FallTech Web SRL’s - Manual (Page 6)

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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’)
2’
Deceleration
Distance
(Typically 3.5’ or less)
3.5’
Height of Worker 6’
Safety Factor
(Minimum of 2’)
2’
Total
(Sum of all values)
13.5’
See figure 2.1 on the next page 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.
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Figure 2.1: Clear-Fall Diagram
2.10: Swing-Fall
Swing-Fall is the phenomenon that occurs when the user falls from a
location that is not directly adjacent to, or directly below the anchorage
connector. This is also referred to as the “pendulum effect”, and can
result in a situation where the user is not only falling vertically, but is also
swinging on the horizontal as well. This can bring additional hazards into
play, as you may swing into an obstruction or structural element, causing
serious injuries (see figure 2.2). A significant Swing-Fall may also
require increased Clear-Fall distance. As a rule of thumb, you should
ensure work in an area that does not exceed an angle greater than 15
degrees in any direction from your anchorage.
Figure 2.2: Swing-Fall Diagram