Attack of the Seawolf

Course — The direction a ship is going measured in true compass degrees. North is 000. East is 090.

South is 180, etc.

Critical — The point that a nuclear reactor’s fission rate is constant without an external source of neutrons.

The chain reaction keeps fissions continuing using neutrons from fissions.

Deck — (1) Floor of the submarine. Each compartment is either two or three decks high. (2) Responsibility for the physical operation of the ship. The officer who has the Deck makes decisions about equipment lineups, how to run and operate ship systems, etc.” while the conning officer concerns himself with ship navigation, course, speed, and relationship to the target. Usually the OOD has both the Deck and the Conn.

Depth Control — Ability to control a ship’s depth within a narrow control band. Done either manually, with a computer, or with the hovering system (when stopped). Particularly vital at periscope depth because failure to maintain depth control can cause the sail to become exposed (broach), giving away the ship’s position.

Dogs — Banana-shaped pieces of metal that act as clasps to keep a hatch shut.

Dolphins — Pin worn above left pocket of submariner’s uniform, indicating the person is qualified in submarines. Qualification typically takes one gruelling year. Enlisted men wear silver dolphins; officers wear gold. Dolphins, when not worn on the pocket, are a general symbol of the Submarine Force.

Doppler Effect — Effect responsible for train whistles sounding shrill when the train approaches and low pitched when the train is past. When a moving platform emits sound waves, the waves are compressed ahead and rarefacted (spread apart) behind the source. The compression of the waves raises their frequency, making a higher note.

EMBT Blow — Emergency main ballast tank blow.

Emergency Blow — Blowing the water out of the main ballast tanks using ultra-high-pressure air. Empties ballast tanks in seconds, lightening the ship, allowing the ship to get to the surface in an emergency such as flooding.

Emergency Propulsion Motor (EPM) — A large DC motor aft in the engine room capable of turning the shaft to achieve 3 knots using battery power alone. An electricity hog.

EO (Electrical Operator) — Enlisted nuclear-qualified watch stander who mans the Electric Plant Control Panel and reports to the EOOW.

EOOW (Engineering Officer of the Watch) — Nuclearqualified officer who runs the nuclear power plant. Responsible to the OOD for propulsion and propulsion plant damage control.

Escape Trunk — A spherical airlock used on American nuclear submarines. The device can be used to make emergency exits from a sub sunk in shallow water. Principally used for divers to lock in or lock out.

ESGN — Ship’s inertial navigation system using a small metal ball that spins at about 10,000 RPM to gyroscopically maintain a constant reference (north).

ESM (Electronics Surveillance Measures) — The gathering of intelligence through the analysis of enemy signals, including radars and radio transmitters.

EWS (Engineering Watch Supervisor) — A Chief who is a roving supervisory watch stander in the engineering spaces. Reports to the EOOW.

Fathom — Unit of depth equal to six feet.

Fathometer — Bottom sounding sonar that directs an active sonar pulse down to the ocean bottom and measures the time for the pulse to reflect back and hence the distance to the bottom. New units transmit a secure pulse, using a short duration random high frequency pulse.

Final Bearing and Shoot — Order of the captain to shoot a torpedo after he takes one last periscope observation of a surface target.

Firecontrol Solution — A contact’s range, course, and speed. A great mystery when using passive sonar.

Determining the solution requires maneuvering one’s own ship and doing calculations on the target’s bearing rate. Can be obtained manually or with the firecontrol computer.

Firecontrol System — A computer system that accepts input from the periscope, sonar, and radar (when on the surface) to determine the firecontrol solution. The system also programs, fires, steers, and monitors torpedoes. If a ship is cruise missile equipped, the system will program and fire the missile.

Firecontrol Team — A collection of people whose task is to put a weapon on a target. Includes the sonar operators, OOD, JOOD, Captain, XO, firecontrol operators on Pos One, Pos Two, Pos Three, the firing panel, and the manual plotters (geographic, time-bearing, time-range, and time-frequency).

Firing Panel — A console section between Pos Two and Pos Three. The vertical section is a tube weapon status panel. The horizontal section has the trigger, a lever used to fire a torpedo or cruise missile.

Firing Point Procedures — An order by the captain to the firecontrol team to tell them to prepare to fire the weapon, done during a deliberate approach when the solution is refined, as opposed to a Snapshot. The solution is locked into the weapon and the ship is put into a firing attitude.