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.
Type 2027 A computer processor hooked to the Type 2020 to determine range based on multiple arrival paths of a target's noise. Multipath ranging.
Type 2046 Royal Navy towed array for submarines. This clip-on array is attached to one of the stern planes.
Type 2072 A new flank array for Royal Navy SSNs, to replace the older Type 2007.
Typhoon SSBN The size of a small WW II battle cruiser, the Typhoon is the largest submarine ever built. Very quiet, and equipped with modern sensors. A total of six units have been built.
U-boat Unterseeboot. The German name for submarines.
UAP ESM system on Royal Navy SSNs.
UHF Ultra High Frequency.
Ultra Allied special intelligence during World War II, obtained by the interception and decryption of German Enigma communications.
Upholder (S-40) Latest diesel-electric submarine in the Royal Navy. Intended to replace the aging Oberon class SS, the Upholders have been experiencing a number of teething pains including problems with their torpedo tubes. With the collapse of the Soviet Union, only four out of a projected class run of twelve units are to be built.
Valiant (S-102) Second-generation Royal Navy SSN. Based on the Dreadnought, the entire submarine was produced in the United Kingdom. A total of five units built.
Vanguard Second-generation Royal Navy SSBN. Twice as large as the Resolution class, the Vanguard class will carry sixteen U.S. Trident II (D-5) missiles. Described as being very quiet submarines. A total of four units are expected to be built.
VHF Very High Frequency.
Victor I & II SSNs Second-generation Soviet SSNs. Larger, quieter, and better equipped than November class. Victor IIs differ from Victor Is in that the Victor IIs have four 650mm torpedo tubes and are about 16 feet longer. A total of twenty-two units were built.
Victor III SSN A further modification of a second-generation design. The Victor III class is the first Soviet SSN that came close to Western standards in terms of quieting and sensors. The teardrop-shaped pod on the rudder is the housing for a towed sonar array. The Victor III is the most numerous class of SSN in the Russian inventory, with twenty-six units built.
VLF Very Low Frequency.
VLS Vertical Launch System. A set of twelve external tubes located in the number two main ballast tank on SSN 719 and on the Los Angeles-class SSN.
VSEL Vickers Shipbuilding Enterprises, Limited. The U.K. equivalent of Electric Boat Company.
Waterfall display Phrase used to describe the appearance that a modern passive sonar display makes while showing bearing versus time information. A contact will look like a bright line on a CRT against a speckled background of other noise sources.
WEO Weapon Engineering Officer. Royal Navy equivalent of the weapons officer; however, the WEO is not eligible for command.
XO Executive Officer. U.S. Navy term for the second in command of a ship.
Bibliography
International Defense Review
Jane's Defense Weekly
Jane's Intelligence Review
Maritime Defense
Morskoy Sbornik
Naval Forces-International Forum for Maritime Power
Naval Institute Proceedings
Navy International