As an experienced safety consultant, I’m called on to investigate a wide range of premises liability incidents. In any slip and fall investigation it is important to assess the type of walking surface material involved and its corresponding slip resistance.
Slip resistance is a critical factor to consider when choosing the right flooring material for any space. It’s especially important in areas that are prone to moisture, spills, or other hazards that could make floors slippery and dangerous. A slip-resistant surface can help reduce the risk of Read More
Wire ropes are critical components of cranes and play a crucial role in ensuring the safety and efficiency of crane operations. To extend the life of these ropes and maintain their strength and performance, it is essential to regularly lubricate them. Read More
Around Christmas day of 2022, a mass of very cold air settled in the deep south/southeastern United States (where I live). It remained below freezing for over 24 hours. That is very unusual down here. There was a spate of burst pipes all over the area. Why? Water is one of a very few compounds that expands when it freezes…by approximately 9%!! If a volume of water is sealed off in a section of piping, and that water freezes, it is likely the pipe will rupture. Then, when it warms up again and thaws, liquid water will leave the pipe for an adventure!!
Water expands when it freezes because the water molecules form a six sided crystalline structure in its solid form (remember those six sided snowflakes we all cut out in grade school?). These large crystals cannot nestle together as closely as individual water molecules. So frozen water needs more elbow room, so to speak. The other way to state this phenomenon is that ice is less dense than water. Which is a really good thing for all the fish that live in ponds where it gets cold enough to freeze! The layer of ice on top of a pond insulates the water beneath it from colder air temperatures. If that ice sunk to the bottom of the pond instead, the water on top would freeze then sink and eventually the entire pond could freeze and kill the fish in it.
This made me start to think about all the other ways that water is unlike other liquids… and there are quite a few. They all stem from the fact that water has something called hydrogen bonds or polar bonds between its molecules. You all know that water has 2 hydrogen atoms and 1 oxygen atom: H2O. What most folks don’t know is that each hydrogen atom has one electron to donate to a bond and oxygen needs two electrons to fill its orbital shell. This configuration gives a slightly negative charge to the oxygen end of the molecule, and a slightly positive charge to the hydrogen ends. These charges act like little magnets and opposites attract!
These bonds give water properties that other compounds of similar molecular weight do not have…. Such as
This capability is also why water is used in industrial sites for absorbing or transferring heat…there’s literally no better liquid for it. This ability to absorb heat without changing temperature is why the oceans don’t get as hot or as cold as the land… water takes a long time to heat or cool
Lastly, the volumetric ratio of steam to liquid water is higher than most other liquids….1700:1. In other words, if I had a 1ft x 1ft x 1ft cube of liquid water (1 cubic foot) that I turned it into steam and kept at atmospheric pressure, that steam would take up 1700 cubic feet of space. Comparing to ammonia, that ratio is 850.
In the same way that frozen water can rupture pipes, water vaporizing to steam can have devastating effects on systems that aren’t designed for it. If you need an investigation of a loss involving water, in any of its forms, please call our experienced engineering experts at Warren.
As President of The Warren Group, Jennifer Morningstar, B.S.Ch.E, P.E., CFEI, has over 20 years of engineering experience. A licensed professional engineer in several states and a NAFI Certified Fire and Explosion Investigator, she 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. Throughout her engineering career, Jennifer has conducted forensic investigations involving chemical release/exposure, OSHA process safety management, industrial accident investigation, equipment failures, fires & explosions, and scope of damage/cost to repair. Jennifer is a member of the National Association of Fire Investigators (NAFI), the South Carolina chapter of the International Association of Arson Investigators (SCIAAI), and the American Institute of Chemical Engineers (AIChE).
As the temperature outside slides from the cold to the “bitter” cold range on the thermometer, most people tend to turn the heat on inside their home. Some homes, however, do not have whole house heat or sufficient heating capacity and therefore the occupants may rely on portable space heaters. Portable space heaters, used properly, can be a good choice to warm a small area of a home. Unfortunately, while they can warm your cold and tingling hands and feet, they can also warm nearby materials to the point of ignition. Read More
If there is a human involved in the case, there is a good chance that human factors theories and principles will be applicable. Human factors is the study of people interacting with their surrounding environment. A human factors expert applies their knowledge of human capabilities and limitations to each unique case to assess the physical, sensory, and cognitive factors that caused a person to behave a certain way within the surrounding environment.
Consider the following situations in which a human factors expert would be beneficial: Read More
Across industry and construction sites, there are times when employees of different employers are working side by side, or at least on the same site at the same time. Some industry examples are when chemical plants have contractors on-site for routine maintenance or during process shutdowns for major overhauls or repairs. OSHA refers to these as multi-employer worksites. In December of 1999, they revised their citation policy which allows for more than one employer at a worksite to be cited for conditions that violate OSHA standards. Read More
An unexpected severe winter freeze will remind many people and businesses that when water in a pipe freezes, the ice will expand and burst the pipe or pipe fitting. Large losses will result from flooding when the temperatures rise. Insulation will help, but not prevent freezing. Insulation simply slows down the rate of heat loss. The time of exposure to subfreezing temperature is an important factor.
The American Society of Refrigeration and Air Conditioning Engineers (ASHRAE) Handbook of Fundamentals has a short entry on the topic (Chapter 23, page 23.5-6), which gives an equation for estimating the time that it will take an insulated pipe to freeze, 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
Heavy machinery fires are often caused by hydraulic hose failures. Pressurized hydraulic fluid escaping from a failed hose assembly can be atomized into a fine spray that can be ignited by heated engine surfaces such as the engine exhaust or turbocharger.
Hydraulic hoses near the engine compartment of an excavator that burned.
Hydraulic hoses often fail due to age and wear, requiring regular inspection and replacement of hydraulic hoses to prevent failures. Hoses may also fail if they are misrouted. Misrouting can lead to the hose being pinched or causing it to chafe against a sharp metal surface. Read More
Surge Protective Devices (SPD), formerly known as Transient Voltage Surge Suppressors (TVSS) have been around for a long time. The most recognized version is integrated into outlet strips and used to protect sensitive electronics from surges, or higher than expected voltages on the power line. Early versions of these surge strips were known to have problems where internal components could overheat and cause a fire. Thermal protection was added to the designs to greatly reduce the potential for a fire hazard. Such an implementation in an outlet strip is considered a Type 3 SPD. Read More
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