Theatre Design & Technology - Fall 1997 - 33

GIMBLED FLYING SCENERY
James Kempf
Yale School ofDrama

he design for the Yale RepertOlY Theater and
the New York Shakespeare Festival's co-production of Venlls
contained an unusual flying lightbox. The unit measured approximately 4'-0" deep by 10'-0" wide by 2'-0" high and contained 8,000 watts of blinding PAR lamps. Richard Foreman,
the director/designer, specified that the unit needed to simultaneously fly in and out, tilt stage left and stage right, and pan
upstage and downstage. The motion had to be smooth and
non-mechanical. He described the unit as an additional c1lal~
acter in the dranla that could follow actors around like a visible on-stage followspot.
The first teciUlical design involved three separate motol~
ized pickups that could shill the unit into any position desired.
This approach soon proved undesirable for three reasons.
First, the anlOunt and complexity of control programnting to
be done in the short technical rehearsal time period was intimidating. Second, the production was going to the New York
Shakespeare Festival for an unspecified length of time, leaving
the majority of Yale's motion controls unavailable for subsequent school and repertory productions, which were already
known to contain large mechanical effects. Last, if there was a
control problem willie the show was in New York, the programmers would not be readily available to repair it.
The basis for the design came from two sources; a marionette puppet and a gimbled ship's compass. The unit was mechanically connected to a gimbled frame that could rotate
freely around three axes. When the operator moved the frame
to the desired position, the unit on stage would exactly mintic
it. Two indicators and protractors welded to tile franJe showed
the operator how many degrees to pan or tilt the franle/unit
had achieved. Asecond operator positioned the unit vertically
with a boatswain's winch built for the effect. An analog readout
on the reducer gave the exact height.
Four evenly spaced pickups on the unit went to four spot
sheaves on the grid and then across to a custom head block of
eight 6" resin sheaves. The cables flowed through every other
sheave down to the purchase block of four sheaves and back
up to the head block creating a loop. After passing through the
other four sheaves in the head block, the cables attached to
the turnbuckles on the gimble frame bolted to the floor.
In order to copy the movement of the franle, the cables
coming down from the head blocks needed to crisscross to
the opposite corner. For example: the downstage left cable on
the unit needs to attach to the upstage right corner of the
frame. By pulling on the purchase block, the hand winch ex-

pands and contracts the loop of cables, which lowers and
raises the unit. Since this is a backwards double purchase, the
hand winch has to pull with twice the weight of the unit, plus
friction. But its cable only has to travel half as far as the unit. A
sandbag was attached to the purchase block to counterweight
part of the load and ease its operation. The power cord for the
PAR lamps was picked by a separate counterweight through a
hole in the top center of the unit. With the two operators working togetller, the unit could move in three different axes at the
same time.
In actual performance, the movement proved less complicated than originally specified. Although the operators
could see the unit from the wings, they could have moved it
blindly. The tilt and pan operator placed colored tape marks
on the protractor to indicate each position. Since the system
was well-balanced and friction kept the frame in the desired
position, the locking knobs supplied were never used. The
only major drawback, compared to a motorized system, was
the need for two operators; but at Yale student labor is free.
When the production moved to the Public Theater, they had to
add more counterweight to overcome additional friction
caused by the increased muling blocks needed to guide tile
cable around the building architecture.*:.
LOFT
BLOCKS

HEAD BLOCK

i\\

I -Ii!
LIGHT FIXTURE
MAX TRAVEl 10'
WEIGHT 175 LBS.
MAX ANGLE 75"

I \ \,,
; I \
\
,

TRAVEl

·s'

""
HAND
. WINCH

/1I

GIMBLE
FRAME

BOLTED TO FLOOR

TD&T

Table of Contents for the Digital Edition of Theatre Design & Technology - Fall 1997