How Underwater Microphones Helped The US Detect Russian Subs Entering The Atlantic
Story by Bob Sharp • 12h
The Cold War introduced the world to the concept of mutually assured destruction. This was an arms race that saw sides on both sides of the Iron Curtain scrabble to gain an edge. One area where this was fought was under the ocean. However, despite making some of the best submarines of the Cold War era, early Soviet submarines were not known for their stealth qualities. Notoriously noisy, they could be detected with the right equipment. This is where a classified US program known as Project Caesar came into play. More formally known as the Sound Surveillance System (SOSUS), it started life in 1954 with the aim of tracking Soviet submarines by listening for the sounds of machinery and the noise created by the cavitation effect of their propellers.
The development of the SOSUS system was made possible by a convergence of two events. These were the discoveries that low-frequency sounds could travel hundreds of miles underwater, and that submarines produced such sounds. Once this was realized, the US Navy moved quickly to build the system. SOSUS used passive hydrophone arrays that were connected by cables to ground stations. At the height of the Cold War, there were over 4,000 personnel based in 20 shore stations and hydrophone arrays situated in strategic locations across both the Pacific and Atlantic Oceans. Despite such a large presence of both hardware and personnel, the Soviets remained unaware of the system's importance until they received intelligence through the Walker spy ring in the 1970s and 1980s.
How SOSUS Detected Soviet Submarines
The first SOSUS base was commissioned at the Naval Facility at Ramey Air Force Base in Puerto Rico on 18th September 1954. These bases were to become known as "Caesar Stations," and in each station were rows of recorders. These displayed the sounds received by the hydrophone arrays on large scrolls of paper. The recorders each displayed the sound from an individual "beam" -- a beam being a sound received from a particular direction. The analysts who manned stations walked up and down the rows of recorders, interpreting the data that each machine was recording. This was an exercise that became known as "walking the beams." Although there is no longer a requirement to perform the walking function, the process of monitoring the stations is still called walking the beams.
https://www.msn.com/en-us/news/world/how-underwater-microphones-helped-the-us-detect-russian-subs-entering-the-atlantic/ar-AA1JKVRs?ocid=msedgdhp&pc=HCTS&cvid=688df93576314c2bb05f7587c6eb8ede&ei=138
