99. This Contractor
shall furnish and install the necessary mechanism for the second proscenium
effect, consisting of two (2) side maskings and a vertical masking. For the side maskings, there shall be a
grooved track built up of lignum vitae rollers on four and one-half
(4-1/2") inch centers. Each roller
is to be set in an individual forged steel frame and to run on a machine turned
pin bolt. The underside of the rollers
to have a brass friction bushing and washer.
These rollers are to be shaped so that they will take the contour of a
three-quarter (3/4") inch rope. At
the end of the track there shall be an electrically operated cylinder
machine. These machines to be of the spiral
screw cone type for taking in the maskings and winding them up. The rope used for this track shall be
furnished by this Contactor and shall be four (4) strand Russian hemp rope
which has been thoroughly stretched before installation. The track shall be hung from the gridiron and
properly braced to the walls. There
shall be geared machines with the necessary steel framing supports, set in
perfect alignment with the two cylinders.
At each end of the track, there shall be a mouthpiece with necessary
attachments for a rise and fall of about eight (8") inches together with
the necessary hangers. This operation to
be automatically taken care of by springs.
100. For the vertical masking there shall be an
electrically operated set of rigging for raising the masking vertically. It shall consist of the necessary pipe
battens, cables and loft blocks, head block, counterweight frames,
counterweight tracks, counterweight and electric machine.
101. This
installation shall be so arranged that the vertical and side maskings can be
operated independently or together.
102. This Contractor shall furnish the motors,
control panels, limit switches and push buttons but all other electrical work
shall be done by OTHERS.