There is an all too common situation where a shock-absorbing fall protection lanyard does not meet fall protection requirements.

Miller Fall Protection puts it like this, “when using a shock-absorbing lanyard, it is important to understand how to calculate potential fall distance to avoid contact with a lower level“. A lower level can be the decking of a lower floor, an obstruction below you, or even the ground.

Whenever the distance from your anchor point to that lower level is less than 18.5 feet a shock-absorbing fall protection lanyard cannot be used. Take a look at Miller’s diagram below to see why.

Miller explains the above diagram as follows:

1. When using a six-foot shock-absorbing lanyard and a full-body harness, first add the length of the shock-absorbing lanyard [6 ft.] to the maximum elongation of the shock absorber during deceleration [3-1/2 ft.] to the average height of a worker [6 ft.].
2. Then, add a safety factor of 3 ft. to allow for the possibility of an improperly fit harness, a taller than average worker, and/or a miscalculation of distance. 
3. The total, 18-1/2 ft., is the suggested safe fall clearance distance, the height at which you must attach to an anchorage to minimize the risk of contact with a lower level.