Proper Use Of D-Rings; Calculating Fall Clearance Distance - Miller DURAFLEX 2PT MA04 Manuel D'utilisation

3.6 Proper Use of D-Rings

Back D-rings are for
fall arrest
or retrieval only.
[Note Exception: Front D-rings may be used for fall arrest only in applications where the personal fall arrest sys-
tem limits the maximum free fall distance to 2 ft. (0.6m) and limits the maximum arrest force to 900 lbs. (4.0kN).]

4.0 Calculating Fall Clearance Distance

It is important to understand how to calculate potential fall clearance to avoid contact with a lower level.
The following diagrams demonstrate sample calculations using a shock-absorbing lanyard and self-
retracting lifeline. When actually calculating fall clearance distance, the authorized person/user must
consider all variables, including but not limited to, the height of the worker, the length of the lanyard, the
maximum arrest distance of the self-retracting lifeline, the position of the person (standing or crouched),
and the anchorage connector used, and then make necessary adjustments to the calculations.
Before Fall
6 ft.
(1.8m)
Height of Worker
Always refer to the instruction manual of the connecting device being used for more specific
information and warnings regarding calculating fall clearance distance. If there is any question
about calculating fall clearance distance, please contact Miller Technical Services at 1-800-873-5242.
Us er Ins tru ct ion s - Engl is h
Front D-rings are for
positioning. Note front
D-ring exception below.
Illustration: Self-Retracting Lifeline with D-Bolt Anchorage Connector
After Fall
Bottom of Retractable
2 ft.
Maximum Free Fall Distance
2
Maximum Deceleration Distance
1 ft.
5 ft.
To Worker's Back D-Ring
3 ft.
Safety Factor
Side D-rings are for
positioning only.
(.6m)
4
Maximum Arrest Distance
ft.
(.8m)
(per ANSI)
(.3m) Harness Stretch
(1.5m)
(.9m)
9
Shoulder D-rings are
ft.
(1.4m)
13
for retrieval only.
(4.1m)