Figure 5-5.--Line cutout switches in the open and closed positions

All primary circuits are provided with a tie line

primary stations, the talker can easily reestablish

between their respective switchboard or switchbox for

communications with the control station by unplugging

cross-connection with their auxiliary circuits. The tie

the headset from the primary jackbox and plugging it

lines are fitted with a tie switch at one end and a tie +

into the auxiliary jackbox.

(tie plus) switch at the other end. The tie switch is

One disadvantage of paralleling circuits is

normally open and is closed only to parallel two circuits.

overloading transmitters. Each sound-powered

The tie + switch is normally closed and is opened only

telephone receiver unit consumes electrical energy

in the event of casualty, to disconnect the defective

when converting transmitted electrical signals to

circuit or tie line.

audible signals. As receiver units are added, the demand

for electrical energy may exceed the capability of the

When the patch cord method of paralleling is used,

transmitter unit, resulting in the transmitter becoming

the following conditions may be obtained:

overloaded. An overload condition reduces the input

1. When the line cutout switches of both lines are

electrical energy available to each receiver unit, with a

open, the two lines will be connected together, but will

corresponding reduction in receiver output volume. The

not be tied in with any other station of either circuit.

reduced audio output may render the circuit ineffective.

Figure 5-5 is an illustration of line cutout switches in the

The number of receivers it takes to overload a circuit

open and closed positions.

varies; therefore, the controlling station should be alert

to garbled messages or frequent requests for repeats,

2. When the line cutout switch of only one line is

indicating the circuit is overloaded.

closed, the two lines will be tied together and also

connected to the other stations on the circuit of which

A second disadvantage of paralleling circuits is that

the line cutout switch is closed.

as the number of stations on a circuit increases,

conversations may increase, resulting in confusion. This

3. When the line cutout switches of both lines are

can be remedied by all stations exercising good circuit

closed, all lines of the two circuits will be tied together.

discipline.

Thus, by manipulating patch cords and individual

Under normal operating conditions, circuits are

line cutout switches, you can connect any pair of lines

usually paralleled to reduce the number of talkers

together and any line to any circuit or combination of

required. As conditions of greater readiness are set,

circuits on the switchboard.

more talkers are assigned and fewer circuits are

C i r c u i t s connected to switches on the

paralleled. Few, if any, primary circuits are paralleled

communication consoles in the combat information

under the highest condition of readiness.

center (CIC) may also be paralleled by the console

operators. Since each circuit is routed to a number of

CASUALTY COMMUNICATIONS

plotter's positions, you must take care to avoid

Circuit X40J is designated the casualty

In an extensive sound-powered telephone system,

communication circuit. This supplementary string

circuit provides a means of rigging emergency

paralleling of circuits has both advantages and

disadvantages. One advantage is that it allows a

communication lines between vital stations after a

controlling station to extend supervision over several

casualty has occurred. This circuit applies to combatant

different stations, using fewer talkers. Another

ships and auxiliary ships, 200 feet and over in length,

fitted with weapons.

advantage is that if communications is lost to one of the

Permanent vertical riser cables are installed

between single telephone jackboxes located port and

s t a r b o a r d in vital below-deck stations and

corresponding four-gang jackboxes located port and

starboard on the first weather deck directly above each

below-deck station (hangar deck on aircraft carriers).

Each single jackbox installed in the below-deck

stations contains a nameplate that indicates the circuit

Figure 5-5.--Line cutout switches in the open and closed

identification X40J. Below-deck stations include

positions.

steering gear rooms, engine rooms, emergency

5-7