One of the finest man-made inventions that sink but still able to move inside water is a submarine. Most of us know, it is used in military and marine studies. For those who are new to a submarine, it is basically a watercraft able to move inside ocean like an aircraft in the sky. What makes us wonder is why submarine is difficult to search after it is missing.
Before we decode, to refresh our understanding on a submarine and how it works. It all goes back to the concept of Archimedes principle, which explains buoyancy of object that floats or sink in the water depends on object’s density. Imagine you immerse an empty bottle of water, it tends to float but if you fill some liquid like water or some material like sand, the bottle will sink.
In reality, Submarine uses the same concept. It can float or sink depends on buoyancy (a.k.a Buoyancy force). In order to control buoyancy, the submarine has special tanks that can be filled with water or air. to return to the surface, the tanks are filled with air and to submerge when tanks are filled with water.
Modern Submarine is designed to have highest safety standards. Having advanced detection systems in place. still, submarines are difficult to locate after it lost its communication. Simplest answer here could be ocean are so large in comparison to a submarine. Second, submarines are built with an emphasis on stealth. especially in the military.
Submarines are generally detected by SONAR (device), a technique which a sound wave or echo generated by an object from that a distance and object’s approximate shape and size can be identified. The very technique naturally used by Bats, whale, and dolphins to communicate or prey on other species. Sonar, a device used is only really effective when we are detecting for a submarine between some distance from the seafloor and the surface of the ocean. But this is only about detection, which surface ship used to identify enemy submarine.
Submarines use extremely low frequency to communicate with control room, this frequency is hard to detect by attackers at the same time has limitations in communicating with the control room. If submarine goes out of some range and that happens mostly because of an accident which results in pilot to lose buoyancy control, then he would be prepared to send some distress signal to rescue. Once signal goes out of range or communication is lost (a.k.a disabled sub or dissub). these leaves room for options to escape and rescue. Escape is the process where the DISSUB’s crew leaves the boat and reaches the surface without external assistance; while rescue is undertaken by outside parties who remove the trapped crew from the submarine.
As part of a rescue operation, general detection method are applied such as SONAR. if this doesn’t work other options to detect via magnetic field disturbance. but this could work only when a submarine is built with some parts of the magnetic material. Again This option is ruled out while searching stealth submarine. Nuclear submarines are designed to be underwater for years so the crew could be safer for a longer time.but not all, some submarines could have supplies for 3 months or even lesser till crew can survive. This makes it more difficult to search having limited time in place.
The last resort used to detect on map ocean floor, unsuccessful search for Malaysia Airlines Flight 370, which officials believe sank to the bottom of the ocean off the coast of West Australia in 2014. This is carried out by specialized aircraft or by sea car but this is extremely costly operation and very few countries have such a technology and this makes a way to abandon rescue operation in the end.
Author: Varun Raj