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The SOSUS System A Personal Perspective of the Early Years

By Bruce Rule - Jun 17, 2015


SOSUS may have been one of the few (the only?) defensive system that was fully operational years before there was a demonstrable need for the surveillance capabilities it provided.

This “prescience” is attributed to the memory of the WWII Battle of the Atlantic against German submarines and the knowledge that the Soviet Union had embarked on a massive submarine construction program albeit then centered around the WHISKEY Class which was a coastal or – at best – a European th eater attack platform, and was not a threat to the Western Atlantic or the Eastern Pacific.

As previously discussed in an article archived on this site, detection problems the System experienced in the early days of the Cuban Missile Crisis – the System's first real large scale test – were actually target recognition issues, the result of an intelligence support failure: no one knew what acoustic detections of Soviet diesel submarines operating in a hostile environment would look like. That problem – self-corrected by the System – was the first step in what the writer likes to call Operation Bootstrap: the System became its own source of threat acoustic signature data, and the entire ASW intelligence community benefited, not to mention the unique contributions System data made to assessments of the design and performance characteristics of Soviet submarines: speeds as much as 50 percent higher than the fastest US platforms available before the LOS ANGELES Class (1976). In terms of installed shaft horsepower, it was 80,000 versus 15,000.

So, what was going on during the years before the Cuban Missile Crisis? It is the writer's assessment that the greatest contribution made by the System during that period was to highlight the acoustic vulnerabilities of US nuclear submarines. This evolved into a love-hate relationship with the submarine community. On the one hand, they begrungingly acknowledged the value of assessments based on real-world acoustic data rather than canned noise trials which were not representative of actual submarine operations. On the other hand, they did not like the publicity given to SOSUS detections of US nucs even though it was classified. The US submarine community mirror-imaged US acoustic detection capabilities and concluded that if we could do it, so could the Soviets. Of course, this was dead-wrong but it was a useful misapprehension because it gave acoustic quieting a higher priority than it otherwise would have had.


This posting also gives the writer another opportunity to debunk the still widely accepted but completely erroneous assessment that a NOVEMBER Class Soviet nuclear submarine operated at speeds as high as 30 knots while on an intercept course with the USS ENTERPRISE (CVAN 65) during a transit from the US west coast to Viet Nam in early January 1969. Although this event occurred 46 years ago, such inaccurate information needs to be corrected from an historical perspective.

The following, from the linked site, is typical of those erroneous assessments:

(Quote) The Enterprise Incident is the name for an event which occurred in 1969, in the Pacific Ocean.

The USS Enterprise, nuclear powered aircraft carrier CVN-65, and her escort fleet left their San Francisco base for a war cruise to Vietnam. At the time the Enterprise was departing, US Intelligence received word that the Soviet Union had dispatched a November Class attack submarine to shadow the battle group. The Enterprise battlegroup was given ASW (Anti-Submarine Warfare) helicopter cover, and was ordered to try and outrun the November, in order to determine the November class's maximum speed.

The November was one of the Soviet Union's very first nuclear submarines, and thus, was expected to have capabilities similar to that of the United States' own USS Nautilus (about twenty knots). Much to the surprise of the Americans, the November kept pace with the Enterprise battlegroup, all the way up to thirty knots. At that point, the US Navy command ordered the November to be chased off.

The Enterprise Incident, as it has come to be called, caused US Naval Intelligence to completely re-assess the capabilities of all Soviet submarines. The November was a first generation Soviet sub. It immediately raised the question of 'how do the MODERN Soviet subs perform?'. It turns out that the reason the November had such a speed advantage over the Nautilus and other Skate Class submarines was because of the utter lack of shielding around the nuclear reactor. This did drastically decrease the November's necessary mass, but it also exposed the crew to massive doses of gamma radiation.

This startling revelation about Soviet submarine speeds gave Admiral Hyman Rickover an opportunity to advance his proposed class of high speed attack submarines, the Los Angeles Class, which today is one of the mainstays of the United States' Navy's submarine fleet. (end quote)

The following is what really happened based on a detailed reconstruction at ONI of the PACSOSUS continuous detections of the 37.4 hour event.

The NOVEMBER was operating about 400 nm off the Oregon coast when it began a high speed event aimed at intercepting the USS ENTERPRISE near Hawaii.

It was a flank-speed run for that NOVEMBER but that speed – held constant for 37.4 hours - was only between 25 and 26 knots, about three knots lower than the class average because of additional drag produced by a modified hull form unique to that unit. At our suggestion, the Navy directed the ENTERPRISE to increase speed in two knot increments which was done up to 31 knots. The NOVEMBER never - repeats, never - responded to that evolution and terminated the chase while still about 60 nm astern of the ENTERPRISE and an opening range.


The NOVEMBER had a significant speed advantage over NAUTILUS not because of “an utter lack of shielding around the nuclear reactor” but because its installed shaft horsepower was 37,000 compared to 15,000 for the NAUTILUS.

If ADM Rickover was surprised, he should not have been. As early as 1966, based on System data from April 1964, NAVSTIC had assessed the NOVEMBER's maximum speed to be about 30 knots. What the ENTERPRISE incident did was to turn an estimate into reality, albeit “clouded” by misinformation, i.e. the 30 knot value for the event. The writer never heard anything about the NOVEMBER being “chased off.”