Acoustic homing torpedoes did not see action until 1943 with the Falke/T4 from Germany and the Mark 24 Mine from the USA. These torpedoes were passive in that they homed in on the loudest sound that already existed in the water.

I would like to know who first invented this concept and did physical research on it, that is, actually tried to build a working prototype.

From Wikipedia, I was able to glean a few small parcels of information:

Acoustic Torpedo

The first passive acoustic torpedoes were developed independently and nearly simultaneously by the Allies and the Germans during World War II.

Mark 24 Mine:

The concept of a torpedo which would "home" on its target had been studied by torpedo designers as far back as the first World War. While the concept was highly interesting, implementation had to await a better understanding of the physics of sound generation and transmission in the sea and the development of the technology from which such a torpedo could be designed and constructed. During W.W. II, German submarines were equipped with electrically driven acoustic homing torpedoes which had started development as far back as 1933.

G7e Torpedo

The T4 was not an ordinary straight-running torpedo, however; it was the world's first acoustic homing torpedo. It ran at 20 kt (37 km/h) for 7500 m and was introduced in March 1943.

Early in 1933 Germany started development and testing of acoustic homing mechanisms for torpedoes.

So apparently this concept dates back to 1933. However, there isn't a single citation for any of this. I find that surprising. Wikipedia fails here, as those 3 relevant articles don't have a single citation for what I'm interested in.

There is a very interesting site called maritime.org that has a bit more:

Division 6 (Sub-Surface Warfare, headed by Dr. John T. Tate) was the group tasked with the torpedo research and development role. The division's first objective was "the most complete investigation possible of all the factors and phenomena involved in the accurate detection of submerged or partially submerged submarines and in anti-submarine devices."5 Through the systematic study of all phases of underwater acoustics, the ground work was laid to permit engineering development and deployment of the acoustic homing torpedo during World War II.

It didn't give a date, but from the previous paragraph I inferred it was from 1940. I googled the name John T. Tate and surprisingly, could not find him. There were two "John Tate"s I found, one a mathematician and one a physicist (yes, both found on Wikipedia), but I couldn't find mention of them working on torpedoes.

And then there's this:

In 1943, it became known in the technical community that the Germans were using a torpedo called the German Naval Acoustic Torpedo (GNAT) with terminal homing, a torpedo that guided itself to contact with the target by the noise generated by the ship's propellers (cavitation). German development of the GNAT had been known in the U.S. Intelligence community, and in 1940, the NDRC sponsored a project to develop an acoustic homing torpedo.

That's written very anachronistically. If GNAT had been known to the US intelligence community on or before 1940, then I think it's safe the say the Germans had been developing it for at least a year. If Wikipedia is trustworthy, it goes back to 1933.

So I'm here to post the question. Who "invented" it (conceived and developed it)?

Just a cautionary endnote: Submarine tech history, even the "new stuff" of WW2, can often be traced back to WW1. Classic example is the Snorkel:

An early submarine snorkel was designed by James Richardson, an Assistant Manager at Scotts Shipbuilding and Engineering Company, Greenock, Scotland as early as 1916, during World War I. Although the company received a British patent for the design, no further use was made of it—the British Admiralty did not accept it for use in their Royal Navy submarines.

That wiki paragraph actually has citations. The reason I bring it up here is because the snorkel is often attributed to the Dutch, because they apparently had two submarines using them in 1940, which were captured by the Germans. For example, you read this article on u-boat.net and it makes it sound like the Germans first discovered the snorkel concept in 1940 from the Dutch. For all I know, that may be true, but it can only be true if the Germans were unaware of the British patent from 1916. I think this is a prime example of how the history of these things can be tricky. I wouldn't be surprised if something similar was going on here with the acoustic torpedo.

  • 3
    Just think how much earlier WWII could have ended if England had paradropped in their best patent law team.?
    – T.E.D.
    Apr 1, 2018 at 0:05
  • @T.E.D. You mean the snorkel patent? That alone wouldn't change anything. A sub at periscope depth can be spotted from the air almost as easily as a surfaced one, due to a silhouette. Now, the Type 21 submarine coulda won if Germany had it earlier. I think the real lesson here is that Germany never seriously considered war with Britain...until it was upon them. It's a wonder why the Kriegsmarine restarted sub production at all and had a modest few dozen subs by 1939 Sep.
    – DrZ214
    Apr 1, 2018 at 8:14
  • 4
    The "Oslo Report" (en.wikipedia.org/wiki/Oslo_Report) of 1939 describes an acoustic torpedo as being in use then. Apr 1, 2018 at 15:21

2 Answers 2


Karl Oskar Leon of Gottenborg, Sweden, (apparently owning a US company) filed for a US patent titled Torpedo and other Submarine Apparatus 11 February 1908:

The main object of the invention is to provide a torpedo adapted to automatically steer, without any control, toward the object to be destroyed, and to change its course according to the movement of the said object.

A torpedo constructed according to this invention is especially adapted to detect submarine boats or other hostile vessels and to automatically steer toward the same, whatever be the original course of the torpedo. In torpedoes of the kind described in my earlier patent application Serial No. 400215, filed November 1, 1907, (patented March 22, 1910, No. 952,451,) special arrangements may be provided for causing the torpedo, after the propulsion of the same has ceased and it has taken up a vertical position, at a predetermined depth of submersion, to again start, as soon as a vessel enters its sphere of action, and steer for the vessel to destroy it.


The invention consists, chiefly, in so placing, on the torpedo, suitably at its fore end, a number of microphones, telephone receivers, or other receivers sensible to vibrations of the water, such as vibration of sound, or the like, that the said receivers are adapted to be actuated by vibrations issuing from the object to be destroyed, each receiver being connected, by suitable apparatus, to one or more of the devices (steering, propulsion, exploding or other devices) of the torpedo in such a manner that the said device or devices will be actuated, as soon as the receiver is made active.

For more information on the above see Providing a Torpedo with Ears in The Book of Modern Marvels (1917). Work of Christian Berger of Hungary and John Gardner of England is also discussed.

John Hays Hammond, Jr. of Gloucester, Massachusetts filed for a patent titled Echo Torpedo 2 April 1928:

This invention relates to the control of moving bodies and, more particularly, to an automatic means for controlling the direction of a torpedo and for causing the same to pursue an enemy ship.

The invention provides a mechanism whereby a series of high frequency compressional waves are emitted from a torpedo and impressed upon a surrounding medium. These waves are reflected from a solid object such as an enemy ship and are again impressed upon the torpedo where they are picked up by suitable microphones and caused to actuate relay mechanisms for operating the rudder.

The usual gyroscopic mechanism is employed for maintaining a torpedo on a preselected course until in the proximity of the target. It is then directed by the reflected compressional waves and caused to automatically follow the target until a hit is obtained.


Alfred N. Goldsmith of New York, New York filed for a patent 12 December 1935.

Such a control system readily lends itself to ... acoustical control of torpedos, and automatic steering


my invention is to provide a homing torpedo control system

  • 1
    It should be noted that the granting of a patent doesn't require that the named invention actually works (or even exists in any fashion).
    – Steve Bird
    Jul 18, 2018 at 15:06
  • 2
    @SteveBird The answer shows that such a torpedo was conceived at least by 1908, and that the US, Swedes, Hungarians and Brits were all developing such technology by 1917.
    – DavePhD
    Jul 18, 2018 at 15:29
  • 1
    As, or more, interesting is that "high frequency compressional waves are emitted ... These waves are reflected " is essentially SONAR.
    – user18963
    Jul 18, 2018 at 17:09
  • 2
    @DrZ214 The Leon patent wasn't granted until 27 April 1915. That's when it would have been available to the public. Then it was further publicized in the Patent Office Gazette, Electrical Review, Naval Engineers Journal, General Electric Review and other publications.
    – DavePhD
    Jul 18, 2018 at 18:08
  • 2
    @DrZ214 and described in great detail in the October 1915 Popular Science Monthly books.google.com/…
    – DavePhD
    Jul 18, 2018 at 18:14

I am researching the same subject as I have been told my grandfather Hans Ernst Henrich worked on these torpedos as he was stationed in Penemünde.

  • 2
    Hi Hans A Henrich and welcome to History SE. Can you expand on this answer at all? At the moment, it seems more appropriate as a comment so anything you can add would help make it look more like an answer. Jul 8, 2019 at 4:21

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