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Figure 16-1 GENERAL LAYOUT DIAGRAM OF GENERAL ANNOUNCING AND SUBMARINE CONTROL ANNOUNCING SYSTEMS.

16
COMMUNICATION AND ALARM SYSTEMS
 
A. DESCRIPTION
 
16A1. General. The general announcing system provides a means of broadcasting orders and information by voice from any one of 3 stations, bridge, conning tower, and control room, simultaneously to all compartments of the submarine. The submarine control announcing system provides a means of 2-way loud-speaking voice communication between the bridge, conning tower, and control room, and between these stations, the 2 torpedo rooms and the maneuvering room. It is principally designed for the rapid interchange of orders, acknowledgments and information between the above stations in combat, and for this purpose may be regarded as part of the fire control system. The general announcing and the submarine control announcing systems are interconnected and utilize the same equipment.

Three alarm systems having distinctive

  tones and known as the general alarm, collision alarm, and diving alarm are incorporated in, and are a part of, the general announcing system. The general alarm, a single stroke repeated gong sound, calls all hands to their stations for battle and is used as an alarm for fire. The collision alarm, the sound of a motor siren, is the signal that collision is imminent or has occurred and is the order to rig the ship to minimize and localize the damage. The diving alarm is the sound of a motor-driven horn and is the signal to submerge the ship or to surface if submerged. Due to its importance, this system is paralleled by a set of motor-driven horns installed in certain key stations, which operate independently of the electronically produced signals in the general announcing system. They are provided so that the diving signal can be given even when the general announcing system has failed.
 
B. GENERAL ANNOUNCING SYSTEM
 
16B1. Description. Equipment for the late fleet type general announcing system is manufactured by the Victor Division of the Radio Corporation of America. A detailed description of the equipment is given in the instruction book provided by the manufacturer.

Power is supplied from the 120-volt alternating current bus on the I.C. switchboard through a double pole, single throw, fused switch. Circuit 1MC is provided for the general announcing system and circuit 7MC is provided for the submarine control announcing system. Circuit 7MC is closely tied in with circuit 1MC.

This same amplifier equipment is also used for the 7MC circuit. Normally, one channel is set up for use on the 1MC circuit and one channel for use on the 7MC circuit, but switches are provided so that in an emergency both circuits may be operated through either of the 2 individual amplifier channels.

  Figure 16-2. General announcing bridge units, switch
box and bridge reproducer and microphone.
Figure 16-2. General announcing bridge units, switch box and bridge reproducer and microphone.
 
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16B2. Components. The system consists of the following components:

1. The transmitter control station, which contains a microphone, control switches, a volume indicator, and a socket into which a portable microphone may be plugged. There are 2 of these stations, one in the conning tower and another in the control room.

2. The signal generator, which produces the audio frequency signals that are broadcast over all reproducers for alarm signals. There are 2 signal generators located in a common housing in the 1MC stack in the control room.

3. The amplifier, which raises the energy level of the input voice or alarm signal high enough to operate the reproducers with adequate volume. There are two 120-watt amplifiers built into the 1MC stack; they are designated as channel A and channel B.

4. The reproducer, which converts the electrical output of the amplifier into sound waves; with proper connections, such as those available at the bridge reproducers, they can also be used as microphones. There are 19 reproducers installed for use on the 1MC circuit. The number installed in each location is shown in the table at the bottom of the page.

Supplementing the reproducers are 11 type H-9 horns which are operated by the diving

Figure 16-3. General announcing reproducer, class H.
Figure 16-3. General announcing reproducer, class H.

  Figure 16-4. General announcing system showing
reproducer talk-back switch, reproducer, and
transmitter control station.
Figure 16-4. General announcing system showing reproducer talk-back switch, reproducer, and transmitter control station.

alarm. Two of these horns are located in the forward engine room, 2 in the after engine room, and one horn in each of the following locations forward torpedo room, officers' quarters, control room, crew's mess, crew's quarters, maneuvering room, and after torpedo room.

An overhead fixture, non-watertight, with a green globe, is connected in parallel with the type H horns in each engine room for a visual signal.

The reproducers on the bridge can be used either on circuit 1MC or 7MC. When it is desired to talk over circuit 7MC, it is necessary only to speak into the reproducer. If it is desired to talk over circuit 1MC, the pressure-proof switch located near the reproducer must be held down.

The reproducers on the bridge can be cut out by a switch labeled BRG. 1MC-7MC at the control panel on the amplifier. The water pressure from submerging also cuts out these reproducers.

LOCATIONNO.LOCATIONNO.
Forward Torpedo Room2Crew's Mess1
Officers' Quarters1Crew's Quarters1
Control Room1Forward Engine Room3
Bridge2After Engine Room3
Conning Tower1Maneuvering Room1
Radio Room1After Torpedo Room2
 
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16B3. Operation. This system provides one-way voice communication from the bridge, conning tower, and control room to all compartments and also provides the means for generating, amplifying, and reproducing the general alarm, or gong signal, the diving alarm, or horn   signal, and the collision alarm, or siren signal, in all compartments. The general alarm takes precedence over voice communication. The diving alarm takes precedence over general alarm and voice, and the collision alarm takes precedence over all other uses of the IMC circuit.
 
C. SUBMARINE CONTROL ANNOUNCING SYSTEM
 
16C1. Description. This circuit, known as the 7MC circuit, is closely tied in with circuit 1MC. (See description of circuit 1MC in the preceding sections,)

16C2. Operation. Circuit 7MC provides two-way voice communication between the bridge, conning tower, control room, forward torpedo room, after torpedo room, and maneuvering room.

On this circuit, all reproducers can be used as microphones by pressing the TALK switch. In the normal position the bridge reproducers are connected for TALK and all other reproducers for LISTEN. Closure of the TALK switch at any other location connects that reproducer to the input of the amplifier for use as a microphone and transfers the bridge reproducers to LISTEN.

16C3. Older installations. Many of the

  earlier fleet type submarines were equipped with the 1MC system only, with microphone transmitter stations on the bridge and in the conning tower and control room and with provisions for use of throat microphones at the forward and after torpedo tube nests if desired. Intercommunication by voice between the bridge, conning tower, control room, torpedo rooms, and in some installations, the maneuvering room, was provided by means of a conventional interoffice type of loudspeaking system. The 1MC systems in these submarines did not incorporate the electronic signal generators for the alarm systems but were equipped with the auxiliary horns for the diving alarm system. The general alarm and collision notes were produced by picking up by microphones, and amplifying the sounds produced by an electric gong and an electric siren located in the control room, and transmitting these sounds over the 1MC system.
 
D. GENERAL ALARM SYSTEM
 
16D1. Description. Late fleet type submarines use 2 manual contact makers which are installed in the control room and in the conning tower. The latter is connected through a double pole, single throw, unfused cutout switch on the I.C. switchboard to the 1MC system. The general alarm circuit designation is G.

16D2. Operation. Operation of either contact maker energizes a circuit in the 1MC

  system which takes precedence over voice inputs to the 1MC system but is subservient to inputs either from circuit CA or circuit GD. This circuit causes the signal generator in the 1MC system to generate a gong sound which will continue automatically at a rate of about 100 strokes per minute for a period of 10 seconds, and is sounded over all loudspeakers of the 1MC system.
 
E. COLLISION ALARM SYSTEM
 
16E1. Description. Three manual contact makers are installed, one in the control room, one in the conning tower, and a third on the bridge. The latter two are connected through separate double pole, single throw, unfused cutout switches on the I.C. switchboard to the 1MC system. The collision alarm circuit designation is CA.   16E2. Operation. Operation of any contact maker energizes a circuit in the 1MC system that takes precedence over all other circuits using the 1MC system and produces electronically a siren signal which is sounded over all the 1MC loudspeakers.
 
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F. DIVING ALARM SYSTEM
 
16F1. Description. Three manual contact makers are installed: one in the control room, one in the conning tower, and the third on the bridge. The latter two are connected through   except the CA circuit, to which it is subservient. This circuit causes the signal generator of the 1MC system to generate electronically the sound of a klaxon horn which is sounded over all
Figure 16-5. Motor-operated horn, type H-9.
Figure 16-5. Motor-operated horn, type H-9.
separate double pole, single throw unfused cutout switches on the I.C. switchboard to the 1MC system. The diving alarm circuit designation is GD.

16F2. Operation. Operation of any contact maker energizes a circuit that takes precedence over all other circuits using the 1MC system

  loudspeakers of the 1MC system. Simultaneously, a relay operates to energize auxiliary H-9 horns located in each compartment having a 1MC loudspeaker except the bridge, conning tower, and radio room, which are not equipped with H-9 horns.
 
G. COMMUNICATION AND ALARM SYSTEM MAINTENANCE
 
16G1. General maintenance. All components of the system should be subjected to a routine inspection. This inspection should cover an examination of relay contact and switch action and in case of the amplifier, plate readings should be checked by means of the test buttons and jack with the circuit analyzer.

Relay contacts should be periodically cleaned. This is easily done by running a piece of bond paper between the contacts, holding the relay manually in such a position that the contacts are closed on the paper.

Inspection of a routine nature should also cover the removal of accumulated dust and dirt from the amplifier cabinet and other apparatus

  being inspected. A bellows blower is convenient for the removal of dust from the amplifier cabinet and the relay panels.

Units other than the amplifier should be checked for electrical connections and loose mechanical parts such as mounting bolts and similar items.

A thorough and frequent routine inspection will, in many cases, prevent subsequent system failure. Any parts that are in doubtful operating condition should be readjusted or replaced.

The manufacturer's instruction book should be consulted for complete details of maintenance, construction, and operation.

 
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H. SOUND-POWERED TELEPHONE SYSTEM AND
TELEPHONE CALL CIRCUITS
 
16H1. Description of sound-powered telephone. A sound-powered telephone is a telephone system in which the power comes from the sound of the voice rather than from batteries.

Vibrations from the voice cause vibration of a diaphragm in the transmitter. Attached to the inside of the diaphragm is a delicate needle called the armature. Surrounding this armature is a coil of fine wire, held in place by a magnet. Every time the diaphragm vibrates from the sound of the voice, the armature also moves inside the coil. This induces a current in the coil which passes through the line to a receiver. Internally, the receiver is constructed exactly like the transmitter. Thus, the current from the transmitter passes through the coil in the receiver causing its diaphragm to vibrate and reproduce the speaker's voice.

This type of telephone is supplied in both the conventional handset form and the headset type which consists of a headset and a separate transmitter mounted on a breastplate and supported by a neckstrap.

16H2. Circuits and stations, battle telephone system. The telephone system is divided into 2 circuits, the XJA (handset) used for routine ship's service communication, and the JA (headset) used on all battle control stations. The installations vary on different ships. The following is a description of a recent fleet type installation.

There are 2 independent JA circuits with 8 stations. One circuit runs from the spotter's position on the No. 2 periscope support to a headset receptacle at the 4-inch gun. This circuit has no interconnection with any other circuit. The other JA circuit has 5 lines running from the switch box in the control room to jack boxes located as follows: forward torpedo room (2 outlets in 1 circuit), control room, conning tower, maneuvering room, and after torpedo room. Each station may be independently cut out by means of toggle switches in the switch box in the control room.

  Each station consists of a jack box into which a headset can be plugged. The box is equipped with a luminous disk marked with the identifying letters of the circuits.

Headsets are stowed in lockers near the jack boxes in the forward and after torpedo rooms and maneuvering room, on stowage hooks in the control room, and in the chart table in the conning tower.

The XJA system consists of 12 circuits running from the same switch box in the control room which also serve the JA system. The circuits connect to stations located as follows:

1.forward torpedo room
2.wardroom
3.captain's stateroom
4.forward battery space
5.control room
6.conning tower
7.radio room
8.crew's mess
9.forward engine room
10.after engine room
11.maneuvering room
12.after torpedo room

Each station consists of a jack box with a type L handset wired into it and held in a shockproof clip. A headset can also be plugged into any jack box if desired.

The switch box is located between the periscope walls in the control room, and facing to starboard has 20 toggle switches. Twelve of the switches in the 3 left-hand vertical rows serve the circuits of the XJA system, and 5 in the 2 right-hand vertical rows serve the JA system. The other 3 switches are spares.

16H3. Telephone switchboard.The telephone switchboard is made up of several small single throw, double pole switches. Each pair of telephone leads to each handset and each headset is connected to its own switch on the switch board.

 
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Figure 16-6. Schematic diagram of sound-powered telephone system.
Figure 16-6. Schematic diagram of sound-powered telephone system.
 
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Figure 16-7. Sound-powered telephone diaphragm and
armature.
Figure 16-7. Sound-powered telephone diaphragm and armature.

One of the 2 sets of bus bars on the back of the switchboard makes up the JA bus, the other the XJA bus. Switches connect the respective JA and XJA phones to their respective buses. Thus, the JA and XJA circuits are common talking bus circuits and only one conversation can take place at a time over each bus.

Provisions are made to cross-connect the XJA and JA bus by means of either a crossconnect switch on some boards, or by means of

  a patching cord. The patching cord is a plain, 2-conductor, rubber-covered cable about 3 feet long with a jack plug on either end.

Each switch on this type of board has a jack connected to it. To cross-connect with the patching cord, plug one end of it into any JA switch and the other end into any XJA switch. Normally all switches are in the CLOSED position. The patching cord thus connects the JA and XJA bus together in the same way as the cross-connect switch previously mentioned. Any two phones can also be connected together by patching cords.

CAUTION. As previously described, the voice causes the transmission voltage to be generated in the units. Neither the telephone switch-board nor the telephone circuits are connected in any way to an outside source of electrical power. Never plug in or connect any part of the telephone switchboard or any headset or handset to any light or power connection as this will burn out the coils of the units.

Figure 16-8. Sectional view and wiring diagram of sound-powered telephone handset.
Figure 16-8. Sectional view and wiring diagram of sound-powered telephone handset.
 
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Figure 16-9. Headset sound-powered telephone.
Figure 16-9. Headset sound-powered telephone.
16H4. Operation. it should be noted that the headset as well as the handset is made of delicate parts and must therefore be worn in the correct position, used carefully, and properly stowed. Telephones that are out of order may prevent other telephones on the circuit from working properly.

In the event of a casualty to the transmitter on the headset telephone, it is possible to speak into one earpiece while listening through the other. In the event of casualty to the earphones on a headset, hold the transmitter button down and receive and transmit with the transmitter.

With the headset telephone, push the button only when speaking; it is not necessary to

  push the button while listening. With the heandset telephone, the button is held down when speaking and listening. It is a bad practice to keep the button taped down or held down by a rubber band as this will permit outside noise to get into the circuit. All the power required for operation is generated by the voice; no other source of power is needed; hence, it is necessary to speak loudly and clearly in order to supply the necessary power.

16H5. Maintenance. The equipment must always be handled carefully. Time after time, this equipment has been the only means of communication remaining between various parts of the submarine when other sources had

 
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Figure 16-10. Headset wiring diagram.
Figure 16-10. Headset wiring diagram.

become inoperative due to power failure during combat. Constant exposure to moisture will

  Figure 16-12. Ship's service handset telephone.
Figure 16-12. Ship's service handset telephone.

harm the instruments. Keep them as dry as possible at all times.

Rubber cables should be inspected frequently and renewed when they show excessive wear. Some of the wires in the system are very fine and should therefore be handled carefully to avoid breaking them.

Figure 16-11. Sectional view of receiver unit.
Figure 16-11. Sectional view of receiver unit.
 
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Figure 16-13. Schematic diagram of telephone call circuit.
Figure 16-13. Schematic diagram of telephone call circuit.
 
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I. TELEPHONE CALL CIRCUIT
 
16I1. Description. All call stations are connected with TTHFA-15 cable (24 active conductors and 6 spares). The cable to the conning tower goes through a, cutout switch located on the hull over the action cutout switchboard. The call circuit letter marking is E. The system consists of a rotary switch and a 115-volt bell mounted at each handset station, and the connecting cable. The rotary switch has a dial, operated by the switch shaft, and marked to show the various compartments and stations with which the system connects.

Any station can be called from any other station by setting the selector switch to the station desired and then pressing the call lever. This completes the circuit and operates the 115-volt bell at the designated station or compartment. The circuit is operated on either 115-volt a.c. or d.c., depending upon the type of bell, supplied from a switch on the I.C. switchboard. Some later submarines are equipped with handcranked signal generators and "howlers" at each call station. Such a system requires no supply

  voltage. It is a separate and complete circuit and is in no way connected to the telephone switchboard or to any part of the telephone circuit.

Figure 16-14. Telephone call bell station.
Figure 16-14. Telephone call bell station.

 
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