PROMPT CRITICAL RAPID DISASSEMBLY Polite term for the unlikely event of a core undergoing a nuclear explosion.
PROPULSOR Sophisticated screw that uses ducting and multistage water turbine blades for propulsion instead of a conventional screw. Similar to a water jet. Extremely quiet and nearly impossible to cavitate. Disadvantage includes slow response and acceleration due to relatively low thrust compared to conventional screws.
P.A. CIRCUIT ONE Ship wide Public Address announcing system.
P.A. CIRCUIT SEVEN Speaker announcing system used between the Conn, Maneuvering, the bridge, and the torpedo room.
P.A. CIRCUIT TWO Similar to P.A. Circuit One, except that it only announces in the engineering spaces (aft of frame 57).
RANGE Distance to a contact.
RANGE GATING The action of an emitter of active sonar pulses. The ship being tracked can tell how close the pinging platform is by the time between pulses, assuming the transmitter does not ping the second pulse until it receives a return ping from the first pulse. The closer the pinging object gets to own ship, the shorter the interval between pings.
REACTOR Nuclear core. An assembly of fuel elements containing U-235, control rods, shielding, and inlet and discharge of primary coolant. Heat source that allows steam to be generated in the steam generators to produce propulsion and electricity.
REACTOR COMPARTMENT Compartment housing the reactor, pressurizer, steam generators, and reactor main coolant pumps. Access fore and aft is through a shielded tunnel, since anyone inside the compartment when the reactor is critical would be dead within a minute from the intense radiation.
REACTOR MAIN COOLANT PUMPS Massive pumps, each consuming between 100 and 400 horsepower, that force main coolant water through the reactor and then to the steam generators. Three are in each main coolant loop. Special design allows zero leakage.
REACTOR PLANT CONTROL PANEL (RPCP) Control panel in the maneuvering room where the Reactor Operator controls the reactor.
REACTOR PROTECTION Circuitry containing safety interlocks and control functions preventing reactor damage in an accident.
REACTOR VESSEL Heavy steel shell housing the reactor core.
REAR GUARD SONAR New Russian passive and active sonar that looks astern into the baffles. Mounted in the aft section of the pod atop the rudder of the Project 985 (Kaliningrad or OMEGA) class Russian submarines. Eliminates need to do baffle clearing maneuvers.
RECONSTRUCTION Six-hour period following a watch when an enemy submarine is trailed. The offwatch fire-control team meets in the officer’s wardroom and compares data from charts, geo plots, computer readbacks, and logs, in an effort to “get the story straight” for the patrol report. Conflicting information is resolved during reconstruction.
REDUCTION GEAR The mechanism that converts the high RPMS of the two main engines (propulsion turbines) to the slow RPM of the screw. Solves the problem of how to get two turbines to drive a single screw. Also solves the problem of how to let the main engines rotate at high RPM where they are efficient while letting the screw rotate at the low RPM where it is efficient. Unfortunately, the reduction gear is one of the noisiest pieces of equipment aboard.
RELAY Electrical device that acts as a smart switch.
RELIEF VALVE A spring loaded valve that will open and relieve the pressure on a tank or vessel instead of allowing the tank to rupture or fail.
REM Roentgen Equivalent Man. A unit of radiation dosage that takes into account tissue damage due to neutron radiation. Convenient since it allows gamma, alpha, and neutron radiation to be measured with the same units. 1000 rem will kill. 500 rem may kill. Yearly dose for submarine personnel is restricted to less than 25 to 100 millirem.
RIG FOR BLACK Submarine term meaning “turn off the lights in the control room.”
RIG FOR COLLISION A ship wide lineup consisting of shutting hatches in bulkheads and shutting hardened ventilation dampers in bulkheads to minimize possible risk to the ship during a collision. Generally same as rig for flooding.
RIG FOR DIVE A detailed valve and switch lineup done in preparation to dive. Initially done by a dolphin-wearing enlisted man and checked by a dolphin-wearing officer.
RIG FOR FLOODING Similar to rig for collision. Bulkhead hatches and ventilation dampers are shut to isolate each compartment from the neighboring compartment. Ship is buttoned up to ensure maximum survivability.
RIG FOR PATROL QUIET Ship systems lineup to ensure maximum quiet while allowing normal creature comforts such as cooking and movie watching. Maintenance on equipment is allowed, if it does not involve banging on the hull. Noisy operations are only permitted with the captain’s permission, such as reactor coolant discharge, steam generator blowdowns, etc.
RIG FOR WHITE Submarine term meaning “turn on the lights in the control room.”
TO (REACTOR OPERATOR) Nuclear trained enlisted man who mans the Reactor Plant Control Panel and reports to the EOOW.
ROUTINE A message priority below PRIORITY. Delivery assurance in weeks or months.
RULES OF ENGAGEMENT A formal manual detailing what actions a U.S. vessel may take in response to enemy actions, such as an intentional collision by an enemy vessel in peacetime. In general, the rules require that no weapon may be shot unless the enemy ship has already launched a weapon.
RUN-TO-ENABLE Initial torpedo run taking it away from own ship. During the run-to-enable, the warhead is not armed and the sonar is not operational. When the run-to-enable is complete, the weapon activates the active or passive sonar and swims the search pattern. The warhead is not armed until it has a detect on the target.
R-114 AIR CONDITIONER Two air-conditioning units that control the high temperatures and humidity caused by the steam plants. Ship is air-conditioned to allow electronic equipment to function, not for creature comfort.
SAFETY LANES Special routes for submarine transit in time of war. Submarines detected by U.S. forces inside these lanes are assumed to be friendly.
SAIL Conning tower. Named because, unlike the conning towers of World War II diesel boats, which were misshapen and asymmetrical, modern nuclear submarine conning towers are smooth fins with square profiles when viewed from the side. Someone called it a sail in the distant past and the term became official.
SCI (SPECIAL COMPARTMENTED INFORMATION) A classification of information separate from the Confidential/Secret/Top Secret system. SCI information is compartmented or sectioned, so that no one person has the full story. Capture or compromise of one compartment of the information will be damaging but not catastrophic. SCI information is usually so sensitive that it is generally considered a higher classification than Top Secret. SCI is also information that compromises intelligence methods and sources.
SCRAM An emergency shutdown of a nuclear reactor, done by driving control rods to the bottom of the core using springs.