Glossary
Visitor view1 MC
A general announcing system to all compartments in the submarine.
7 MC
Announcing system to only some key spaces.
ADM
Admiral, comparable to a general. Generically, the five officer grades above a Navy captain.
Aft
Toward the rear or after part of a ship or boat.
AFTAC
Air Force Technical Applications Center. This project was developed to monitor Soviet nuclear weapons testing. It included monitoring splashdowns of warhead re-entry vehicles.
Allied Powers In WW1
Initially, the main allied powers were Britain, France and Russia. The U.S., Italy and Japan joined later.
Allied Powers In WW2
The main allied powers were the US, Britain (plus the Commonwealth countries, such as Canada, India, Australia and New Zealand) and Russia. France was an ally until it was defeated by Germany. Many other nations were actively allied with or leaning toward the allied side of the war.
Amidships
The center of the boat, usually along the long (fore to aft) axis but can also be side to side.
ASR
submarine rescue ship.
ASW
Anti-submarine warfare.
Attack officer
The officer in charge of the mechanics of the attack. This was most often the commanding officer. However, some captains designated the XO as the attack officer so the captain could monitor the big picture.
Axis Powers In WW2
The main Axis Powers were Germany and Japan. Italy was an Axis nation until the overthrow of Mussolini in 1943. Even then, a large part of Italy was occupied by Germany. Other nations, particularly Spain and Argentina, were nominally neutral but in practice leaned toward the Axis.
Ballast Tanks
Various tanks that could hold sea water used to dive and surface the boat. These tanks are along the side of and below the pressure hull.
Bathythermograph
A device that measures water temperatures at various depths as the submarine moves up and down in the water.
Battle Station
An individual's job when the submarine went into combat.
Battle Stations
The condition when preparing to attack a target or being attacked. Also known as General Quarters.
BB
a battleship. In common usage today, this term could mean any type of combat ship. That is quite understandable since the only true battleships around at this time are museums. However, during WW2, a battleship was a specific type of ship. It was the largest combat vessel other than an aircraft carrier. Our battleships were heavily armored and usually had nine large guns (three turrets of three barrels each) and 70 or more multi-purpose or anti-aircraft guns of various sizes.
Bearing
Compass direction of an object or target.
Berthing
Sleeping quarters.
Bioluminescence
Plankton that glow when the water is disturbed, often by propellers. These plankton normally live in the deep but come near the surface at night to feed. When disturbed, they leave a streak in the water that glows for a few minutes.
Bow Planes
A pair of wings or fins near the bow to control depth when submerged. The bow planes are "rigged in" when on the surface and are up against the superstructure to prevent damage from waves or swells. The plane on the star board side is visible from the pier. They are rigged out together in the process of diving. Bow planes are generally used for small changes in depth.
Bubble pulse
the repeated expansion and contraction of the gas bubble created in an underwater explosion. These pulses can continue to cause damage until the oscillations ends or the gas bubble reaches the surface.
Bubbleheads
Nickname for submariners.
Bulkhead
Wall.
Buoyancy
Buoyancy is the force on the submarine pushing it upwards toward or on the surface.
CA
a cruiser or heavy cruiser
CAPT
The Navy rank of captain or O-6, the sixth officer grade.
Casualty
We think of a casualty most often in human terms. Casualties in war are the people that are injured or killed. However, we also speak of mechanical casualties. In this sense, it is equipment or machinery that breaks down or fails.
CDR
The Navy rank of commander or O-5, the fifth officer grade.
Central Powers
In WW1, this consisted of Germany, Austria-Hungary, the Ottoman Empire and Bulgaria.
Charts
A map of part of the seas. It would include land masses in the area as well as the depth of the water, if known.
Chief Of The watch
The senior enlisted watch who is stationed in the control room.
Christmas Tree
The panel in the control room with multiple red and green lights. A red light indicates a critical valve or hatch is open; green shows that it is closed. A "green board" indicates that it is safe to dive. The panel is not shaped like a tree. The name comes from the colors used.
CL
a light or scout cruiser
Clean fuel oil tank
tank that is inside the pressure hull holding fuel that is ready for use in the engines. It has been through the collecting tank to remove any sea water and then through the fuel oil purifiers. There is one clean fuel oil tank in each engine room.
CO
Commanding Officer, the position of captain of a ship.
COB
Chief of the Boat. A specific position for the senior enlisted sailor on a boat. This chief petty officer is treated as the third most senior person on the boat, at the level of or above most officers. The COB is responsible for training, morale and informal discipline.
Commissioned
For a submarine, it is when it is accepted by the Navy and put into service. Further testing with sea trials is still pending. For an officer, it is when he or she is sworn in and begins serving.
Compartment
A room or space, part of the submarine.
Conn
Responsibility for control of the ship under the captain's orders. The officer of the deck normally had the conn on a submarine.
"
CPO
Chief petty officer, the highest enlisted grade.
Cubicle
The electrical configuration in the maneuvering room where power from the generators and battery is directed and then distributed.
CV
a large aircraft carrier as opposed to an escort carrier
DD
a destroyer. A ship that is the primary foe of a submarine. A destroyer carried depth charges in addition to a variety of guns. Destroyers were used to hunt for submarines, to guard convoys, to guard the larger ships of the fleet and as anti-aircraft vessels.
DE
a destroyer escort, a somewhat smaller version of a destroyer. They were most often used as escort ships to protect convoys from submarines.
Dead Reconning
Estimating your location based only on the direction, speed and time of your travel. This works well on land but, at sea, does not include the probable effects of wind and currents (set and drift). Navigators may have to add those impacts to have a more accurate estimate of the boat's location.
Deck
Floor.
Decommission
Taking a ship out of service. This could be temporary for major upgrades or for maintenance in the reserve fleet. It is more often permanent at the end of the vessel's useful life.
Depth Bomb
A bomb dropped from an aircraft to attack a submarine.
Depth Charge
A device dropped or thrown from a surface ship to attack a submarine. It uses a pressure switch to explode at a predetermined depth. The ship using depth charges has to estimate the depth as well as the location of the submarine.
Design Depth
The maximum depth for which the submarine was designed. For example, Balao class boats were designed for 600 feet. Fortunately, that is a conservative calculation. We know that boats such as the USS Pampanito have been below design depth and survived.
Displacement
Essentially, the weight of a ship. The weight of the water that it displaces as it floats or submerges.
Diving Officer
Officer or chief petty officer responsible for getting to and maintaining depth and neutral trim. Based on what the planes need to do to maintain depth, the diving officer then orders water pumped in and out of trim tanks, or between tanks, to get to neutral buoyancy.
Dogging The Watch
splitting one watch into two shifts. This has the effect of changing everyone’s watch forward by four hours Then everyone is on the new schedule so no one always stands watches at the same the times during the day and night.
EB
Electric Boat, submarine building company located in New London and Groton, Connecticut.
End Around
A maneuver to get back ahead of a target that was missed or turned away. The submarine would turn 90 degrees so it was perpendicular to the target. When it was far enough away from the target so it would not be seen, it would turn to the target's course and run at high speed to get ahead of it. Ideally, the submarine can still see the masts or funnels of the target but the target wasn't likely to see the boat's periscope. When the boat is far enough ahead of the target, it would turn back toward the target's expected position and prepare to attack.
Enlisted
Crewmen who are not commissioned officers.
ENS
The Navy rank of ensign; usually the first rank that an officer holds on graduating from the Naval Academy or college with a reserve officer training unit.
Escape Trunk(s)
Trunks that can be used to escape from a sunken boat at depths down to around 200 feet.
Fathom
A depth measurement of six feet. A traditional nautical measurement. Charts may specify depth in fathoms. Otherwise, the term is not often used by submarines.
Fire Control
The process and equipment used to aim weapons at targets. This can be for guns or torpedoes, or even missiles.
Fish
Slang for torpedoes. German U-boat sailors called their torpedoes "eels".
Fix
Determining your location using stars or LORAN. Today it would done using stars or GPS.
Flapper Valve
A flat valve that seals an opening. These valves are used where pressure against them helps seal them shut.
Fleet Boats
Usually refers to the US subs built between WW1 and WW2. Some also consider the Gato/Balao/Tench classed as fleet boats. They were originally expected to operate with the fleet, but that wasn't practical.
Fore
Toward the front or forward part of the ship or boat.
Foundered
Flooded with sea water and sank. Boats may founder due to operational errors or equipment failure. Sinking due to battle damage would normally be assigned to the damage as the primary cause rather than foundering.
Fuel Ballast Tank
A ballast tank that was reconfigured to hold either water or fuel. Fuel in these tanks would be used first. Then the tank would be converted to a ballast tank and flushed.
Fuel Tanks
Various tanks that hold diesel fuel for the engines. These tanks are among the ballast tanks located along the side and below the pressure hull.
Galley
Space to prepare and cook meals.
General Quarters
Battle stations.
Goat Locker
Chief petty officers' quarters.
GUPPY
The Greater Underwater Propulsion Program conversion. This was a major upgrade for existing submarines begun after WW2. It included, among other things, removal of the guns and ready ammunition storage containers, addition of a snorkel, upgrading the batteries, and streamlining the sail. There were various levels of GUPPY upgrades. Some boats were only given a fleet snorkel upgrade which included much of the above but without the battery improvements.
Gyrocompass
A ship's compass that is based on the tendency of a gyroscope to remain oriented in space. In this case, the gyroscopes can remain oriented to north, and are not affected by the steel of the boat all around it.
Hatch
Opening through a deck that allows movement up or down in a ship.
Hedgehog
An anti-submarine weapon developed during WW2. Unlike a depth charge, it consisted of a circular pattern of smaller charges launched forward rather than a few large charges dropped from the stern. A hedgehog exploded when it made contact with a submarine rather than at a predetermined depth. These features meant that the attacking destroyer could use a slower attack speed and still have effective sonar. By the end of the war, hedgehogs achieved a kill once in every 5 or 6 launches. Depth charges were successful only once for every 80 charges dropped.
HMAS
His or Her Majesty's Australian Ship.
IC Electrician
The rating responsible for interior communications equipment. This included alarms, motor order telegraphs, internal announcing system and sound-powered communication.
ICBM
intercontinental ballistic missile, normally with a nuclear warhead.
IFF
Identification Friend or Foe. A radio frequency query used to determine whether a ship or aircraft is on our side.
IJN
Imperial Japanese Navy.
In ordinary
essentially in reserve; not in active service.
JANAC
Joint Army-Navy Assessment Committee to audit Japanese and American naval losses in WW2.
Kingston Valve
Valves used both to vent ballast tanks and to flood water into the bottom of the tanks. Beginning with the early Gato boats, most of the flood valves were eliminated in favor of open ports at the bottom of the tanks. This allowed faster dives.
Knot
a nautical mile or 2,027 yards. It is equal to 1.151 statute miles. It is defined as one minute of one degree of latitude at the equator. Sailors speak of speed at sea in knots (per hour). However, distances, which are in knots, are generally referred to as (nautical) miles, often rounded to 2,000 yards.
Knots
sailors speak of speed at sea in knots, as in nautical miles per hour.
La Perouse Strait
the northern entrance or exit to the Sea of Japan.
Ladder
Stairs or steps on a ship.
LCDR
lieutenant commander or O-4, the grade above lieutenant. Many of our submarine captains in World War 2 were lieutenant commanders when they assumed command.
Leave
Extended time off, similar to vacation time in the civilian world.
Liberty
Overnight or weekend time off for sailors when not on duty.
Limber Holes
The holes along the side of the superstructure that look like windows. These openings allow water to quickly fill or drain the space above the pressure hull and below the deck. They allow the submarine to dive and surface more quickly.
LORAN
the long range aid to navigation is a system somewhat similar to GPS. The device uses ground-based radio stations rather than satellites.
LT
The Navy rank of lieutenant or O-3, the third officer grade, above ensign and lieutenant junior grade. Some captains, most often the skippers of the older and smaller R and S class boats, were lieutenants.
LTJG
Lieutenant, junior grade or O-2, the second officer grade, above ensign and below lieutenant.
Main Induction
The large valve that allows air into the boat, primarily to run the engines.
Mark
The designation of the "model" number of a device or weapon. For example, the Mark 14 torpedo was developed or designated just after the Mark 13 aerial torpedo and before the Mark 15 version for surface ships.
Maru
The Japanese word for a commercial or private ship. "Maru" is normally the last part of the ship's name. "Maru" was not used for the names of Japanese warships.
Mess
Space where the crew eats. Mess is a term used by all of the military, not just the Navy.
MINSY
Mare Island Naval Shipyard, located in Vallejo in the San Francisco Bay Area.
Mk
Short for "Mark".
Motor Mac
The rating of motor machinist mate. This would later evolve into engineman, which is a clearer description of the duties.
Nansei Shoto
another name for the Ryukyu Islands which include Okinawa.
Neutral Buoyancy
Is the state of an object weighing as much as the water it displaces. The object floats but is submerged. If a submarine is in neutral buoyancy when submerged, it neither rises or settles. It tends to remain at the current depth. Note that neutral buoyancy may be changing frequently based on factors such as depth, water temperature and salinity.
New construction
a new submarine, while still being built. The crew is added slowly, starting with the senior officers and other key personnel. Being assigned to new construction meant that the men would be out of combat for a few months, until the boat is finished, necessary training is done, sea trials are completed, and the boat transits to its new home port.
Officer Of The Deck
Officer on duty who has control of the boat, under the direction of the captain. The OOD has the conn.
Overhaul
A lengthy maintenance in a shipyard. This is for more extensive repairs than a refit. It often included significant repairs and equipment upgrades. Overhauls were usually done after six war patrols. Generally, it was also an opportunity for the crew to take some leave even though there was an intensive work schedule.
Overhead
Ceiling.
Passageway
An aisle or route through a ship.
PCO
prospective commanding officer. Such an officer has been selected for command and is riding a boat for one patrol before assuming command, typically of a different submarine.
Periscope Shears
The structures housing and protecting the periscopes.
Periscopes
Complex tubes with mirrors and lenses that allow the user to see above the water.
Petty Officers
Enlisted ranks with increasing expertise and responsibility. Not commissioned officers.
Pharmacist Mate
A Navy medic during WW2. Submarines did not have doctors assigned and, at this time, only our large missile boats do. Pharmacist mates are now known as hospital corpsmen.
Picket
A ship or boat stationed between the fleet and the enemy to warn of approaching forces. Depending on the size and capability of the picket, it may also attempt to reduce the threat by attacking some of the hostile forces.
PNSY
Portsmouth Naval Shipyard. It is named after Portsmouth, New Hampshire but is actually located in Kittery, Maine which is across the Piscataqua River.
Port
The left side of the ship when facing forward. The word is used for clarity, rather than right or left.
Position
Your location on the earth, usually on the open ocean.
POW
Prisoner of war.
PPI
The plan position indicator displays for radar and some sonar. This is the type of display that we think of with radar where a spot shows up on a display scope in the direction and at the distance of the item of interest. It was usually a ship or plane in WW2, but is now most often seen in weather reports.
Pressure Hull
Inside part of the submarine where the men live and work. Sometimes known as the people pipe.
PSI
Pounds per square inch, usually a measure of air or water pressure.
Q-ship
a very shallow draft, heavily armed vessel disguised as a freighter. The goal is to lure a submarine or other warship into an attack and then destroy the attacker. The Allies and the Axis Powers both used Q ships.
Radar
Radio Detection And Ranging. An electronic method of using radio waves to locate objects around you. In this case, it would normally be enemy ships and aircraft, but it could also be features on land that can be used for navigation.
Range
The distance to an object or target, usually given in yards.
Reduction Gears
Large gears between the main motors and the propeller shafts. These gears allow the main motors to run efficiently while reducing the revolutions per minute that are transferred to the propeller shafts. Propeller shafts need to be able to run at much slower speeds than the main motors.
Refit
a down period between patrols for resupply and limited repairs and upgrades. This was not as extensive as an overhaul.
Relative Bearing
Azimuth or direction to an object (target) relative to the direction that your ship is heading.
Reserve Fleet
Storage of ships that might be needed in the future. The ships are decommissioned, preserved and sealed so that, if needed, they can be restored to operation. Even if the ships need to be upgraded, the process is much faster than building new ships.
Reverse Engineer
To create a copy by first studying and deconstructing an existing device.
RN
British Royal Navy.
Running lights
external lights to help other ships determine direction in which the vessel is going to avoid collisions. There are strict specifications for these lights but, essentially, a vessel must show green to starboard, red to port, and white for the stern and masthead lights. Running lights were generally not used during WW2.
Sail
The superstructure above the main deck enclosing the Conning Tower.
Scuttle
the sinking of one's own ship to prevent it, its weapons and classified materials from falling into enemy hands.
Sea Trials
Operating tests after commissioning or overhaul to identify any problems that still need to be corrected. The ship needs to be in commission so that the crew is assigned and able to conduct the tests.
Sink
this is what submarines do to enemy shipping. Hopefully, submarines don't sink themselves; they dive or submerge.
Skivvies
Underwear, particularly undershorts or briefs.
Smoking Lamp
General permission to smoke. Not literally a lamp any longer. Smoking was very common on WW2 boats and cigarettes were given away free to servicemen during the war. Smoking is no longer allowed on submarines.
SOFAR
the sound fixing and ranging system. This system utilizes a natural channel at around 3,000 feet deep that uses the top and bottom of the channel to focus the sound with little loss of volume. In the case of the loss of the Scorpion, the sounds of her implosion were heard at about 1,000 miles away at two different SOFAR listening stations.
Sonar
Sound Navigation And Ranging, an acronym similar in origin to radar. A method of using sound waves to locate objects around you. In this case, it would normally be enemy ships but could also be mines or the ocean bottom. Britain calls sonar ASDIC.
SOSUS
the Sound Surveillance System (SOSUS) that the U. S. created in order to listen to the ocean to detect submarines and other underwater threats.
Specific Gravity
The measurement of the electrolyte in the cells which indicates the amount of charge in the battery.
SS
Steam ship, not a ship in the US Navy. Also, the designation that the hull number, as in "SS-383", is a submarine.
Standing Watch
Working a shift while operating the submarine.
Star Fix
Marking the elevation of known bright stars, usually three, along with the time noted. From that, the position (location) of the ship can be calculated.
Starboard
The right side of the ship when facing forward. The word is used for clarity, rather than right or left.
Stern Planes
A pair of short wings or fins near the stern to control depth when submerged. Unlike the bow planes, they are always rigged out. They are below water and protected by a guard. Stern planes are generally used for large changes in depth. They change the angle of the boat, up or down, so that forward motion changes the depth more quickly.
SUBLANT
Navy abbreviation for Commander of Submarines, Atlantic Fleet.
Submerged
Operating while below the surface of the water.
SUBPAC
Navy abbreviation for Commander of Submarines, Pacific Fleet.
Superstructure
Part of the submarine above the pressure hull that includes the main deck.
TBT
Target Bearing Transmitter.
TDC
Torpedo Data Computer, an electro-mechanical computing device used to determine the final course for a torpedo to collide with the target. The final course is then fed into the torpedo gyroscope.
Test Depth
The depth to which the boat is "tested". This is normally about two-thirds of design depth. For a Balao class boat like the USS Pampanito and designed for 600 feet, test depth would usually be between 400 and 450 feet. The boat is not intended to go below that depth for safety reasons. However, in wartime, you do what you have to do to survive and keep on fighting.
TH
Territory of Hawaii, prior to it becoming a state in 1959.
Torpedo
A self-propelled underwater weapon used to damage and sink ships.
Torpedo Skid Or Torpedo Rack
The tray on which reload torpedoes were stored until needed.
Trim Dive
The first dive after leaving port or the daily dive while in transit. This would be a brief dive to get back to neutral buoyancy. The goal is to compensate for changes in the weight of the boat since it was last submerged.
Trim Tanks
Internal tanks used to add or pump out water to get the boat to neutral buoyancy when submerged.
True Bearings
Direction to another vessel or plane given in relationship to north, east, etc.
Typhoon
A hurricane in the western Pacific is called a typhoon.
Ultra
intelligence gathered from breaking Japanese naval codes was labeled "ultra". For security reasons, most captains did not know the actual source of the top-secret information.
USAAF
United States Army Air Forces. The Air Force was part of the Army during WW2 and didn't become a separate service until 1947.
USS (As In USS Pampanito)
United States Ship. A vessel of the US Navy.
Watch
the normal shift when operating the submarine or any ship.
Watertight Door
An opening between the compartments on the same level of a submarine.
WW1
World War 1, from 1914 to 1918. Also known as The Great War until WW2 was fought.
WW2
World War 2; for the United States, the declared war was from December of 1941 to August of 1945. In Europe, the war was from September of 1939 to May of 1945. However, there was earlier fighting in China and Africa that would continue into the World War.
XO
Executive Officer. The position of second in command of a ship and administrative officer.