Explain the potential effects of swing falls on a worker using a fall arrest system, and describe three methods to minimize the severity of this type of fall.
Swing falls are a significant hazard associated with fall arrest systems, occurring when the anchor point is not directly overhead of the worker. This results in a pendulum-like motion during a fall, which can significantly increase the severity of injuries. Here's a breakdown of the potential effects of swing falls and three methods to minimize their impact:
Potential Effects of Swing Falls:
1. Increased Fall Distance: Swing falls often result in a greater effective fall distance compared to a straight vertical fall. This is because the pendulum motion causes the worker to travel both downwards and sideways, extending the time and distance they are accelerating. The energy absorber in the fall arrest system is designed for vertical falls, and the added distance of a swing fall can overload it, or result in higher impact forces on the worker, increasing the chance of injury. For example, a worker who falls two feet vertically, but swings five feet sideways, effectively falls much further before the system engages.
2. Collision with Objects: The swinging motion increases the risk of the worker colliding with surrounding objects and structures. Workers might swing into walls, scaffolding, equipment, or other obstacles, leading to serious injuries such as fractures, lacerations, concussions, and internal injuries. These collisions can also cause secondary impacts. The pendulum effect makes it harder for a worker to brace themselves or protect their head and body from the impacts. For instance, a worker might swing into a nearby steel beam, resulting in a head injury.
3. Increased Severity of Injuries: The combined effects of increased fall distance and the risk of impact with objects often lead to more severe injuries from swing falls compared to vertical falls. Injuries may be more traumatic, including spinal injuries, head injuries, and internal organ damage, all of which can lead to long term health issues. The forces that the body is exposed to in a swing fall are often much higher.
4. Difficult Rescue: Swing falls can complicate rescue operations. If a worker swings into a location that is difficult to reach, rescue personnel might struggle to access the worker quickly. Entanglement with objects or the fall arrest system may also complicate rescues and create a more dangerous situation for the rescuers.
5. Unpredictable Movement: The pendulum motion of a swing fall makes it difficult to predict exactly where a worker will end up, further complicating rescue efforts. The unpredictable movements also increase the risks to the worker.
Methods to Minimize the Severity of Swing Falls:
1. Proper Anchor Point Positioning: The most critical step in minimizing swing falls is selecting and positioning anchor points directly above the work area. When the anchor point is directly overhead, a fall will be predominantly vertical with minimal swing. Careful planning should be done to ensure the correct anchor point is used, and to minimize any chance of sideways movement during a fall. For example, when working on a horizontal surface, an anchor point should always be directly overhead, and if this is not possible, a system of multiple anchor points or horizontal lifelines must be used to minimize side to side movement. If working on a structure, an anchor point should be used so that the swing zone will be minimized. Planning where each anchor point is located can be critical in reducing the chances of a swing fall.
2. Shorter Lanyards or Self-Retracting Lifelines (SRLs): Using shorter lanyards or SRLs reduces the potential fall distance and limits the swing arc. Shorter lanyards restrict the worker’s range of movement and limit the pendulum effect. SRLs lock quickly in the event of a fall and can reduce the distance a worker falls before the system engages. SRLs are better than a long lanyard for limiting the distance of a swing fall. This is especially important when working in areas where there are obstructions nearby. Using shorter devices reduces the chances of the worker coming into contact with any objects. A lanyard that is too long will result in a much longer fall and may allow the worker to swing into objects or structures. Personal fall limiters should also be considered when a limited fall distance is needed.
3. Controlled Work Zones and Fall Hazard Planning: Establishing controlled work zones can help limit the areas where workers can move, which also helps to limit the potential for a swing fall. Careful job planning can greatly reduce the risk of swing falls. These plans should identify potential swing fall areas, and include plans to reduce those areas as much as possible. By analyzing the potential swing path, and removing any objects that can be struck by the worker during a fall, you can create a much safer area. This must be communicated to all workers. Plans should also include guidance on choosing and positioning anchor points, selecting the correct equipment, and establishing safe working practices to reduce the risk of a fall. Work at height should never begin until a thorough assessment has been completed, and the risks and potential hazards have been addressed.
In conclusion, swing falls are a serious risk associated with fall arrest systems and can cause more severe injuries than a direct vertical fall. By implementing these proactive strategies—correct anchor point selection, shorter connection devices, and controlled work zones—organizations can significantly reduce the severity of swing falls and create a safer working environment. Training workers to recognize and avoid swing fall hazards is essential. Companies must develop thorough plans and procedures for all work at heights and must ensure that all work is planned with safety in mind.