The Last Line Between Work and Catastrophe

Falls from height are still the largest single cause of work fatalities in the UK’s construction industry. Sometimes from corners cut, sometimes from equipment failure, but often from decisions made on the basis of what was known at the time but turned out not to be the case. And the fall arrest system is there to catch the individual when everything else has failed.

It is important to note the distinction between the terms fall arrest, fall prevention, and fall restraint. The equipment used for fall arrest is the equipment that catches the individual who has started to fall. This is different from fall prevention equipment, which prevents the individual from reaching the edge in the first place, and fall restraint equipment, which prevents the individual from reaching the edge by restricting the length of the lanyard.

The Calculation Nobody Wants to Get Wrong

The calculation for the required clearance from the working position is not as simple as it sounds. The calculation has to take into consideration the free fall before the system arrests the fall, the length of the lanyard required for the fall to stop, the height of the person, and a safety factor.

If any of these variables are not included in the calculation, then the person can hit the ground or a lower level despite being attached to fall arrest equipment. The calculation varies depending on the type of connecting device in use. The self-retaining lifelines have the least free fall before the arresting device arrests the fall. The traditional shock-absorbing lanyards have more free fall before arresting the fall. The required clearance varies by several meters depending on the type of fall protection equipment. Thus, the wrong type of equipment can prove disastrous for the worker.

Not all work sites have sufficient height for fall protection to be of concern. Sites such as working on low-pitched roofs, working over voids, or working near ground level require careful planning to ensure sufficient fall distance. If there is insufficient fall distance, then fall arrest is not possible. In such cases, fall prevention or fall restraint has to be used. 

The Human Factor Nobody Likes Discussing

Having the right equipment available is no guarantee that it will be used in a correct manner. Harnesses are often not adjusted tightly enough, which causes unwanted movement during arrest, thus exposing a worker to potential injury. The choice of anchor points, while convenient, may not always be appropriate, which can undermine the entire system. The lanyard is attached to a less than adequate anchor point simply because the correct anchor point is difficult to reach.

Training can help to resolve these problems, but it does not completely remove them. Human nature dictates that we take short cuts, especially when we have to perform the same action over and over. The more familiar we become, the more we get complacent, and that is when we set ourselves up to fall, even though we have all the equipment in place.

The unpleasant truth is that fall arrest systems only work when everything, and we mean everything, lines up correctly. If we miss one piece, we might as well not have it.