Los Angeles class submarine

Periscope Depth.jpg
USS Key West off the coast of Honolulu, Hawaii with masts and antennas raised at periscope depth.
Class overview
Operators: United States of America
Preceded by: Sturgeon-class submarine
Succeeded by: Seawolf-class submarine
Completed: 62
Active: 45
Retired: 17
General characteristics
Displacement:

Surfaced: 6,082 tons

Submerged: 6,927 tons
Length: 362 ft (110 m)
Beam: 33 ft (10 m)
Propulsion: 1 GE PWR S6G nuclear reactor, 2 turbines 35,000 hp (26 MW), 1 auxiliary motor 325 hp (242 kW), 1 shaft
Speed:

Surfaced: 20 knots

Submerged: 20+ knots (official)[1], 33+ knots (reported)[2][3]
Range: Refueling required after 30 years[4]
Endurance: 90 days
Complement: 129
Sensors and
processing systems:
BQQ-5 passive SONAR, BQS-15 detecting and ranging SONAR, WLR-8 fire control RADAR receiver, WLR-9 acoustic receiver for detection of active search SONAR and acoustic homing torpedoes, BRD-7 radio direction finder[5]
Electronic warfare
and decoys:
WLR-10 contermeasures set[5]
Armament: 4×21 in (533 mm) bow tubes, 10 Mk48 ADCAP torpedo reloads, Tomahawk land attack missile block 3 SLCM range 1,700 nm, Harpoon anti–surface ship missile range 70 nm, mine laying Mk67 mobile Mk60 captor mines

The Los Angeles class, sometimes called the LA-class or the 688-class, is a class of nuclear-powered fast attack submarines (SSN) that forms the backbone of the United States submarine fleet. With 62 submarines, this class has more boats than any other nuclear powered submarine class in the world. The class was preceded by the Sturgeon class and followed by the Seawolf class and Virginia class. Submarines of this class are usually named after U.S. cities, breaking a long-standing Navy 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 planes are on the bow rather than on the sail, and they have reinforced sails.

Contents

Characteristics

Capabilities

According to the U.S. government, the top speed of Los Angeles-class submarines is over 25 knots (46 km/h, 29 mph) and the precise speed is classified. Some estimates put the top speed at 30 – 33 knots.[6][2]

Similarly, government sources give the maximum operating depth as 650 feet (200 m),[7] while Patrick Tyler, in his book Running Critical, suggests a maximum operating depth of 950 feet (290 m).[8] Although Tyler cites the 688-class design committee for this figure,[9] the government has not commented on it.

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 cruise missiles horizontally (from the torpedo tubes). The last 31 boats of this class also have 12 dedicated vertical launch (VLS) tubes for launching Tomahawks.

Engineering and auxiliary systems

USS Greeneville with Advanced SEAL Delivery System (ASDS) attached.

There are three watertight compartments in the Los Angeles class of submarines. The aft compartment contains the bulk of the ship's engineering systems, power generation turbines and water making equipment. The Reactor Compartment (RC) is the only watertight compartment designed to be completely flooded to emergency cool the reactor in the case of a catastrophic reactor cooling accident. The second watertight compartment, the Engine Room (ER) can be partially flooded but can only flood to a lesser degree than the Forward Compartment (FC) since the FC contains the crew living spaces, weapons handling spaces and control spaces not critical to recovering propulsion. The two personnel-occupied compartments are separated by a single watertight door and two ventilation shafts (fore to aft) for mixing fresh air throughout the boat. In port, these three openings are arranged such that natural ventilation from open hatches in the conning tower and aft escape trunk vent outside air into and through the ship[10] Some submarines in the class are capable of delivering SEALs through either the Dry Deck Shelter (DDS) system or the Advanced SEAL Delivery System (ASDS).[11] A variety of atmospheric control devices are used to remain submerged for long periods of time without ventilating, including an Electrolytic Oxygen Generator (EOG) nicknamed "the bomb".[12][4]

While on the surface or at periscope depth the submarine may use the ship's auxiliary or emergency diesel generator for power or ventilation[13][14] (eg. following a fire).[15] 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 snorkle 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, it should be noted that 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 ship's chief engineer, if necessity dictates such actions to a) restore electrical power to the ship, 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.[16] Normally, steam power is generated by the ship's nuclear reactor delivering steam to the steam driven turbines generators. While the emergency diesel generator is starting up, power can be provided from the ship's battery through the Ship Service Motor Generators (SSMGs).[17] Likewise, propulsion is normally delivered through the ship's steam driven main turbines that drive the ship's propeller through a reduction gear system. The ship has no main shaft conventional engines.[18]

In the media

Los Angeles-class submarines have been involved in a number of major submarine incidents.

Los Angeles-class submarines have also been featured prominently in numerous Tom Clancy novels and film adaptations, most notably USS Dallas (SSN-700) in The Hunt for Red October.[19]

In the film, the Captain of the Dallas is portrayed by actor Scott Glenn.

Los Angeles class submarines have been the subject of video games and simulations such as 688i.

Notes

  1. "U.S. Navy Fact Sheet - Attack Submarines - SSN". United States Navy. Retrieved on 2008-04-20. "General Characteristics, Los Angeles class ... Speed: 20+ knots (23+ miles per hour, 36.8 +km/h)"
  2. 2.0 2.1 Polmar, Norman; Moore, Kenneth J. (2003), Cold War Submarines:The Design and Construction of U.S. and Soviet Submarines, Brassey's, pp. 271, ISBN 1574885944 
  3. "Officials: U.S. submarine hit undersea mountain", CNN (11 January 2005). Retrieved on 2008-04-20. "The submarine was traveling in excess of 33 knots -- about 35 mph --when its nose hit the undersea formation head-on, officials said." 
  4. 4.0 4.1 SSN-688 Los Angeles class from Federation of American Scientists retrieved 02/29/2008 :The 18 SSN-688 class submarines that will be refueled at their mid-life could make good candidates for a service life extension because they could operate for nearly 30 years after the refueling. After these submarines serve for 30 years, they could undergo a 2-year overhaul and serve for one more 10-year operating cycle, for a total service life of 42 years.
  5. 5.0 5.1 Polmar, Norman "The U. S. Navy Electronic Warfare (Part 1)" United States Naval Institute Proceedings October 1979 p.137
  6. Tyler, Patrick (1986). Running Critical. New York: Harper and Row. pp. 24, 56, 66–67. ISBN 978-0-06-091441-7. 
  7. Waddle, Scott (2003). The Right Thing. Integrity Publishers. pp. xi (map/diagram). ISBN 1591450365. "This reference is for operating depth only". 
  8. Tyler, (1986). pp. 66-67, 156
  9. "Notes in pp. 64-67: Deliberations of ad-hoc committee on SSN 688 design taken from confidential sources and from interviews with Admiral [Ret] Rickover...." From Tyler, p. 365
  10. SSN-688 Los Angeles Class Design. Los Angeles Class at Globalsecurity.org. Accessed on 29 April 2008
  11. Polmar & Moore, (2003). pp. 263
  12. Treadwell Supplies Oxygen Generator Components for Nuclear Subs Defense Industry Daily 28-Jan-2008
  13. Fairbanks Morse Engines Marine Installations Accessed on 29 April 2008
  14. Auxiliary Division on USS Cheyenne USS CHEYENNE SSN-773 Department & Divisions from Federation of American Scientists. Accessed on 29 April 2008
  15. Firefighting and Damage Control Update 181044Z JUN 98 (SUBS) Message COMSUBLANT (1998) Accessed on 29 April 2008
  16. DiMercurio, Michael; Benson, Michael (2003), The complete idiot's guide to submarines, New York, NY: Alpha Books, pp. 49–52, ISBN 978-0-02-864471-4 
  17. Elger, Wallace (2007). "Development of Metal Fiber Electrical Brushes for 500kW SSMG Sets". Naval Engineers Journal 117 (4): 37–38. 
  18. Nuclear Propulsion Pressurized water Naval nuclear propulsion system at Federation of American Scientists Accessed on 30 April 2008
  19. .  | last = Clancy | first = Tom | authorlink =Tom Clancy | coauthors = | title = The Hunt for Red October | publisher = Naval Institute Press | date = 1984 | location = | pages = 71, 77, 81 | url = | doi = | id = | isbn = 0-87021-285-0}}

References

This article includes information collected from the Naval Vessel Register, which, as a U.S. government publication, is in the public domain.

See also

See also: List of Los Angeles class submarines, List of active Los Angeles class submarines by homeport, and List of inactive Los Angeles class submarines by disposition

External links