The NS Savannah holds a unique place in maritime history as the first nuclear-powered merchant ship, launched on July 21, 1959. This vessel was not merely a ship but a grand demonstration project, showcasing the potential peacetime applications of nuclear energy. Conceived as part of President Dwight D. Eisenhower's 1955 "Atoms for Peace" program, the Savannah was a joint venture by United States government agencies, built to explore the technical
feasibility of nuclear propulsion for commercial shipping. Her construction, including a substantial nuclear reactor and fuel core, cost $46.9 million, a significant investment for its time.
Design and Initial Operations
The Savannah was designated with the new prefix "NS" for "Nuclear Ship," distinguishing her from traditional commercial vessels that used "SS" for "Screw Steamer." Her name paid homage to the SS Savannah, the first steamship to successfully cross the Atlantic Ocean, linking her to a legacy of maritime innovation. The ship was designed to be visually striking, resembling a luxury yacht more than a typical cargo vessel. This aesthetic choice was deliberate, intended to impress and highlight the advanced nature of her propulsion system. She featured thirty air-conditioned staterooms, each with a private bathroom, a dining facility for 100 passengers, a lounge that could double as a movie theater, a veranda, a swimming pool, and a library. Even the cargo-handling equipment was designed with an eye for appearance.
Her dimensions were impressive for the era, measuring 596 feet 6 inches in length and 78 feet in beam, with a loaded draft of 29 feet 6 inches and a loaded displacement of 21,800 short tons. The ship was built with seven cargo holds, a reactor compartment, and a machinery compartment, creating nine watertight sections. The reactor compartment was centrally located, with the superstructure positioned just aft to allow for refueling access. The topmost deck of the superstructure housed the pilothouse, radio room, chart room, a battery room, and an emergency diesel generator. Below this, officers' accommodations and a lounge were situated. The promenade deck featured an elliptical main lounge, a main stair and elevator, and the Veranda Lounge, complete with a bar and a glass wall overlooking the swimming pool.
Technical Specifications and Performance
The heart of the NS Savannah was its 74 MW Babcock & Wilcox nuclear reactor, designed to civilian standards with a strong emphasis on safety and reliability, rather than the shock resistance or compactness typical of military reactors. This pressurized water reactor used low-enriched uranium and was housed within a cylindrical containment vessel. The containment vessel, with wall thicknesses ranging from 2.5 to 4 inches, was built to withstand the pressure generated by a ruptured primary coolant pipe. It also featured manholes designed to allow water into the vessel if the ship sank in deep water, preventing collapse.
The reactor itself was 17 feet high, with a core 62 inches in diameter and 66 inches high, containing 32 fuel elements. Each element comprised 164 fuel rods, clad in stainless steel and housing uranium oxide pellets enriched to an average of 4.4% U-235. Twenty-one control rods, 66 inches long, were capable of full insertion in just 1.6 seconds. The reactor powered two De Laval steam turbines, which drove a single propeller shaft. The propulsion plant was designed for 20,000 horsepower, aiming for a service speed of 20 knots. In practice, the Savannah achieved about 22,000 horsepower and a maximum speed of 24 knots, demonstrating excellent performance at sea. Her range was an astonishing 300,000 nautical miles at 20 knots on a single load of 32 fuel elements.
Operational Successes and Challenges
By many accounts, the NS Savannah was a technical success. She performed well at sea, maintained an impressive safety record, and her gleaming white paint remained unsmudged by exhaust smoke, a testament to her clean nuclear propulsion, except when the diesel generator was in use. However, the ship was not expected to be commercially competitive, and indeed, faced several economic and operational challenges. Her cargo capacity was limited to 8,500 short tons of freight in 652,000 cubic feet, significantly less than many of her competitors. The streamlined hull, while aesthetically pleasing, made cargo loading laborious, a disadvantage as port operations became more automated.
Furthermore, the Savannah required a crew one-third larger than comparable oil-fired ships, and these crew members needed specialized training beyond conventional maritime licenses. This led to the establishment of a Nuclear Engineer Program at the United States Merchant Marine Academy. Labor disputes arose over pay disparities between deck officers and nuclear engineering officers, causing delays and changes in operators. These factors contributed to higher operating costs, with the Savannah costing approximately $2 million more per year in subsidies than a conventional Mariner-class ship. The Maritime Administration eventually placed her out of service in 1971 to save costs, though it was noted that by 1974, with rising fuel oil prices, her operating costs might have been comparable to conventional vessels. Despite these commercial hurdles, the NS Savannah successfully demonstrated the viability and safety of nuclear propulsion for merchant shipping, leaving a lasting legacy as a symbol of the "Atoms for Peace" initiative.
