The Navy Is Researching "Acoustic Superiority" to Keep Its Submarines Alive

Kyle Mizokami, Popular Mechanics
14 October 2016 

The U.S. Navy is beginning a top-to-bottom review of its underwater operations to make sure subs are quiet as possible. According to Scout Warrior, the Navy is also starting up a parallel effort to make its sensors more capable of detecting the quietest enemy submarines. It's all part of drive to maintain the edge in submarine technology in the face of strong Russian and Chinese competition. In the world of submarines, noise kills. A noisy submarine plowing though the oceans will be quickly detected and killed by its opponents. Right now, the United States enjoys a technology advantage in quiet submarines, particularly its Virginia-class nuclear attack submarines. But Russian submarine designers, after a nearly quarter century hiatus, are back to their drawing boards. Chinese submarines are growing increasingly sophisticated, too. The quest to make American submarines quieter, like much submarine tech, is highly classified. Some obvious solutions the Navy must be considering, though, are things such as isolating the engine from the hull as much as possible to prevent vibrations from escaping from the submarine. Others include improving anechoic tiling, which provides a layer of sound-deadening rubber tiles on the submarine's hull.
As far as improving a submarine's sensors so it can detect an enemy first, most of this work is concentrated on so-called "passive" sensors. While sonar is very useful for locating the enemy, it also reveals the location of the submarine using it. Passive sensors are used to not only detect enemy sonar, but now to detect the sound of enemy submarines moving through water. The goal is to gather as much detail as possible, including the sub's depth, speed and bearing, and even its type. Finally, the Navy is working towards a fourthgeneration of submarine communications. A submarine that is totally silent isn't very useful if it can't share information and receive orders. The catch, of course, is to design a means of communications that can't be detected by the enemy. The Navy plans to roll out what it learns on future submarines, including future versions of the Virginia-class submarine and the upcoming Columbia-class ballistic missile submarines, currently under development.