Figure 8 - Calculating Minimum Required Fall Clearance SRL-LE
* If a potential Swing Fall Hazard condition is also present, additional Fall Clearance is needed in the
above calculation; see Chart 3 on the previous page for calculating this additional required distance.
5.2.3 0’ Setback From Leading Edge and 5’ Below the Dorsal D-Ring Anchorage
With the anchor installed at zero set back and below the D-ring, as shown in Figure 8, there are eight metrics to consider when calculating
the MRFC. These eight metrics are labeled A, B, C, D, E, F, G and H. These metrics are:
A = Free Fall Distance due to Below D-ring Anchorage
B = SRL-LE Deceleration Distance
C = Additional Deceleration Distance - Note the added deceleration distance for 0’ setback.
D = Dorsal D-Ring Shift and FBH Stretch
E = Safety Factor
F = Sub Total- Minimum Required Fall Clearance
G = Additional Fall Clearance Calculation for Swing Fall – 4’ maximum
H = Total Required Fall Clearance
Use Figure 8 as a worksheet. The MRFC for this anchorage geometry is calculated as A+B+C+D+E= F. F is the Sub Total-MRFC. This total
does NOT account for swing fall. If a swing fall condition exists, use Chart 3 to determine “G”, the additional fall clearance needed. G+F=H
is the total fall clearance required.
0’ Minimum Setback from Leading Edge and 5’ below Dorsal D-Ring Anchorage
A
3.8 m
(12.5 ft)
SRD Deceleration Distance
(Worst Case Value, See Table 1B for Exact Model)
B
0.5 m
(1.6 ft)
Dorsal D-Ring Shift and FBH Stretch
Combined amount of Dorsal D-ring up-shift and harness webbing elongation during a
fall event
C
1.5 m
(5 ft)
Dorsal D-Ring Height
Height of the Dorsal D-Ring from the walking surface
D
0.5 m
(1.6 ft)
Safety Factor -
Added length to account for other factors such as an improperly
adjusted harness, actual worker height or worker weight
E
6.3 m
(20.7 ft)
Sub Total- Minimum Required Fall Clearance
for Below D-ring Anchorage of SRD with
No Swing Fall (sum of A thru D only)
F
*Additional Fall Clearance Calculation
-
due to Swing Fall (using Chart 3)
H
Total Required Fall Clearance
Including sub-total E and Swing Fall F (from Chart 3)
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CMSRD08 Rev A
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