FallTech Sling Anchors - Manual (Page 6)

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2.8: Free-Fall
Free-Fall is the distance that a worker will fall before the connecting
device or deceleration device elements of the PFAS will begin to engage
during a fall event. OSHA allows a maximum Free-Fall Distance of 6’ (6
feet) when rigging a Personal Fall Arrest System (PFAS). In some
cases, exceptions may be allowed when there is no practical way to limit
the Free-Fall Distance to 6’, such as a job-site where no overhead
anchor-point is available. Tying off in a manner that would create a
Free-Fall greater than 6’ should always be a last resort. If you are
rigging a system that allows more than 6’ of Free-Fall, make sure your
Connecting Device/Deceleration Device is rated for this application.
2.9: Clear-Fall
Clear-Fall or Clear-Fall Distance is the distance that is required to
safely arrest the fall of a user. When working at heights and using a
PFAS, it is important to consider the distance between the
walking/working level and the next lower level to ensure that the
components selected are capable of arresting the user’s fall before they
hit the next lower level. The required Clear-Fall Distance can easily be
calculated by adding together the Free-Fall Distance, the Deceleration
Distance, the height of the user plus a safety factor of 2 feet. The
formula for calculating Clear-Fall Distance is shown below:
Free-Fall Distance + Deceleration Distance + Height of Worker + Safety Factor = Clear-Fall
Distance
The matrix below can be used as a guide for calculating Clear-Fall
Distance on your job-site:
Example Values Actual Values
Free-Fall Distance
(OSHA allows up to 6’)
6’
Deceleration
Distance
(Typically 3.5’ or less)
3.5’
Height of Worker 6’
Safety Factor
(Minimum of 2’)
2’
Total
(Sum of all values)
17.5’
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See figure 2.1 below for a graphic illustration of Clear-Fall Distance and
the method for calculating. It is also necessary to consider the fall path
when determining the Clear-Fall limitations in your application. Ensure
the fall path is clear of obstructions, protrusions, equipment or materials
that may be a hazard in the event of a fall. Pay special attention to those
items which may present an impalement hazard. Obstructions in the fall
path may be just as hazardous as the fall itself, and your PFAS may not
be able to protect you from these hazards. Failure to clear the fall path
may result in serious injury or death. Rig your PFAS with extreme
caution, and be aware of all of the factors that may come into play in the
event of a fall.
Figure 2.1: Clear-Fall Diagram