Los Angeles class submarine

The Los Angeles class, sometimes called the LA class or the 688 class, is a class of nuclear-powered
Nuclear marine propulsion
Nuclear marine propulsion is propulsion of a ship by a nuclear reactor. Naval nuclear propulsion is propulsion that specifically refers to naval warships...

 fast attack submarines (SSN
Hull classification symbol
The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration use hull classification symbols to identify their ship types and each individual ship within each type...

) that forms the backbone of the United States submarine fleet
Submarines in the United States Navy
There are two major types of submarines in the United States Navy: ballistic missile submarines and attack submarines. In the U.S. Navy, all combatant submarines are nuclear-powered. Ballistic subs have a single, strategic mission: carrying nuclear submarine-launched ballistic missiles...

. With 43 submarines on active duty and 19 retired, the Los Angeles class is the most numerous nuclear powered submarine class in the world. The class was preceded by the and followed by the and es. Except for , submarines of this class are named after U.S. cities, breaking a long-standing Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 tradition of naming attack submarines after sea creatures.

The final 23 boats in the series, referred to as "688i" boats, are quieter than their predecessors and incorporate a more advanced combat system. These 688i boats are also designed for under-ice operations: their diving plane
Diving plane
A diving plane, also known as a hydroplane, is a control surface found on submarines which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when submerged....

s are on the bow rather than on the sail, and they have reinforced sail
Sail (submarine)
In naval parlance, the sail or fin of a submarine is the tower-like structure found on the dorsal surface of submarines...




According to the U.S. government, the top speed of Los Angeles-class submarines is over 25 knots (46 km/h, 29 mph), although the precise maximum is classified. Some estimates put the top speed at 30–33 knots. Tom Clancy, in his book Submarine: A Guided Tour Inside a Nuclear Warship, puts the top speed of a Los Angeles class submarine at 37 knots.

Government sources give the maximum operating depth as 650 feet (198.1 m), while Patrick Tyler
Patrick Tyler
Patrick E. Tyler is an author and formerly chief correspondent for the New York Times. He is the author of three books: A World of Trouble: The White House and the Middle East from the Cold War to the War on Terror, A Great Wall: Six Presidents and China, a history of U.S.-China relations since...

, in his book Running Critical, suggests a maximum operating depth of 950 feet (289.6 m). Although Tyler cites the 688-class design committee for this figure, the government has not commented on it. The maximum diving depth is 1475 feet (449.6 m) according to Jane's Fighting Ships, 2004-2005 Edition, edited by Commodore Stephen Saunders of Royal Navy.

Weapons and fire control systems

Los Angeles class submarines carry about 25 torpedo-tube-launched weapons and all boats of the class are capable of launching Tomahawk
BGM-109 Tomahawk
The Tomahawk is a long-range, all-weather, subsonic cruise missile. Introduced by General Dynamics in the 1970s, it was designed as a medium- to long-range, low-altitude missile that could be launched from a surface platform. It has been improved several times and, by way of corporate divestitures...

 cruise missile
Cruise missile
A cruise missile is a guided missile that carries an explosive payload and is propelled, usually by a jet engine, towards a land-based or sea-based target. Cruise missiles are designed to deliver a large warhead over long distances with high accuracy...

s horizontally (from the torpedo tubes). The last 31 boats of this class also have 12 dedicated vertical launching system
Vertical Launching System
A vertical launching system is a system for holding and firing missiles on surface ships and submarines used by many navies around the world. Each VLS system consists of a number of cells, which can hold one or more missiles ready for firing...

 (VLS) tubes for launching Tomahawks.

Engineering and auxiliary systems

There are two watertight compartments in the Los Angeles class of submarines. The forward compartment contains crew living spaces, weapons handling spaces and control spaces not critical to recovering propulsion. The aft compartment contains the bulk of the submarine's engineering systems, power generation turbines and water making equipment. Some submarines in the class are capable of delivering SEAL
Seal commonly refers to:* Pinniped, a diverse group of semi-aquatic marine mammals many of which are commonly called seals* Seal , a device which helps prevent leakage, contain pressure, or exclude contamination where two systems join...

s through either the Dry Deck Shelter
Dry Deck Shelter
A Dry Deck Shelter is a removable module that can be attached to a submarine to allow divers easy exit and entrance while the boat is submerged...

 (DDS) system or the Advanced SEAL Delivery System (ASDS). A variety of atmospheric control devices are used to remain submerged for long periods of time without ventilating, including an Electrolytic
Electrolytic cell
An electrolytic cell decomposes chemical compounds by means of electrical energy, in a process called electrolysis; the Greek word lysis means to break up. The result is that the chemical energy is increased...

 Oxygen Generator (EOG) nicknamed "the bomb".
While on the surface or at snorkel depth the submarine may use the submarine's auxiliary or emergency diesel generator for power or ventilation (e.g., following a fire). The diesel engine in a 688 class can be quickly started by compressed air during emergencies or to evacuate noxious (non-volatile) gases from the boat, although 'ventilation' requires raising of a snorkel mast. During non-emergency situations, design constraints require operators to allow the engine to reach normal operating temperatures before it is capable of producing full power, a process that may take from 20 to 30 minutes. However, the diesel generator can be immediately loaded to 100% power output, despite design criteria cautions, at the discretion of the submarine commander via the recommendation of the submarine's Engineer, if necessity dictates such actions to a) restore electrical power to the submarine, b) prevent a reactor incident from occurring or escalating, or c) to protect the lives of the crew or others as determined necessary by the commanding officer.

Normally, steam power is generated by the submarine's nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

 delivering pressurized hot water to the steam generator, which generates steam to drive the steam driven turbines
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

 and generators
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...

. While the emergency diesel generator is starting up, power can be provided from the submarine's battery through the Ship Service Motor Generators (SSMGs). Likewise, propulsion is normally delivered through the submarine's steam driven main turbines that drive the submarine's propeller through a reduction gear system. The submarine has no main shaft conventional engines.

In the media

  • Los Angeles-class submarines have also been featured prominently in numerous Tom Clancy
    Tom Clancy
    Thomas Leo "Tom" Clancy, Jr. is an American author, best known for his technically detailed espionage, military science, and techno thriller storylines set during and in the aftermath of the Cold War, along with video games on which he did not work, but which bear his name for licensing and...

     novels and film adaptations, most notably the in The Hunt for Red October
    The Hunt for Red October
    The Hunt for Red October is a 1984 novel by Tom Clancy. The story follows the intertwined adventures of Soviet submarine captain Marko Aleksandrovich Ramius and CIA analyst Jack Ryan.The novel was originally published by the U.S...

  • In the film Terminator Salvation
    Terminator Salvation
    Terminator Salvation is a 2009 American science fiction action film directed by McG and starring Christian Bale and Sam Worthington. The fourth installment in the Terminator series, the film is set in 2018 and focuses on the war between Skynet and humanity, with the human Resistance fighting...

    , Resistance Headquarters is located aboard a Los Angeles-class submarine, called the USS Wilmington according to the novelization and several behind-the-scenes books.
  • The class has also been the subject of video games and simulations, such as Electronic Arts
    Electronic Arts
    Electronic Arts, Inc. is a major American developer, marketer, publisher and distributor of video games. Founded and incorporated on May 28, 1982 by Trip Hawkins, the company was a pioneer of the early home computer games industry and was notable for promoting the designers and programmers...

    ' 1997 release, 688(I) Hunter/Killer
    688(I) Hunter/Killer
    688Hunter/Killer is a 1997 submarine simulator game. Developed by Sonalysts Inc. and published by Electronic Arts and more recently by Strategy First for Windows 95 compatible operating systems. It is named after the 688 Los Angeles class of United States submarine, and was a successor to the...

  • Call of Duty: Modern Warfare 2
    Call of Duty: Modern Warfare 2
    Call of Duty: Modern Warfare 2 is a first-person shooter video game developed by Infinity Ward and published by Activision for the Xbox 360 and PlayStation 3 video game consoles and the Microsoft Windows operating system. Officially announced on February 11, 2009, the game was released worldwide on...

    (2009) features the USS Chicago (SSN-721)
    USS Chicago (SSN-721)
    USS Chicago is a Los Angeles-class submarine, the fourth ship of the United States Navy to be named for the city of Chicago, Illinois. The contract to build her was awarded to Newport News Shipbuilding and Dry Dock Company in Newport News, Virginia on 13 August 1981 and her keel was laid down on 5...

     as the launching platform for TF 141's operations. Another Los Angeles class, the USS Dallas (SSN-700), can also be seen in game, specifically in the level "The only easy day... was yesterday".

See also

External links

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