point
relative
to
the
user’s
FBH
D
‐
ring,
i.e.,
overhead
or
non
‐
overhead
anchorage
condition,
plus
swing
fall
and
how
an
expanded
work
zone
affects
these
variables.
4.3.1
Overhead
(Above
the
D
‐
ring)
Anchorage
Condition:
In
an
overhead
anchorage
condition,
the
SRD
is
installed
anywhere
in
the
allowable
attachment
area,
which
ranges
from
directly
above
the
user
to
as
low
as
the
level
of
the
FBH
D
‐
ring,
as
shown
in
Figure
3A
in
Appendix
A.
The
overhead
condition
MRFC
has
three
metrics,
labeled
A,
B,
and
C,
measured
from
the
walking/working
surface.
The
sum
total
of
these
metrics,
labeled
D,
is
the
MRFC.
A
=
SRD
deceleration
distance
B
=
D
‐
ring
shift
and
harness
stretch
C
=
Safety
factor
The
MRFC
for
an
overhead
anchorage
is
calculated
as
A+B+C=D.
4.3.2
Non
‐
Overhead
(Below
the
D
‐
Ring)
Anchorage
Condition:
In
a
non
‐
overhead
anchorage
condition,
the
anchor
point
is
level
with
the
FBH
dorsal
D
‐
ring,
or
up
to
2'
below
it,
as
shown
in
Figure
3B
in
Appendix
A.
The
MRFC
for
a
below
the
D
‐
ring
condition
has
five
metrics,
labeled
A,
B,
C,
D,
and
E,
and
are
measured
from
the
walking/working
surface.
The
sum
total
of
these
metrics,
labeled
F,
is
the
MRFC.
A
=
Anchorage
Distance
below
Dorsal
D
‐
ring
B
=
SRD
Deceleration
Distance
C
=
Additional
Deceleration
Distance
due
to
Below
D
‐
ring
attachment
D
=
D
‐
ring
shift
and
harness
stretch
E
=
Safety
factor
The
MRFC
for
an
anchorage
below
the
D
‐
ring
is
calculated
as
A+B+C+D+E=F.
Be
aware
that
if
the
user
is
kneeling
or
crouching
while
performing
work,
add
up
to
an
additional
3
feet
to
the
total
MRFC.
4.4
Swing
Fall:
A
swing
fall
occurs
when
the
worker
moves
laterally
out
from
the
center
of
the
work
zone
and
creates
an
expanded
work
zone
condition.
See
Figure
4
in
Appendix
A.
If
a
fall
event
occurs,
the
worker
would
swing
back
toward
the
anchorage.
The
swinging
action
generates
considerable
force,
and
if
the
worker
strikes
an
obstruction
or
came
into
contact
with
the
lower
level
or
the
ground,
this
force
could
cause
severe
injury
or
death.
4.4.1
Overhead
Anchorage
and
Swing
Fall:
For
each
foot
of
work
zone
expansion,
the
risk
of
severe
injury
or
death
from
a
swing
fall
increases.
Also,
as
an
anchorage
becomes
lower
relative
to
the
FBH
D
‐
ring,
risk
increases.
Combine
an
expanded
work
zone
with
a
lower
anchorage
and
the
risk
increases
greatly.
This
increased
risk
requires
additional
MRFC
distance.
See
Chart
1
for
instructions
on
how
to
determine
a
safe
work
zone.
4.4.2
Non
‐
Overhead
Anchorage
and
Swing
Fall:
A
swing
fall
from
an
expanded
work
zone,
combined
with
the
much
lower
height
of
a
non
‐
overhead
anchorage,
will
significantly
increase
the
risk
of
severe
injury
or
death
due
to
the
longer
distance
the
user
would
fall.
This
condition
requires
an
increased
MRFC.
See
Chart
1
for
instructions
on
how
to
determine
a
safe
work
zone.
WARNING
An
expanded
work
zone
combined
with
an
SRD
used
in
a
non
‐
overhead
(below
the
D
‐
ring)
condition
is
extremely
hazardous.
DO
NOT
attach
to
an
anchorage
more
than
2
feet
below
the
level
of
the
FBH
D
‐
ring.
4.5
Locking
Speed:
The
SRD
utilizes
a
centrifugally
activated
pawl
locking
mechanism
to
apply
a
disc
brake
to
slow
and
arrest
a
fall.
This
requires
a
certain
minimum
pay
‐
out
rate
to
function.
Some
situations,
confined
or
cramped
spaces,
shifting
footing
such
as
sand,
gravel,
grain,
or
a
sloped
surface,
may
not
allow
the
lifeline
to
reach
sufficient
speed
to
activate
the
lock
mechanism.
A
clear
path
is
required
to
assure
positive
locking
of
the
SRD.
4.6
Installation
and
Use
of
the
SRD:
Use
compatible
connectors
when
connecting
to
the
anchorage
and
ensure
unintended
disengagement
cannot
occur.
Visually
ensure
the
connector
closes
and
locks
securely.
See
Figure
13
in
Appendix
B.
The
SRD
is
configurable
into
two
orientation
options;
4.6.1
Housing
End
Attached
to
the
FBH
:
The
SRD
housing
end
is
installed
to
the
dorsal
D
‐
ring
of
an
FBH
and
the
leg
end
attached
to
a
suitable
anchorage.
The
anchorage
may
range
from
directly
overhead,
to
as
low
as
2'
below
the
dorsal
D
‐
ring.
Refer
back
to
Figure
2A
in
Appendix
A
.
To
attach
the
SRD
on
the
harness
see
Figure
5A
in
Appendix
A.
Follow
these
steps:
1.
Don
the
harness
in
accordance
with
the
harness
manufacturer’s
instructions.
2.
Insert
the
nose
end
of
an
ANSI
compatible
double
‐
locking
carabiner
through
the
SRD
housing
swivel
eye.
3.
Attach
the
carabiner
to
the
dorsal
D
‐
ring
of
the
FBH.
Ensure
the
carabiner
is
oriented
with
the
lock
opening
up
and
will
take
the
load
along
its
major
axis.
Visually
ensure
the
carabiner
lock
is
fully
closed
and
locked.
4.
Connect
the
leg
end
connector
to
an
approved,
suitable
anchor
that
meets
work
zone
requirements.
The
SRD
will
pay
out
and
retract
smoothly
to
maintain
a
taut
line
during
normal
movement.
Work
as
directly
under
the
anchor
as
possible.
If
necessary,
the
leg
end
connector
may
be
attached
to
a
lower
level
anchorage,
up
to
2
ft.
below
the
user’s
harness
D
‐
ring.
Be
aware
that
a
lower
anchorage
increases
the
risk
of
injury
due
to
swing
fall.
Additional
fall
clearance
is
required.
4.6.2
Housing
End
Attached
To
The
Anchorage
:
The
housing
end
connector
is
installed
to
a
suitable
anchorage.
The
anchor
point
may
range
from
directly
overhead
to
as
low
as
2'
below
the
dorsal
D
‐
ring.
Refer
back
to
Figure
2B.
The
leg
end
is
connected
to
the
dorsal
D
‐
ring
of
the
FBH.
To
attach
the
housing
to
an
anchorage,
see
Figure
5B
and
follow
these
steps;
1.
Don
the
harness
in
accordance
with
the
harness
manufacturer’s
instructions.
2.
Insert
the
nose
end
of
an
ANSI
compatible
double
‐
locking
carabiner
through
the
SRD
housing
swivel
eye.
3.
Attach
the
carabiner
to
the
anchor
point.
Ensure
the
carabiner
is
oriented
with
the
lock
opening
up
and
will
take
the
load
along
its
major
axis.
Visually
ensure
the
carabiner
lock
is
fully
closed
and
locked.
4.
Connect
the
leg
end
connector
to
the
dorsal
D
‐
ring
of
the
FBH.
Visually
ensure
the
connector
is
fully
closed
and
locked.
The
SRD
will
pay
out
and
retract
smoothly
to
maintain
a
taut
line
during
normal
movement.
Work
as
directly
under
the
anchor
as
possible.
If
necessary,
the
leg
end
connector
may
be
attached
to
a
lower
level
anchorage,
up
to
2
ft.
below
the
user’s
harness
D
‐
ring.
Be
aware
that
a
lower
anchorage
increases
the
risk
of
injury
due
to
the
swing
fall
effect.
Additional
fall
clearance
is
required.
DO
NOT
attach
the
SRD
leg
end
to
the
FBH
with
a
rebar
hook
or
any
large
‐
throat
snap
hook
or
large
carabiner.
A
side
load
could
cause
an
unintentional
disengagement.
Use
small
snap
hooks
only.
DO
NOT
attach
the
housing
to
the
FBH
with
a
rebar
hook
or
any
large
‐
throat
snap
hook
or
large
carabiner.
A
side
load
could
cause
unintentional
disengagement.
4.7
Impact
Indicator:
The
SRD
incorporates
a
fall
arrest
impact
indicator
in
the
web
lifeline,
between
the
housing
and
leg
end
connector,
in
the
form
of
a
stitched
fold.
Broken
or
torn
stitching
indicates
the
SRD
has
been
subjected
to
fall
arrest
forces.
Remove
the
SRD
from
service
immediately.
DO
NOT
allow
the
lifeline
to
become
tangled
or
twisted
as
this
may
prevent
it
from
retracting.
DO
NOT
allow
the
lifeline
to
pass
under
arms
or
between
legs
during
use.
