Supplementary Circuits

Supplementary circuits are primary circuits as related to their principal functions. However, when the circuit is also used for damage control communications, the circuit is considered as a supplementary circuit. The following primary circuits are examples of supplementary circuits when they are used for damage control purposes.

CIRCUIT 3JG provides communication between such stations as primary and secondary fly control, flight and hangar deck control stations, each aviation lubricating oil station on the hangar and the gallery deck walkway, flight deck crew shelters, and the lubricating oil pump controllers.

CIRCUIT 4JG provides communication for the supervision of the various elements of the high-capacity aviation gasoline and JP5 system. Communication facilities are provided between such stations as flight deck control station, DCC, secondary DCC, forward and after gasoline pump and control rooms (or gasoline control rooms), and aviation gasoline filling stations.

CIRCUIT 1JV is the maneuvering and docking circuit. This circuit provides communication between the pilot house, open bridge, secondary conn, DCC, engine rooms, emergency stations, steering gear rooms, k/gyro rooms, standard compass, fog watch forward and aft, secondary DCC, fog generator station, and each linehandling and transfer-at-sea station.

CIRCUIT 2JV is the engineering circuit for main engines. This circuit provides communication between DCC, each propulsion engine throttle station, auxiliary machinery room, refrigerating machinery room, air-conditioning machinery room, each shaft alley, and Repair 5.

CIRCUIT 3JV is the engineering circuit for boilers. This circuit provides communication between each boiler operating station, each main feed pump and feed booster pump, smoke watch, DCC, control engine room, auxiliary control engine room, and Repair 5.

CIRCUIT 4JV is the engineering circuit for fuel and stability. This circuit provides communication between DCC, the oil king, control engine room, secondary DCC, Repair 5, fuel oil transfer pumps, fuel oil manifolds, and sounding tubes.

CIRCUIT 5JV is an engineering circuit that provides communication between each ship's service power switchgear group, each load center switchboard, each emergency power switchboard, each IC/gyro room, each turret power transfer panel, DCC, secondary DCC, Repair 5, and steering gear room.

CIRCUIT JL is for surface and sky lookouts. The circuit is used primarily to pass reports from lookouts to the captain, gunnery officer, and CIC. Because of the location of the lookouts topside, they can help locate damage caused by high-angle shellfire and bombs.

Emergency Circuits

Emergency circuits are used to provide a means of re-establishing communications once a casualty has occurred to the primary lines. The emergency sound-powered circuit of main concern to damage control personnel is the X40J casualty control communication circuit. The X40J circuit provides portable emergency communications between the main below-deck stations after casualties have occurred to the primary circuits. Portable leads are used for communication between the outlets that are permanently connected to the below-deck stations forming this emergency circuitry. The below-deck stations are usually located in the firerooms, engine rooms, forward and aft IC rooms, emergency generator rooms, DCC, and steering gear rooms. These stations have individual single-gang jack boxes. These boxes are permanently installed and connected to individual four-gang jack boxes above decks. The four-gang outlets are wired in parallel but are not interconnected.

Repair party lockers are equipped with portable jack boxes and two-conductor twisted cable. These are commonly referred to as salt-andpepper rigs. The salt-and-pepper rigs may be used to connect the individual X40J circuits to operating primary or auxiliary circuits or directly to the bridge.

Miscellaneous Circuits

There are several miscellaneous circuits that provide for the transmission of information of direct interest to damage control stations. The miscellaneous circuit that will affect you the most is the general announcing system circuit (1MC). The 1 MC is used to put out information to the ship's crew on a regular basis each day. Some of the other miscellaneous circuits include the flooding alarm (FD), remote draft indicator (DG), and security alarm (FZ) circuits. Not all of the miscellaneous circuits transmit verbal messages. Some of the circuits are used for alarms that have a definite meaning. You will become acquainted with most of the miscellaneous circuits aboard ship while performing your daily duties.

INTERCOM UNITS

Intercom units (circuit 4MC) provide fast and dependable two-way communication between DCC and each repair party locker. One-way communication from each repair party locker to its unit patrol stations can be provided by using extra speakers at various places.

SHIP'S SERVICE TELEPHONES

Many ships use ship's service telephones for damage control communications when there are telephones installed at or near repair party lockers. The ship's service telephones are standard telephones. They are either rotary-dial or push button. The majority of the compartments aboard ship will have a telephone installed within them. However, do not depend too much on this system. It is not part of a rugged battle system, and it could easily be knocked out of commission early during battle action.

SHIP'S GENERAL ANNOUNCING SYSTEM

Another means of damage control communication is the ship's general announcing system (1MC circuit). Through use of the 1 MC, information can be passed throughout the ship. This system should be used only to pass warnings or vital information that affects the entire ship's company. When information does not affect the entire ship, and other communication methods are available, the 1MC should not be used.