The terminology on this page is as used
in our existing articles. As we add more articles, we will add more terms
and explanations.
| Abbreviation
|
Full
Term |
Meaning
|
| - |
Air-Cooled
|
Air
is used to cool a barrel heated by firing |
| AA
|
Anti-Aircraft
|
Gunfire
or a weapon used to counter aircraft |
| AFV
|
Armoured
Fighting Vehicle |
|
| - |
Barrel
|
The
metal tube from which the projectile emerges upon firing |
| - |
Barrel
Jacket |
A
housing surrounding a barrel, can be to protect the user from the
hot barrel or filled with water to assist in cooling |
| - |
Belt
Feed |
System
of supplying ammunition to a machine gun in the form of a continuous
belt |
| - |
Bolt
|
The
part of a weapon which contains the firing and chamber closing mechanism
|
| - |
Box
Magazine |
Type
of ammunition supply which takes the form of a metallic box, either
detachable from the weapon and held in a magazine housing, or actually
forming part of the weapon’s body. |
| - |
Bullet
|
The
projectile of a cartridge fired from the barrel. |
| - |
Butt
|
The
rear stock of a weapon. |
| Cal
|
Calibre
|
Internal
diameter of a weapon’s barrel, measured from land to land.
|
| - |
Carriage |
A
mounting used for both the transportation and firing of a weapon. |
| - |
Cartridge
|
The
complete unit of ammunition, i.e. The casing containing the propellent
and the projectile |
| - |
Chamber
|
Also
called the breech, enlarged portion of the barrel at its rear end,
into which the cartridge is placed prior to firing |
| - |
Cyclic |
The
rate of fire to be attained when it is possible to fire the weapon
continuously, e.g. belt fed. |
| - |
Drum
Magazine |
Magazine
for an automatic weapon in the form of a shallow cylinder or drum
|
| - |
Gas
Operation |
A
system where a portion of the propelling gas is tapped from the barrel
and used to cycle the weapon’s action |
| GPMG
|
General-Purpose
Machine Gun |
A
light air-cooled machine gun, which with the addition of a tripod
and a dial sight can be adapted to the role of the heavy machine gun
|
| HMG
|
Heavy
Machine Gun |
A
machine gun used for sustained long-range fire |
| - |
Lands
|
The
raised spiral ridges between the grooves of the rifling |
| LMG
|
Light
Machine Gun |
A
machine gun used to support a rifle squad |
| - |
Logistics
|
The
system of supply |
| - |
Muzzle
|
The
front end of a barrel from which the projectile emerges |
| - |
Muzzle
Velocity |
Speed
of the projectile measured at the muzzle |
| - |
Recoil
Intensifier |
A
device attached to the muzzle of an automatic weapon which impedes
the muzzle blast to give the barrel additional rearward velocity to
intensity the recoil action and make the automatic operation more
positive |
| - |
Recoil
Operation |
A
system where the recoiling of the barrel, due to firing, is used cycle
the weapon’s action |
| - |
Receiver
|
The
‘body’ of a weapon, to which the barrel, stock etc. are fixed and
within which lies the firing and chamber closing mechanism
|
| - |
Rifling
|
The
spiral grooves cut in the interior of a barrel which improve accuracy
by imparting a spin to the projectile |
| RPM
|
Rounds
per Minute |
- |
| - |
Trigger
Guard |
A
guard to protect against accidental tripping of the trigger
|
| SMG
|
Sub-Machine
Gun |
A
short-barrelled, magazine fed automatic weapon which fires a pistol
cartridge |
| - |
Velocity
|
The
measure of the speed of the projectile |
| - |
Water-Cooled
|
Water
is used to cool a barrel heated by firing |
| Term |
Explanation |
|
AA
|
Anti-aircraft
|
|
Abaft
|
‘Aft
of’.
|
|
Aft
|
The
part of the ship that is towards the stern (behind) from the point
of reference (eg ‘aft of the crane’), or the rear portion of the
ship.
|
|
Aircraft
carrier
|
"Any
surface vessel of war, whatever its displacement, designed for the
specific and exclusive purpose of carrying aircraft and so constructed
that aircraft can be launched therefrom and landed thereon. The
fitting of a landing-on or flying-off platform or deck on a capital
ship, cruiser or destroyer, provided such vessel was not designed
or adapted exclusively as an aircraft carrier, shall not cause any
vessel so fitted to be charged against or classified in the category
of aircraft carriers." – (London Treaty, 1930)
|
|
Asdic
|
Original
British name for sonar (Sound Navigation and Ranging). A device
that sends out an underwater sound pulse to detect objects (submarines).
If the sound pulse strikes an object it is reflected back, and by
knowing the time taken for the round-trip the distance of the object
can be estimated. The direction of the sound pulse is controlled
by the operator, with reflections this giving a distance and bearing
for the object. The name comes from the Allied Submarine Detection
Investigation Committee, which investigated the system in 1917.
|
|
Barbette
|
The
cylinder that the a main gun turret sits on. It supports the turret
and contains the ammunition hoists.
|
|
Beam
|
The
maximum width of the ship.
|
|
Block
coefficient
|
Cb
= V/(L x B x T), where V is the total underwater volume of the ship,
L is the waterline length of the ship, B is the breadth of the ship
and T is the draft of the ship. The block coefficient gives a crude
indication of the underwater shape of the ship, with low values
implying that the ship is shaped for speed at the expense of useable
space, and high values implying a slow vessel concerned more for
maximising useable internal space than for speed (note - this is
a rule-of-thumb). A block coefficient of 1 would indicate that the
ship was a rectangle, without any underwater shape. Modern supertankers
have block coefficients above 0.9 and container ships (fast merchant
ships) are around 0.65.
|
|
Bow
|
The
most forward part of the ship that meets the water
|
|
Bulkhead
|
An
internal subdivision of a ship. Bulkheads are not necessarily watertight.
|
|
Bunker
|
A
fuel tank. When ships ran on coal this referred to the coal bunkers,
however nowadays this term also refers to fuel oil storage.
|
|
Bunkering
|
Refuelling.
See Bunker.
|
|
Capital
ship
|
Surface
vessels of war, the standard displacement of which exceeds 10,000
tons, or with a gun above eight inch (203 mm) calibre.
|
|
Cb
|
Block
coefficient
|
|
Cruiser
|
"Surface
vessels of war, other than capital ships or aircraft carriers, the
standard displacement of which exceeds 1,850 tons (1,880 metric
tons), or with a gun above 5.1 inch (130 mm) calibre." – (London
Naval Treaty, 1930)
|
|
Cruiser
- heavy
|
A
cruiser with a gun above six inches in calibre. (London Naval Treaty,
1930)
|
|
Cruiser
- light
|
A
cruiser with all guns of calibre six inches or less. (London Naval
Treaty, 1930)
|
|
Deadweight
|
The
weight of all cargo and stores (including fuel, water, food and
other supplies) carried by a ship. For a cargo ship it is one of
the primary measures of ship size (along with gross tons), as it
approximates to the cargo carrying capacity of the ship.
|
|
Depth
|
The
depth of a ship is the vertical distance between the deck and the
keel
|
|
Destroyer
|
Surface
vessels of war the standard displacement of which does not exceed
1,850 tons (1,880 metric tons), and with a gun not above 5.1 inch
(130 mm) calibre. (London Naval Treaty, 1930)
|
|
Displacement
|
The
weight of the ship. The term ‘displacement’ comes from Archimedes
principle, which states that the upthrust on a vessel is equal to
the mass of the volume of water displaced, and that a ship will
sink until the mass of displaced water equals the weight of the
ship. A ship’s displacement varies continuously - as stores are
consumed, ammunition fired and fuel burned the displacement decreases;
as modifications are added and supplies brought on board the displacement
increases. It is thus not possible to get a definitive value of
the total displacement of a ship, and different sources for displacement
often quote different values.
|
|
Draft
|
The
vertical distance from the waterline to the lowest point on the
ship.
|
|
Gross
Tons
|
A
measure of the internal volume of the ship, expressed as 100 sq ft
to 1 ton. The volume includes all enclosed spaces, including bridge
and accommodation. Along with deadweight, this is one of the primary
means of measuring the size of a merchant ship. Gross tons was extensively
used as a measure in the past, however for modern cargo ships deadweight
is now the most common measure. |
|
HA
DCT
|
High
angle direction control tower. Used for engaging air targets.
|
|
HF/DF
|
High
frequency direction finding equipment, used to get a bearing on
submarine radio emissions.
|
|
Huff-Duff
|
Common
name for HF/DF equipment
|
|
Keel
|
The
outside of the bottom of the ship
|
|
Knot
|
One
nautical mile per hour, or 0.5144 meters per second.
|
|
LA
DCT
|
Low
angle direction control tower. Used for engaging surface targets.
|
|
Length
(OA)
|
The
overall length of the ship, from the aft-most part to the forward-most
part.
|
|
Length
(pp)
|
The
length between perpendiculars. The forward perpendicular is defined
as the point where the forward-most part of the ship meets the water
at the fully loaded draft. The aft perpendicular often defined as
the centre of the rudder stock.
|
|
Length
(WL)
|
The
length of the ship from the point where the aft end meets the water
until the point where the forward end meets the water.
|
|
Nautical
mile
|
1,852
metres
|
|
Port
|
When
facing forward, the port side is the left side of the ship.
|
|
SHP
|
Shaft
Horse Power - power delivered to the propeller shaft.
|
|
Starboard
|
When
facing forward, the starboard side is the right side of the ship.
|
|
Stern
|
The
back end of the ship.
|
