SSN-597 Tulibee
In 1956 Admiral Arleigh Burke, then CNO, requested that the Committee on Undersea Warfare of the National Academy of Sciences study the effect of advanced technology on submarine warfare. The result of this study, dubbed "Project Nobska" was an increased emphasis on deeper-diving, ultraquiet designs utilizing long-range sonar. The USS Tullibee incorporated three design changes based on Project Nobska. First, it incorporated the first bow-mounted spherical sonar array. This required the second innovation, amidships, angled torpedo tubes. Thirdly, Tullibee was propelled by a very quiet turboelectric power plant.
Tullibee combined the ASW focus of the SSKs with the smallest nuclear reactor then feasible with an eye toward a relatively cheap, dedicated ASW asset that could be deployed in the numbers still considered necessary to fully populate the forward barriers. Compared to the 15,000 SHP S5W type reactor of a Skipjack, Tullibee had a 2500 SHP reactor and turbo-electric drive. She could barely make 20 knots, but she lacked the reduction gears whose loud tonals made prior SSNs so easy for SOSUS to detect at extreme range. She also continued the tradition established by the BQR-4 equipped SSKs by mounting a large, bow mounted, passive, low frequency array, the BQR-7. On Tullibee, the BQR-7 was wrapped around the first spherical active sonar, the BQS-6, and together they formed the first integrated sonar system, the BQQ-1.
As an ASW platform her performance was unmatched, but almost as soon as the decision to deploy Tullibee was made, a further decision was made to avoid specialized platforms and pursue instead a multipurpose SSN that best combined the speed of Skipjack and the ASW capability of Tullibee into one platform. This became the USS Thresher.
