An acoustic mine is a type of naval mine which monitors audio activity in its vicinity. Depending on its design, it will either passively listen to its environment, depending only on the noise that is made by passing ships or actively send out audio pulses, not unlike a sonar, listening to the lapse in time in which the echo returns to it.
The mine may freely drift, be moored at a certain location and depth, or lie at the bottom of the ocean floor.
The first acoustic mines were deployed by the German navy in the Thames Estuary in October 1940. These mines could be set to broad spectrum or narrow spectrum sound signature. The broad setting would be triggered by the sound of any passing ship's propeller; the narrow would be set to only explode when the propeller of a large ship was detected.[1]
The US Navy deployed acoustic mines as an anti-submarine device from 1948.[2]
Mechanism
In naval warfare, an acoustic mine is defined as one being equipped with a hydrophone that functions as a listening device. This hydrophone listens for particular noises made by any ship or vessel's machinery (propellers). It can also detects structural sounds from the hull of a passing ship. An acoustic mine is mainly operated by a sensitive diaphragm located inside the hydrophone. This diaphragm is actuated when a certain noise reaches a predetermined intensity and duration. This initiates the closing of a switch causing an electrical circuit to flow and the mine to detonate.
Counter measures
When first encountering this type of mine in the 1940s the British Royal Navy responded with a series of devices that produced loud noises underwater to trigger the mines . Experiments were conducted with jackhammers, sirens, handgrenades, and bundles of loose metal pipes. They eventually settled on the jackhammer (known as breakers in the UK). This was initially set up to hammer against a bulkhead of a minesweeper but this resulted in the mine exploding dangerously close to the vessel. The hammer was then located in a metal box that was extended over the bows of the ship so that its sound preceded the ship itself. Towing the hammer in a floating vessel off to the side of the ship was also used. An off the shelf electrically powered breaker called a Kango was used and the approach became known as the "Kango sweep".[1]
Notes
^ abMoffatt, Iain (1 July 2005). (PDF). Edinburgh Model Boat Club. Archived from the original (PDF) on 6 April 2016.
acoustic, mine, acoustic, mine, type, naval, mine, which, monitors, audio, activity, vicinity, depending, design, will, either, passively, listen, environment, depending, only, noise, that, made, passing, ships, actively, send, audio, pulses, unlike, sonar, li. An acoustic mine is a type of naval mine which monitors audio activity in its vicinity Depending on its design it will either passively listen to its environment depending only on the noise that is made by passing ships or actively send out audio pulses not unlike a sonar listening to the lapse in time in which the echo returns to it The mine may freely drift be moored at a certain location and depth or lie at the bottom of the ocean floor Contents 1 Usage 2 Mechanism 3 Counter measures 4 Notes 5 BibliographyUsage EditThe first acoustic mines were deployed by the German navy in the Thames Estuary in October 1940 These mines could be set to broad spectrum or narrow spectrum sound signature The broad setting would be triggered by the sound of any passing ship s propeller the narrow would be set to only explode when the propeller of a large ship was detected 1 The US Navy deployed acoustic mines as an anti submarine device from 1948 2 Mechanism EditIn naval warfare an acoustic mine is defined as one being equipped with a hydrophone that functions as a listening device This hydrophone listens for particular noises made by any ship or vessel s machinery propellers It can also detects structural sounds from the hull of a passing ship An acoustic mine is mainly operated by a sensitive diaphragm located inside the hydrophone This diaphragm is actuated when a certain noise reaches a predetermined intensity and duration This initiates the closing of a switch causing an electrical circuit to flow and the mine to detonate Counter measures EditWhen first encountering this type of mine in the 1940s the British Royal Navy responded with a series of devices that produced loud noises underwater to trigger the mines Experiments were conducted with jackhammers sirens handgrenades and bundles of loose metal pipes They eventually settled on the jackhammer known as breakers in the UK This was initially set up to hammer against a bulkhead of a minesweeper but this resulted in the mine exploding dangerously close to the vessel The hammer was then located in a metal box that was extended over the bows of the ship so that its sound preceded the ship itself Towing the hammer in a floating vessel off to the side of the ship was also used An off the shelf electrically powered breaker called a Kango was used and the approach became known as the Kango sweep 1 Notes Edit a b Moffatt Iain 1 July 2005 Mines And Minesweeping Techniques Of WW2 PDF Edinburgh Model Boat Club Archived from the original PDF on 6 April 2016 Naval Mines Acoustic Aircraft laid www hartshorn us Retrieved 2016 11 18 Bibliography EditBrown David K 2002 Question 49 01 Warship International XXXIX 4 348 349 ISSN 0043 0374 Levie Howard S Mine Warfare at Sea Norwell MA Kluwer Academic Publishers 1992 ISBN 079231526X This article relating to landmines is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Acoustic mine amp oldid 1070016135, wikipedia, wiki, book, books, library,
