Submarine: A Guided Tour Inside a Nuclear Warship

SUBGRU SUBmarine GRoUp.

SUBROC SUBmarine ROCket. A submarine-launched ballistic rocket with a nuclear depth bomb payload.

SUBRON U.S. SUBmarine SquadRON.

Subsafe Procedural and system changes instituted to increase the safety of U.S. submarines following the loss of the USS Thresher (SSN- 593) in April 1963.

SURTASS SURveillance Towed Array Sensor System (AN/UQQ-2). Essentially a mobile SOSUS array towed by small Ocean Surveillance Ships (T-AGOS).

Swiftsure (S-104) Third generation of Royal Navy SSNs. Improved quieting and sensors over the Valiant class. In the redesigned location of the main conformal array the Swiftsures lost a torpedo tube (five instead of six). A total of six units were built.

TASO Torpedo and Anti-Submarine warfare Officer. Royal Navy term for the junior seaman officer in charge of the submarine's torpedo launching system.

TB-16 (A-D) Standard U.S. Navy SSN 'fat line' towed array. The various modifications (mods) allow the submarine to search at higher speeds without degrading performance. The array is stored in a sheath that runs along the hull.

TB-23 First U.S. Navy 'thin line' array found on SSNs equipped with AN/BSY-1 and AN/BQQ-5E. This array is about four times longer than the TB-16 series and is stored entirely on a reel located in the aft ballast tank area.

TDU Trash Disposal Unit. A tube that ejects weighted trash cylinders from the bottom of a U.S. submarine.

Tea kettle Royal Navy term for the reactor on nuclear-powered submarines.

TERCOM TERrain-COntour Matching. A navigation system on Tomahawk land attack missiles. The system uses the Tomahawk's radar altimeter to make terrain profiles at preselected points along the missile's route. These profiles are compared to a radar reference map to determine if flight corrections are needed.

TEZ Total Exclusion Zone.

Thresher (SSN-593) Lost April 4, 1963, during deep-diving trials following an overhaul period. The loss caused the U.S. Navy to institute the Subsafe program.

Tigerfish (Mk 24, Mods 0–3) A quiet, electric-powered dual-purpose torpedo in service with the Royal Navy.

TMA Target Motion Analysis. The process by which computers or men determine a target's course, speed, and range so that a torpedo or missile can be fired accurately.

TMPS Theater Mission Planning System. U.S. TMPS centers plan Tomahawk land attack mission routes to various targets around the globe using maps and navigation information provided by the Defense Mapping Agency.

Tomahawk (UGM-109) Family of cruise missiles that are launched from standard torpedo tubes or special vertical launch tubes on SSNs. The different variants are:* Tomahawk antiship missile (TASM)* Tomahawk land attack missile-nuclear (TLAM-N)* Tomahawk land attack missile-conventional, HE warhead (TLAM-C)* Tomahawk land attack missile-conventional, bomblets (TLAM-D)

Torpedo The self-propelled torpedo was invented by Robert White-head, an Englishman, in 1866. Since then, the torpedo has undergone significant improvements in speed, range, and depth. Present-day torpedoes are all homing weapons using either active/passive acoustics or wake sensors.

Towed array String of passive hydrophones towed at some distance behind the ship. By separating the hydrophones from the ship, the array was no longer limited by platform noise, thereby increasing detection range. The towed array can also be made as long as necessary to detect sounds with long wavelengths (very low frequency).

Trafalgar (S-107) Fourth-generation Royal Navy SSN. Basically a slightly larger Swiftsure to accommodate additional quieting measures. Production has just ended, with a total of seven units being built. A modified Trafalgar design, called Trafalgar Batch II, is being worked on with the cancellation of the SSN 20 ('W' class).

Trident I (C-4) Third generation of U.S. Navy submarine-launched ballistic missiles.

Trident II (D-5) Fourth generation of U.S. Navy submarine-launched ballistic missiles.

Triton (SSN-586) Only U.S. Navy SSN built with two nuclear reactors. Originally designed as a radar picket submarine, Triton made a submerged round-the-world cruise in 1960.

TSO Tactical Systems Officer. Royal Navy term for the junior seaman officer in charge of the submarine's fire control system.

Tullibee (SSN-597) First U.S. Navy SSN with torpedo tubes placed amidships to make room for the large 15-foot spherical sonar array. This design is the basis for all later U.S. SSN designs. Tullibee was also fitted with a troublesome turboelectric drive, which earned her the reputation of being a hangar queen, and she was often referred to as 'Building 597.'

Turtle A semisubmersible craft designed and built by David Bushnell during the American Revolutionary War. It was the first submarine to conduct an attack, albeit unsuccessful, against a hostile surface ship (HMS Eagle).

Type 18 A multifunction search periscope found on U.S. SSNs.

Type 2 An optics-only attack scope, reminiscent of WW II periscopes, on U.S. submarines.

Type 2019 Acoustic intercept receiver on Royal Navy submarines.

Type 2020 Active/passive conformal array on Royal Navy SSNs.