5.0 Installation and Use
7
MDRE01 Rev B
112618
Installation of D-Ring Extenders must be under the supervision of a Competent Person trained in their design and use.
NOTE:
Approved fall protection may be required during installation of all extender units discussed in this manual.
DO NOT
use any extender discussed in this manual until the system has been completely installed, inspected, and approved for use by a Competent
Person.
5.1
Anchorage Location:
Select a suitable anchorage point that will support the strength requirement and minimize free fall and swing
hazards. See Section 4.5.1 of this manual for anchorage strength requirements.
DO NOT
allow free fall to exceed six feet.
5.2
Fall Clearance Distance:
Take action to reduce the danger of falls. Ensure sufficient clearance in the fall area to arrest the fall before
contact with the ground or other obstructions. The actual clearance required is dependent upon the type of connecting subsystem used
(EAL, SRL). See Figure 4.
Figure 4: Minimum Required Fall Clearance:
D-Ring Extender and 6ft Energy Absorbing Lanyard
A
6 ft
Length of Shock Absorbing Lanyard
Original working length before a fall event occurs/before
activation of energy absorber
B
4 ft
Elongation/Deceleration Distance
Maximum allowable amount of elongation that may payout
from the energy absorber upon activation during a fall event
C
11/2 ft
Length of D-Ring Extender (18”)
D
1 ft
Harness Stretch and Dorsal D-Ring Shift
Combined amount of harness webbing elongation and
dorsal back D-ring up-shift during entire fall event
E
5 ft
Height of Dorsal D-ring
Typical average height of the dorsal D-Ring on a user’s full
body harness measured from the walking/working surface
up
F
1 1/2 ft
Safety Factor
Added length to account for other factors such as an
improperly adjusted harness, actual worker height or
worker weight
G
19 ft
Total Minimum Clear Fall Distance Required
1. Overhead Anchorage 2. Walking/Working Surface
3. Nearest Lower Level or Obstruction
NOTE: Use of an extender will increase the users potential fall distance. The user must be sure the increased total length of a lanyard is
accounted for in calculating fall clearance distances, including swing fall. Be aware that when using an SRL, there may be additional fall clearance
required depending on anchor point location. If unsure, consult a Competent Person.
A Anchorage
B
Self-Retracting Lifeline
C Walking/Working Surface
D
Swing Fall Impact after fall event
E
Next Lower Level or Obstruction
Figure 5 -
Swing Fall Hazards: Overhead
5.3
Swing Fall:
Swing falls occur when the anchorage point is not directly above the point where a fall occurs. The total fall distance may be
greatly increased during a swing fall. The force of striking an object in a swing fall may cause serious injury. Minimize swing falls by
installing anchors at least six feet from exposed edges and by working as directly below the anchorage point as possible. Consult the
equipment manufacturer’s user instructions. See Figure 5.
