Chapter 7 — BASIC FIRE CONTROL 



Figure 7-1. 



3.129 



Torpedo tube Mk 32. 



the torpedo steers toward the target. If contact 

 is lost, the torpedo searches for a short time 

 in the general direction in which it is running, 

 then resumes a helical search pattern if contact 

 is not regained. Some types have a passive 

 capability in conjunction with their active feature 

 which enables them to detect a submarine that 

 is beyond their active acoustic range. 



The depth charge currently in use is the 

 teardrop-shaped type, and is either influence- 

 detonated or hydrostatically detonated. These 

 depth charges are launched from racks on the 

 ship's fantall. A direct hit is unnecessary for 

 a kill, but to be effective the explosion must be 

 quite close to the submarine. For this reason, 

 depth charges are launched in patterns covering 

 the submarine's position and the area into which 

 he may maneuver. In general, it can be said that 

 because of their slow sinking rate, depth charges 

 are not too effective against modern submarines. 

 Although depth charges are being phased out of 

 operation, many reserve destroyers, as well as 

 some active shdps, still are equipped with them 

 and with hedgehogs. 



Hedgehogs are impulse-propelled charges. 

 In order to explode, they must come in contact 

 with a submarine. They usually are fired in a 

 circular pattern. Two general types of hedge- 

 hog mounts are in operational use. One is fixed 

 to the deck and has spigots (from which the 

 hedgehogs are fired) that can be tilted to allow 



for last-minute changes in the relative positions 

 of the ship and the submarine. The other type, 

 the trainable mount, can be rotated to the firing 

 bearing. When a full pattern is fired from either 

 mount, the charges fall into the water in a 

 large circular pattern. Tilting the spigots causes 

 a distortion in the pattern, however, so that it 

 is advantageous to fire with zero tilt set on the 

 spigots. In the trainable mount, pattern distortion 

 does not occur because the entire mount is 

 trained to the correct bearing at the time of 

 firing. 



Shipboard antisubmarine rockets are of 

 several operational types. The earliest one, 

 labeled Weapon A still is in operational use. It 

 has a maximum range of nearly 1000 yards, 

 contains several hundred pounds of explosive, 

 and is detonated by a magnetic influence fuze 



Another shipboard rocket device is the anti- 

 submarine rocket, better known as ASROC, dis- 

 cussed in chapter 2. 



Submarine Antisubmarine Weapons 



Today's submarine has a choice of many 

 types of torpedoes, each designed for a specific 

 purpose. The three main classes of torpedoes 

 are straight-running, acoustic homing, and wire- 

 guided. 



Although the straight-running contact torpe- 

 does are useful in certain tactical situations. 



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