Self-retracting lifelines (SRLs) connect workers’ safety harnesses or body belts to anchor points on a nearby building or structure. SRLs extend and retract as the workers move, allowing them to move freely until a fall is detected. If a worker starts to fall, the SRL will brake suddenly to stop the fall and absorb its energy. They stop workers from free-falling and expand to help dissipate the force of the fall as it is arrested.