World War II made use of acoustic mines. In circuit simulation a 1milliohm resistor is added. Where SPST switch is located is microphone which closes circuit at certain volume level (sound wave source is nearly over head) to send current to step up transformer to fire detonator of a boost charge that explodes 500 to 1500 pounds of TNT. Acoustic mines could be 3000 feet deep and affect submarines. Depth limit for a ship is 250 feet.
Minesweeping acoustic mined area is done with “noisemaker” or hammer box built like an a pneumatic hammer mounted on front of ship to send sounds ahead of ship to explode mine and bundle of “parallel pipes” towed off side and behind ship to create sound waves to explode acoustic mine.
Black ball contact mines, the mines with the pointed horns have a simple electrical circuit. The horn makes a ground connection and completes the TNT (300 to 500 pounds) firing circuit. Use your underwater cable cutters at proper depth to cut mine cables. After mine floats to surface explode from a good distance with your three inch deck guns. It may still rock your ship.
