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Unguarded Shear Point on Force Tester Amputates Worker’s Finger

A worker was injured while testing gas springs similar to the type that hold the hatchback of an SUV open. The hazard that injured the worker was an unguarded shear point. The tester contained a mounting plate that was raised and lowered by a pneumatic cylinder.

The pneumatic cylinder lowered the mounting plate while the worker’s fingers were in the hazardous, unguarded shear point. The force testing machine violated applicable safety standards including ASME B15.1-2000 Safety Standard for Mechanical Power Transmission Apparatus sections 1.3 and 3.1.

Unguarded Shear point 1 white

The force tester. 

It was technologically and economically feasible for the manufacturer to have guarded the hazardous shear point at the time they designed and built the force testing machine by installing a fixed guard to prevent a worker from getting too close to the hazard. The hazardous, unguarded shear point on the force testing machine was capable of producing serious injury, including amputating fingers.

The risk of injury associated with the hazardous shear point was high because the hazard was unguarded, workers were exposed to the hazard every time the force testing machine cycled, and serious injury would occur every time a worker’s body part became trapped in the rapidly closing shear point. The high risk of injury associated with the hazardous, unguarded shear point was not tolerable because it was feasible to control the hazard using a fixed guard with no effect on the utility of the force tester.

It was or should have been foreseeable to the manufacturer at the time they designed and manufactured the force testing machine that the hazardous, unguarded pinch point would cause serious harm any time an operator got too close to the hazard.

Unguarded Shear Point Img 2

A shear point was created between the fixed frame and the movable mounting plate when the pneumatic cylinder lowered the mounting plate.

The force testing machine was unreasonably dangerous and defective.  It contained an uncontrolled hazard with a high, foreseeable and intolerable risk of serious injury with a certain probability of occurrence any time a worker’s body part is caught in the shear point.  There were technologically and economically feasible means that existed to control the hazard at the time of the machine’s design and manufacture. The unreasonably dangerous and defective condition of the force tester was a cause of the worker’s injury.

Unguarded Shear Point IMG 3 whiteA simple Lexan guard was all that was required to protect a worker from the hazardous shear point.

If you have a case involving personal injury involving a worker injured on a machine in an industrial setting, please give us a call. We are happy to consult with you.

Electric Hazard Guardrail photo

Hazards Can Lurk Anywhere … Watch Your Step …

Author

While on a lunch stop during a recent vacation trip through Tennessee, I happened across a safety hazard that required immediate attention.  The establishment had a raised concrete patio at the front with a steel railing around the perimeter.  At one edge of the patio was a set of stairs with a continuation of the steel railing used as a handrail.  The top edge of the patio had light strings wrapping the top metal bar as accent lighting for the perimeter.  The light string continued down the stair handrail wrapped in the same manner as the rest of the patio.

Electric Hazard Guardrail photo

FIGURE 1 – A view of the subject patio

While walking down the stairs, it was noted that two bulbs were missing from the sockets on the portion of the light string that wrapped the handrail.  The sockets, a common Edison-style base, were open to the weather.  More significantly, the open sockets were in the path of a person’s hand (adult or child) sliding down the handrail while traversing the stairs.  The damaged condition of the light strings due to the missing bulbs presented an electrocution hazard.  While the risk of electrocution may be mitigated if the light strings are supplied by the required National Electric Code (NEC) Article 527.5, Ground Fault Circuit Interrupter (GFCI) protected circuit, the condition of the light string presented a hazard.

Closeup photo of one of the open lamp sockets

FIGURE 2 – Closeup photo of one of the two open lamp sockets

Further, the wrapping of the light string around the handrail violates the International Building Code (IBC) requirements.  Section 1012.4 Continuity states that “Handrail gripping surfaces shall be continuous, without interruption by newel posts or other obstructions.”  The random placement of the cable from the light string randomly interferes with the continuous profile of the handrail.

View of the cord wrapping the handrail interfering with usability

FIGURE 3 – View of the cord wrapping the handrail interfering with usability

While there was likely good intent with the placement of the light string to add light to the stairs, the method that was used impeded the use of the handrail.   Further, lack of maintenance by not replacing the missing bulbs crated a shock or electrocution hazard.   Beware of these lurking hazards, if things don’t look right, they probably aren’t.

Tom Kelly has a Bachelor of Science in Electrical Engineering and a Master of Science in Electrical Engineering from Florida Atlantic University, Boca Raton, Florida, along with a Master of Business Administration with emphasis in strategic leadership from Winthrop University, Rock Hill, South Carolina. Tom’s 25-year career in electrical engineering includes forensic engineering investigations involving industrial electrical accidents, electrical equipment failure analysis, control system failures, robotics and automation components, and scope of damage assessments.  He has conducted investigations for fires, arc flash incidents, electrocution and electric shock accidents and lightning strike evaluations.

Green Hotrod with Fancy Rims and Huge Tires

The Pressure to Keep Rolling – Part 1

Author

Over my years of law enforcement, crash investigation, and collision reconstruction I have come to become more and more particular about my tires. I have watched people purchase tires from these “Used Tire Stores” and when I buy my tires I can understand why; quality tires are expensive. The question of how old is that tire and how was it serviced before it ended up for sale is a huge concern. I have watched people put their compact spare tire (commonly called the donut spare) on their vehicle and ride on it for weeks even traveling down the interstate a speeds way above the recommended rating on the tire. I have had a tire dealer (that sold new tires) try to sell tires and rims that are not safe combinations because they go against the vehicle and tire design. Needless to say, much to their dislike, I wouldn’t cooperate with them because it didn’t make them money; however, they did not end up in civil litigation either.

Used Tire Sign

I have seen people do things to be trendy like lifting or lowering a vehicle way beyond the vehicle manufacturer’s intent. People lift and lower their vehicles by changing the size of their tire or wheels (this brings in a whole new concern if they change the rims because they too are rated and designed for specific applications) without consideration of the vehicle’s relationship to its tire design. Sometimes the tires rub, causing wear and damage to the tires, which becomes a safety issue.  Each time you go up or down in the height of the tire you are changing the revolution speed of the tire. This in turn changes such things as the accuracy of the speedometer. The change in speed being displayed compared to actual speed may only be 1 or 2 mph difference at 5 or 10 mph, but 15 to 20 mph off at 55 or 60 mph.

Green Hotrod with Fancy Rims and Huge Tires

With the complicated safety systems communicating with each other within a modern vehicle’s computer system and making decisions in milliseconds (especially things like airbags, traction control, and anti-lock brakes), having erroneous data generated by the use of improper tires yields not only a concern for a speeding ticket but to a vehicle’s improper response to conditions of a crash. If there is a need to change tire sizes, find a trusted and reputable tire company to walk you through the change so that you have the least amount of repercussions from the switch.

In part 2 of this blog we will go over where to find the proper tire and loading information for your vehicle, and what these values mean, to ensure you are getting the maximum safe performance from your tires.

Orange mini excavator

Case Study: Fatality Servicing Unsupported Excavator Boom

A mini-excavator at a job site developed a leak at a hydraulic fitting at the base of the cylinder that raises and lowers the boom. A subcontractor foreman at the site raised the boom to search for the leak. The foreman found and attempted to tighten the leaking fitting. When he did, the fitting separated from the base of the cylinder, releasing the hydraulic pressure that held the boom aloft. The boom fell and the bucket struck a nearby superintendent for the general contractor.

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Gas Appliance testing lab

Testing As Part of Gas Appliance Incident Investigation

Author

Equipment and appliances supplied with fuel gases like natural gas, propane and butane are a common and convenient part of most of our lives.  Such devices as gas grills and ranges, ovens, furnaces, space heaters and water heaters usually perform without incident.  However, when they malfunction the potential for incidents such as fires and explosions, carbon monoxide (CO) poisoning and burn injuries may occur. These incidents may be due to design and manufacturing defects in the product, or improper installation or operation of the device.

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3D Collision Impact Angle

Why investigators should have “Scaled Diagrams” of scenes?

Author

When it comes to diagramming a crash scene, there are several methods to complete the task. Forensic Mapping, (locating, positioning, and documenting the evidence of a collision scene to scale) is essential to having the answers to the questions “Who, What, Where, When, and Why”. Photographs do a great job showing what the investigators saw post collision; yet they lack scale and the ability to describe pre-collision movement. Having a computer aided diagram (CAD) of the collision scene goes much further than the pictures can; here is why.

basic intersectionA scale diagram gives the full overview of a collision scene from either a 2D or 3D point of view. Being able to see how things lined up, how they came together and how they parted helps explain the events within a crash. When a scene can be viewed from top down or any angle, that helps relay the facts. The investigator, judge, or jury will get Read More

Hot Tub Hazards

Danger Lurking in the Hot Tub

Author

Several dangers involving the use of a hot tub (spa) may readily come to mind, such as the risk of shock or electrocution, or the risk of drowning for unsupervised young children.  Not so readily apparent is the effect of overheating the human body, or “hyperthermia”.

Some individuals are more susceptible to the effects of hyperthermia, including the elderly, young children, and those in poor health.  The effects of hyperthermia, or overheating of the human body, cause direct responses such as headache, nausea, heat exhaustion, increased cardiac output, lethargy, confusion, heat stroke and unconsciousness.  The onset of hyperthermia is defined as being at 99.5° F; if the body temperature reaches 104° F, a life-threatening medical emergency exists.  Read More

box bailer

Defective Vertical Baler Causes Serious Crush Injury to Operator’s Arm

I recently worked on an interesting case involving a box baler. An employee of a butcher shop put some empty cardboard boxes in a vertical box baler and pushed the control switch to compact the boxes. After the 30 by 60 inch platen weighing 851 pounds returned to its raised position, the employee reached into the open space above the bottom door on the baler and began to clear cardboard from the bale tie slots in the bottom of the raised platen. Suddenly, and without warning, the steel pin attaching the platen to the raised hydraulic cylinder rod failed. The heavy steel platen fell and crushed his arm which was outstretched over the baler door into the compaction space.

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Under the sink chemicals

Not Your Father’s House Fire

Remember the good old days when our homes were built with only lumber, dry-wall, and roofing?   Me neither.  However, we talk about ‘modern’ construction materials like this is a new phenomenon.  The truth is ‘modern’ construction materials started sneaking into homes over fifty years ago.  It’s not only construction materials that have changed: a century ago, we furnished our houses with wood, cloth, metal, and glass. Today, it’s plastics, foams, and coatings.

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Right Turns Only main photo

Right Turn Only

Author

 

In my 25 years of investigating collisions and traffic related incidents, one thing I have noticed repeatedly is that right turns are considerably better than lefts. I know it is obvious and sometimes seems a little petty; however, when it comes to the safety of your family, it is a big deal. Since I am currently in the process of teaching my second child how to drive, I am harping on vehicle safety a lot and this is one of the many practices I teach. I have instilled in my children (and my wife has picked up on it as well) that they should always plan out their route and, in doing so, make right turns instead of lefts whenever possible. The “Right Turn Only” practice will make your travels safer.

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