Case study: Fall protection
Standing approximately 160 feet above the lower level, the height of the bridge had raised concern from the safety director. Because of this forethought earlier in the year, the safety director had contacted his local safety system specialist to devise a solution in case one of his workers would need to be rescued from a fall. He had already mandated all workers to use a personal fall arrest system (PFAS) when working from the bridge. Was this enough to save a life if necessary?
One step too manyWhile working from a suspended scaffold, the workers were to detach cables that were used in prior stages of the construction process. This required the removal of certain brackets that held these heavy cables in place. While not an extremely difficult task, workers needed to be very careful due to the extreme winds as well as the height of the bridge.
The first few cables were removed smoothly without incident; however, this was not the case for all of them. When a worker removed the next bracket, the cable began to slide. Due to the size and weight of the cable, the worker could not halt the cable from sliding out of his reach. As he reached to save the cable from falling to the ground, he found himself taking one step too many and he fell off the suspended scaffold.
Fortunately, the worker was properly wearing his full body harness, which was connected to a self-retracting lanyard. His safety equipment managed to stop him within just a few feet from the leading edge. He was fortunate that he did not plummet more than 150 feet to an almost certain death.
But was he really safe at this point? After all, he was now dangling approximately 150 feet from the ground and was awaiting a rescue by his coworkers.
To the rescueBecause the bridge was 160 feet above the lower level, it was not feasible to reach the fallen worker from the ground. They would have to reach him from the bridge deck. As part of the rescue plan, the safety director had acquired several MSA Suretymanâ„¢ Rescue Utility Systems to be strategically placed throughout the working areas on the bridge. In short, this is a rescue system that is primarily used for raising and lowering people. The unit offers a mechanical advantage of 4:1. Specifically, if the victim with all his tools weighs 200 pounds, then the necessary lifting strength will be just 50 pounds.
The fallen victimâ€™s counterpart immediately went to retrieve the rescue utility system from the storage bag and connect it to an anchorage just above the bridge level. Since the safety director had already calculated the total fall distance that a typical individual would encounter, the system was preset to that length.
The rescuer lowered the rescue utility system to the conscious victim. (If the victim was unconscious, the rescue plan would have to be implemented in a different way.) The victim then attached the carabiner from the rescue utility system to the D-ring of his harness. After the victim gave the signal that he was now attached to the rescue utility system, the rescuer, standing above at a safe working level, began to pull him up to the surface of the bridge where the fallen worker could climb to safety.
From the time the worker fell until the time he reached safety no more than 15 minutes elapsed. A follow-up examination revealed no injury to the victim; he was just a little shaken up due to the shock of what had happened.
Are you ready?What could have happened if the crew had no rescue plan? More than likely, the coworkers would have had to call the local fire company to come to the bridge. This may not have been the best solution for a couple of reasons. First, no one knew for sure what the expertise level of that particular local fire company was for saving someone under those circumstances. Also, how long would it take for the rescue squad to reach the bridge to help the victim? Ten minutes? 20 minutes? Longer?
When a victim is brought to safety, there is a tendency to lay the person down in a prone position. This creates a surge of de-oxygenated blood to the heart, resulting in potentially severe shock. The consequences of suspension after a fall can be serious, especially if the worker is immobile or unconscious. To reduce the risk of post-fall suspension trauma, it is essential to have a rescue plan in place and the means to implement it in an emergency.
As this example shows, a properly executed fall protection program and rescue plan can turn potential tragedy into nothing more than a good scare.
SIDEBAR: Time-criticalTime becomes critical for fallen victims as some people suffer more bodily harm due to the length of time they remain suspended from their fall than they do from the fall itself. After a certain period, depending on the individual, a condition called venous pooling may occur.
When the victim falls, the majority of the harness support is in the lower region of the body by the leg straps. This is by design since the upper leg area is one of the strongest regions of the human body. The pressure of the leg straps decreases blood flow to the lower portion of the legs, which creates a dangerous pooling effect.