Comparing shock absorbing fall protection

Comparing shock absorbing fall protection

 

Here we are comparing shock absorbing fall protection lanyards and self-retracting lifelines. The impact forces generated in a fall are substantial. To illustrate this we are first showing a regular webbing fall restraint lanyard with no shock absorber here. The weight is 220 lbs of steel. Note the sudden stop and violent rebound. This short fall generated just over 4000 lbs of impact force. OSHA says that we can transmit a max of 1800 lbs while the ANSI standard says 900lbs. All DBI/SALA products use that ANSI 900 lb limit.

 

So how do they do that? The energy from the fall must be dissipated by spreading the force out over time. In the case of a lanyard, and many SRL’s, this is done by the controlled ripping of specially sewn webbing. In the case of the EZ-Stop II, 2 pieces of webbing are torn apart, with a backup web strap so the tear is never complete.

 

This next internal type lanyard has an elastic band inside to keep the length (and slack) minimized while working. In the case of a fall, it extends to its full 6 ft length and the internal stitching starts to tear. One interesting note is that except for the tag that pops out, the lanyard still looks good after a fall. (But, after a fall, it must be taken out of commission and, preferably, thrown away. It is no longer good to use. Be sure to inspect your lanyards before each use to be sure they have not been in a fall already.)

 

Lastly, here is a DBI UltraLok self-retracting lifeline. This device has an internal braking system. The big deal with an SRL is the shortened fall distance. This means that you can use it closer to the ground or next to a lower obstacle. A very short fall distance also means low impact forces, less danger of hitting other objects, and no lanyard hanging around.