Innovation in the Submarine Force:
Ensuring Undersea Supremacy

by Dr. Owen R. Cote, Jr.

Meeting this challenge, however, requires a willingness to experiment with new missions and new approaches, even when such experiments appear to threaten existing ways of doing business. During the Cold War, the Submarine Force had a great, if largely untold, record of innovation, and there are useful lessons for today’s Submarine Force to be drawn from that experience.

Cold War Developments
One of the most dramatic examples of Cold War innovation was the emergence of the submarine as the dominant anti-submarine warfare (ASW) platform. In World War II, the submarine was primarily an anti-surface weapon, and ASW was performed exclusively by surface ships and aircraft. By the mid-1950s, in contrast, U.S. submarines had established themselves as an important member of the Navy’s Cold War ASW team, and by 1960, with the launching of the USS Thresher (SSN-593), they were arguably the dominant member.

In USS Thresher (SSN-593), the innovative features of her predecessors
were brought together to create the first fast-attack SSN optimized for ASW.

Thresher exploited three technological innovations that had been developed independently in the preceding decade. Taken separately, none of these innovations was sufficient to transform the submarine into the dominant ASW platform, and their initial development was not justified with that end in mind. In fact, in today’s austere fiscal environment, these experimental programs might not have survived budget cuts, because none were obvious solutions to near-term problems. Yet, all required substantial investment at a time – 1949 – when the defense budget was little more than a third the size of today’s.

The first ingredient was the Navy’s nuclear power program, which led to USS Nautilus (SSN-571) in 1954. Nuclear power had obvious attractions for the Navy and for the Submarine Force in particular. To the latter, it promised the unlimited, submerged endurance required to implement a true submersible. Nuclear power would make American submarines immune to the ASW measures used by the Allies to defeat German U-boats in World War II, assuring success in future anti-shipping campaigns against new enemies. But what future enemy was vulnerable to such an anti-shipping campaign? The Soviet Union, the largest threat to the United States, was freed from dependence on the sea for its commerce by its size and location. Thus, while Nautilus appeared to make the submarine immune to Soviet ASW, the Soviet Union’s geopolitical situation seemed to make it immune to the submarine.

The world's first nuclear submarine, USS Nautilus (SSN-571),
demonstrated the advantages of unlimited submerged endurance.

Another new opportunity was offered by the high-speed test submarine USS Albacore (AGSS-569), the first submarine with a revolutionary teardrop hull. Albacore was designed to explore the hydrodynamics of high speed, submerged operations. In a sense, its development could be interpreted as an "if-you-build-it-they-will-come" bet that nuclear or some other high-power, air-independent propulsion would soon prove feasible.

USS Albacore (AGSS-569), first submarine with a "teardrop" hull-form,
explored the hydrodynamics of high-speed, submerged operations.

The third element was Project KAYO. KAYO was designed to explore the feasibility of diesel-electric submarines (SSKs) for ASW barrier operations using passive acoustics with low-frequency, bow sonar arrays. As part of KAYO, three small SSKs – Barracuda (SSK-1), Bass (SSK-2), and Bonita (SSK-3) – were built around the large BQR-4 array. Listening with the submarine on battery, these arrays gave then unheard-of convergence zone detection ranges against snorkeling submarines. But the SSKs remained hampered by their inability to close a target quickly, which led to their use in sub-air barriers in conjunction with ASW aircraft. Additionally, their own need to snorkel periodically limited their ability to operate in far-forward areas.

USS Bonita (SSK-3) was the third of the project KAYO SSKs, which
established the feasibility of large, low-frequency, passive bow sonar arrays.

These initially independent experiments fed upon each other in unanticipated fashion. Nautilus proved the feasibility of nuclear power, and Albacore demonstrated the optimum hull form for a fast submarine. In combination, they produced the 30+ knot USS Skipjack (SSN-585). At the same time, the SSKs had demonstrated the ASW value of a quiet submarine with a large bow sonar array and the preferability of nuclear power for fully autonomous, forward-barrier operations. Unfortunately, Nautilus proved to be very loud acoustically. This led to the USS Tullibee (SSN-597), a smaller and slower SSK(N) with electric drive for quieting and the first integrated sonar suite, including both a low-frequency passive array for long-range detection and a spherical array for approach and attack. Finally, the Thresher design resulted from combining Tullibee, the first quiet nuclear submarine, and Skipjack, the first fast nuclear submarine, to create what became the paradigm for all subsequent Cold War development – the quiet, fast-attack SSN, optimized for ASW.

Post-Cold War Initiatives
The process of innovation that produced Thresher demonstrates that when both technology and the external security environment are changing rapidly on multiple fronts, experimentation with new approaches is likely to be rewarded by the discovery of unexpected capabilities. At least some of these new capabilities, in turn, may prove relevant for new missions and countering unexpected new threats that the Navy will face in the 21st century.

This experience is applicable to today’s Submarine Force as it expands its role in the land-attack mission.2 Geopolitics will demand that the Navy enhance its capability for precision strike, because only the Navy can exercise it in contingencies where the United States lacks assured access ashore, as along much of the Mediterranean-Indo-Pacific littoral. At the same time, our capability for better precision land attack from the sea is being enabled by several new technologies currently developing at the same exponential pace as the microprocessor power that animates our personal computers. These innovations include miniaturized Global Positioning System/ Inertial Navigation System (GPS/INS) guidance packages for cheap, precision, standoff weapons and new satellite communication systems with global reach. By exploiting our cumulative experience with military satellites in the UHF, SHF, and EHF bands and using leased commercial connectivity where applicable, communication links with the mobility, wide bandwidth, jam resistance, and stealth needed for exchanging intelligence and targeting data will become commonplace.

While these geopolitical and technical trends ensure a place for all three of the Navy’s platform communities in precision strike from the sea, they are especially promising for enlarging the submarine’s hitherto limited role in that mission area. This fact argues persuasively for experimenting with selected concepts that will confirm the Submarine Force’s potential for land attack. These include possible conversion of excess Trident ballistic missile submarines (SSBNs) into land-attack guided missile carriers (SSGNs); an initiative to build on the Strategic Systems Program Office’s proposed navalized Army Tactical Missile System (NTACMS) to create the next generation of sea-launched precision weapons; and the new payload innovations likely to emerge from recent Defense Science Board recommendations on the "Submarine of the Future."

The motivation for assigning the Submarine Force a pivotal role in littoral warfare follows directly from its inherent qualities of mobility, endurance, lethality, and stealth, together with the geopolitical and technological opportunities of a new security environment. To facilitate the required transition, the undersea warfare community needs to "return to its roots" in the tradition of innovation that turned the submarine from a part-time-submersible, anti-surface platform at the dawn of the Cold War into the potent deep water ASW platform of today.

Dr. Cote is the Associate Director of the MIT Security Studies Program.