Fall Arrest Systems: Rope Grabs vs. Self-Retracting Lifelines

Choosing the most appropriate fall arrest system can be a challenge. Both “rope grab” and “self-retracting lanyard” (or lifeline) (SRL) systems comply with OSHA requirements and can stop a fall in progress. Here, we’ll take a brief look at each and weigh their respective advantages and limitations.

For accuracy and simplicity, we’ll use the OSHA definitions for a “rope grab” device and a “self-retracting lanyard.” OSHA 1910.66 Appendix C defines a rope grab as “a deceleration device which travels on a lifeline and automatically frictionally engages the lifeline and locks so as to arrest the fall of an employee. A rope grab usually employs the principle of inertial locking, cam/lever locking, or both.” The same document defines a self-retracting lanyard as “a deceleration device which contains a drum wound line which may be slowly extracted from, or retracted onto, the drum under slight tension during normal employee movement, and which, after onset of a fall, automatically locks the drum and arrests the fall.”

Rope grab systems by their nature imply that the rope (or cable) to which the device (and the worker) are attached may extend far below the point at which the worker is engaged. Thus, in the event of a fall, the burden of fall arrest rests both on the device and on the integrity of the rope/cable. An incomplete or ineffective grab can result in a worker descending the full length of the rope—far beyond the 6-foot maximum free fall distance requirement prescribed by OSHA. A compromised, damaged, or tangled rope or cable can also result in a severe fall. Such systems should be protected from compromise by foreign substances like oils or corrosives—anything that could reduce friction or damage the rope or cable. Such systems do have an advantage in roof work, however, finding a suitable attachment point for an SRL may be problematic. They are also useful where an overhead attachment point is unavailable.

SRLs, by their nature, protect within the drum that portion of the lanyard that is not exposed, and thus guard it from tangling, fraying, wear, or compromise by oils or corrosives. They also reduce obstacles in a worker’s immediate area. Because the SRL relies upon an overhead attachment point, there is no dangling rope or cable. Another advantage of SRLs is their ability to stop a fall smoothly. The smoother the stop is, the less likely it is that a worker will sustain a severe injury. Even a harnessed worker is subject to the risk for traumatic injury by a sudden fall arrest. Perhaps most importantly, the SRL allows for a faster, and easier rescue, should one be required.

When choosing the right fall arrest system, ask your manufacturer’s representative. They’ll be able to address your specific needs and concerns, and help you make the right purchase decision.