Figure 5-18.--Type A-26A selector switch.

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

condition areas.

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

SOUNDPROOF BOOTHS

this switch.

In spaces where the ambient noise level at the

SELECTOR SWITCHES

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

another.

on the outside of the booth.

The selector switch is a multiple rotary switch

PLOTTERS TRANSFER

designed for use in connection with sound-powered

telephone systems. The switch is constructed with 2

SWITCHBOARDS

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

5-20