2.1.4 Flashcards
Name the types of natural fibres which may be used with ammunition and explosives?
Cellulose
Silk
Wool
Rubber
What are the 2 main types of plastics used with ammunition? And what is the main difference between them?
Thermoplastic
-Can be reheated and reshaped
Thermosetting Plastics
- incapable of being again being softened by heat
What are Engineering Plastics?
Higher tolerance than normal plastics
Most are fibrous reinforced which improves their performance
What are the types of Paints and Varnishes?
Copal Varnish
Shellac
Considerations for Adhesives, Cements and Lutings(glues) ?
Must not react to explosives Must have strength and be water-resistant Permanent - Adhesives or cement Temporary - Luting(soft setting)
What is used for non-permanent seals?
Luting
What Non-metallic materials are used with ammunition?
Natural fibres Rubbers Plastics Paint & varnishes Adhesives, cement, luting
Paints and Varnishes
Must not react with explosives
Varnishes based on bitumen
Developed for coating iron and steel surfaces
of HE stores
Cementing in cardboard closure caps
Slow drying and all excess must be removed
What are the 2 main types of metal
defects?
Mechanical
Cracking due to stress
Chemical
Corrosion due to impurities
Name 3 types of corrosion?
Rust (Ferrous Oxide) Aluminium Oxidation Mazak Contamination Cupric Azide Zinc Exudation
How do you remove corrosion from cart
cases?
Use of white spirit or light grade emery paper
If the corrosion is severe sentence ammo according to inspection pam
Explain Cuprous Azide Contamination?
- Occurs in copper detonators
- Lead Azide reacts in moisture to produce Hydrazoic Acid,
- combines with copper
- Copper (ii) Azide is a sensitive explosive
Can occur in copper detonators containing Lead Azide which when exposed to moisture liberate small amounts of Hydrazoic acid vapour which attacks the copper
What is the DEFINITION of Corrosion?
CONVERSION of a metal to a non-metallic state
When are stresses most likely to be
formed in metal & what can aggravate
them?
- formed during manufacture
- further aggravated by the environmental changes
Define Season Cracking?
Stressed areas of metal cracking
due to the affect of ammonia forming Cuprammonium during storage in either hot or cold temperatures
Types of Corrosion?
Rust (ferrous oxide)
Aluminium Oxidation
Cupric Azide Contamination
Zinc Exudation “free copper”
Process for Inspection, Sentencing and Repair?
Cleaning (scouring / scrubbing)
Post Cleaning (acetone, paint)
Inspection (serviceability)
Sentencing (if unserviceable)
Reporting (details of corrosion or other defects)
METALLURGY
The process of producing metals by extracting
them from their base ores
•
Refining and purifying these metals
•
The study of the physical and chemical
properties of these metals
•
The mechanical working of these metals
The formation of alloys of these metals
•
Enhancing the desirable properties of these metals
and alloys to suit a particular application
•
The study of the relationship between the properties of
the structure and the use of metals and alloys
Define ANODISE
- An electrolytic passivation process
- used to increase the thickness of thenatural oxide layer on the surface of metal
parts - increases corrosion resistance
and wear resistance, and provides better
Define BRASS
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- Yellow alloy of COPPER and ZINC
- malleable and ductile and harder and stronger than copper
- Relatively low melting point
- Not magnetic
- Susceptible to seasonal cracking
Define BRONZE
- Alloy of Copper and Tin
- malleable and ductile and harder and stronger than copper
Define COPPER
- malleable and ductile
- one of the best conductors of HEAT and ELECTRICITY
What is Copper used in Ammunition for?
Driving Bands Detonators Shaped charge liners Cartridge Cases SAA jackets (gilding Metal)
Define CREEP
A permanent change to the dimensions of a metal due to continuous stress
Define DUCTILE
The ability of a metal to be DRAWN OUT in to an elongated form
without affecting the structure of the metal
Define ORE
- A native or natural mineral that can be mined
- Treated for the extraction of any it
constituents.
Define Malleability
The ability of a metal to be shaped using
forces
without breaking the structure of the metal
Metalloid
Element having some properties characteristic of metal, others of non metals.
eg Arsenic, antimony
Define ALLOYS
Alloys are metallic substances that contain more
than one chemical element
Difference between Ferrous and non-ferrous
Ferrous - contains Iron
Non-ferrous - doesn’t contain Iron
Define Steel
Iron and Carbon
Define LUSTRE
This a measurement of the ability of the surface of a metal
to reflect light. The reflected light is affected by surface
Define HARDNESS
The measure of a metal’s ability to resist
deformation
Property of DENSITY
It is generally considered that the strength to weight ratio is more important in selecting the right metal for a particular application than purely weight.
Define LUSTRE
This a measurement the ability of a surface of a metal
to reflect light.
CO-EFFICIENT of EXPANSION
This is the measurement of the amount a metal expands at a given temperature
(eg. brass expands and contracts quickly with changes of temp.)
What are the four main types of filling HE
Shell?
Casting Pressing Extruding Preforming/Cocooning
What are the disadvantages of Hot/Melt
filling?
Shrinkage Dusting Cracking
What compounds are used for the coating of
the internal Shell walls?
Shellac Varnish Lacquer Bitumen Resin
What are the 3 methods of CASTING explosive
fillings?
Straight Pour Creamed Liquid and Biscuit
What are the 3 methods of CASTING explosive
fillings?
“pour cream into the biscuit”
Straight Pour Creamed Liquid and Biscuit
Purpose of Tracers
Emit light
May be used as a Self Destruct (SD)
Principle requirements of tracer
composition are:
Luminosity . Strength . Consistency of Performance . Ease of Ignition
Name and describe two means of ignition
for tracer.
Direct Ignition
. A cap sets back onto an anvil to initiate the igniter composition.
Propellant Ignition
. Ignited by hot propellant gases on firing.
Name and describe two Means of Ignition
for tracer.
Direct Ignition
. A cap sets back onto an anvil to initiate the igniter composition.
Propellant Ignition
. Ignited by hot propellant gases on firing.
Name and describe two Means of Ignition
for tracer.
Direct Ignition
. A cap sets back onto an anvil to initiate the igniter composition.
Propellant Ignition
. Ignited by hot propellant gases on firing.
Classification of Tracers
Tracer projectile
. separate components
Tracer and Igniter Projectile
. includes a Self-destruct (SD)
Integral Tracer
Integral part of the main projectile
Types of Primers
Percussion
Electric
Design features of Primers
Produce sufficient Flash IOT Ignite
Pass flash evenly
Be self obturating
Protect the gunpowder and propellant from moisture
Flush fitted
Primer Components
Body Cap Anvil Plug Magazine
Percussion Primer Components
Body Cap Anvil Plug Magazine
Name the type of Obturating Systems on Primers
External
Internal
Employing some form of stopper in the body,
which on the ignition of the Magazine effectively
plugs any attempt by the gases to escape
rearwards
- Ball Seal
- Cone/plug seal
Percussion Cap - Action on Firing
Striker/Firing Pin strikes the Cap
Crushes the initiating composition against the anvil
Flash passes through the Firing Channels in the anvil & plug to
the Gunpowder in the Magazine
Magazine Fires, Primer Body Expands against the Cart Case,
thereby ensuring external obturation
Ball or Cone is forced back into the fire channels internal
Obturation
What are the Components of a Conducting Cap
Base
Pole unit
Cap
Magazine
What are the components of the Bridge Wire Primer
Base
Contact piece
Bridge
Magazine
Tubes (primer)
Used with separate loading bagged propelling charges (ie. Arty)
Projectile Classifications
Operational projectiles
-mortar, grenade, bullet
Weapon Functioning / Inspection
- blank, proof, gun functioning, paper shot
Training Projectiles
- Prac, drill, cut-away/instructional, sub-cal
Projectile Terms / Types - KE
AP AP Capped Windshield Penetrative Cap Ballistic Cap AP Capped Ballistic Cap APDS Semi Armour Piercing (SAP) APFSDS
What is the Ogive
The shaped part of a normal projectile from the shoulder forward. It is the main radius of the head.
Driving and Rotating Bands - Functions
To centre projectile in bore and impart spin
To prevent the forward escape of
propellant gases
To assist in prevention of slipback of the
projectile when loaded at high elevations
Requirements for a Driving Bnd
No excessive pressure on the shell or barrel Cater for change in bore diameter (wear) Remain firmly attached to the projectile Must not alter the ballistic shape of the projectile (engraved state) Cause no excessive friction or bore wear Simple to make and fit
Limitiations to Drive band Positioning
Driving band near to the base
Streamline shells (Boatailed)
Fixed Ammo
METHODS OF ATTACHMENT for Driving Bands
Split Ring
Solid Ring
Driving and Rotating Bands - Functions
xx
To centre projectile in bore and impart spin
To prevent the forward escape of
propellant gases
To assist in prevention of slipback of the
projectile when loaded at high elevations
Driving and Rotating Bands - Functions
Why are Driving Bands Required
xx
To centre projectile in bore and impart spin
To prevent the forward escape of
propellant gases
To prevention of slipback of the
projectile when loaded at high elevations
Methods to Prevent Twist
xx
Wavy Rib
Knurling
Types of Driving Bands
Orthodox
Modern
Double
Gas Check Type Probert
Drive Band Slip Ring - Design description
To ensure that the spin imparted by the
weapons barrel does not reach a rate that would
influence the fin stabilisation of a projectile
Slip Ring Materials
Plastic
Vulcanised Rubber
Polycarbonate
Drive Band Slip Ring - Design description
xx
To ensure that the spin imparted by the
weapons barrel does not reach a rate that would
influence the fin stabilisation of a projectile
or reduce the effectiveness of a hollow charge
Types of Cartridge Systems
Breech Loading
Quick Firing
How is separate ammunition loaded into a breech loaded gun?
xx
- The projectile and charge bags are loaded into the chamber of the gun
- The breech is closed to provide obturation
- The tube or primer is inserted into the breech
Breech Loading Adv / Disadv
Less stowage problems
Quick Firing Systems
QF Separate
QF Semi-fixed
QF Fixed
Quick Firing Description
QF is a system in which the breech is usually
closed by a simple sliding motion resulting in
a higher rate of fire
Rearward obturation is provided by the Cart
Case
Propelling Charge is contained in an
incombustible Cart Case
Parts of the QF System
Cart case with Primer
Propelling charge (can be charge bags)
Projectile
Quick Firing Description
QF is a system in which the breech is usually
closed by a simple sliding motion resulting in
a higher rate of fire
Rearward obturation is provided by the Cart
Case (also called ammunition obturation)
Propelling Charge is contained in an
incombustible Cart Case
REQUIREMENTS OF CHARGE BAGS
xx
Non smoulder Non stretch Non wear Be insect, vermin and rot proof
Breech Loading Components
Tubes / primers
Bagged charge
projectile
Breech Loading Components
xx
Tubes / primers
Bagged charge
projectile
Advantages of QF Separate
Less stowage problems due to length Replace damaged Cart Case Adjustable charge
Types of Loading systems
BL - Separate
QF - Separate
- Semi-fixed
- Fixed
List the four types of bagged charges
Equal Cylinders Unequal Cylinders Stem & Segment Stem & Ring
What are the two design principles of Bagged
Charges?
The lowest charge must be stable so
it does not lose its shape
- when loaded alone and cause a misfire or delay in complete ignition
The igniter, which is always fitted over the lowest
charge
-is made of the largest possible diameter.
What is the difference between a Combustible and
Consumable cart case?
CONSUMABLE. (no bang)
Material that is used up during the
process of the combustion of the propellant. It is
an inert material and does not contribute to the
explosive process.
COMBUSTIBLE. (adds to bang)
Material that is capable of burning
and contains ingredients that contribute
significantly to the production of propellant
gasses.
List the 7 charge types.
Normal Super Reduced Fractional Incremental Blank Charge De coppering charge
What are the 2 types of Recoilless Ammunition Designs?
xx
Perforated CART. case
Solid CART case with a bow out disc
What are the 2 types of Recoilless Ammunition Designs?
xx
Perforated CART. case
Solid CART case with a bow out disc
Explain the method of operation of the solid CART. case with blow out disc?
xx
Propellant charge initiated, pressure builds up, blow out disc ruptures, the projectile is propelled forward and the propellant gases escape through the rear breech hole and out through the venturi.
Advantages of RCL Systems
No Recoil Low Weight Man Portable Mounted on Light Vehicles
Disadvantages of RCL Systems
xx
Flash / Dust signature (BBDA) Low Velocity Large Propelling Charge
Explain Rocket Assist Projectile Action
xx
- Rocket cap removed prior to loading
- On firing propellant gases ignite delay composition – 7 sec delay
- Delay ignites rocket igniter and main rocket motor propellant
- Boost phase – 2 secs, Sustain – 7 secs
- Propellant gases released through venturi
Propellant Charges are made of 3 components:
Charge container Propellant Initiator
The cartridge case must fulfil the following
tasks:
Protect the propellant
Provide early obturation by expanding ASAP
Recover to a diameter less than the internal
Withstand unseating and extraction forces
Support the projectile in a fixed round which is
Materials used for CART cases
Brass
Steel
Aluminium
Plastic
Methods of attaching projectiles to CART cases are?
xx
Coning
Canneluring
Coning and canneluring
What advantages does a combustible CART case offer?
xx
Everything loaded into the chamber plays some
part in ballistics
Minimal produce
Why use brass?
xx
Performs well on most equipment
Metallurgy & techniques are well known
Does not corrode to give hard abrasive particles
6 Factors Affecting HE Shell Design?
xx
Target effect Ballistic performance Strength to withstand firing stresses Economy in manufacture User requirements Safe handling ,transportation and storage
Name forces that act on a projectile (8)
Gas pressure Acceleration Setback Heat Centrifugal force Driving band pressures Side slap (hoop stress / shear stress) Drag (nose drag, base drag)
How is nose and base drag reduced?
Nose drag is reduced by head shape (Ogive)
Base drag is reduced by base shape (Boat tail)
Manufacture of Shell
xx
Normally steel
Cast
Forged
Extruded
What is the definition of a carrier projectile?
A vessel/vehicle that contains the payload
What are the different types of carrier projectiles
Smoke Illumination Conventional Anti-Personnel Sub-munitions Flare Incendiary Radar Echo Chemical Proganda
What are the methods of operation for carrier projectiles?
Bursting
Base Ejection
Nose Ejection
Base Emission
Define Exploder System
The components used for transmitting the
impulse from the fuze or booster to the HE filling
“A charge in the form of a pressed pellet or filled
container of secondary explosive
designed to amplify the detonation wave produced by a fuze detonator or magazine
to ensure efficient detonation of the main charge.”
Supplementary charges contained in metal
provide three main benefits, list them
Ease of removal Setback movement eliminated No explosive migration
Define the Term “Supplementary Charge”
A cylindrical aluminium container,
(filled with either TNT or Comp B)
used to fill the cavity below the fuse in deep cavity projectiles.
Removed when some proximity fuzes are fitted to the projectile
Define Exploder
“A charge in the form of a pressed pellet or filled
container of secondary explosive
designed to amplify the detonation wave produced by a fuze detonator or magazine
to ensure efficient detonation of the main charge.”
Projectile Design
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- Body
- Head
- Base
- Baseplate
- Bands
- Band Bourrelet
- Driving Bands
8 .Ogive
(the shaped part of the projectile from the shoulder forward)
9 .Shoulder - Cavity
- Wall
- Governing Section
- Fuze Hole
- Lip
