AT SGT Explosives and Propellants Flashcards
2.2.2 / 2.2.3 / 2.2.4
What is the definition of primary / initiating explosives?
A substance of mix of substances to initiate a detonation or burn
What are the characteristics of primary explosives?
Stability over long storage period
Optimum sensitivity to applied stimulus, FoI <50
Optimum output the is required
Compatibility with materials
Safety in loading and handling
What are the 2 types of initiator?
Detonators (disruptive)
Igniters (Igniferous)
What are 3 means of initiation for primary explosives?
Mechanical
Thermal
Electrical
Describe Figure of Insensitivity?
The measure of impact stimulus required to make an explosive material detonate.
What makes up ASA composition?
Lead Azide 68%
Lead Styphnate 29%
Aluminum 3%
Name 3 low explosives.
Gunpowder
Pyrotechnics
Propellant
What is the make up of Comp B?
RDX 59.5%
TNT 39.5%
Wax 1%
(60/40 and shave a little off and add wax)
List some HE.
CE - Composition Exploding (Tetryl
TR1 - Tetryl Replacement 1 (RDX 98.75% Wax 1.25%)
TNT - Trinitrotoluene
RDX
PETN
Picric Acid
Comb B - Composition B (RDX 59.5% TNT 39.5% Wax 1%)
PE4 - Plastic Explosive No.4 (RDX 88% Plasticiser 12%)
C4 - Composition 4 (RDX 91% Plasticiser 9%)
HMX
OCTOL - (HMX 70% TNT 30%)
What is the definition of HE?
Any explosive when initiated that decomposes by detonation into its original molecular structure producing heat, gas and blast effect.
What is the purpose of additives in HE?
Increase Sensitivity
Decrease Sensitivity
Improve stability
Increase blast effects
Improve moldability
Name 3 de-sensitisers?
Wax
TNT
Aluminum
Name 4 advantages of Aluminum as an additive?
Takes no part in the initial stages of the detonation
Absorbs energy and lessens the release
Reinforcing action due to exothermic reaction to gases
Increases blast effect
What is Phlegmatization and 4 additives that can be used?
A term that indicates an explosive has had additives added to it to stabilize or desensitize it.
Wax
Oil
Alcohol
Water
What is a propellant?
An explosive with a controlled burn rate that provides gas pressure to move a projectile or missile.
What are 2 categories of propellant and their types?
Liquid
- mono and bi-propellant
Solid
-Colloidal and composite
What are the 3 advantages of single based propellants?
Cooler burning (less erosive)
Less flash
Less affected by temperature change
What are the 4 advantages of double based propellant?
Easily ignited
Hotter flame
Higher burn rate
Higher energy rate
What are 8 effects of additives that can be used in propellants?
Stabilisers
Plasticiser
Coolant
Surface moderant
Surface lubricant
Flash Inhibitor
De-coppering agent
Anti wear additives
What 4 effects does Carbamite have as an additive?
Stabiliser
Plasticiser
Coolant
Surface Moderant
Name 2 de-coppering agents?
Tin
Lead
How do you control the burn rate of propellants?
Composition
Shape
Size
What are the 3 burn rates of propellant?
Digression
Neutral
Progessive
What are 3 shapes for degressive burn rate?
Cord
Flake
Strip or Ribbon
What are 4 shapes for neutral burn rate?
Tubular
Cogged
Star centred
Slotted tubular
Identify these images.
What is a pyrotechnic?
A chemical or mix of chemicals when ignited burn at a controlled rate releasing energy and producing a reaction that can be converted into an effect
What are the 4 main pyrotechnic effects?
Heat
Light
Smoke
Sound
What are the common ingredients in illumination pyrotechnics?
Magnesium or aluminum with nitrates as the oxidant
What is added to illumination compositions to produce different colours?
Red - Strontium
Yellow - Sodium
Green - Barium + potassium
What is added to smoke compositions to produce different colours?
Red - Strontium nitrate
Yellow - Sodium nitrate
Blue/Violet - Copper carbonate
Green - Barium nitrate
White - Barium nitrate and potassium nitrate
Orange - Calcium nitrate
What 9 groups of pyrotechnic composition are there?
Illumination composition
Smoke composition
Signal composition
Delay composition
Tracer composition
Incendiary composition
Priming composition
Simulators
Pyromechanisms
What are some additives to pyrotechnic compositons?
Paraffin wax
Beeswax
Carauba Wax
Chinese Wax
Boiled linseed oil
shellac
Bakelite resin
Polyester resin
Chlorinated Rubber
Epoxy resin
What is a first fire composition?
A booster between a low energy initiator and a composition that is difficult to ignite.
List 3 properties that must be considered with pyrotechnics?
Degradation - highly reactive metals, protect from moisture
Salt - hygroscopic, moisture produces gas that breaks seals
Impurities - Over time can cause issues, undesired reactions
What are 3 methods to ignite/initiate a primer(cap)/igniter?
Mechanical
Electrical
Igniferous
List cap (primer) compositions.
Primary (initiating) Explosive
- Lead Styphnate
- Potassium chlorate
Sensitiser
- Powdered glass
- Sulphur
Oxidiser
- Potassium chlorate
- Barium nitrate
The function of a igniferous initiator is to ignite what?
ignite propellant
Primers
Delay
Gaines
What does a disruptive initiator function and the 2 types?
Induce detonation in high explosive.
1. Fuze detonation - intiated by Stab, Elec, Pyrotechnic delay
2. Demolition detonation - initiated by Pyrotechnic delay FBT,
Elec, Shocktube, Percussion
What is the 3 roles of illuminating composition?
Steady source of light to illuminate targets
Provide clear coloured signals over considerable distances
Tracer filings
What are the 3 design requirements of illuminating compositions?
Burn for the correct time
Correct luminosity
Withstand firing forces
What are the chemical ingredients for illumination compositions?
Fuel - Normally magnesium
Oxidant - Supplies the oxygen (commonly nitrates)
Binding materials / additives
What do binding materials provide to illumination compositions?
Cohesion of particles
Protect magnesium from corrosion
Control rate of burning
Control luminosity and colour
Change sensitivity
What additives are used to colour illumination effects?
Red - Strontium nitrate
Yellow - Sodium nitrate
Green - Barium nitrate
Blue - Copper carbonate
White - Barium nitrate and potassium nitrate
Orange - Calcium nitrate
What is the role of signal compositions?
Transmit clear visual message over considerable distances.
What are the 2 pyrotechnic means of sending a signal message?
Light of distinctive colour
Produce coloured smoke
Why is dark ignition (not visible for 100-200m) important for tracers?
Not mark the firers position
Avoid dazzling the firer
What are 4 design requirements of tracer composition?
Luminosity
Strength
Consistency of performance
Ease of ignition
What are the 2 main types of smoke composition?
Zinc powder (fuel)
zinc oxide / carbon tetrachloride (oxidizers)
Kieselghuhr (diatomaceous earth) / Magnesium carbonate (looseners)
Zinc powder (fuel)
zinc oxide (oxidizers)
Hexachlorethane (oxidizer-solid)
What are the 2 main uses for smoke in the military?
Screening smoke
Signaling smoke
List 3 types of EO which has WP as a screening smoke?
Grenades
Mortar bombs
Artillery projectiles
What are the 5 colours of signaling smoke?
Red
Green
Blue/Violet
Yellow
Orange
What are the 2 types of screening smoke?
Tactical
Defensive
What are 6 disadvantages of WP smoke?
Pillaring
Severe burns
Harassing effect on people
Ongoing fire risk
Expensive filling
Storage and Transport
What effect with the atmosphere causes obscuration? (WP, Berger, Chemical)
Moisture drawn from the air creating a fog or mist
What are 5 advantages of the Berger smoke composition?
No pillaring
Minimal fire risk
Minimal health risks (short term)
No irritant effects on personnel
Easy to fill EO
What are 5 ideal properties of smoke?
Immediate in effect
Minimum affected by weather
Persistent
Non Anti-personnel
Non incendiary
What are the 3 groups of flame/heat compositions?
Igniter
Priming
Incendiary
Define flame/heat igniter?
To initiate propellant or pyrotechnic systems with hot flames, sparks or hot gas.
Name 3 priming compositions?
Gunpowder
Organics + oxidiser
Slag producers (minimal gas)
What are the 2 types of flame/heat delay priming compositions?
Gas
Gasless
Define the purpose of delay composition.
Provide pyrotechnic delay between 2 igniting or exploding events.
What are 4 characteristics of incendiary compositions?
Produce hot molten mass or persistent flame
Heat not released to quick
Hard to extinguish
Max heat - Min weight
What are 6 characteristics of flame/heat priming compositions?
Easy to ignite flame/flash
Not burn too violent or quick
Generate a lot of heat
Compatible with mixture/materials
Produce some solids
Not too sensitive
What are the 2 types of incendiary compositions?
Metals/Alloys
Combustible fluids
What 2 metals are usually used in metal incendiary compositions?
Aluminum
Magnesium
Describe burn to detonation.
The flame from of a igniferous reaction accelerates to become a disruptive shockwave.
What is the composition of gun cotton?
Cotton/wood steeped in nitric and sulphuric acid.
5 Factors influencing explosions?
Initiation
Type
Mass
Density
Confinement
Describe an explosive train.
A sequential arrangement of initiator, intermediary and main charge
What are 3 measures of explosives?
Velocity of Detonation - m/s
Brisance - shattering effect
Figure of Insensitivity - sensitivity to impact
What does Ballistite consist of?
NC. NG, Camphor
