In personal fall arrest systems, the shock-absorbing lanyard is the critical component that saves a worker's life during a fall. Inside the webbing tube (or behind the clear plastic window) is a specially woven section of webbing with heavy, contrasting stitching. When a worker falls, the force of the deceleration rips these heavy stitches apart, expanding the lanyard by up to 3.5 feet. This ripping action dissipates the kinetic energy, keeping the impact force on the worker's body below the OSHA limit of 1,800 pounds, preventing the harness from snapping their spine or ribs.
However, workers routinely destroy the life-saving physics of these lanyards through two critical maintenance failures: re-packing and knotting.
When a lanyard is dropped, dragged, or heavily snagged, the shock pack often "deploys" slightly-the tail pops out of the protective sleeve, exposing the ripped stitching. A worker who doesn't want to fill out incident reports or wait for a replacement will often shove the tail back into the sleeve and secure it with tape, zip ties, or rubber bands. This is fatal. If the lanyard deploys again in a real fall, the stitches have already been torn. The lanyard will violently extend to its maximum length without absorbing the proper amount of energy, generating peak forces that will crush the worker's internal organs. If the tail is out, the lanyard is garbage. Destroy it immediately.
Even worse is the worker who ties a knot in the lanyard to shorten it or keep it from dragging. A knot reduces the breaking strength of synthetic webbing by over 50%. Furthermore, if a knot is tied *over* the shock pack, it physically prevents the stitches from ripping. When the worker falls, the shock pack cannot deploy, turning the lanyard into a rigid, non-absorbing strap that will violently jerk the worker to a stop, causing catastrophic spinal compression. Never alter, knot, or tamper with a shock-absorbing lanyard. If it's too long, you need a different length lanyard or a self-retracting lifeline.
