In my previous blog , I discussed the most basic and most common fire system type: wet sprinkler systems. The possible failure areas discussed with wet systems will also apply to dry sprinkler systems (control valves closed, obstructions, issues in the system, installation, or deficiencies with inspection, testing, and maintenance). Dry systems are even more prone to obstructions than wet systems, so close attention should be paid to that possibility. Read More
Machine guards can be compared to the clothes we wear every day. Indeed, they serve a very important purpose. Imagine someone leaving their home on a fine, sunny morning wearing nothing but a smile. Wonder how far they will get through the day before things start going poorly for this individual?
There will be more than a few raised eyebrows and blushes when he stops into the local Starbucks for his usual morning double-dipped and whipped, chocolaty chip with a touch of pumpkin spice cappuccino fix. Good luck with that! Probably going to leave disappointed, empty-handed, and likely wearing handcuffs. This will be the beginning of a very long, very bad day for that individual. Had he recognized the risks associated with this type of behavior, and then put forth a little effort to cover up, he would have prevented many unfavorable and possibly life-changing personal and legal problems from ever occurring!
Ladders…not a particularly exciting topic I’ll admit. But hey, we need ladders to help us accomplish all kinds of tasks. Most people have used at least one of the many types of ladders that are available today. And the odds are probably pretty good that many of those users strayed outside the limits of safety a time or two while on a ladder. It is amazing the risks some people will take to save some time or avoid the inconvenience of getting down to move the ladder into a safer position. I wonder how many of those risks would be taken on a ladder if the users knew they were on camera.
Think about astronaut Neil Armstrong. He travelled by rocket almost 239,000 miles through space and has just successfully landed the lunar module on the surface of the moon. Quite an accomplishment! Now, with the eyes of the world on him, he is going to come down a ladder and become the first person to set foot on the moon. I wonder how many times Neil Armstrong practiced coming down that ladder. Now imagine him saying during that historic moment: “That’s one small step for a man… one giant leeee….aaaaaahhhhhhh!” And then the world watches as he falls back off the ladder and comes to rest lying on his back….on the surface of the moon….with a broken leg, a sprained wrist, and a bruised back, and clutching a ladder rung in one of his hands! And 239,000 miles from the nearest Urgent Care!
Image Credit: NASA Archives
That would have drastically changed everything about the overall mission of the astronauts! The investigation into this ladder accident would be an interesting and important one for sure, and the fact that such strong evidence was caught on video would be a luxury not usually available to the investigator. Well, fortunately that accident did not happen! Neil Armstrong finished his famous quote, he successfully stepped off the lunar module ladder, and the overall mission of the Apollo 11 flight was incredibly successful.
Obviously, the everyday use of ladders at factories and homes across the U.S. lacks the drama and suspense of a moon mission ladder descent, but there are some similarities that we can look at. Using a ladder always involves a level of risk. That risk level is dependent on things such as the type of ladder, the height climbed, the attention of the user to follow all ladder safety rules, as well as the design and stability of the ladder used. Ladders that are available these days are typically safe with respect to their design and the materials they are constructed of. However, statistics show that in the US, on average, work-related ladder falls result in one death and more than 180 nonfatal injuries every two days. In some of these cases, questions are raised about what actually caused or contributed to the accident. When this happens, it is common for a forensic engineer to be hired to investigate the accident to determine if there was a defect in the ladder’s design or the materials it was manufactured from, or if the user of the ladder was possibly at fault.
The things a forensic engineer will consider in the investigation are dependent on the specific circumstances of each accident as well as the scope of the accident request. Typically, the type of ladder and whether it adhered to the design standards that were in place when it was manufactured will be a part of the investigation. A quick internet search will show whether there are or have been recalls for that particular ladder model. A thorough study of the ladder, whether through quality photos or having the actual ladder involved in the accident, can reveal evidence that will show whether a defect was present in the ladder at the time of the accident. The specific members that were damaged can sometimes show how the ladder was loaded when it failed, and whether that failure may have been due to either a defect or the user’s bad judgment. The goal of the investigation will be to find the truth as to what happened and to give a concise explanation of the expert’s findings along with his /her opinions in the final report.
If you need an investigation of an accident involving any type of ladder, please call our experienced mechanical engineering experts at Warren.
Bob Hickman is a Licensed Professional Engineer and Certified Machinery Safety Expert. He has over 30 years of manufacturing and machine design experience in production and quality-driven environments. Bob holds a Bachelor of Science in Mechanical Engineering from Clemson University. Over his 30-year engineering career, Bob has designed many custom manufacturing machines and processes that improved quality, productivity, reliability, and safety. He designed several machines to automate manual processes, replacing inefficient/unreliable manual equipment and has assisted with plant layout/production line planning. He has significant experience with pneumatic systems and components, as well as hydraulics. Bob regularly investigates personal injury, wrongful death, and product liability claims, as well as property damage claims involving machinery and equipment in a variety of environments for both insurance adjusters and attorneys. Bob has an in-depth knowledge of many standards with emphasis on ANSI B11 standards for machine tool safety.
After a major fire, it is necessary to investigate the fire sprinkler system to see if and why it malfunctioned. Wet sprinkler systems are the most common and least complex fire sprinkler systems in use. The following are major items addressed in an investigation involving a wet system.
If available, drawings of the supply piping and sprinkler system are helpful. If these are not available, a sketch of the system will be made. Requests will also be made for inspection, testing, and maintenance documentation as well as fire alarm logs.
The top reason that fire sprinkler systems do not function correctly during a fire is Read More
Please join us in welcoming Mechanical Engineer Bob Hickman, P.E., to the WARREN family! Bob has over 30 years of manufacturing and machine design experience in production and quality-driven environments. Bob holds a Bachelor of Science in Mechanical Engineering from Clemson University.
Bob’s Areas of Expertise Include:
-Industrial Accident Investigation
-Codes & Standards
-Machinery & Equipment Damage Assessment
-Products Liability Read More
Temporary wiring is just that….temporary, and is typically used for repair and maintenance projects. In this blog I am going to discuss guidance offered by Article 590 of the National Electric Code (NEC), as well as some points to consider when using temporary wiring, including extension cords and holiday lighting.
Before each use, extension cords need to be inspected for visual damage. Cords with cuts or splits to the insulation need to be discarded. Cords with damage to the connectors, including those that feel loose when connected, need to be taken out of service. Failure to properly select and use extension cords can have a catastrophic result. Read More
This is the second in a two-part blog series about conveying equipment that severely injured a worker at a mine. In case you missed it, click here to read Part 1 where I describe the incident and the mining equipment. In this part, I will discuss my engineering analysis of the incident and the machinery involved and share the conclusions I reached.
The injured miner was a front-end loader operator. He was not a maintenance worker. He simply responded to a radio request for help with the conveyor. Power to the electric conveyor motors was locked out, but none of the maintenance workers did anything to lock out or block the hazardous gravitational potential energy in the heavy load of stone on the belt. Read More
Construction defects can appear in many forms. The building does not necessarily have to fall down. There are many types of construction defects, including roof leaks, water intrusion into walls, as well as Heating, Ventilation, and Air Conditioning (HVAC) defects.
One extreme example of this was an office complex I was called to for an investigation of the source of mold observed on the walls. The occupants complained that they could not find a temperature setting on the thermostat where they could make the office comfortable. When I inspected the office, I couldn’t believe what I was seeing. A band of black mold Read More
In the old-timey Fire Triangle, you have heat, fuel, and oxygen. Get these three together in the right quantities, and you get fire. What if the fuel provides its own heat? That’s spontaneous combustion, or spontaneous ignition. NFPA921 defines this as “initiation of combustion of a material by an internal chemical or biological reaction that has produced sufficient heat to ignite the material.” Read More