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An Assessment of Naval Hydromechanics Science and Technology
The Navy's first research submarine, the USS Albacore (SS 569), was built to evaluate at sea the innovative ideas of control and propulsion that had been derived from the basic research program, and it provided firm support for these ideas. With this submarine, the Navy, the science and technology community, and the shipbuilding industry stepped outside the traditional technology box of the fleet submarine. The fundamental data obtained on a new hydrodynamic hull, control surfaces, and propulsion, along with the utility of low-carbon, high-yield-80 structural steel, became the foundation of U.S. submarine design and construction for the next half century. The development of the high-speed submarine hull form is a prime example of a technological breakthrough. It enabled a submerged submarine to travel well in excess of 30 knots. More importantly, when combined with the parallel development of nuclear propulsion, it resulted in the U.S. Navy' s first truly high-speed submarine. The research foundation and technical expertise made possible by sustained investments in Navy S&T substantially enabled this revolutionary advance in naval warfare capability.
Equally important to the continued superiority of U.S. submarines have been the sustained improvements in submarine stealth. The sudden increase in submarine speed and endurance produced an urgent need for quiet propulsion for stealth and for effective control for submarine safety. This drove the hydromechanics S&T community to continue to improve the stealth and hydromechanics performance of the submarine fleet. A long-term national S&T research program was implemented to solve the acoustic side effects of sustained submerged high speed and to meet the threat of the Soviet submarine fleet during the Cold War period. Fundamental and applied stealth and hydromechanics research was vigorously pursued in the Navy's laboratories and in universities, under the sponsorship of the ONR. Hydromechanics innovations ranging from advanced propeller designs to reduced hull acoustic radiation have enabled a large reduction in submarine signatures. As a result of a broad range of technological developments, U.S. attack and ballistic submarines have maintained an underwater acoustic advantage over the submarines of all other navies.
The Small Waterplane Area Twin Hull (SWATH) ship concept was developed from the technology base and design methods established by sustained investments from Navy 6.1, 6.2, and 6.3. This concept permits greatly improved seakeeping and seaway performance, particularly in small and medium-sized ships. Innovative design configuration capabilities were also developed, including the unique steering system embodied on the TAGOS 19 and a number of semiactive and active control system concepts. SWATH technology has been applied commercially to a large (12,000-ton) passenger/cruise ship and to all-weather ferries and hydrographic and survey ships. At present, about 40 naval and commercial SWATH ships have been built worldwide.
Surface ship hull form technology and design methods have been applied to recent classes of surface combatants, resulting in superior seakeeping, powering, and acoustic performance. This major performance advance is a direct result of years of investment in hull form technology R&D.
Continued compilation of the variability of sea conditions and their statistics has improved the seakeeping design specification for surface combatants, and satellite ocean wave observations have provided timely guidance for ship operations. The basic understanding of ship response to the ocean waves associated with different sea states has improved the ability to design surface combatants with better seakeeping characteristics, less deck wetness, cost-effective shell plating and hull girders, and improved helicopter landing and takeoff operations.
The sustained development and implementation of numerous innovations in the fleet have reduced energy consumption and operating costs for U.S. Navy ships. Innovations include new, environmentally acceptable, effective hull antifouling coatings; improved hull and propeller cleaning and maintenance programs; and stern modifications that permit fuel savings of 3 to 10 percent for several