January 8th, 2013
The Self-Retracting Lifeline (SRL) is one of the most common, and one of the most useful, pieces of fall protection equipment used in the construction industry today. Depending on the model, these versatile units can be either mounted on a full-body harness or to an anchorage connector, thereby allowing them to be either mobile or stationary, and many can also be used in combination with horizontal lifelines.
SRLs consist of a housing component with an integrated braking mechanism, in which is wound either a web or cable lifeline. They maintain constant tension on the lifeline in order to eliminate slack and prevent free fall, and function to immediately engage their braking mechanism in the event of a fall to catch the worker as quickly as possible.
Not all SRLs are alike however, and understanding the differences between the two primary types is key to maintaining worker safety. The first and most common type of SRLs are those that are NOT certified for use in horizontal applications or leading edge work, meaning that the SRL must always be positioned at or above the harness dorsal D-ring (which is the only Fall Arrest attachment point on a full-body harness). The lifelines of these SRLs are not designed to absorb the necessary forces to safely impact the leading edge of a fall hazard, or to be subjected to free fall. While such SRLs are perfect for work in many environments, they are not sufficient when working, for example, on the top level of a structure where there are no overhead attachment points available.
The second and less common type of SRLs are Leading Edge/Heavy Duty (HD) SRLs, such as those in the Guardian Fall Protection Heavy Duty Edge Series. The HD Edge Series is specially designed to be used down to (but not below) the height of the edge over which a fall may occur (usually the foot-level of the worker). In the event of a fall these SRLs, because of their integrated shock absorbers and durable system housing, function to preserve the integrity of the lifeline through the more efficient dispersal of forces of Fall Arrest.
The automatic lifeline retraction feature of any SRL is integral to its functionality because when a fall occurs the unit is already, in effect, in deceleration mode. This serves to virtually eliminate any free fall when the unit is at or above the harness dorsal D-ring because the retraction is already pulling against the direction of the fall. But, if a fall occurs when the SRL is positioned below the dorsal D-ring, the lifeline retracts in the same direction as the fall until the dorsal D-ring reaches the same level as the SRL, thus resulting in the free fall of the worker. And, when a worker experiences free fall, the forces of Fall Arrest increase significantly.
Luckily for users of the Guardian HD Edge Series, if subjected to free fall, the integrated shock absorbing component will deploy in order to refocus forces away from the portion of the lifeline that comes into contact with the edge, thereby helping protect both the lifeline and the user from harm. HD Edge Series SRLs are some of the best available on the marketplace, and are the ideal SRLs for work on leading edges or where no overhead anchorage connectors are available.
HD Edge Series SRLs are all lightweight, compact, and supremely durable. They are composed of stainless steel and other non-corrosive materials, are available in lengths from 20 to 65 feet, and have everything it takes to get the job done as safely as possible.