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Saturday, February 6, 2010

How Nuclear Submarine are Made

A nuclear submarine is a ship powered by atomic energy that travels primarily under-water, but also on the surface of the ocean. Previously, conventional submarines used diesel engines that required air for moving on the surface of the water, and battery-powered electric motors for moving beneath it. The limited lifetime of electric batteries meant that even the most advanced conventional submarine could only remained submerged for a few days at slow speed, and only a few hours at top speed. On the other hand, nuclear submarines can remain under-water for several months. This ability, combined with advanced weapons technology, makes nuclear submarines one of the most useful warships ever built. 

  • The manufacture of a submarine is highly complex and utilizes both manual and automated processes. Large sheets of steel are rolled and welded into the shape of the inner and outer hulls. Scaffolding is erected during manufacture so accessibility remains unencumbered. Every aspect of manufacture is checked by inspection and quality control measures. For example, welded steel components are inspected with x rays. Pipes are filled with helium in order to check for leaks. As a result, the Naval Reactors program is considered to have the best safety record of any nuclear power program.
    bars of steel until they are soft enough to bend. Automatic hammers strike the ends of the bar, producing a curve matching the hull.
  • 8 Welding several sections together produces an inner hull. The same process is repeated to form an outer hull. The inner hull is welded to steel ribs that are then welded to the outer hull. The steel ribs separate the two hulls, allowing space for the ballast tanks that control the depth of the submarine. The outer hull only extends as far as the bottom and sides of the inner hull, allowing the submarine to remain upright.
  • 9 Meanwhile, steel plates are welded in place inside the inner hull in order to divide the submarine into several watertight compartments. Steel decks and bulktheads are also welded in place. Exterior welding seams are polished by high-speed grinding wheels, making them smooth. Not only does this improve the surface for painting, but it also provides the submarine with a streamlined surface that experiences little friction during travel. The hull is then painted with layers of protective coatings.

Finishing the exterior

  • 10 External components such as rudders and propellers are made using various metalworking techniques. One important method used for many metal components is sand casting. This process involves making a wood or plastic model of the desired part. The model is then surrounded by tightly packed, hardened sand held in a mold. The halves of the mold are separated, allowing the model to be removed. The shape of the desired part remains as a cavity in the hardened sand. Molten metal is poured into the cavity and allowed to cool, resulting in the desired part.
  • 11 The hull is surrounded by scaffolding, allowing workers to reach all parts of it. The external components are welded or otherwise attached. Certain components, such as sonar equipment, are attached to the hull then covered with smooth sheets of steel in order to reduce friction during underwater travel.

Finishing the interior

  • 12 Large equipment is placed within the inner hull as it is being built. Smaller equipment is brought into the inner hull after it is completed. The submarine is launched before much of the interior equipment is installed. After the launching ceremony, the submarine is towed into a fitting-out dock, where work on the interior continues. Vital components such as periscopes, snorkels, engines, and electronic equipment are installed. Equipment for the comfort of the crew, such as refrigerators, electric stoves, air conditioners, and washing machines are also installed at this time.
  • 13 The nuclear reactor begins operating as the submarine begins its first sea trials. The crew is trained during an Atlantic Ocean cruise. Weapons are launched and tested, often in waters off Andros Island in the Bahamas. The submarine is officially commissioned in a ceremony which changes its designation from "Precommissioning Unit" (PCU) to "United States Ship" (USS). The submarine then undergoes a shakedown cruise before entering active service.

Quality Control

The vital role it plays in national defense, the fact that the lives of its crew depend on its proper functioning, and the dangers inherent in its nuclear reactor ensure that quality control is more important for a nuclear submarine than for almost any other manufactured product. Before construction begins, the materials which will be used to build various components are inspected for any structural flaws. Previously when a new design for a nuclear submarine was proposed, a scale model was built to see if any improvements could be made. Scale drawings of the new design were made, then expanded into full-size paper patterns that allowed small details to be studied closely. A full-sized mockup of the interior was made in order to give builders a chance to adjust the location of components in order to save space or make them more readily accessible. Presently, design modeling, modification, and simulation are all enhanced by the use of computers. 

When the steel plates are cut and rolled to form the hull, they are inspected to ensure that all dimensions are accurate to within one sixteenth of an inch (0.16 cm); smaller parts may need to be accurate to within one ten-thousandth of an inch (0.00025 cm) or less. Proper welding of all steel components is inspected with x rays. Pipes are inspected by filling them with helium and checking for leaks. Every instrument is tested to ensure it works properly. In particular, the nuclear reactor undergoes stringent tests to ensure that it is safe. As a result of these precautions, the Naval Reactors program is considered to have the best safety record of any nuclear power program. 

After the submarine is commissioned, it undergoes a shakedown cruise to see how it would operate in wartime conditions. The speed and maneuverability of the submarine is tested to ensure that it meets the necessary requirements.


The greatest concern dealing with wastes produced by nuclear submarines involves the radioactive waste produced by nuclear reactors. Although the waste produced by a nuclear submarine is much less than that produced by a larger nuclear power plant, similar problems of disposal exist. The Naval Reactors program has an excellent record of safely storing radioactive wastes. Some environmentalists, however, have expressed concern about the possibility of radioactive material being released if a nuclear submarine is sunk by accident or during military operations.

The Future

Nuclear submarines are expected to remain a vital part of naval defense systems for many years to come. Future designs will feature new ways to improve the speed and depth capabilities of nuclear submarines. Research will also lead to an improved ability to detect enemy ships while remaining undetected. With the demise of the Soviet Union, leading to reduced defense budgets, the U.S. Navy faces the challenge of reducing the cost of nuclear submarines while retaining their effectiveness. With this goal in mind, the New Attack Submarine program was devised in the 1990s, with the goal of replacing large and expensive Seawolf attack submarines with smaller, less expensive, yet equally effective nuclear submarines.

Where to Learn More


Clancy, Tom. Submarine: A Guided Tour Inside a Nuclear Warship. Berkley, 1993.


George, Glenn R., and Lisa Megargle George. "The Naval Reactor Program: From Nautilus to the Millennium." Nuclear News (October 1998): 26-33.
Newman, Richard J. "Breaking the Surface." U. S. News and World Report (April 6, 1998): 28-31.
Wilson, Jim. "Run Silent, Run Deep." Popular Mechanics (January 1998): 62-66.


"Nuclear Submarines of the World." January 24, 1998. .
Rose Secrest 
 (source madehow)