Many of us use laptops and are familiar with the long power cords from the wall to the adapter and the cord from the adapter that eventually connects to the computer. Some of us think about the tripping hazard but we are not always as careful as we ought to be about taping down the cord. Most power cords will break apart from the adapter block—a feature that further reduces the consequences should someone trip over the cord. Those with MacBooks have the added engineering protection of a magnetic breakaway power cord that further reduces the tripping hazard.
A few days ago, I was sent a picture of a product that takes the idea of a breakaway cord even further. The “safety socket” appears to be sold under both the Stanley and Westinghouse brands. It takes the magnetic breakaway to the wall socket with a two-part assembly.
This sort of technology is not rocket science and it doesn’t replace proper taping of cords or other procedures but it can make a difference—if it is used. Some of you will also be familiar with a table saw that stops and retracts instantly if it senses the blade is touching flesh . This technology does not replace the need for saws to have guards. Proper adherence to safe work procedures does effectively reduce the risk of injury. So, what does a $20 breakaway socket or a $70 brake cartridge (and the marginal extra cost at purchase) in a table saw add to the safety equation?
To answer this question, you need to remember that most work activities carry risks. Safety is about reducing or eliminating the active risks and effectively managing the residual risks. We manage the residual risks by putting in place barriers, safeguards and defenses. Knowledge is one of the best defenses so training is one way we can reduce risk. Safe work procedures, personal protective equipment, and effective supervision further reduce the risk of the inherent danger of a cut from a saw blade or a fall injury because of a trip over a power cord.
James Reason, an expert in human factors that lead to injury, speaks in terms of barriers and holes that protect workers from injury. In his "Swiss cheese" model, the inherent danger in a work situation can only harm a worker if there is a hole in each of the defenses, barriers, or safeguards, AND these holes align.
In my own view, I think of these holes as active or latent defects in the barriers, safeguards, and defenses that protect the worker from harm. The effect of improved supervision, better training, more complete adherence to safe work procedures is the reduction of the number and size of the defects in the barriers and safeguards that protect workers. And that is effectively what the design solutions the breakaway power cord and the sawstop device provide. These are examples that make the barriers and safeguards more complete, which further lessen the opportunity for the inherent risk of tripping or being cut by a spinning saw blade.
This blog is not intended as an endorsement of these products. I think, however, they are good illustrations of how technology and good design can contribute to safer work environments by reducing the size and number of holes in the barriers, safeguards, and defences that can protect workers from harm.