CHAPTER 7 



BASIC FIRE CONTROL 



Although the overall objective of all Sonar 

 Technicians is to aid in destroying enemy sub- 

 marines, the manner in which the task is accom- 

 plished varies with the individual branch of the 

 rating. The shipboard Sonar Technician, for 

 example, tries to maintain continuous contact 

 through echo ranging sonar and aggressively 

 enters the submarine/ship duel, using every 

 available means to hold contact. The submariner 

 has a tendency to sneak up on the target, gather- 

 ing attack information from the noises produced 

 by the target itself, perhaps making one sonar 

 transmission just before firing. In each instance, 

 the ultimate goal of the antisubmarine unit is 

 destruction of the enemy submarine. 



The system by which information is collected 

 and translated into weapon firing data {including 

 positioning of trainable weapon launchers) is 

 called fire control. 



UNDERWATER FIRE CONTROL 



Fire control is defined as the technique by 

 which weapons are directed to a selected target. 

 It consists of the material, personnel, methods, 

 communications, and organization necessary to 

 destroy the enemy. Underwater fire control 

 includes all of the foregoing components, with 

 the added difficulty that the selected target is 

 a submarine, capable of moving in three dimen- 

 sions — in range, bearing, and depth. 



WEAPONS 



Some of the antisubmarine weapons controlled 

 by underwater fire control equipment and used by 

 ships and submarines against enemy submarines 

 are described in the topics that follow. The 

 discussion also points up some of the problems 

 that must be overcome by the underwater fire 

 control system torealizesuccess.Not all weapons 

 are discussed because of the nature of their 

 classification. 



Shipboard Antisubmarine Weapons 



Aboard ship, several kinds of antisubmarine 

 weapons are available. The principal one is the 

 homing torpedo. Others include depth charges, 

 hedgehogs, and rocket-propelled ordnance. 



Figure 7-1 shows a Mk 32 torpedo tube 

 mount used for launching homing torpedoes of 

 the Mk 43, Mk 44, and Mk 46 types. The usual 

 destroyer installation has one triple-tube mount 

 on each side of the ship. 



Homing torpedoes are of two types — active and 

 passive. The active type transmits sound pulses 

 and homes on the echoes reflected from the target. 

 The passive type is guided to the target by noise 

 emanating from the target itself. 



Early antisubmarine torpedoes had two serious 

 drawbacks. First the endurance or active period 

 was relatively short— a matter of minutes. The 

 second concerned their speed capability. Com- 

 pared with speeds of many modern submarines, 

 the homing torpedo was slow and could be 

 outrun by a submainne. These drawbacks have 

 been eliminated for the most part in modern 

 high-speed torpedoes. The newer torpedo also 

 is quite maneuverable, in contrast to the sub- 

 marine, and has a tighter turning circle. Except 

 for attempting to delude the torpedo with a 

 decoy-type device, one of the best defenses 

 the submarine skipper can provide against a 

 modern antisubmarine torpedo is to call for 

 all available power in an effort to clear the 

 area at maximum speed. Modern torpedoes, 

 however, normally are faster than the submarine. 

 Inasmuch as the primary mission of an A/S 

 escort vessel is to prevent the submarine from 

 making an attack, causing the submarine to 

 evade a torpedo and run from the area would 

 accomplish the escort's mission. 



When conducting an antisubmarine torpedo 

 attack, the ship must maneuver into a favorable 

 launching position. A typical homing torpedo runs 

 in helical patterns while seeking a submarine. 

 Once contact with the submarine is achieved. 



110 



