Los Angeles (SSN 688)
The 62 boats in this class represent the largest class of nuclear-powered submarines to have been built to a single basic design. Initially developed in the late 1960s to counter the Soviet Vz’ctor-class fast attack submarines, production carried on far longer than originally expected, setting a construction duration record for submarines of any type.
As built, the LosAngeles class subs were about five knots faster than the earlier US Sturgeon (SSN 637) class. Like all US submarines, the LA is a single-hulled design, which is quieter than a comparable double-hull boat, but also more vulnerable to ASW weapons. The speed advantage was later diminished by upgrades in weaponry, sonars, and survivability. Those upgrades have also eliminated a 250-ton reserve designed into the class. The LAs were significantly quieter than Soviet submarines until improved Soviet design (and propeller-milling machinery from Norway and Japan) helped to narrow the gap in the mid-1980s.
One of the most apparent changes is the 12-tube Tomahawk Vertical Launch System (VLS) in the bow introduced in Providence (SSN 719). The troubled BSY-1 advanced sonar and fire control system was potentially so great an advance that boats so equipped—San Juan (SSN 751)and later—are described as a subclass— Improved 688 or ISSN 688. Other ISSN 688 features include modifications to permit minelaying and an under-ice capability with retractable bow planes. (Virtually all other US submarines had diving planes on the sail.)
In addition to the large BQQ-5 series bow sonar, a large towed-array passive sonar is carried in a sheathlike housing fitted to the upper starboard side of the hull. Later boats have the BSY-1 sonar system.
DEVELOPMENT •
As with most US shipbuilding programs begun in the late 1960s, the Los Angeles class had a rocky start with cost overruns, material price inflation, and rancorous fault-finding between the Navy and the builders. Newport News Shipbuilding was lead yard and was awarded 29 boats. General Dynamics’ Electric Boats contracted for 32 submarines. The Los Angeles was commissioned in November 1976.
Problems with integrating the BSY-1 system were so nearly intractable that average building times stretched out considerably. Incorrect engineering drawings, delays by the sonar’s contractor, and Navy changes were blamed. The last boat—Greeneville (SSN 773)—will complete in late 1996.
LosAngeles Submarine
U.S. GOVERNMENT DEPARTMENT OK DEFENSE
Meanwhile, defense cutbacks caused the Navy to begin retiring LosAngelesclass submarines early. The Baton Rouge, due for an expensive refueling, was “inactivated” instead in September 1993, 16 years after her commissioning.
COMBAT EXPERIENCE •
In November 1986, as the Augusta operated submerged (playing “cat and mouse”) in the Atlantic in October 1986, she collided with an apparently undetected Soviet attack submarine while evading another. Both submarines survived the collision with no personnel losses. The Augusta returned to Groton, Connecticut, where her damage (external ballast tank and bow sonar cap) cost about $2.7 million to repair. Other such collisions may have contributed to the loss of one or more Soviet submarines.
The first known operational use of submarine-launched Tomahawks was the launch by Louisville (SSN 720) during Operation Desert Storm; approximately 12 were fired by submarines. The Pittsburgh was later revealed to have launched Tomahawks from the Mediterranean. The Philadelphia, Chicago, and Neivport News were also reported by the Navy as having supported Desert Shield. Altogether 13 submarines, most or all of them Los An-geles-c\a.ss ships, were reported to have been deployed to the region.
The Topeka was the first US submarine to enter the Persian Gulf, visiting Saudi Arabia in January 1993 in response to the delivery of the first Russian-built Kilo-class attack submarine to Iran.
SPECIFICATIONS •
DISPLACEMENT 6,080 tons standard, 6,927 tons submerged
DIMENSIONS
length 360 ft (109.7 m) overall beam 33 ft (10.1 m)
draft 32 ft (9.8 m)
MACHINERY 1 General Electric S6G pressurized-water nuclear reactor, 2 steam turbines, approx 30,000 shp on 1 shaft=30+ kts submerged
CREW 133
WEAPONS
4 21-in (533-mm) Mk 67 torpedo tubes amidships for Mk 48 torpedoes (total stowage 26 torpedoes/missiles)
Harpoon anti-ship and Tomahawk land-attack launched from torpedo tubes
12 vertical launch tubes for Tomahawk in SSN 719 and later submarines SENSORS
BPS-15A surface-search radar
BQQ-5A/B/C/D multifunction bow-
mounted low-frequency sonar (being upgraded to BQQ-5E)
BSY-1 multifunction sonar in SSN 751 and later submarines
TB-16 or TB-23 towed-array sonar
BQS-15 under-ice/mine-detection high-frequency sonar
Mine and Ice Detection System
(MIDAS) in SSN 751 and later submarines
BRD-7 direction finder
WLR-8(V) radar-warning receiver
WLR-9 sonar receiver
WLR-12ESMreceiver
Seawo/f(SSN21)
This attack submarine design was intended to succeed the Los Angeles (SSN 688) class. Reflecting increased concern over the quieter Soviet submarines, the emphasis in this class lay on improved machinery, quieting (especially in machine isolation from the hull), and improved combat systems, both sensors and additional weapons.
The result was a large, plump boat with a relatively low length-to-beam ratio that was the largest attack submarine to be built outside of the Soviet Union. Despite its size, the most powerful US submarine nuclear reactor propels the submarine at a maximum speed slightly faster than the Los Angeles (SSN 688) class (making it the fastest US submarine design).
One Navy design goal was a high maximum “acoustic speed” of more than 20 knots (i.e., the speed at which the submarine can transit while maintaining a sufficiently low noise level to employ passive sonar; 1980s-era Soviet submarines had a maximum acoustic speed of six to eight knots). The pump jet propulsors, designed in Great Britain, are the same as those used in the very quiet British Trafalgar-class SSNs.
Bow-mounted diving planes retract into the bow for under-ice operations. The forward edge of the sail-hull joint is covered by a “cusp,” or fairing, that is similar in appearance to the dorsal fillet on an airplane. It distributes the stresses imposed by surfacing through the ice.
Installation of Seawolf& BSY-2 sonar/ fire control system was delayed by a variety of technical and programmatic problems. In addition, construction delays and early problems with the propulsor played their parts in raising the cost to over $1 billion per boat.
Armament has more torpedo tubes and internally stowed weapons than in existing subs, but no external Tomahawk Vertical Launch System (VLS) tubes like those in the later units of the Los Angeles class. 30-in (762-mm) diameter tubes allow a quiet, “swim-out” torpedo launch.
The Seawolfs place as the core of the 21st-century Navy’s nuclear-powered attack submarine force eroded during continuing, at times acrimonious, debate over its design and increasing resistance to its cost. Further weakening the case was the collapse of the Soviet Union and the apparent diminution of the successors’ submarine fleet.
Critics strongly disagreed with the emphasis on size and weapons load, arguing that the cost per boat would make it impossible to respond to the high building rates established for Soviet Akula and Sierra nuclear attack boats as well as the very compe-tentKilo-classdiesel-eleetriedesign.
DEVELOPMENT •
Despite the debate over its size and cost, Seawolfbegan construction at Electric Boat in Groton, Connecticut, in 1990. Delivery fell behind by more than a year when inspectors discovered cracks in many of the Seazuolfs hull welds; all welds had to be inspected and many redone.
Attempts by Newport News Shipbuilding to share construction were frustrated by a sharply declining building rate. By the mid-1990s, the program had been scaled down from a 30-boat force to fewer than five (probably no more than three), and studies had already begun of a smaller, less expensive design known as the Centurion.
Seawolf, which had been canceled by the Bush administration in FY1992, was revived in the election year of 1992, primarily as an industrial-base preservation program. Naming the SSN 22 Connecticut honored the sub’s home state even as it ignored a recent policy directive that reestablished the names offish as proper for submarines.
SPECIFICATIONS •
DISPLACEMENT 9,150 tons submerged
DIMENSIONS
length 350 ft (106.7 m) overall beam 40ft (12.2m)
draft 35 ft 11 in (10.9m)
MACHINERY 1 pressurized-water nuclear reactor, 2 steam turbines, approx 60,000 shp on 1 propulsor= 35 kts submerged, diving depth over 1,500 ft (460 m)
CREW approx 130
WEAPONS
8 30-in (762-mm) torpedo tubes amidships (50 weapons)
Harpoon antiship and Tomahawk land-attack missiles launched from torpedo tubes
Mk 48 torpedoes SENSORS
surface-search radar
BSY-2 suite with bow-mounted transducers, wide-aperture array, and towed-array sonar
TB-16 towed-array sonar
TB-23 towed-array sonar
WLQ-4{V) 1 passive EW system
Sturgeon(SSN637)
These 37 submarines are improved versions of the Permit (SSN 594) class, with a taller sail structure, an improved electronics suite, under-ice operational capability, and low-mounted sail planes for better depth-keeping when near the surface. They are slower than the Permits because the same propulsion machinery drives a bigger, heavier hull. This is accentuated in the last nine boats, which are 10 ft (3 m) longer than the others.
Interest in Arctic Ocean operations is reflected by the attention given to operating under the ice. Both the sail and rudder were reinforced, the sail planes can be rotated 90° to slice upward, and upward- and forward-looking navigational sonars allow safer operations between the seafloor and the jumbled blocks of ice.
Many, if not all, of these submarines have an acoustic device known as GNAT fittedjustforward ofthe upper rudder fin.
Many Sturgeons have been modified for a variety of purposes. Some have been modified to carry the the Deep Submergence Rescue Vehicle (DSRV). Others, including the Cavalla, were altered to support covert swimmer-delivery concepts and equipment such as a removable Dry Deck Shelter (DOS) hangar that permits loading and deployment of a group of free-swimming divers or a Swimmer Delivery Vehicle (SDV) while fully or partially submerged.
DEVELOPMENT •
The Sturgeon was ordered in November 1961 and delivered in March 1967; the last in the class was completed by Newport News Shipbuilding in August 1975. Sharing the yards with the higher-priority Lafayette-class ballistic missile boats slowed the pace. Electric Boat in Groton, Connecticut, built 13 altogether. Other yards included Newport News (10), General Dynamics’ Bethlehem yard at Quincy, Massachusetts (two), Litton’s Ingalls yard at Pascagoula, Mississippi (five plus one begun by New York Shipbuilding), Mare Island Navy Yard (five), and Portsmouth Navy Yard (two).
COMBAT EXPERIENCE •
The Whale became the first of the class to operate under the Arctic ice pack for more than a brief period. In late 1989 and early 1990, the Silversides (SSN 679) became the first ship since the Nautilus (SSN 571) to circumnavigate the North American continent. The trip took 89 days and included surfacing at the North Pole.
Several Sturgeon-class submarineswere reported to have supported US naval forces during Operations Desert Shield and Desert Storm in 1990-91. In March 1993, the Grayling collided with a CIS (Commonwealth of Independent States) Navy Delta Ill-class ballistic missile submarine in the Barents Sea. Although such meetings are thought to have occurred often, very few were publicized before the collapse of the Soviet Union.
The Qiieenfish was the first of the class to be decommissioned (October 1990), followed by nine more by the end of FY1994.
SPECIFICATIONS •
DISPLACEMENT 4,250 tons standard except SSN 678-687 4,460 tons; 4,780 tons submerged except SSN 678-687
4,960 tons
DIMENSIONS
length 292 ft 0 in (89.0m)
overall (except SSN 678-687 302 ft (92.1
m))
beam 31 ft 8 in (9.7 m)
draft 28 ft 10 in (8.8 m)
MACHINERY 1 Westinghouse S5W
pressurized-water nuclear reactor, 2 De Laval or General Electric steam turbines, 15,000 shp on 1 shaft, approx 15 kts surface, approx 30 kts submerged
CREW 129 WEAPONS
4 21-in (533-mm) Mk 63 torpedo tubes amidships Mk 48 wire-guided torpedoes
Harpoon antiship and Tomahawk land-attack missiles launched from torpedo tubes SENSORS BPS-14/15 surface-search radar BQQ-5 multifunction bow-mounted
BQS-14 mine-avoidance/under-ice sonar
TB-16 or TB-23 towed-array sonar WLR-9 sonar receiver
