sound-powered telephone headset-chestset plug into the
two-way communications at normal sound-powered
jack outlet. Switches located in normally darkened-ship
level for other circuits not selected to be amplified.
condition areas are provided with dial illumination.
These switches are multiple rotary-type S-3R and are
provided with dial illumination for darkened-ship
At stations where only two circuits are involved, a
double-throw lever or double-throw rotary snap-type
selector switch is used rather than the larger rotary type.
The incoming sound-powered telephone circuits are
connected to the sound-powered telephone amplifier via
In spaces where the ambient noise level at the
handset location is 90 dB or more during any condition
of operation, soundproof booths are installed for use
Type A-26A sound-powered telephone selector
with sound-powered telephone handsets. Wherever
switches (fig. 5-18) are located throughout the ship at
practicable, the telephone booths are installed so that the
control and operating stations served by more than one
front faces away from the direction of maximum noise.
sound-powered telephone circuit. The selector switch
The deck area under the booth will be solid or walkway
enables the operator to connect the sound-powered
grating. Only handset(s) with holder(s) and an
telephone to any one of several circuits brought to the
illumination fixture are mounted inside the booth; all
switch without having to change from one jackbox to
other associated sound-powered equipment is mounted
on the outside of the booth.
The selector switch is a multiple rotary switch
designed for use in connection with sound-powered
telephone systems. The switch is constructed with 2
sections and has 16 stationary contacts for incoming
Plotters transfer switchboards are found in areas
lines on each section. The rotor has a movable contact
aboard ship, such as the CIC, where the tactical situation
and is driven directly from the shaft attached to the
governs the sound-powered circuit to which the plotters
handle, which has an indexing mechanism for selecting
are to be connected. For instance, the situation may
the desired circuit. The switch has a built-in jack outlet
require that the CIC plotters connected to jackboxes JS1
connected to the rotor contacts.
through JS5 be connected to circuit 21JS, while the
Most of the switches are installed with a
plotters connected to jackboxes JS6 through JS10 be
sound-powered telephone handset permanently
connected to circuit 22JS. Another situation may call for
connected to the rotor contacts. Where a handset is not
an entirely different arrangement.
provided, the switch operator must insert a
The switchboards consist of one or more
SB-82/SRR panels (fig. 5-19, view A). Each panel
consists of five vertical rows of 10 double-pole,
single-throw switches. Each row on the panel is
connected to a sound-powered circuit, and each switch
on the panel is connected to a sound-powered jackbox.
The switches are continuously rotatable in either
direction. Several different sound-powered jackboxes
and circuits are connected to these switchboards, thus
permitting the plotters to be shifted from one circuit to
another quickly and efficiently as the situation dictates
a n d eliminates the necessity of installing
multiple-circuit phone boxes at each station.
As shown in figure 5-19, view B, the closing of any
one of the five switches associated with each jackbox
permits the jackbox to be connected to one of the
sound-powered circuits. In the figure, jackbox JS 1 is
shown connected to sound-powered circuit 22JS, and
Figure 5-18.--Type A-26A selector switch.
jackbox JS2 is shown connected to sound-powered