Theatre Design & Technology - Winter 1996 - 18

worker. The lifeline deflects several feet off
arena that the engineers have deemed riggable, the syss the lifeline resists tem has its drawbacks. An ideal fall protection system,
horizontal in the span between the intermediate D-ring/hanger supports. Part of this
the downwardpull of according to the riggers in Cleveland, would allow them
deflection is due to dynanlic elongation of
to move at random anlOng all the interconnected
the falling riggeJ; the glidwork of beams. nrestricted access to anywhere they
the line and part is due to the controlled
expansion of the end-mounted energy ablanyard pulls up on can climb is Irhat top riggers experienced in arenas withsorber. As the lifeline resists the dmrBward
out fall protection have come to expect through long
pull of the falling rigger, the lanyard pulls
the dorsal lanyardathabit. In tllis system at the Gund Arena. their movement is
up on the dorsal lanyard attachment on the
restricted by the location and number of entry/exit points
tachment on thefullfull-body harness, orienting the falling
for each lifeline, and the inability to move direcuy beworker into an upright position. If the
body harness, ol'ient- tween intersecting lifelines.
force of the falling rigger exceeds 450 lbs.,
More entry/exit points for the Transfasteners would
ing thefalling wOl'kel' be nice. While each lifeline crosses five or sLx catwalks,
the lanyard shock absorber \\~u partially
tear open and lengthen, thus absorbing
liggers who have traversed the length of a beanl are
into a basically upsome of the energy. The shock absorber
forced to return to ule single entry/exit point to disenkeeps ule forces communicated to the fallgage ule Transfastener. As a result, uley spend a lot more
rightposition...
ing worker within safe levels-900 Ibs.
time walking the beams than if they could enter and exit
Maximum Arresting Force. After a minor
at any catwalk intersection.
rebound the fallen worker comes to a stop and reBeing able to transfer between intersecting lifelines would add to the convemains hanging in an upright position several feet
nience of the system as well. For instance, if a rigger is on a roof truss beanl and
below Ule beam until he or she is rescued. The plan
needs to get to a location on an intersecting Box Rigging Beanl just a few feet away,
for rescue at the Gund is to have a nearby fire dehe cannot move there direcuy. He must go back to the enlIy/exit point of the lifeline
pal1ment bring a ladder truck into Ule building to
he is on, remove his Transfastner, walk on ule catwalks to Ule enlI)' point for tile
rescue the fallen worker.
Box Rigging beanl he needs to be on, inse11 llis Transfastner, and ulen walk that
beanl to where he needs to be. Moving to intersecting beanls always involves going
Ule
long way around. The Gund Arena Rigging Plan on page 15 shows the entry/exit
LIMITATIONS AND REFINEMENTS
points and you can get an idea of ule choreography necessary to rig several motor
Riggers in Ule Gund Arena have had a few months to
points. FOlwnately, Tom Villeneuve of Fall Arrest Systems, Inc., says llis company
get used to ule fall arrest system, and on the whole,
will be coBling out with a new Transfastner unit in a few months that will be able to
uleir reactions have been positive. Working atattach and detach at any point on Ule lifeline cable without the need for special entached to the horizontal lifelines provides them with
try fittings on the line.
peace of !llind allowing them to work quickly and
AlulOugh not in use in the Gund Arena, a two-legged V-shaped lanyard is
\\~th less worry.
sometimes used instead of a del~ce like the Transfastener. A two-legged lanyard
Even tllOugh ule installed system of lifelines
(see illustration on p. 23) has two webbing legs WiUl snaphooks attached to a
provides safe access to virtually eve1Y beam in Ule
single shock absorber on the end that attaches to the harness. The two legs allow
the rigger to attach one of ule legs directly to the lifeline at any point along ule lifeline, and then use the second leg to leap-frog over support hangers, or even change
from one lifeline to anouler, without disconnecting entirely from the system.

END
ANCHORAGE

CABLE GUARD@
ENERGY ABSORBER
TURNBUCKLE

UNE TENSION
INDICATOR

5116" 7x7
STAINLESS STEEL CABLE

MID-ENTRY/EXIT

NOTE: CENTER SUDES OPEN
TO AUOW
TRANSFASTENER
ENTRY/EXIT

ANGLE A TTACHEa

TO VERTICAL STEEL

All the components of the lifeline assembly have been selected to be able to support the forces communicated to them by two or
three falling workers. The CableGuard~ energy absorber spreads the shock force over time, thereby decreasing by up to 30% the
Maximum Arrest Force (MAF) experienced by the lifeline.

WINTER

996

TD&T

Table of Contents for the Digital Edition of Theatre Design & Technology - Winter 1996