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14
FIRE CONTROL AND GUNNERY SYSTEMS
 
A. TORPEDO FIRE CONTROL SYSTEM
 
14A7. Description. The torpedo fire control system employs several electrical devices which assist in solving fire control problems and firing the torpedo tubes. The devices that perform these functions are the torpedo data computer, the gyro angle indicator regulators, and the torpedo ready and firing light systems.

The torpedo data computer is located in the conning tower and is energized by circuit GA1, having 115-volt alternating current, and circuit 17GA1, having 115-volt direct current, through individual double pole, single throw, fused switches on the I.C. switchboard.

The gyro angle indicator regulators for automatically setting the gyro angles on the torpedoes in the tubes are located at the forward and after tube nests and are controlled by separate fire control circuits from the torpedo data computer. The regulators are supplied with 115-volt direct current through circuit 17GA3 which

  is energized through a double pole, single throw switch on the forward auxiliary power switchboard in the control room, and circuit 17GA4 which employs a similar switch on the after auxiliary power switchboard located in the maneuvering room. Sixty-ampere fuses, in special fuse boxes, are included in each circuit.

The following circuits are provided in addition to those mentioned above:

1. A Pitometer log repeater circuit to the torpedo data computer from a rotary transfer switch on the action cutout switchboard.

2. A gyrocompass repeater circuit to the torpedo data computer from the gyrocompass repeater panel.

14A2. Operation. Detailed operating procedures are given in Bureau of Ordnance publications and the manufacturer's instruction pamphlets.

 
B. TORPEDO READY LIGHT, TORPEDO FIRING, AND
BATTLE ORDER SYSTEMS
 
14B1. General description. The torpedo ready light and torpedo firing systems perform several important functions: They provide a means 1) of informing the fire control party when the tube is ready to fire, 2) of directing the tube crew to stand by a tube to fire, 3) of firing the torpedoes remotely from the conning tower and simultaneously indicating to the tube crew by means of an audible and visual signal that the tube has been fired, and 4) of indicating by a visual signal in the conning tower that the tube has fired. They also indicate, by means of a visual signal to the fire control party in the conning tower, that the gyro angle indicator regulators are matched.

14B2. Torpedo ready light and battle order system. This system, circuit 6R, is energized from the 120-volt direct current bus on the I.C.

  switchboard through a fused double pole, single throw supply switch labeled 6R. Forward and after transmitters in the conning tower are used to transmit torpedo orders to an indicator at each tube nest. When power is turned on in the conning tower, the GYRO SPINDLE and READY pilot lights in the transmitter, the READY AT TUBE, and the STANDBY pilot lights in the corresponding indicator in the torpedo room are lighted. When the gyro retraction spindle switch contacts are closed, an amber GYRO SPINDLE IN light in the indicator in the conning tower for that tube is lighted. When the tube interlock switch contacts are closed, the amber READY AT TUBE light for that tube in the indicator in the torpedo room is lighted. When the operator turns the indicator switch for that tube, it lights a green READY light for the tube in the transmitter in the
 
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Figure 14-1. DIAGRAM FLEET TYPE SUBMARINE READY LIGHT AN FIRING CIRCUITS, FOR TORPEDO TUBE 7 ONLY.

conning tower. When the gyro mechanism of the tube nest is matched upon closing the manual contact of the gyro setting mechanism contact maker, a red ANGLE SET light in the transmitter in the conning tower is lighted. When a particular tube standby switch in the conning tower is turned to STANDBY at the transmitter, the corresponding green STANDBY light for that tube in the indicator in the torpedo room is lighted. When the firing contact maker is pressed, the tube is fired through operation of the pilot valve solenoid; a red FIRE light in the indicator is lighted and a buzzer is operated at the tube nest.

14B3. Torpedo firing system. The torpedo firing system, circuit 6PA, is energized from the 120-volt direct current bus on the I.C. switchboard through a fused double pole, single throw supply switch labeled 6PA.

Separate fixed and portable contact makers or firing keys, for independently controlling the forward and after groups of firing solenoids, are located at the torpedo ready light and firing panels in the conning tower. A key mounted on the gyro angle regulator indicators operates a light on this panel to show that the regulator is matched.

Firing circuits are interrupted through

Figure 14-2. Conning tower torpedo firing panel.
Figure 14-2. Conning tower torpedo firing panel.

  Figure 14-3. Torpedo room ready light and ready
switch panel.
Figure 14-3. Torpedo room ready light and ready switch panel.

Figure 14-4. Torpedo tube interlock switch and pilot
valve solenoid.
Figure 14-4. Torpedo tube interlock switch and pilot valve solenoid.

 
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Figure 14-5. Spindle switch on torpedo tube gyro
setting mechanism.
Figure 14-5. Spindle switch on torpedo tube gyro setting mechanism.

switches on the torpedo ready light and firing panel and through local interlock switches at each torpedo-tube as shown in the wiring diagram, Figure 14-1, which is complete for one tube only.

  Figure 14-6. Gyro angle regulating indicator with
right handgrip turned to show trigger switch.
Figure 14-6. Gyro angle regulating indicator with right handgrip turned to show trigger switch.

14B4. Operation. A full description of the method of operation is given in Bureau of Ordnance publications and in the manufacturer's instruction pamphlets. They should be consulted frequently.

 
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C. TARGET DESIGNATION SYSTEM
 
14C1. General. The target designation system is used for the purpose of transmitting and indicating the bearing of the target from the bridge or radar to the torpedo data computer (TDC) and the 2 plotting stations. It is a simple selsyn-operated system using manually operated bearing transmitters on the bridge and an automatic transmitter coupled to the train mechanism of the radar. The indicators at the plotting stations show the true as well as the relative bearing. A buzzer system with hand contactors at the transmitting stations and buzzers at the plotting stations, radar, and TDC is provided for indicating when the transmitter is on the bearing of the target. A set of rotary cutout switches is located at the TDC so that the operator may shift the bearing indicators to the transmitter that is to furnish the bearings. The circuit designation is GT. It is energized from the a.c. bus by a fused switch on the I.C. switchboard. Own course input for the indicators that show the true as well as the relative bearing is obtained from the gyrocompass repeater panel through a rotary switch.

14C2. Target bearing transmitter. This instrument consists of 2 permanently mounted peloruses on the bridge. One is located at each end of the bridge. Each pelorus has a pair of watertight and pressure-proof binoculars of the high light transmission type. An illuminating system is built into them to make the cross wires visible when the instrument is used at night. The pelorus can be rotated through 360 degrees in azimuth and is equipped with a scale so that the operator may read the bearing at which the instrument is set. A selsyn generator inside the pressure-proof case of the instrument transmits the bearing of the target when the pelorus is pointed at it. The hand contactor for the buzzer system is built into one of the training handles.

14C3. Target bearing indicators. These instruments, when energized and connected to a transmitter, indicate the bearing as transmitted by the target bearing transmitters. Their construction is similar to any other simple selsyn indicating device. The type installed at the plotting stations in the conning tower and in the

  control room indicate the true as well as the relative bearing by means of a second dial which receives from the gyro system and indicates own course. The type used at the TDC shows the relative bearing only, but utilizes 2 dials, coarse and fine, so that increased accuracy is gained. An additional indicator showing both the true and the relative bearing is located at the radar to aid in coaching the operator of this latter instrument on the bearing of the target. This is a coarse reading instrument, its dial being graduated in 5-degree increments. Selector switches are provided at the TDC so that various indicators may be switched to the transmitter that is to furnish the bearing.

14C4. Operation. Full instructions for the operation of this system are contained in publications of the Gunnery Department of the Submarine School and in manufacturer's instruction books.

14C5. Maintenance. Maintenance of the target designation system is identical with that of any other system containing selsyn instruments. Special care must be taken in sealing the target bearing transmitters to insure that the watertight joints and the cable packing glands are carefully made up in order to prevent flooding and consequent disabling of the instrument.

14C6. New installations. The latest design installations have, in addition to the units described above, additional transmitters operated by the sound gear and the periscopes for the transmission of both bearing and range to the stations equipped with indicators. In addition, an improved model of the target bearing transmitter is provided with an own course dial energized from the gyro repeater panel so that the true as well as the relative bearing may be read at the instrument. The ship's plans should be consulted for details.

A center section containing three 2-dial bearing indicators, and a range indicator with selector switches so that the bearing may be received from the target bearing transmitters on the bridge, the periscopes, radar, or the sonar system has been added to the TDC. A range in

 
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Figure 14-7. Schematic diagram of target designation system.
Figure 14-7. Schematic diagram of target designation system.
 
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Figure 14-8. Target bearing transmitter, Mark 8.
Figure 14-8. Target bearing transmitter, Mark 8.

Figure 14-9. Target bearing indicator, type installed
at TDC.
Figure 14-9. Target bearing indicator, type installed at TDC.

  Figure 14-10. Target bearing indicator, type installed
At plotting stations.
Figure 14-10. Target bearing indicator, type installed At plotting stations.

Figure 14-11. Target bearing indicator, type installed
at radar.
Figure 14-11. Target bearing indicator, type installed at radar.

 
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Figure 14-12. Bearing Indicator and bearing indicator
selector switches installed at TDC.
Figure 14-12. Bearing Indicator and bearing indicator selector switches installed at TDC.
  Figure 14-13. True bearing and range indicator at
plotting stations, newest installations.
Figure 14-13. True bearing and range indicator at plotting stations, newest installations.

dicator for receiving range either from the radar or from the sonar system is also provided. Auxiliary pointers, mechanically controlled by movement of the TDC input dials for bearing and range, are provided so that the indicated values of relative bearing and range may be introduced into the TDC simply by matching the pointers with the value indicated.

 
D. TORPEDO BATTERY CHARGING AND HYDROGEN BURNING SYSTEMS
 
14D1. Torpedo battery charging system. The battery charging circuits are brought to indicating panels and receptacles located at the racks and the tubes. The circuits take main battery voltage, through a rheostat, to outlets from which connections may be made by portable cables to charge torpedo batteries either when the torpedoes are in the tubes or when they are in the racks. Ammeters are provided in the charging circuits.

The arrangement of outlets for the charging circuits varies from ship to ship, but in general, individual units are identical.

Supply switches are usually located at the forward torpedo room auxiliary power panel and the maneuvering room auxiliary power distribution panel.

14D2. Torpedo hydrogen burning system. The battery compartment of each torpedo is equipped with 3 hydrogen burners located

  directly under the inspection plates. Each burner is constructed of a small coil of resistance wire mounted in a copper mesh casing. The coil of resistance wire reaches a temperature sufficiently high to ignite any hydrogen gas that may be generated by the batteries.

Power supply to the burning units is provided by control panels located in each torpedo room. They have a sufficient number of outlets to accommodate all torpedoes in the tubes and on the racks. Each burner is supplied with a.c. from the I.C. switchboard through a transformer in the control panel. Each outlet is controlled by a switch, and the current to each burner can be read on an ammeter through a selector switch. A line level compensator is provided in the panel to keep the current to each torpedo at 4.75 amperes. Fine adjustments for individual circuits may be made by adjusting a resistor provided for each outlet.

 
206

Figure 14-14. Schematic diagram of torpedo battery charging controller.
Figure 14-14. Schematic diagram of torpedo battery charging controller.
 
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Figure 14-15. Schematic diagram of hydrogen burning circuit.
Figure 14-15. Schematic diagram of hydrogen burning circuit.
Figure 14-16. Electric torpedo battery charging panel.
Figure 14-16. Electric torpedo battery charging panel.
  Figure 14-17. Electric torpedo hydrogen burning
circuit controller.
Figure 14-17. Electric torpedo hydrogen burning circuit controller.
 
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