During the Second World War the submarine proved its worth as a potent fighting weapon. In the early part of the Battle of the Atlantic, U-Boats in the hands of the German Kriegsmarine wreaked havoc among allied shipping convoys, sinking 2,282 ships totalling 14.4 million tons. The largest monthly loss occurred in March, 1943 when 693,000 tons were sunk. This was primarily the work of U-Boats working in 'Wolf-Packs' laying in wait for passing convoys on the known shipping lanes across the Atlantic Ocean.

They were not, however, invulnerable and as anti-submarine techniques on the Allied side improved, the tables were turned in the latter half of the war. The submarine's 'Achilles heel' lay in its lack of speed and inability to stay underwater for long periods. Submarines could neither keep up with their prey nor could they outrun their hunters. Almost all submarines of the period used a combination of Diesel-Electric power. An air-breathing diesel engine provided power for running on the surface and to charge banks of lead-acid batteries that were used to power electric motors for underwater running. Once the batteries were depleted the submarine was forced to surface to run the diesel engine for recharging, and it was then that it was at its most vulnerable.

How much more devastation could have been wreaked if the submarine had been as fast as its prey and able to outrun its hunters while staying submerged during their stay in the battle zone barely bears contemplation. It may well have meant that with supplies from the United States cut off, Britain would have been unable to pursue the war, and would almost certainly have been forced to sue for peace.

In the United States the development of nuclear power in all its forms was a priority. Apart from the devastating power of 'The Bomb', the peaceful harnessing of the atom was promising to be the answer to energy needs. One avenue of development, that of a compact nuclear reactor, was to make possible a practical power plant for marine use. One of the first such uses was the production of the world's first nuclear powered submarine, the USS Nautilus.

USS Nautilus (SSN-571), was the sixth vessel of the US Navy to bear the name. It is commonly thought that the name is derived from the fictional submarine in the novel by Jules Verne, Twenty Thousand Leagues Under the Sea. This at least cannot be said of the first two surface ships to bear the name as they both preceded the novel's publication in 1870. The original ship, a twelve gun schooner, was active against Tripolitan pirates in the Mediterranean until it was captured by a British squadron in 1812. A second schooner of that name was built in 1838 for the hydrographic survey of the US coast and eventually was used by the US Navy in the war with Mexico. Also during World War One another vessel named Nautilus was commissioned and assigned to patrol and escort duties within the New York harbour area.

No doubt, though, there was at least a tacit nod towards the fictional ship when the first submarine to bear the name was commissioned in 1911. This vessel served throughout the First World War until decommissioned in 1922. The fourth ship named Nautilus, also a submarine, was commissioned in 1918 and served with the navy until scuttled in 1931 in a Norwegian fjord. The fifth vessel was built in 1930 and was one of the largest American submarines to take to the sea. It served with distinction throughout the Second World War, sinking seven enemy ships and was awarded the Presidential Unit Citation, the Navy's highest award to a fighting unit.

The Nuclear Power Plant

In 1948 Admiral Hyman Rickover, the 'Father of the American Nuclear Fleet', working together with the United States' Atomic Energy Commission, created the Naval Reactors Program to explore the viability of a compact nuclear power plant that could be used within the confines of a naval vessel. At first there had been some doubt that a nuclear reactor could be built small enough to fit within the confines of a submarine, but the original concept was taken to a practical design by the Bettis Atomic Power Laboratory, a research facility at West Miffin, Pennsylvania and owned by the United States government. It was operated for the Department of Energy by the Westinghouse Corporation.

The Westinghouse Electric Corporation was contracted to construct and develop the prototype submarine reactor plant which was designated the Submarine Thermal Reactor (STR). The STR was developed into the S1W, (Submarine, Model 1, Westinghouse) and powered up for the first time on 30 March, 1953. The S2W was developed from the Model 1 as the first unit to be installed in a vessel.

The S2W was a Pressurised Water Reactor (PWR) which used Uranium U235 as a fuel. The enriched uranium inserted as pellets into rods and bundled together were used to build the core of the reactor. The fission of this material produced heat within the core. The heat generated by the core was removed by thermal conduction to water circulating around it under high pressure. This pressure enabled the water to absorb a greater amount of heat without boiling and was pumped at temperatures of around 300°C in a continuous loop from the core to a heat exchanger. Here, the heat was transferred to water in a secondary loop which, not being under pressure, boiled creating steam, which was used to drive a steam turbine. The water in the primary loop then returned to the core to repeat the cycle. The secondary loop steam passed through a condenser to return it to liquid form and was pumped back to the heat exchanger to repeat its own cycle again.

The steam turbine provided propulsion for the ship through two drive shafts to propellers at the rear of the ship and drove generators which produced electricity to power the auxiliary systems of the ship. These included lighting, heating, air purification and oxygen and water generation.

Construction

Meanwhile, in July, 1951 the US Congress authorised funds to build the first nuclear submarine. In December of that year the Navy Department announced that the new ship would carry the name Nautilus and its hull number would be SSN-571. Work began at the Electric Boat Division of the General Dynamics Corporation at Groton, Connecticut and the ship's keel was formally laid by President Harry S Truman on 14 June, 1952, who in his speech said:

This vessel is the forerunner of atomic-powered merchant ships and aeroplanes, of atomic power-plants producing electricity for factories, farms and houses. The day that the propellers of this new submarine first bite into the water and drive her forward will be the most momentous in the field of atomic science since that first flash of light down in the desert seven years ago¹.

Some 18 months later, on the 21 January, 1954 Nautilus took to the water for the first time as she was launched into the Thames river with the traditional champagne over the bows by Mrs Mamie Eisenhower, the wife of the new president, Dwight D Eisenhower.

Nautilus was the largest submarine constructed up to that time and adopted the motto 'First and Finest'. She had an overall length of 323 feet, a beam of 27 feet and a draft of 22 feet. Her submerged displacement was 4,092 tons. She carried an armament of 24 standard 21-inch torpedoes, firing through six forward facing torpedo tubes. The normal compliment of crew was 13 officers and 92 enlisted men.

By comparison, conditions for the crew within Nautilus were far more comfortable than the earlier conventional submarines. Whereas sleeping arrangements formerly involved bedding down within the machinery, the Nautilus's crew had some dedicated rest areas. Further provision was made for food preparation and messing, and even a wardroom that could double up as a cinema. Music from gramophones could be piped throughout the ship from a large stock of the latest recordings, and a small library was also available.

Nautilus was commissioned into the US Navy on 30 September, 1954. Fitting out and testing culminated in the running up to full power of the nuclear engine for the first time at the dockside on 3 January, 1955. Finally on the morning of 17 January, Nautilus cast off under the command of Commander Eugene P Wilkinson (USN), who sent the historic signal: 'Underway 11:00 on Nuclear Power'. A new era in submarine warfare had begun.

Sea trials took place until April 1955, testing the vessel for seaworthiness and its capabilities submerged and on the surface. On the 22 April Nautilus was taken on charge by the US Navy. During the next month she embarked on her first shakedown cruise from her home port to San Juan, Puerto Rico and set several new submerged distance and speed records. Not least she travelled the distance of 1,381 miles in 89.9 hours and included the longest period of submerged travel at an average speed of 16 knots.

Through the remainder of 1955 and into the early part of 1956 Nautilus joined in exercises with surface ships to establish the effects of the increased underwater speed and endurance on anti-submarine warfare, and soon established a top speed in trials of 22 knots (41 km/hr) running on the surface and 25 knots (46 km/hr) underwater. She also made visits to various eastern seaboard ports to be displayed to navy personnel and made a number of dives taking over 300 navy personnel and Atomic Energy Commission officials to sea. Nautilus returned to her home port in April 1956 after making a submerged run of 1,152 miles. She was finally accepted on by the Navy 'for unrestricted service' on 11 May, 1956.

In February 1957 Nautilus returned to Groton, Connecticut to be refuelled. She had logged a total of 62,562 miles on the first fuelling, of which over half that distance was underwater. This overall mileage surpassed the 20,000 leagues covered by her fictitious namesake in Jules Verne's novel. It was estimated that a conventional diesel powered submarine would have burned two million gallons of fuel-oil to travel the same distance.

Heading North

Nautilus's capability to stay underwater for long periods made possible a submerged transit under the Arctic ice pack. During August 1957 with a new commanding officer Captain TK Kimmel (USN), she made three dives under the ice pack steaming over 1,300 miles and finally reaching latitude 87 degrees north, the furthest north travelled by any vessel. Before returning home Nautilus carried out her first visits to several foreign ports. She put into the British ports of Rothesey and Faslane² in Scotland, Plymouth in England and Le Havre, France. During her visit to Britain she took to sea a number of government officials including the then Minister of Defence, the Rt Hon Duncan Sandys and the Parliamentary Secretary to the Admiralty, Rt Hon Christopher Soames, both of whom would be involved with the introduction of Britain's own first nuclear submarine, HMS Dreadnaught.

Operation Sunshine.

Under strict security Nautilus departed from Seattle on 9 June, 1958 to attempt the crossing of the geographic North Pole. Under the command of Commander William R Anderson she approached the polar ice pack from the Bearing Sea and attempted to make her way through the Chukchi Sea. At this time of year deep sea ice and shallow water forced her to turn back and put into Pearl Harbour, Hawaii. In July, Nautilus returned, and this time was able to pass through the Chukchi Sea and the Barrow Sea Valley. On 3 August, 1958, she reached 90 degrees north³ and the commander announced: 'For the World, Our country and the Navy...the North Pole'. and broadcast the message Nautilus 90 North. After 96 hours under the polar ice, Nautilus surfaced in the Greenland Sea on the 5 August, 1958.

Nautilus returned to the naval shipyard on 22 June, 1959 for a refit and the second refuelling of the reactor. On completion Nautilus was deployed to the Mediterranean and was attached to the US Navy's Sixth Fleet. By December 1960 she had logged 175,000 miles on nuclear power. Nautilus continued to carry out exercises with the Mediterranean and Atlantic fleets evaluating new techniques of submarine warfare and defence. In the summer and autumn of 1962 she was deployed to assist with the enforcement of the naval quarantine of Cuba during the missile crisis.

Nautilus carried on with routine fleet duties interspersed with public relations visits to ports throughout the world. She received major overhauls on a further two occasions during 1964 and 1972, by which time she had travelled over 400,000 miles. In 1976 Nautilus was awarded the 'White A' for Anti-submarine Warfare, Weapons and Operations Excellence.

In 1979, Nautilus completed her last voyage under her own power from Groton, Connecticut to Mare Island Naval Shipyard, Vallejo, California arriving on the 26 May, 1979. In her 25 years service she had completed a total of over 2,500 dives and travelled over a half a million nautical miles. She was decommissioned and stripped of the nuclear reactor in preparation for her new role as an exhibition historic ship. On 20 May, 1982 she was designated a National Historic Landmark.

Nautilus was towed back to her birthplace at Groton, Connecticut and arrived on 6 July, 1985. She was opened to the public as the prime exhibit⁴ at the new Submarine Force Museum in 1986. With the introduction of the nuclear powerplant giving submarines the ability to stay submerged for months at a time, it allowed their development into mobile launch platforms for nuclear armed ballistic missiles⁵. Submarines were now able to hide in the oceans carrying their potent cargo while being practically invulnerable to being traced and destroyed. Nautilus was the first of her kind, and had changed the face of warfare forever.