CA-38 painting

Terminology and Rank


Officers take responsibility for leadership in the Navy. They are responsible for the management, development and coordination of the teams and posts that they are assigned to. 

Officers, in most instances, lead projects to improve the capabilities and design plans of the way forward. At sea, officers fill various leadership roles including being the officer on the bridge, who is in charge of the ship, or responsibility for the engineering department.

Essentially your qualifications and duration of your time in the Navy contribute to your rank and progression path.  In most cases officers start at midshipman rank for the first two years (and while undertaking Junior Officer Common Training). The next step is to be promoted to Ensign, and then one year later, depending on your entry scheme, to Sub Lieutenant. Promotion to Lieutenant is usually made after six years service. Again, the speed of progression may vary dependent on any previous qualifications and/or your duration in the Navy.

Promotion to Lieutenant Commander, and above, is based on merit, providing you have eleven years of qualifying service.  Entry schemes can affect timing but this is a rough guide to give you an indication of the ranks you could progress through.

Senior Officers:
Vice Admiral (VA)
Rear Admiral (RA)
Commodore (CDRE)
Captain (CAPT)
Commander (CDR)
Lieutenant Commander (LT CDR)

Junior Officers:
Lieutenant (LT)
Sub Lieutenant (SLT)
Ensign (ENS)
Midshipman (MID)

Find out more about becoming an Officer and the possible job options.

Sailors, otherwise known as Naval Ratings and ranked as such, are the practical people who provide specialist hands-on skills in their chosen field.  Naturally duties and responsibilities increase with rank. As you gain promotion your tasks become more complex, and at higher levels, you’ll have your own staff and be responsible for managing them and looking out for their welfare.

All sailors have to complete task books for promotion. You will become eligible for a higher rank once you have passed the various courses and examinations; and have been recommended for promotion by your Commanding Officer. Promotion itself takes place under a roster system when a vacancy occurs (with the exception of Able Rating).

You can complete additional training for extra qualifications to broaden your career.
Rankings and specialisations are combined.  Essentially your specialisation will follow your rank.  For example WOCH equals Warrant Officer, Chef.

Senior Ratings:
Warrant Officer (WO)
Chief Petty Officer (CPO)
Petty Officer (PO)

Junior Ratings:
Leading Hand (LH)
Able Rating (AB)
Ordinary Rating (O)

Find out more about each job and the progression options within each trade: Logistics, Hospitality and Support, Technical trades and Operational trades.

Specialised Sailor Roles
After a period of service, there are opportunities for internal transfer to a number of specialised sailor roles. Candidates for transfer will only be considered after first attaining competence in their original career streams. It is therefore not possible to join and start your career in these roles; they are ‘progression only’ based.

The specialised roles available are helicopter crewman, Naval police and physical training instructors.

Naval Police
Naval Police are responsible for the preservation and maintenance of discipline and standards within the Navy. Naval Police serve at sea and ashore and are a vital part of the Naval Leadership structure. Naval Police develop expertise in conducting investigations, and traffic operations.

Physical Training Instructor
Otherwise known as PTIs, Physical Training Instructors are responsible for physical, recreational training, and sea survival training. They serve at sea and develop skills in planning and conducting physical sessions.

In additional to your branch career path there are opportunities to qualify for additional operational skills. Each skill requires differing levels of qualification and experience and includes Defence Diver, Flight Deck Officer and Damage Control Instructor. 

Helicopter Crewman
The Helicopter Crewman is an integral member of a three person crew onboard the Kaman SH-2G Super Seasprite helicopters. Their duties include assisting in search and rescue operations, vertical replenishment, winch operations, warfare duties, and airborne photography.



Above Board

The term today means someone who is honest, forthright. It's origin comes from the days when pirates would masquerade as honest merchantmen, hiding most of their crew behind the bulwark (side of the ship on the upper deck). They hid below the boards.


This old traditional greeting for hailing other vessels was originally a Viking battle cry.

Between the Devil and the Deep

In wooden ships, the "devil" was the longest seam of the ship. It ran from the bow to the stern. When at sea and the "devil" had to be caulked, the sailor sat in a bo'sun's chair to do so. He was suspended between the "devil" and the sea — the "deep" — a very precarious position, especially when the ship was underway.

Chewing the Fat

"God made the vittles but the devil made the cook," was a popular saying used by seafaring men in the 19th century when salted beef was staple diet aboard ship.

This tough cured beef, suitable only for long voyages when nothing else was cheap or would keep as well (remember, there was no refrigeration), required prolonged chewing to make it edible. Men often chewed one chunk for hours, just as it were chewing gum and referred to this practice as "chewing the fat."

Crow's Nest

The raven, or crow, was an essential part of the Vikings' navigation equipment. These land-lubbing birds were carried on aboard to help the ship's navigator determine where the closest land lay when weather prevented sighting the shore. In cases of poor visibility, a crow was released and the navigator plotted a course corresponding to the bird's flight path because the crow invariably headed towards land.

The Norsemen carried the birds in a cage secured to the top of the mast. Later on, as ships grew and the lookout stood his watch in a tub located high on the main mast, the name "crow's nest" was given to this tub. While today's Navy still uses lookouts in addition to radars, etc., the crow's nest is a thing of the past.

Cup of Joe

Josephus Daniels (18 May 1862-15 January 1948) was appointed Secretary of the Navy by President Woodrow Wilson in 1913. Among his reforms of the Navy were inaugurating the practice of making 100 Sailors from the Fleet eligible for entrance into the Naval Academy, the introduction of women into the service, and the abolishment of the officers' wine mess. From that time on, the strongest drink aboard Navy ships could only be coffee and over the years, a cup of coffee became known as "a cup of Joe".

Devil to Pay

Today the expression "devil to pay" is used primarily to describe having an unpleasant result from some action that has been taken, as in someone has done something they shouldn't have and, as a result, "there will be the devil to pay." Originally, this expression described one of the unpleasant tasks aboard a wooden ship.

The "devil" was the wooden ship's longest seam in the hull. Caulking was done with "pay" or pitch (a kind of tar). The task of "paying the devil" (caulking the longest seam) by squatting in the bilges was despised by every seaman.

Eight Bells

Aboard Navy ships, bells are struck to designate the hours of being on watch. Each watch is four hours in length. One bell is struck after the first half-hour has passed, two bells after one hour has passed, three bells after an hour and a half, four bells after two hours, and so forth up to eight bells are struck at the completion of the four hours. Completing a watch with no incidents to report was "Eight bells and all is well."

The practice of using bells stems from the days of the sailing ships. Sailors couldn't afford to have their own time pieces and relied on the ship's bells to tell time. The ship's boy kept time by using a half-hour glass. Each time the sand ran out, he would turn the glass over and ring the appropriate number of bells.


Fathom was originally a land measuring term derived from the Ango-Saxon word "faetm" meaning to embrace. In those days, most measurements were based on average size of parts of the body, such as the hand (horses are still measured this way) or the foot (that's why 12 inches are so named). A fathom is the average distance from fingertip to fingertip of the outstretched arms of a man — about six feet. Since a man stretches out his arms to embrace his sweetheart, Britain's Parliament declared that distance be called a "fathom" and it be a unit of measure. A fathom remains six feet. The word was also used to describe taking the measure or "to fathom" something. Today, of course, when one is trying to figure something out, they are trying to "fathom" it.

Feeling Blue

If you are sad and describe yourself as "feeling blue," you are using a phrase coined from a custom among many old deepwater sailing ships. If the ship lost the captain or any of the officers during its voyage, she would fly blue flags and have a blue band painted along her entire hull when returning to home port.


The appropriate pronunciation for this word is fo'ksul. The forecastle is the forward part of the main deck. It derives its name from the days of Viking galleys when wooden castles were built on the forward and after parts the main deck from which archers and other fighting men could shoot arrows and throw spears, rocks, etc.


The galley is the kitchen of the ship. The best explanation as to its origin is that it is a corruption of "gallery". Ancient sailors cooked their meals on a brick or stone gallery laid amidships.

Gun Salutes

Gun salutes were first fired as an act of good faith. In the days when it took so long to reload a gun, it was a proof of friendly intention when the ship's cannon were discharged upon entering port.


The "head" aboard a Navy ship is the bathroom. The term comes from the days of sailing ships when the place for the crew to relieve themselves was all the way forward on either side of the bowsprit, the integral part of the hull to which the figurehead was fastened.

He Knows the Ropes

In the very early days, this phrase was written on a seaman's discharge to indicate that he was still a novice. All he knew about being a sailor was just the names and uses of the principal ropes (lines). Today, this same phrase means the opposite — that the person fully knows and understands the operation (usually of the organization).


The last Navy ships with teak decks were the battleships, now since decommissioned. Teak, and other wooden decks, were scrubbed with a piece of sandstone, nicknamed at one time by an anonymous witty sailor as the "holystone." It was so named because since its use always brought a man to his knees, it must be holy! However, holystones were banned by the Navy by General Order Number 215 of 5 March 1931 because they wore down the expensive teak decks too fast.


The term meaning everything is O.K. was coined from a street named "Honki-Dori" in Yokohama, Japan. Since the inhabitants of this street catered to the pleasures of sailors, it is easy to understand why the street's name became synonymous for anything that is enjoyable or at least satisfactory. And, the logical follow-on is "Okey-dokey."


Today it means to be dull or without pep. It comes from the days of sail when a ship was becalmed and rode on an even keel .... without the port or starbord list experienced under a good breeze. No wind, no list; no list, lifeless.

Log Book

In the early days of sailing ships, the ship's records were written on shingles cut from logs. These shingles were hinged and opened like a book. The record was called the "log book." Later on, when paper was readily available and bound into books, the record maintained it name.

Long Shot

Today it's a gambling term for an event that would take an inordinate amount of luck. It's origins are nautical. Because ships' guns in early days were very inaccurate except at close quarters, it was an extremely lucky shot that would find its target from any great distance.


"Mayday" is the internationally recognized voice radio signal for ships and people in serious trouble at sea. Made official in 1948, it is an anglicizing of the French m'aidez, "help me".

No Quarter

"No quarter given" means that one gives his opponent no opportunity to surrender. It stems from the old custom by which officers, upon surrender, could ransom themselves by paying one quarter of a year's pay.

Pea Coat

Sailors who have to endure pea-soup weather often don their pea coats but the coat's name isn't derived from the weather. The heavy topcoat worn in cold, miserable weather by seafaring men was once tailored from pilot cloth — a heavy, course, stout kind of twilled blue cloth with the nap on one side. The cloth was sometimes called P-cloth for the initial letter of "pilot" and the garment made from it was called a p-jacket — later, a pea coat. The term has been used since 1723 to denote coats made from that cloth.

Port holes

The word "port hole" originated during the reign of Henry VI of England (1485). King Henry insisted on mounting guns too large for his ship and the traditional methods of securing these weapons on the forecastle and aftcastle could not be used.

A French shipbuilder named James Baker was commissioned to solve the problem. He put small doors in the side of the ship and mounted the cannon inside the ship. These doors protected the cannon from weather and were opened when the cannon were to be used. The French word for "door" is "porte" which was later Anglicized to "port" and later went on to mean any opening in the ship's side, whether for cannon or not.


The origin of the word "scuttlebutt," which is nautical parlance for a rumor, comes from a combination of "scuttle" — to make a hole in the ship's hull and thereby causing her to sink —- and "butt" — a cask or hogshead used in the days of wooden ships to hold drinking water. The cask from which the ship's crew took their drinking water — like a water fountain — was the "scuttlebutt". Even in today's Navy a drinking fountain is referred to as such. But, since the crew used to congregate around the "scuttlebutt", that is where the rumors about the ship or voyage would begin. Thus, then and now, rumors are talk from the "scuttlebutt" or just "scuttlebutt".


Contrary to popular notion, the letters S.O.S. do not stand for "Save Our Ship" or "Save Our Souls". They were selected to indicate a distress because, in Morse code, these letters and their combination create an unmistakable sound pattern.

Splice the Main Brace

In the age of sail, ship's rigging was a favorite target during sea battles because destroying the opponent's ability to maneuver or get away would put you at obvious advantage. Therefore, the first and most important task after a battle was to repair damaged rigging (also known as lines- but never "rope"!). Examples of lines include braces (lines that adjust the angle at which a sail is set in relation to the wind) and stays (lines supporting the masts).
The main brace was the principal line controlling the rotation of the main sail. Splicing this line was one of the most difficult chores aboard ship, and one on which the ship's safety depended. It was the custom, after the main brace was properly spliced, to serve grog to the entire crew. Thus, today, after a hard day (or, not so hard day), the phrase has become an invitation to have a drink.


The Vikings called the side of their ship its board, and they placed the steering oar, the "star" on the right side of the ship, thus that side became known as the "star board." It's been that way ever since. And, because the oar was in the right side, the ship was tied to the dock at the left side. This was known as the loading side or "larboard". Later, it was decided that "larboard" and "starboard" were too similar, especially when trying to be heard over the roar of a heavy sea, so the phrase became the "side at which you tied up to in port" or the "port" side.

Taken Aback

One of the hazards faced in days of sailing ships has been incorporated into English to describe someone who has been jolted by unpleasant news. We say that person has been "taken aback." The person is at a momentary loss; unable to act or even to speak. A danger faced by sailing ships was for a sudden shift in wind to come up (from a sudden squall), blowing the sails back against the masts, putting the ship in grave danger of having the masts break off and rendering the ship totally helpless. The ship was taken aback.

Three Mile Limit

The original three-mile limit was the recognized distance from a nation's shore over which that nation had jurisdiction. This border of international waters or the "high seas" was established because, at the time this international law was established, three miles was the longest range of any nation's most powerful guns, and therefore, the limit from shore batteries at which they could enforce their laws. (International law and the 1988 Territorial Sea Proclamation established the "high seas" border at the 12-mile limit.)

Three Sheets to the Wind

We use the term "three sheets to the wind" to describe someone who has too much to drink. As such, they are often bedraggled with perhaps shirttails out, clothes a mess. The reference is to a sailing ship in disarray, that is with sheets (lines — not "ropes" — that adjust the angle at which a sail is set in relation to the wind ) flapping loosely in the breeze.

Took the wind out of his sails

Often we use "took the wind out of his sails" to describe getting the best of an opponent in an argument. Originally it described a battle maneuver of sailing ships. One ship would pass close to its adversary and on its windward side. The ship and sails would block the wind from the second vessel, causing it to lose headway. Losing motion meant losing maneuverability and the ability to carry on a fight.


When the French burned the town of Brighton, England, in the 1500s, King Henry VIII send Admiral Wallop to retaliate and teach the French a lesson. He so thoroughly wrecked the French coasts, that ever since, a devestating blow is said to be an "awful wallop."


Traditionally, a 24-hour day is divided into seven watches. These are: midnight to 4 a.m. [0000-0400], the mid-watch; 4 to 8 a.m. [0400-0800], morning watch; 8 a.m. to noon [0800-1200], forenoon watch; noon to 4 p.m. [1200-1600], afternoon watch; 4 to 6 p.m. [1600-1800] first dog watch; 6 to 8 p.m. [1800-2000], second dog watch; and, 8 p.m. to midnight [2000-2400], evening watch. The half hours of the watch are marked by the striking the bell an appropriate number of times.



By Chuck Hawks


Warship Types

·  Battleship (BB):

Historically, the final arbiter of sea power. Descended from "battle ship of the line," which were the largest and most heavily gunned sailing warships (ex: H.M.S. Victory). After the end of the age of sail, the most heavily armed and protected warships were just called "battleships."

After the advent of H.M.S. Dreadnought, battleships were also called, generically, "dreadnoughts." (See below under Miscellaneous Terms for more about the Dreadnought.) This term basically just means a battleship armed with one size of big gun.

Battleships also carry the heaviest armor of all warships, generally intended to protect them from guns of the approximate size they themselves carried.

It was expected that in war, battleships would endeavor to meet their enemy in the sort of battle where one battle line would steam parallel to the enemy battle line and they would shoot it out until one battle line was sunk. This practically never happened (Tsushima and Jutland being the two times I can think of when it did, except that the Germans fled at Jutland and the battle was indecisive).

In WW II, BB's seldom fought each other, and in much smaller engagements when they did, usually just one or two battleships at a time. By then what is now called the 3rd generation of battleships were known as "fast battleships." (Dreadnought, and battleships like her armed with all 11" or 12" guns represented the first generation. The 2nd generation were the super Dreadnoughts with 13.5" to 16" guns, but speed still limited to the range of 20-24 knots.)

With the fast battleship, the battlecruiser and battleship types had merged. Battle line speeds were now 27 to 30 knots, about as fast as destroyers and cruisers could travel in a seaway. The battlecruiser H.M.S. Hood was really the precursor to all the fast battleships that followed. Improvement in power plants and the increase in size made high speed and heavy armor possible in the same ship. By treaty, the 3rd generation battleships built just before WW II were about 35,000 tons displacement. Read the introduction to my essay about the Treaty Battleships for more on this subject.

·  Battlecruiser (CC):

The rather rigid sort of battle as envisioned for the battle line led to the development of the battlecruiser. Battlecruisers, along with battleships, are classed as "capital ships." The battlecruiser was a ship about as large as a battleship and with battleship size guns, but protected against cruiser (6" or 8") gunfire, not against battleship gunfire. In the first and second generation ships, the weight that would have been devoted to additional armor was instead devoted to additional propulsion machinery. This allowed cruiser speeds (26 to 30 knots).

Since the battlecruiser could outshoot cruisers, it could sink enemy scout cruisers, and brush aside enemy cruiser screens to scout the enemy fleet's disposition. Of course, this only applied as long as the enemy did not also have battlecruisers. Since both sides built the type, they evolved toward the fast battleship. Protection against the enemy battlecruiser's big guns became important. This was driven home to the British in WW I at the Battle of Jutland, where they lost 3 CC's to enemy gunfire, which hastened the development of H.M.S. Hood. Hood was the first CC to carry the same thickness of armor as contemporary battleships. In order to combine heavy armor with high speed (given the efficiency of steam turbines at the time she was designed--during WW I), she was about 10,000 tons bigger than contemporary battleships (31,000t vs. 41,000 tons).

Only Russia operates modern, guided missile equipped battlecruisers today. Read the introduction to my essay about battlecruisers for more information about these fascinating ships.

·  Large cruiser (CB), super cruiser, pocket battleship:

All terms used for ships that were basically battlecruisers, built at a time when it was politically incorrect to build battlecruisers. After the loss of three lightly armored battlecruisers at Jutland, the type came into serious question. Yet the need for the type still existed. So navies found other names for the type, names for which politicians would appropriate money. The smallest were the German "pocket battleships" (more properly "pocket battlecruisers") at about 13,000 tons (11 in. guns), and the biggest about 30,000 tons (12 " to 14" guns). Again, read my essay "Battlecruisers, Large Cruisers . . . ."

·  Cruiser (C):

The next biggest surface combatant after the capital ships. During the interwar years cruisers were limited by treaty to a maximum size of 10,000 tons standard displacement. Two types were defined by treaty: heavy cruisers (CA)--cruisers with 8 inch guns, and light cruisers (CL)--cruisers with 6 inch guns.

Cruisers had many roles. One was literally cruising the world; showing the flag, and representing overwhelming force that could be brought to bear far from home in colonial times. In wartime cruisers were to operate alone on the high seas to interdict enemy commerce; also to protect the battle line against enemy scout (light) cruisers. These were mostly heavy cruiser roles. Heavy cruisers are the smallest warships to which the term "heavy ships" is applied.

Light cruisers were primarily scout cruisers, intended to operate far in front of the battle line to find the enemy battle line and report its position. Also to drive off enemy destroyers that might attempt to torpedo friendly capital ships. Also to patrol lines of commerce against raiders. As they grew larger, their role tended to merge with that of the heavy cruisers.

Both wound up about 10,000 ton ships; the heavy cruisers carried 8 to 10 8" guns, the light cruisers carried 12 to 15 6" guns, and both carried a heavy battery of secondary and AA guns. Some cruisers also carried torpedo tubes. Both types usually had top speeds in excess of 30 knots. For more information, read the introduction to my essay "Heavy Cruisers of WW II."

Today, cruisers are primarily guided missile warships, ranging in size from around 7,000 to 10,000 tons. Only the world’s largest navies can afford to build and operate modern cruisers, principally the United States and Russia.

·  Destroyer (DD):

Historically called torpedo boat destroyers. Destroyers came about after the invention of the whitehead (self-propelled) torpedo. Suddenly there was a weapon that could be carried on a small, fast, cheap motorboat type of craft that could strike a capital ship underwater, bypassing all its armor protection (which at that time was designed to protect against gunfire above the surface, not threats below), and sink it.

Small fleets that could not afford capital ships built torpedo boats to defend against them. Naturally, the major naval powers that did have battleships moved to build small, fast, vessels that were larger and much better armed (with guns) than torpedo boats, and which were blue water ships that could travel with the fleet to defend it against torpedo boats.

Thus the torpedo boat destroyer came about. Later the name was shortened to just "destroyer." Soon, the destroyer itself was armed with torpedoes as well as guns. This allowed it to torpedo bigger enemy warships beyond the range of the small coastal torpedo boats. Torpedo boats were revived by all combatants in WW II--we called ours "PT" (Patrol Torpedo) boats, and John F. Kennedy commanded one. As it turned out, torpedo boats did little damage in any war, but destroyers became the jack of all trades among warships. Today, they are the largest surface combatants operated by most navies, ranging in size up to about 6,000 tons.

When submarines became practical, the destroyer was equipped with depth charges, SONAR, and other ASW weapons, and became their major enemy. Destroyers were used to protect convoys and larger warships against submarines. When aircraft became a major threat to ships, destroyers became AA ships as well. WW II destroyers ran around 2,000 tons, and were armed with a main battery of 4 to 6-4" to 5" guns, AA guns, torpedo tubes, and depth charges and other AS weapons. They were fast ships, generally capable of 30+ knots in calm seas.

·  Destroyer Escort (DE):

A small destroyer, typically designed more for antisubmarine warfare than general purpose fleet defense. Along with frigates, DE's were the smallest blue water surface combatants. They were mass produced in great numbers during the Second World War, primarily as convoy escorts, but served in many capacities and in every theater. WW II DE's ran around 1,200 tons or smaller. DE’s carried a lighter main battery than destroyers (3-3" or 2-5" guns would be typical), plus AA guns, and perhaps a small battery of torpedo tubes. Their AS weapons fit was usually their strength. They were generally slower than fleet destroyers, with top speeds of 20-24 knots.

·  Frigate (FF):

Another term for Destroyer Escort. Most European nations, including the British, called their DE's "frigates." Today, the U. S. Navy has abandoned the destroyer escort nomenclature, and also calls this class of warship frigates. Like all other classes of warships, frigates have grown in size. Today they are larger than WW II destroyers, often displacing up to 3,000 tons, and are usually capable of top speeds of 27 to 30 knots.

·  Submarine (SS):

Submersible Ship. Modern submarines, if not nuclear powered, are sub-classed as "coastal" (short range) or "fleet" (oceanic patrol) types. Nuclear powered submarines are designated "SSN" if they are attack (anti-shipping) boats, and "SSBN" (boomers) if they carry ballistic missiles.

Miscellaneous terms

·  AAA (Triple A):

Anti-Aircraft Artillery.

·  AA:


·  Abaft:

Towards the stern (rear) of the ship.

·  AS:


·  ASW:

Anti-submarine warfare

·  Barbette:

A column of armor that protects the ammunition hoist, and upon which the turret rotates.

·  Broadside:

The guns that can fire to one side of the ship. Also the act of firing all the guns on one side of the ship.

·  BuOrd:

This is the U.S. Navy's Bureau of Ordinance.

·  Casemates:

Gun positions on warships which are protected on all sides by armor. The gun in a casemate fires through a slit or aperture in the armor.

·  C&R:

The U.S. Navy's Bureau of Construction and Repair.

·  Capital ship:

Battleships and battlecruisers, period. Literally, the ships that took the greatest investment of capital to build. In a sense analogous to capital in the financial sense (where capital gives clout or the ability to get things done), as the fleet's battleships and battlecruisers also represented the fleet's ability to get things done.

·  Complement:

The number of people that serve on board a ship.

·  Conning tower:

The place from which a warship is controlled in battle. On a "heavy ship" (like a battleship or cruiser) it is usually armored, unlike the bridge (which is not).

·  Displacement:

The weight of a ship, which is determined by the amount of water displaced by the ship.

·  Dreadnought:

English word which means to fear nothing. Should be in any good dictionary.

The H.M.S. Dreadnought of 1906 was a revolutionary ship, the first modern battleship. She incorporated many firsts: the fastest BB of the time, at 20 knots; the first all big gun battleship (10-12" main battery guns instead of a mix of heavy and medium bore guns); the first BB powered by steam turbine engines. All previous battleships immediately became obsolete after the advent of the Dreadnought. After Dreadnought, all similar battleships (with just one size of main battery gun) were also called, generically, "dreadnoughts."

Later the term became "super dreadnought," as main battery size increased to 13.5" guns, or larger. By WW II, main battery guns were typically 14", 15", or 16". The 11" gunned Scharnhorst and the 18" gunned Yamato classes were the exceptions.

·  Full load displacement:

The weight of a ship fully loaded with stores, fuel, and ammunition.

·  H.M.S.:

Her/His Majesty's Ship. All British warships are "H.M.S. Hood," etc.

·  Heavy Ships:

A term used to refer to the largest surface combatants; includes battleships, battlecruisers, and heavy cruisers.

·  Immune zone:

Discussed in detail in Norman Friedman's book U.S. Battleships. Basically, the zone (typically in thousands of yards) within which a ship's armor is intended to defeat enemy projectiles. So a certain BB might have armor designed to protect it against 14 inch shells from 15,000 yards to 22,000 yards. This means that closer than 15k yards, a 14 inch shell will probably have enough energy to penetrate the ship's side armor, but beyond 15k yards it does not--until the trajectory of the shell becomes so steep so that as it plunges out of the sky that it has enough energy to penetrate the armor on the deck. This happens at 22k yards in my example. At 20k or 21k yards, a shell may hit the deck, but the angle of impact and the armor on the armored deck are sufficient to prevent it from penetrating into the ship's vitals. But at 22,000 yards and farther, it can plunge through the deck armor. So my hypothetical BB is (relatively) protected from 14 inch gunfire between 15k and 22k yards: that is her immune zone. Read Friedman's books for more on this.

·  Knot:

Nautical mile per hour. A nautical mile is somewhat longer than a statute (land) mile at 6080 feet, or 1,856.5m. Therefore, one knot is approximately 1.15 statute miles per hour

·  Magazine:

The space in a warship where ammunition and powder are stored.

·  Metacentric Height:

The distance between a ship's center of gravity and the point through which the ship heels at small angles. The greater the metacentric height, the more stable the ship.

·  Normal displacement:

Displacement measured with the ship fully equipped, but carrying only one-third of its fuel.

·  oa:

Overall; As in the overall length of a ship.

·  pp:

Post to post; the length of a ship measured between perpendiculars. In practice, this is measured between the rudder post and the bow load waterline. It is a measurement that tends to ignore the form of the bow and stern.

·  shp:

Shaft horse power.

·  Sonar:

The American name for underwater sound detection equipment. The British name was Asdic. Sonar can be active (as when "pinging") or passive (listening only).

·  Standard displacement:

Defined by treaty as the measurement of a ship's displacement (weight) when she was ready for sea, but without reserve feed water and fuel. See my Treaty Battleships essay for a brief summary of the Washington Naval treaty.

·  Superstructure:

The fixed structure of the ship above the hull.

·  Turret:

The rotating part of an armored gun mount. Turrets are commonly seen on tanks and warships, and are designed to protect the guns and gun crews from enemy gunfire and the environment.

·  U.S.S.:

United States Ship. All US warships are properly "U.S.S. Alaska," etc

·  wl:

Water line; as in waterline length of a ship (which varies somewhat with displacement).


copyright � 20072013 USS San Francisco Memorial Foundation