7.0 Calculating Fall Clearance Distance
It is essential to understand how to calculate the fall clearance distance required
for each work application to avoid contact with a lower level.
The basic calculation diagrams on the following page may be used to determine Required Fall
Clearance when using a shock-absorbing lanyard or self-retracting lifeline in an overhead ap-
plication. As many additional variables or factors can affect fall clearance, it is imperative that
the user also refer to the instructions provided with the connecting device for more compre-
hensive information. For a more automated approach to calculating Required Fall Clearance,
access the Miller Fall Clearance Calculator online:
Fall Clearance Calculation Guidelines
•
Full-body harness stretch is limited to 18 in. (457.2mm) or less. Full-body harness stretch,
the amount the full-body harness component of a personal fall arrest system will stretch
and deform during a fall, can contribute to the overall elongation of the system in stopping
a fall. It is important to include the increase in fall distance created by full-body harness
stretch, as well as the full-body harness connector length, the settling of the user's body
in the full-body harness, and all other contributing factors when calculating total clearance
required for a particular fall arrest system. Honeywell Safety Products recommends and
includes a 3 ft. (0.9m) safety/stretch factor in its calculations.
•
When a D-ring extension is used, add the length of the extension to the fall clearance
calculation.
•
Shock absorbers will elongate when subjected to fall arrest forces. Refer to the labels pro-
vided with the connecting device to determine the maximum elongation distance, and be
sure to use the maximum elongation distance to calculate required fall clearance.
Us er Ins tru ct ion s - Engl is h
www.millerfallprotection.com/fallclearance
IMPORTANT NOTE:
The shock-absorbing lanyard calculation
determines required fall clearance from
the connection point of the lanyard (to the
anchorage connector or anchorage) to the
next lower level or obstruction below the
work surface. The self-retracting lifeline
calculation determines required fall clear-
ance from the work level to the next lower
level or obstruction.
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