When a worker is working at a height, a variety of tools, parts, and systems are utilized to arrest (halt) their fall. These tools are collectively referred to as fall arrest systems. Only when no other fall protection options, such as engineering controls (such as a raised platform), guardrails, safety nets, or travel restraints are available or practical should a fall arrest system be employed. Fall arrest systems ought to be built with the following considerations in mind: minimizing the free fall distance, minimizing the forces that the worker will experience during the fall, preventing the worker from colliding with other surfaces while falling, and guarding against swing or pendulum falls. For more information on fall safety, including a fall protection plan, see other OSH Answers documents. Always utilize a fall arrest system in accordance with your local laws, as well as CSA Z259.17 ""Selection and use of active fall-protection equipment and system,"" Z259.12 ""Connecting components for personal fall arrest systems,"" Z259.16 ""Design of active fall-protection systems,"" and other guidelines. PLEASE NOTE that this paper does not cover all necessary needs. For detailed information, always check with your jurisdiction and the law that is relevant to your circumstance.
What factors come into play while employing a fall arrest system?
It's critical to evaluate both the risks that a worker would face if they were to fall and the fall arrest system's overall effectiveness. Included in the following three crucial components: Bottoming out refers to the possibility that a worker will contact the ground, as well as other objects, machinery, or a lower level of the structure, before the fall is stopped. Pendulum effect, also known as swing fall, happens when a worker swings from side to side. There is a chance that the worker will run into some sort of object, such as a piece of equipment or a piece of building, while swinging. Suspension trauma, also known as orthostatic intolerance, happens when a worker is suspended. Their blood will pool in their legs while they are still dangling, which will cut down on the amount of oxygen the brain receives. Conditions that slow down falling, such as sliding down a slope or stumbling into loose material, can have an impact on fall arrest systems (such as fine granules, or free flowing solid). Use only equipment that is compatible with the other elements in the situation (such as wire rope, synthetic rope, cable, or rail arresters). Before usage, any equipment or systems must be inspected, and if any problems are found, a qualified individual should decide whether the item should be utilized, fixed, or taken out of service.
What can be done to avoid bottoming out?
The fall arrest system should be created to keep the free fall to the lowest distance possible in order to prevent bottoming out. Take into account the following factors when calculating the total fall clearance distance: Length of the lanyard Length of the deployed energy absorber (when in use) the placement and sturdiness of the anchor point, the worker's height, the length of the harness and other equipment when stretched the horizontal (side-to-side) and vertical (up and down) clearances the potential for swing or pendulum falls a safety factor's separation
The complete fall distance calculation method.
Total fall distance is the distance between the worker's lanyard connection point and the anchor or lifeline, which is measured from the ground (or other object below). The length of the lanyard, the length of the energy absorber (when deployed), and a safety factor are other elements that need to be determined. Figure 1: Things to take into account when calculating fall clearance distance (adapted from Infrastructure Health and Safety Association, 2020) The CSA Z259.17 ""Selection and use of Active Fall-Protection Equipment and System"" contains detailed formulae. Other sources for advice include a fall safety training group or the equipment's maker. Note that you can view some CSA Group standards online. You must first register for an account with ""CSA Communities"" in order to access these. Access this page at https://community.csagroup.org/login.jspa?referer=%252Findex.jspa. After logging in, select the text that appears beneath the graphic that says ""OHS Standards / View Access."" To view the CSA Standards as they are mentioned in the relevant legislation, click on the jurisdiction of your choice. The CSA Group's store, located at https://store.csagroup.org, also sells standards.
The pendulum effect is what?
When a worker swings from side to side after a fall has been stopped, it is known as the pendulum effect, sometimes known as a swing fall. There is a risk of the worker hitting the ground (vertical impact), as well as equipment, materials, or the structure, when there is a swing (horizontal impacts). The more the worker swings, the harder they will strike anything in their path. When the lines come into touch with jagged or sharp edges, the movement of the lanyard or lifeline could also cause these lines to break. The anchor point should be immediately above the worker to lessen swing. You can also use a second anchor point at the same time, switch anchor points as the operation progresses to keep the lanyard or lifeline perpendicular (straight above), or utilize a horizontal lifeline as necessary.
Definition of suspension trauma
An employee who is suspended experiences suspension stress. Blood will collect in their legs when they are suspended (hanging) due to pressure from their body weight against the strap. Less blood (and oxygen) will thus be available to the brain. There is a chance of death, severe harm, or unconsciousness. Kidney failure may be one of the delayed effects. An efficient rescue plan will lay out the steps required to promptly rescue suspended employees. A relieving strap or a loop linked to the harness that a worker can put their feet into may help alleviate pressure while they are dangling. Taking these precautions won't assist if the worker is unconscious (from the fall, or from suspension trauma). In order to help activate the muscles required to flow blood, workers may also attempt to frequently ""pump"" their legs. Anyone on the job who slips or trips should be transported to the hospital for evaluation. Inform the emergency medical personnel about the duration of the employee's suspension. Request that the medical professionals keep an eye out for kidney failure.""" - https://www.affordablecebu.com/
