturing, we had reactors that were twelve feet in diameter and over one hundred feet tall.  To physically survey something that big to try to find all the isolation points would be, as my husband would say, a “low percentage move.”  Instead, pull out a P&ID and every pipe leading to and from a vessel is right in front of you.  Feed lines and product outflow are no brainers, but would you have missed the nitrogen blanket feed line at the top of the vessel in the field?  Maybe.

    P&ID’s are identified in the OSHA PSM standard (29CFR 1910.119) as part of the process safety information that must be compiled before any hazard analysis is performed (reviews included). Manufacturing processes covered under the PSM standard, must make sure their P&ID’s are accurate and up to date as part of the ‘Management of Change’ requirement of PSM.

    So if you ever find yourself needing to investigate an incident at a manufacturing facility make sure to ask for the P&ID’s, or your expert surely will.

    As President of The Warren Group, Jennifer Morningstar, B.S.Ch.E, P.E., CFEI, has over 20 years of engineering experience. Her areas of emphasis include chemical release & exposure, OSHA compliance, boiler systems, industrial accident investigation, fires & explosions, product liability and scope of damage/cost to repair analyses. She spent 16 years working at a polyethylene terephthalate (PET) manufacturer.  She is an OSHA-trained Process Hazard Analysis study leader and completed Root Cause Failure Analysis training to become an Incident Investigator. Jennifer authored procedures for lockout/tagout and confined space entry. She has experience as an energy management consultant in a variety of industries including mineral extraction, pulp & paper, animal harvesting & packaging (including rendering) and grain milling.  Jennifer holds a Bachelor of Science Degree in Chemical Engineering from Virginia Polytechnic Institute and State University as well as a Master of Business Administration from the University of South Carolina.


  3. The Paths of Chemical Exposure

    Leave a Comment

    The Safety Hierarchy states that hazards should be mitigated first by engineering controls, secondly by guarding, and lastly by warning/training.  When the first two, engineering controls and guards, fail in a manufacturing setting, a chemical release could occur. A forensic chemical engineer can help determine the root cause of that failure. (more…)

  4. “Introduction to Event Data Recorders (EDRs)” LIVE Webinar | October 22nd, 11am EDT

    Leave a Comment

    Accidents often have devastating consequences. Join WARREN’s Senior Collision Reconstructionist and President of S.C.A.R.S., South Carolina Association of Reconstruction Specialists, Aaron Duncan for an exclusive webinar on “Introduction to Event Data Recorders.”

    Learn from an expert how the information stored in this valuable tool can be utilized to help get to the truth of your loss.  Information like:

    • Change in Velocity
    • Vehicle Speed
    • Service Braking
    • Steering Angle
    • Safety Belt Usage
    • Seat Occupancy
    • Engine RPMs
    • Engine Trouble Codes
    • PLUS, many case studies to consider.

    Join us for this free, 45 minute + Q&A interactive webinar

    CREDITS AVAILABLE: 1.66 Credits for South Carolina CLE and 2 Credits for Georgia DOI.

    LIVE Interactive webinar. You don’t want miss this.

    Register Now, Seats are Limited



  5. Don’t Get Burned With Your Gas Grill!

    Leave a Comment

    If there is one thing Americans can agree upon, it is the enjoyment that comes from an outdoor barbeque.  Whether a summertime cookout or a fall BBQ to watch a football game, we all love the fun and fellowship that comes from sharing a meal that was prepared outdoors on a grill or smoker.  In fact, 64% of Americans own a grill or smoker.  The great majority of these are LP fueled gas grills with comparatively few natural gas fired grills.  These products can be enjoyed safely when designed, installed, and used in a proper manner.  However, given the grill’s use of flammable fuel gas and high temperatures, the potential exists for things to go wrong and result in burn injuries or uncontained fires that spread to the surroundings. (more…)

  6. What You May Not Know About Using a Concrete Test Hammer

    Leave a Comment

    When assessing potential problems in concrete structures, consider a non-destructive test using the concrete test hammer, AKA “rebound hammer,” before investing a lot of time and money needlessly replacing or destructively testing the concrete structure.  The use of rebound hammer tests should be considered before you or your client decide to drill multiple core samples. Large areas of the concrete structure suspected of having potential strength problems can be tested quickly with a rebound hammer.  Analysis of those results can narrow down specific areas for more rigorous testing. (more…)

  7. The Demise of Insulation on Electrical Wiring

    Leave a Comment

    Unlike fine wines and some types of cheeses, not everything ages well.  Such is the case with the materials used as insulation of electrical wiring.  While the copper metal used as the conductor in many wire types will last virtually forever, the cladding used to protect and insulate the wire allowing electrons to flow to their final destination does not. (more…)

  8. Load Holding Valves in Hydraulic Cranes

    Leave a Comment

    Hydraulic cranes absolutely rely on the integrity of their high-pressure fluid systems for safe operation.  A crane can become out of level when an outrigger cylinder leaks over time, possibly leading to a tip over.  A boom can collapse if a hydraulic hose ruptures.  It is not possible to absolutely prevent hydraulic cylinders from developing leaks or prevent hoses from rupturing during the life of a typical crane, therefore crane manufacturers provide load holding valves at key components to prevent these dangerous incidents.  In fact, ASME B30.5, Mobile and Locomotive Cranes, requires load holding valves or equivalent devices at outrigger cylinders, boom support cylinders, and boom telescoping cylinders. (more…)

  9. Working on the Waves While Working the Waves…

    Leave a Comment

    The rumors of my pending retirement have been greatly exaggerated…..

    Ever since I heard about The Great Loop I have wanted to cruise it (  To successfully complete the Loop, one needs to have 3 things: adequate equipment, adequate time, and adequate health. I had the first and third.  To secure the second, I had floated the idea of a two-year sabbatical.  A year to complete any existing cases and a year to execute The Great Loop.

    With the arrival of COVID-19, our firm went to remote work. (more…)

  10. Ammonia – The Good, The Bad, The Smelly… Part Two

    Leave a Comment

    Now that you know what ammonia is (see Part One here), how it behaves, and how to safely store it and work with it, let’s look at some areas in industry where it is used.

    Anhydrous ammonia has a use in pollution control.  Industrial boilers and power plants burn coal or natural gas to make steam and/or electricity. When the fuel is burned using air as the oxygen source nitrogen gets exposed to the heat as well because air is 79% nitrogen.  The nitrogen gets oxidized and forms several compounds referred to as NOx (NO, NO2, NO3).  NOx compounds are harmful to (more…)

Type ofLoss

Not sure what you're looking for?
Browse All

Select Loss Category