CONFIDENTIAL U.S. NAVY AIRCRAFT LAUNCHED, ACOUSTIC TORPEDO TRAINING FILM 81694

This "confidential" U.S. Navy training film gives an overview of the operation of the air-launched, acoustic homing torpedoes designed for anti-submarine and anti-ship use. The film discusses the difference between active and passive torpedoes, and goes on to describe the operation of the active type torpedoes.
At 2:57 the passive Fido acoustic torpedo, also known as the Mine Mark 24, is shown. At 3:18 the Mark 27 Mod 0 acoustic torpedo is shown. USS Chivo (SS-341), a Balao-class submarine, is seen in the background. At 3:36 the Mark 28 Torpedo is seen, similar to the Mark 18. At 3:50 the Mark 34 Torpedo is shown. At 4:00 the Mark 27 Mod 4 is shown. At 4:15, passive torpedoes are shown. At 4;25 active torpedoes are shown including the Mark 32 Mod 1, the Mark 41 Mod 0, the Mark 43 Mod 0 and the Mark 41 Mod 1. The Mark 35 Mod 12 is also shown, but is not discussed in the film.
At 5:09 an early Piasecki PV-3 / HRP helicopter is shown dropping an active torpedo. Animation then shows the "pinging" of the torpedo, as it turns and dives to search for a target (making a search circle). At 6;23 the pursuit circle is defined, and the "on/off steering" method that the torpedo uses to find its target are discussed. At 7:17, the final search circle is entered and the explosive charge is detonated.
At 7:43 some of the non-optimal situations that a torpedo might encounter are shown, including shallow depth "angle blanking".
At 8:54 the Mark 32 Mod 1 is shown, capable of being dropped from a blimp or surface ship. Its characteristics are then discussed. At 11:00, the Mark 41 Mod 0 is shown, an anti-submarine weapon only launched by aircraft. At 13:42 the Mark 43 Mod 0 is shown, again being dropped by a PV-3 helicopter. The torpedo's method of operation is then discussed. At 16:05, the Mark 43 Mod 1 is shown and its characteristics are discussed.
At 19:48 the Mark 43, Mod 1, is shown being rigged for electrical firing, and its arming system shown.
An acoustic torpedo is a torpedo that aims itself by listening for characteristic sounds of its target or by searching for it using sonar (acoustic homing). Acoustic torpedoes are usually designed for medium-range use, and often fired from a submarine.
The first passive acoustic torpedoes were developed independently and nearly simultaneously by the Allies and the Germans during World War II. The Germans developed the G7e/T4 Falke, which was first deployed in March 1943. However, this early model was actually used in combat by only three German U-Boats. It was not until after the deployment of the T-4's successor, the G7es T-5 Zaunkönig torpedo in August 1943 that Germany began to use passive acoustic torpedoes in substantial numbers; the T-5 first saw widespread use in September 1943. This weapon was developed to attack escort vessels and merchant ships in convoys.
Acoustic homing torpedoes are equipped with a pattern of acoustic transducers on the nose of the weapon. By a process of phase delaying the signals from these transducers a series of "acoustic beams" (i.e. a variation of acoustic signal sensitivity dependent on the incident angle of the noise energy). In early homing torpedoes the "beam patterns" were fixed whereas in more modern weapons the patterns were modifiable under on-board computer control. These sensor systems are capable of either detecting sound originating from the target itself i.e. engine and machinery noise, propellor cavitation, etc., known as passive sonar, or responding to noise energy reflections as a result of "illuminating" the target with sonar pulses, known as active sonar. Acoustic torpedoes can be compared to modern fire-and-forget guided missiles. What this means is the enemy (most likely a submarine) will be detected by sonar in any direction it goes. The torpedo will start with passive sonar, simply trying to detect the submarine. Once the torpedo's passive sonar has detected something, it will switch over to an active sonar and will begin to track the target. At this point, the submarine has probably started evasive maneuvers and may have even deployed a noisemaker. The torpedo's logic circuitry, if not fooled by the noise maker, will home in on the noise signature of the target submarine.
We encourage viewers to add comments and, especially, to provide additional information about our videos by adding a comment! See something interesting? Tell people what it is and what they can see by writing something for example: "01:00:12:00 -- President Roosevelt is seen meeting with Winston Churchill at the Quebec Conference."
This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit www.PeriscopeFilm.com

[@steadyashegoes7763]

It's amazing that engineering in the 1940s enabled torpedoes to acquire and track targets without the aid of computers in such a relatively small package.

[@jerkfudgewater147]

They had relay circuits… and logic circuits (and, or) so they did have computers just simple ones.
It is actually VERY EASY to make a homing warhead with “AND” circuits (which amount to a single transistor) you can make a homing missile guidance system with 3 AND circuits, 3 laser LEDs (for a self guided warhead) or 1 laser LED (if you’re going to use it as a laser target designator) , 3 LED detectors (set 120 degrees apart on the nose cone) and 3 servos (to adjust direction based on the feedback given by the LED detectors) i designed my first one about a week after hearing about them back in 3rd grade. It’s really easy.

[@farn1991]

@@jerkfudgewater147
Took me months to stir an r/c car along the line with arduino. Didn't even go to logic gate part, just mcu.
Those engineers did it with wire and transistors.

[@jerkfudgewater147]

@@farn1991 i did it with wires and transistors.
And radioshack’s cheapest soldering iron.

[@michaeldougfir9807]

My Dad would have enjoyed this. He was a TM2 in the Aleutians.

[@jarijari2977]

My grandfather was cob on uss chivo 1945

[@jerkfudgewater147]

UA-cam auto played this at me 🤣 what have i done to the search algorithm to cause this?

[@jerkfudgewater147]

@ET Hardcorgamer 🤣 but all i watch is old European electro pop music videos and Simon Whistler channels
Speaking of Check out:
•Yelle
•Sofie Tucker
•Grimes
•John Lydon
They’re all pretty good

[@HootOwl513]

I wonder if Tang was taken out by one of these circling torpedoes?

[@zillsburyy1]

back when disney was great

[@johnmoss6631]

Wah wah wah