Falltech SRL-LE User Instruction Manual page 8

5.2 Calculating SRL-LE MRFC
5.2.1 SRL-LE in Overhead, Non-Leading Edge Anchorage Application
The Leading Edge SRD may be used may be used as a standard SRD in an overhead condition, in which the SRD is installed anywhere in the
allowable attachment area, which ranges from directly above the user to level with the FBH D-ring, as shown in Figure 4. The overhead
condition MRFC has six metrics, labeled A – F, measured from the walking/working surface.
A = SRD Deceleration Distance
B = D-Ring Shift and Harness Stretch
C = Safety Factor
D = Sub Total- Minimum Required Fall Clearance
E = *Additional Fall Clearance Calculation Due To Swing Fall
F = Total Required Fall Clearance
The MRFC for an overhead anchorage, with no swing fall condition, is calculated as A+B+C=D. The user must be aware that if a swing fall
hazard exists, as shown in Figure 5, additional steps are required. Use Chart 1 on the following page to determine the amount of swing
fall, and place that value in E. Add the E value to the D value to determine the total MRFC.
Figure 4 - MFRC Overhead Anchorage
Deceleration Distance
Maximum allowable length of cable or web that
0.9 m may payout from the SRD once deceleration of the
A
(3 ft) user has begun and after a fall event occurs. For
work in low clearance areas, see Table 1B for Typical
Performance
Dorsal D-Ring Shift and FBH Stretch
0.5 m
B Combined amount of Dorsal D-ring up-shift and
(1.6 ft)
harness webbing elongation during entire fall event
Safety Factor
0.5 m
Added length to account for other factors such as an
C
(1.6 ft) improperly adjusted harness, actual worker height
or worker weight
Sub Total- Minimum Required Fall Clearance
1.9 m
D for direct overhead use of SRD with No Swing Fall;
(1.9 ft)
sum of A, B and C only
*Additional Fall Clearance Calculation
E ____ m
due to Swing Fall (using Chart 1)
Total Required Fall Clearance
F ____ m
Including sub-total D and Swing Fall E (from Chart 1)
1. Overhead Anchorage 2. Walking/Working Surface
3. Nearest Lower Level or Obstruction
CMSRD08 Rev A
Figure 5 - Swing Fall Hazards: Overhead, Non-Leading Edge
A Anchorage
B Self-Retracting Lifeline
C Walking/Working Surface
D Swing Fall Impact after fall event
E Next Lower Level or Obstruction
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