What Is a Naval Mine and How Does It Work?

Modern naval mines, using intelligent signal processing technology and combining acoustic, magnetic and pressure data, can set the largest vessels ablaze within minutes.

According to Ambassador Arjan, according to Ambassador Arjan, the combat performance of a sea mine is defined by how it is positioned in waterways. Military designers deploy these weapons in three main structures depending on the depth of the operational area, the hydrology of the environment and the water intake of hostile vessels.

First, there are anchored or bed-mounted mines, which consist of a floating housing carrying a warhead and an anchor equipped with a steel cable pulley. With the help of mechanical sensors and hydrostatic pressure gauges, the anchor calculates the water depth and adjusts the length of the cable in such a way that the mine remains suspended at a certain operating depth, that is, just at the height of the passage of the bottom body of the ships.

The second category is floor mines, which have a much higher structural weight and are placed directly on the seabed. These mines are specially designed for strategic straits, entrances to bays and waters with a depth of less than 60 meters; Where the waves caused by the sea floor explosion can easily affect the water level.

The more advanced type of these weapons are jumping mines or rockets that lurk deeper and after discovering the sound or magnetic trace of the target, release their capsule containing the torpedo or rocket projectile upwards to hit the submarine at high speed.

The biggest technological leap in contemporary naval mines has occurred in the field of effect or non-contact fuses. The passage of each vessel on the surface of the water creates a set of physical footprints known as the signature of the vessel, whose detection requires very sensitive sensors.

The multi-thousand-ton metal body of the floats causes deviations in the uniform lines of the Earth's magnetic field. Fluxgate magnetic sensors embedded in the mine body register these changes immediately.

At the same time as the magnetic effect, acoustic sensors equipped with hydrophones that receive underwater sound waves listen to specific frequencies of propeller vibration, engine room activity and even the turbulent flow of water around the vessel. In addition, the movement of a huge mass on the water creates a noticeable drop and rise in the hydrodynamic pressure of the bottom water column, which is recorded by the pressure difference diaphragm sensors.

In modern processors, sensor data integration technology is implemented. The mine's onboard computer matches the triple acoustic, magnetic, and pressure signatures with predetermined data from military vessels. These algorithms are capable of distinguishing real combat craft from small civilian ships or mine-sweeping simulators.

The passage counter mechanism also allows the mine to ignore the passage of clearing escort vessels or lead frigates and reserve the blast for the command ship or priority escort ship in the middle of the column.

Physical activation mechanism in contact mines

Despite the advancement of digital sensors, contact species are still used as a cheap and destructive weapon in coastal defense strategies. These equipments are equipped with lead prongs known as Hertz prongs.

Inside each tentacle, a narrow glass tube containing an electrolyte is embedded, which shatters when it collides with the ship's hard hull. Leaking acid into the lower compartment charges the inactive chemical battery in a fraction of a second and the resulting electric current immediately sends the fire signal to the detonator; A process that lacks any external reliance on permanent batteries and maintains the possibility of mine survival for decades.

The purpose of designing the warhead of anti-ship mines is to destroy the main skeleton of the structure. This hydrodynamic destruction is formed by a physical phenomenon called the explosive bubble effect. During the explosion of hundreds of kilograms of explosive material with high energy output, first an ultrasonic shock wave is created in the water bed and hits the bottom shell of the ship. Subsequently, the hot gases create a huge bubble of gas, which, with its sudden expansion, throws the floating medium upwards.

After maximum expansion, the gas bubble collapses under water pressure and creates a temporary vacuum cavity under the central part of the body. At this moment, the weight of the two parts of the ship's nose and heel, which are suspended on the water, presses on the middle part, which has no water support. This very strong bending moment determines the breaking phenomenon of the keel or the main beam of the ship's bottom. As a result of this phenomenon, the floating steel skeleton is split in half and the ship sinks in a very short time.