SSN-688 Los Angeles-class Design

These submarines were built in three successive variants:

• SSNs 688-718 - Orginal Los Angeles class
• SSNs 719-750 - Starting with SSN 719 and beyond the last 31 hulls of the class have 12 vertical launch tubes for the Tomahawk cruise missile, along with an upgraded reactor core which does not require refueling.
• SSNs 751-773 - The final 23 hulls [SSN 751 and later] referred to as "688I" (for improved), are quieter, incorporate an advanced BSY-1 sonar suite combat system and the ability to lay mines from their torpedo tubes. They are configured for under-ice operations in that their forward diving planes have been moved from the sail structure to the bow and the sail has been strengthened for breaking through ice.

The submarines are outfitted with a wide variety of antennas, transmitters and receivers necessary to support accomplishment of their assigned tasks. Interior communication is possible on a wide range of circuits and sound powered phones which do not require electrical power and are reliable in battle situations. Various alarm and indicating circuits enable the Officer of the Deck and the Engineering Officer of the Watch to continuously monitor critical parameters and equipment located throughout the ship.

The nuclear power plant gives these boats the ability to remain deployed and submerged for extended periods of time. To take advantage of this, the ship is outfitted with auxiliary equipment to provide for the needs of the crew. Atmosphere control equipment replenishes oxygen used by the crew, and removes carbon dioxide and other atmosphere contaminants. The ship is equipped with two distilling plants which convert salt water to fresh water for drinking, washing and the propulsion plant. Sustained operation of the complex equipment and machinery on the ship requires the support of repair parts carried on board. The ship carries enough food to feed a crew of over one hundred for as long as 90 days.

Los Angeles class submarines are divided into two watertight compartments. The forward compartment houses all the living spaces, weapons systems, control centers, and sonar/fire control computers. The after compartment houses the nuclear reactor and the ship's propulsion equipment.

1. Engine Room. The engine room houses all the propulsion machinery, as well as the Ship's Service Turbine Generators that supply the ship's electricity, and the evaporator, which distills water for the propulsion plant and other shipboard use.

2. Control Room/Attack Center. Located in the upper level of the forward compartment is the control room--the heart of the ship. The Officer of the Deck stands his watch here, controlling all activities on board. In control, the ship's location is continually determined and plotted, the course and depth are controlled, and all sonar contacts are tracked. The control room also functions as the attack center, where all of the ship's weapon systems are controlled from. The sail helps to add stability to the submerged vessel. Additionally it houses all of the periscopes and antennae. In the forward top portion of the sail is the bridge. When the ship is on the surface, the Officer of the Deck will shift his watch to the bridge. Here he has clear view of all the surrounding waters, in addition to getting a breath of fresh air and seeing the welcome sun.

4. Mess Decks, Berthing, and Wardroom. The middle level of the forward compartment is dedicated to the crew's living spaces. Here is found the mess decks and galley which, when underway, serve four meals a day, one every six hours (allowing for all watchstanders to get a hot meal). Also here are the berthing spaces. Here is the only personal space that a crewman gets--his bed (known as a "rack". These racks are stacked three tall throughout the berthing spaces and have only a curtain to close them off from the rest of the boat. With this as the only private area on board, it is not uncommon to find pictures of family and friends put up on the wall in a rack along with personal cassette and CD players for entertainment. The wardroom is the officers own room. Here is a big table around which the officers eat, train, and work.

The crew of a submarine is often more cohesive than that of a surface ship because of the close quarters submariners live in. There isn't space on submarines for "Officers' Country," an area most surface ships set aside for the exclusive use of commissioned officers. Submarines also lack space for a "Chief's Mess," which means all enlisted Sailors eat together on the mess decks. On surface ships, senior enlisted Sailors eat in a separate area from their junior counterparts.

5. Torpedo Room. The lower level of the forward compartment is the Torpedo Room. This room stores the ship's weapons which include Mk48 ADCAP torpedoes, Tomahawk cruise missiles, and mines. The torpedo room houses the handling equipment and access to the ship's four torpedo tubes. Weapons are moved from their stowage positions, loaded into the tubes, and readied for launch all in this room by the ship's Torpedomen. The torpedo room also houses controls for the vertical launch tubes which add 12 more Tomahawk cruise missiles to the ship's load.

6. Sonar Sphere. Housed in the very forward end of the submarine is the sonar sphere. This is an array of over 1,000 hydrophones which makes up part of the advanced BQQ-5E sonar suite. Out in front of the ship, positions the sphere as far as possible from the ship's own noise, thereby giving it the best listening conditions.