The Los Angeles-class attack submarines (SSN) are the most numerous class of nuclear powered submarines built by any nation, and form the bulk of the U.S. attack submarine force as of 2007. They were preceded by the Sturgeon-class. Named after U.S. cities, the class broke a long-standing Navy tradition of naming attack submarines after sea creatures. The boats are also colloquially referred to as "688-class" subs, after the hull classification symbol of the first boat, SSN-688.
Sea - Military - Submarines
LA-class submarines are extremely fast—they are publicly acknowledged as being faster than 25 knots (46 km/h, 29 mph), and it is widely believed that they can exceed 35 knots (65 km/h, 40 mph) under good conditions (The USS San Francisco was publicly acknowledged to be traveling at 35 knots when she collided with an undersea shoal). They carry about 25 torpedo-tube launched weapons. Any boat of this class may launch a Tomahawk cruise missile from its horizontal torpedo tubes. The last 31 boats of this class also have 12 vertical launch tubes specifically for the purpose of launching Tomahawks.
The final 23 boats in the series, referred to as "688i", are even quieter, incorporate an advanced combat system, and are configured for under-ice operations (with diving planes on the bow and a reinforced sail). The Navy is phasing out older non-Vertical Launch System (VLS) Los Angeles-class attack submarines in favor of the Virginia-class attack submarines.