The Los Angeles class of submarines are nuclear-powered fast attack submarines (SSN) in service with the United States Navy. Also known as the 688 class (pronounced "six-eighty-eight") after the hull number of lead vessel USS Los Angeles (SSN-688), 62 were built from 1972 to 1996, the latter 23 to an improved 688i standard. As of 2024, 24 of the Los Angeles class remain in commission—more than any other class in the world—and they account for almost half of the U.S. Navy's 50 fast attack submarines.
Submarines of this class are named after American towns and cities, such as Albany, New York; Los Angeles, California; and Tucson, Arizona, with the exception of USS Hyman G. Rickover, named for the "father of the nuclear Navy." This was a change from traditionally naming attack submarines after marine animals, such as USS Seawolf or USS Shark. Rickover's response to the decision to name the submarines after cities (and occasionally politicians influential in defense issues) was that "Fish don't vote.”
In the late 1960s, the Soviet Union's advances in submarine technology increasingly threatened the survivability of US Navy (USN) carrier battle groups. Soviet fast-attack submarines became capable of keeping pace with carrier groups, while their newer missile submarines could potentially overwhelm the group's defenses with salvos of missiles. Development of the Los Angeles class commenced in 1967 as a response. The class originally had essentially the same weapons and sensors as the preceding Sturgeon-class submarine, but was approximately 50% larger with "major improvements" in stealth and speed so that they too could keep up with carrier battle groups.
In 1982, after building 31 boats, the class underwent a minor redesign. The following eight that made up the second "flight" of subs had 12 new vertical launch tubes that could fire Tomahawk missiles. The last 23 had a significant upgrade with the 688i improvement program. These boats are quieter, with more advanced electronics, sensors, and noise-reduction technology. The diving planes are placed at the bow rather than on the sail, and are retractable. A further four boats were proposed by the Navy, but later cancelled.
According to the U.S. Department of Defense, the top speed of the submarines of the Los Angeles class is over 25 knots (46 km/h; 29 mph), although the actual maximum is classified. Some published estimates have placed their top speed at 30 to 33 knots (56 to 61 km/h; 35 to 38 mph). In his book Submarine: A Guided Tour Inside a Nuclear Warship, Tom Clancy estimated the top speed of Los Angeles-class submarines at about 37 knots (69 km/h; 43 mph).
The U.S. Navy gives the maximum operating depth of the Los Angeles class as 650 ft (200 m), while Patrick Tyler, in his book Running Critical, suggests a maximum operating depth of 950 ft (290 m). Although Tyler cites the 688-class design committee for this figure, the government has not commented on it. The maximum diving depth is 1,475 ft (450 m) according to Jane's Fighting Ships, 2004–2005 Edition, edited by Commodore Stephen Saunders of the Royal Navy.
Los Angeles-class submarines carry about 25 torpedo tube-launched weapons, as well as Mark 67 and Mark 60 CAPTOR mines and were designed to launch Tomahawk cruise missiles, and Harpoon missiles horizontally (from the torpedo tubes). The last 31 boats of this class (Flight II and Flight III/688i) also have 12 dedicated vertical launching system tubes for launching Tomahawks. The tube configuration for the first two boats of Flight II differed from the later ones: Providence and Pittsburgh have four rows of three tubes vs. the inner two rows of four and outer two rows of two tubes found on other examples.
The 688i (Improved) subclass was initially equipped with the AN/BSY-1 SUBACS submarine advanced combat system that used an AN/BQQ-5E sensor system with updated computers and interface equipment. Development of the AN/BSY-1 and its sister the AN/BSY-2 for the Seawolf class was widely reported as one of the most problematic programs for the Navy, its cost and schedule suffering many setbacks.
Two watertight compartments are used in the Los Angeles-class 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 Navy SEALs through either a SEAL Delivery Vehicle deployed from the Dry Deck Shelter or the Advanced SEAL Delivery System mounted on the dorsal side, although the latter was cancelled in 2006 and removed from service in 2009. A variety of atmospheric control devices are used to allow the vessel to remain submerged for long periods of time without ventilating, including an electrolytic oxygen generator, which produces oxygen for the crew and hydrogen as a byproduct. The hydrogen is pumped overboard but there is always a risk of fire or explosion from this process.
The Los Angeles class is powered by the General Electric S6G pressurized water reactor. The hot reactor coolant water heats water in the steam generators, producing steam to power the propulsion turbines and ship service turbine generators (SSTGs), which generate the submarine's electrical power. The high-speed propulsion turbines drive the shaft and propeller through a reduction gear. In the case of a reactor plant casualty, the submarine has a diesel generator and a bank of batteries to provide electrical power. An emergency propulsion motor on the shaft line or a retractable 325-hp secondary propulsion motor power the submarine off the battery or diesel generator.
Among the retired boats, a few were in commission for nearly 40 years or more, including Bremerton (40), Jacksonville (40), La Jolla (38) and San Francisco (41). With a wide variance in longevity, twelve boats were laid up halfway through their projected lifespans, with Baltimore being the youngest to be retired at only 15 years, 11 months. Another five boats were also laid up early (within 20–25 years), due to their midlife reactor refueling being cancelled, and one was lost during overhaul due to arson. All retired boats have been or will be scrapped per the Navy's Ship-Submarine Recycling Program. In addition, two boats, La Jolla and San Francisco, have been converted to moored training ships.
In Popular Culture
Los Angeles-class submarines have been featured prominently in numerous Tom Clancy literary works and film adaptations, most notably USS Dallas in The Hunt for Red October. Other appearances include USS Chicago in the novel Red Storm Rising and USS Cheyenne in SSN. In addition to fictional works, Clancy's 1993 non-fiction book Submarine: A Guided Tour Inside a Nuclear Warship features an in-depth exploration of USS Miami.
USS Alexandria was used in the 2008 made-for-television film Stargate: Continuum.
688 Attack Sub, a 1989 MS-DOS submarine simulator, allowed the player to control a Los Angeles-class submarine during a set of Cold War missions. The game was also released for the Sega Genesis console.
Jane's 688(i) Hunter/Killer, Sub Command, Dangerous Waters, developed by Sonalysts Inc., and Cold Waters by Killerfish Games, are video games where players control the 688i Los Angeles-class submarine.
(Wikipedia)