BALLISTIC TRAJECTORY Path of an unguided flying object, in a free-fall path determined by gravity, initial velocity, magnetic, Coreolis, and aerodynamic forces.
BARE STEERAGEWAY Minimum speed to allow the rudder and planes to work. About two knots.
BATTLESHORT A condition in which the nuclear reactor’s safety interlocks are removed. Used only in a severe emergency or in battle, when an accidental reactor shutdown is more dangerous to the ship due to loss of propulsion than the potential risk of a reactor meltdown. Only the captain can order Battleshort.
BATTLESHORT SWITCH Rotary switch on a cabinet in AMR 2 upper level that removes reactor safety interlocks.
BAT-EARS SONAR Slang name for the AN/BQQ-7 sonar suite, including the spherical broadband array, the hull broadband array, and the towed narrowband array. Also known as the “Q7.”
BEAM (1) To the side of the ship. (2) An active sonar cone stretching out into the ocean like the beam of a flashlight. (3) A passive sonar reception cone — noise outside the cone will not be received.
BEARING Direction to a contact, expressed in degrees. A contact to the north is at a bearing of 000. A contact to the east is at 090,
BEARING AMBIGUITY When a target is detected on the towed array, its noise could be coming from one of two directions. The ambiguity must be resolved by turning the ship and seeing which new two directions the tonal seems to be coming from, or correlating a narrowband towed array bearing to a broadband bearing. Broadband bearings are never ambiguous.
BEARING DOT STACK A method of finding a firecontrol solution on the Mark I firecontrol system. The operator “stacks dots” using a knob. The display is a graph of the difference between actual target bearing and solution generated target bearing versus time. When the dot stack is in a vertical line, the difference between where a target is and where he should be is zero, indicating a firing solution. If a target zigs, the dots diverge off either left or right, indicating the target is no longer where the computer’s solution says he should be.
BEARING DRIFT The direction of change of a contact’s bearing, i.e., bearing drift is right when the contact moves from 090 to 095.
BEARING RATE The speed (or rate of change) of a contact’s bearing. A contact that has a bearing change from 090 to 095 in one minute has a bearing rate of 5 degrees per minute right.
BIGMOUTH ANTENNA Slang name for the AN/BRA-34 multifrequency antenna. A radio antenna suitable for transmission or reception of several frequencies including HF, VHP, and UHF. Shaped like a telephone pole, it protrudes from the sail about 25 feet.
BILGES The space at the very bottom of the cylindrical hull of a submarine below the lower level deck. In the engineering spaces, the bilges capture leakage from piping systems for pumpout by the drain system. The bilges also capture any water from flooding so that it can be pumped out before it rises above the lower level deck to damage equipment.
BIOLOGICS Ocean noises generated by marine life forms: shrimp, whales, and other fish and mammals fill the sea with clicks, groans, grunts, and even tonals. The sounds can sometimes be mistaken for F’lbmarine sounds. A current theory holds that submarines transiting at low speeds can attract marine animals, thus shrouding the submarine in a cloak of biologies. For this reason, biologies are usually investigated with narrowband sonar to prove they do not hide an enemy submarine.
BLOCKS-OF-WOOD SONAR Code name for a Russian active sonar that sounds like two wood blocks clicking together. Used almost exclusively by Russian submarines to verify a target’s range immediately prior to weapon launch. Immediate action for an American submarine hearing Blocks of Wood sonar is to call a Snapshot.
SLOWDOWN Opening a valve in a pipe from a steam generator (boiler) to the sea to blow out sediment and boiler chemicals. High pressure of the boiler forces the water out to lower pressure of the sea when at fairly shallow depths. Usually done only at periscope depth. Extremely noisy operation that destroys sonar reception completely.
BLOWING SANITARY Application of high pressure air to a sanitary (sewage) tank to force the sewage out of the tank into the sea. The air trapped in the tank must be vented to the inside of the ship to avoid telltale bubbles that could allow the ship to be detected. The venting makes the ship stink.
BLUEOUT Reverberations and noise from the bubbles caused by an underwater nuclear explosion. Masks sonar reception for hours, sometimes days.
BOMB GRADE URANIUM U-235, capable of fissioning and causing nuclear energy release. High concentrations of U235 are used only in nuclear bombs and in high power-density naval reactors.