Gun Theory and Design Principles Flashcards
“A weapon incorporating a metal tube from which bullets, shells, or other projectiles are propelled by explosive force in the form of expanding gases, typically making a characteristic loud, sharp noise.”
Gun
“A propellant and projectile”
Ammunition
“A chemical substance used in the production of energy or pressurized gas that is used to create movement of a fluid or to generate propulsion”
Propellants
“Any object throwin into space by the exertion of a force”
Projectile
“The approximate internal diameter of the gun barrel”
Calibre
Major calibre:
> 8 in
Intermediate Calibre
4 - 8 in
Minor Calibre
0.60 - 4 in
Small Arms (calibre)
< 0.60 in
Manned or Unmanned: “Generally more accurate as they are guided by radar or a dedicated fire control system”
Unmanned
Manned or Unmanned: Cheaper and require less space beacuse they dont require secondary systems to operate.
Manned
“Projectiles that are ejected from a container by means of an initial impulse”
Impulse Projectiles
“The use of naval artillery to provide fire support for land-based combat operations”
Naval Gunfire Support (NGFS)
What are two types of NGFS?
Direct Fire - LOS
Indirect fire - Requires forward observer
What are vulnerabilities while on a gun line (NGFS)?
Air attack from land
Submarines due to predictable course
“The distance a roudn will travel from the gun when fired. This is determined by muzzle velocity, elevation, and exterior ballistic factors.”
Range
“The speed of the projectile the moment it leaves the muzzle of a gun. Determined by the amount of energy imparted to the round by the expasion of gasses in the barrel”
Muzzle Velocity
What factors affect Muzzle Velocity?
Barrel Length
Length to diameter ratio
Projectile Weight
Size and Burn Pattern of propellant
Temperature
Why does a longer barrel increase the muzzle velocity?
Expanding gas has more time to impart energy to the round.
Does a heavy round have a higher or lower muzzle velocity?
Lower. Same energy, more mass, less speed.
How does temperature affect muzzle velocity?
Affects the burn rate and max pressure of the propellant.
“The frequency at which a weapon can fire or launch its projectiels. it is usually measured in rounds per minute or rounds per second”
Rate of Fire
“The mechanical rate of fire, or how fast the weapon cycles. Does not consider magazine changes, aiming, etc.)
Cyclical Rate
“The rate at which the weapon could reasonably be fired indefinitely without failing. Includes factors such as reloading, aiming, changing barrels, cooling. Useful to know for logistics and supply purposes”
Sustained Rate
What are the components of PKill?
P_kill = P_hit + P_destroy
“The number of rounds available for immediate firing, which can be used before reloading”
Round Capacity
“The number of rounds available in a mount to be used before the mount needs to be reloaded”
Ready Use Rounds
What is the Round Capacity of the 57mm?
40 rounds.
“The time it takes the loading system to move ammunition from the storage magazine to the gun mount”
Loading Time
“The time it takes to move ready use ammunition into the feed system”
Reloading Time
“The maximum distance at which the explosino from a round or missile can be expected to destroy its target.”
Miss Distance
Describe Miss Distance Indicator (MDI)
Inert rounds are fired at the target and the MDI system calculates whether the rounds entered the Miss Distance
Data used to improve fire control solution.
Describe CAC
Continuous Aim Correction
Radar places range gate in front of, over, and behind target
The rounds are tracked by radar and a feedback control system compensates.
Describe Spot Correction
Rounds are fired at a fixed point and tracked by radar
The offset is used to calibrate the gun.
“The rate at which the gun moves in both bearing and elecation”
Slew Rate
Are arcs of fire and blind arcs considered performance characteristics?
Yes
“Represent the full area that a projectile may enter when fired on a set course, including defelection error, wind, or ship motion error, tracking system target loss, etc.”
Safety Arcs of Fire
What are all 9 performance characteristics
Range
Muzzle Velocity
Rate of Fire
PKill
Round Capacity
Load/Reload Time
Accuracy and Precision
Slew Rate
Arcs of Fire
“The radius of overage of a given weapon system defined in terms of bearing and elevation”
Arc of fire
What publication governs safety arcs of fire?
MAVORD 4995-0 Safety Firing Orders for Ships and Submarines
