Voyage of the Devilfish

CRAZY IVAN A Russian submarine’s maneuver to clear baffles. Due to the Russian submarines frequently being trailed by U.S. subs, the Russians clear baffles suddenly and come back on the reciprocal course. An intimidation tactic designed to deter American boats from trailing too close. The cause of several undersea collisions.

CREEP Property of some metals at elevated temperatures to stretch when failing instead of rupturing or fracturing. Titanium has the property of exhibiting creep at low temperatures.

CREEP DEPTH A titanium submarine’s depth at which the hull begins to fail in creep.

CRITICAL The point that a nuclear reactor’s fission rate is constant without an external source of neutrons. The chain reaction keeps fissions going on using neutrons from fissions.

CRUSH DEPTH The depth that a pressure hull ruptures from seawater pressure.

CSLINST COMSUBLANT Instruction. An administrative document with administrative orders from COMSUBLANT.

CURVE A curve is obtained when a firecontrol solution is reached. Derives from the days of manual plots when bearing to a target was plotted against time. After two or three legs, the Z-shaped curve defined a solution to the target.

CUTBACK An automatic reactor protection circuitry action to lower reactor power by driving the controlling control rod group into the core. The cutback allows propulsion to continue while saving the reactor from an overpower meltdown accident. A Navy engineering compromise action between a scram (which eliminates propulsion) and continued criticality, which could lead to a nuclear accident.

CUTBACK OVERRIDE Action to stop a cutback by taking the mode selector switch to the cutback override position, stopping control rod motion inward. Used when a cutback is caused by an instrument failure rather than an actual hazard.

C.O. (COMMANDING OFFICER) Official title of the captain of a ship.

DANCING WITH THE FAT LADY Periscope watch. When rotating the number two periscope (type 18 scope), the observer’s pelvis is pressed up against the hot optical control module of the unit. Physically exhausting when done for hours at a time.

DEBALLASTING SYSTEM Russian alternative to an emergency blow system. Explosive charges are placed in the ballast tanks to blow water out and replace the water with hot gases. Cheaper system than an emergency blow system, but rumored to have worsened Russian emergencies by rupturing the hull instead of blowing out ballast tank water.

DECADES PER MINUTE Measure of speed of increase of reactor power during a startup. A decade increase means that there are ten times as many fission neutrons in the core as before. There maybe several dozen decades between the startup range and the power range. Normal startup rate is one decade per minute (about two to ten times faster than a civilian reactor startup rate). Fast recovery startup rate is 5 decades per minute. Absolute emergency rate is 9 dpm, since the maximum visible on the meter is 10 dpm.

DECK OFFICER Russian equivalent to the American Officer of the Deck.

DELOUSING When a submarine temporarily trails another friendly submarine; done to ensure the first sub is not being trailed by an enemy sub.

DEPLOYMENT Extended submarine OP to a distant OPAREA.

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.

DEPTH RATE Speed of change of depth in feet per second. Vertical speed.

DEPTH SOUNDER Fathometer. Measures distance from the bottom of the ship (keel) to the ocean bottom.

DETECT (Noun) When a torpedo is in search mode, a detect is a positive confirmation that a target is where the solution theoretically shows him to be. When a submarine is discovering a target, a detect is the initial sonar bearing to the broadband noise or the initial sonar frequency of the tonal.

DEUTERIUM Heavy water. Used in nuclear fusion reactors or fusion (hydrogen) bombs.

DIALEX Phone system used on submarines for administrative and unofficial communication.

DISK CRASH The failure of the disk module of the firecontrol computer. Memory access and operating system actions are done using the tape module, which is infinitely slower than the disk system. Severe failure, but still allows limited firecontrol and weapon launch functions.

DISTRIBUTED CONTROL SYSTEM (DCS) Computer system that controls a complicated process such as a nuclear propulsion plant.

DIVE POINT The point a submarine plans to submerge. Traditionally where keel depth is greater than 600 fathoms.

DIVING OFFICER Officer or Chief who sits aft of the sternplanesman and helmsman. Responsible for depth control.

DOGS Banana shaped pieces of metal that act as clasps to keep a hatch shut.