LO2 Explosives and Propellants Flashcards
What are the pyrotechnic effects?
- Heat
- Light
- Sound
- Smoke
What is the definition of delay compositions?
A device that provides time delay for a burning train of inflammable composition between events.
What is the makeup of pyrotechnic compositions?
intimate mixtures of solid fuels, oxidants, and various additives
Purpose of Smoke?
Tactical Screening smoke
Signaling smoke
AS Propellant codes?
AR followed by 4 numbers
1st number is the physical form
2nd number is the detterent
Last two digits denote single or double based
Explanation of AS Codes?
1st digit
2 - single perforated
3 - solid
4 - Porous
5 - multi-perforated
2nd digit
0 - no deterrent
2 - Dinitrotoulene
3 - Methyl centralite
4 - Ethyl Centralite
last 2 digits
01 to 50 - single based propellent
51 to 99 - double based propellent
Ideal properties of smoke?
- Persistent
- Non anti-personnel
- Non-incendiary
- Immediate in effect
- Unaffected as far as possible by weather/ climate
Types of screening smoke?
Tactical smoke
Defensive smoke
What are the screening smoke agents?
White Phosphorus
Berger compositions
What are the advantages of WP?
Immediate effect on burning
Excellent screen produced
No priming or ignition devices required
What are the disadvantages of WP?
Pillaring effect on bursting
Severe burns
Fire risk
Harassing effect on eyes, nose and throat
Expensive method of filling
Isolation in storage and transport
What is the main importance of phosphorus-derived smoke?
It is an excellent infra-red screening agent
What are the types of EO which have WP filling?
Artillery projectiles
Mortars bombs
Grenades
What are service propellants based on?
Nitrocellulose (NC)
Who discovered Nitroglycerine (NG)
Italian chemist Ascanio Sobreno (1846)
How is NG made?
A reaction between:
glycerine, and
a mixture of nitric and sulphuric acid
Type of solid propellents?
- Colloidal
* Single-based
* Double-based
* Triple-based - Composite
What are the advantages of single-based propellents?
- Cooler burning
- Produces less flash than cordite
- Ballistics is less affected by change in charge temperature.
What are 2 types of explosive trains/ initiators?
Igniferous
Disruptive
What are the ingredients of cap composition? Include chemical names.
- Primary Explosive
* Lead Styphnate
* Potassium chlorate - Sensitiser
* Powdered glass
* Sulphur - Oxidiser
* Potassium chlorate
* Barium nitrate
What is an initiator?
A small quantity of heat or shock sensitive explosive used to start the process of combustion, explosion or detonation
Caps, igniters, and detonators may be initiated or ignited in what ways?
- Mechanical means
* Percussion/ friction - Electrical means
* Bridge wire - Sparking
* Explosive is receptive to flame and spark.
What are the 3 types of ignition system in SAA?
- Cap and Integral Anvil (Berdan)
- Cap and Separate Anvil (Box)
- Rim Fire
What are the ideal requirements of cap compositions?
- Stability over long storage periods
- Safety in loading and handling
- Optimum sensitivity to applied stimulus
- Optimum output
- Compatibility with materials in contact with them.
- Should not contribute to corrosion or erosion.
What is the difference between igniferous and disruptive initiators?
Igniferous - Produces a flash to start off a pyrotechnic train.
Disruptive - produces a small detonation wave/impulse that can be boosted by an intermediary to initiate the detonation of HE.
What are 2 types of signal compositions?
- Those which produce light of distinctive colour
- Those which produce coloured smoke
What are the ideal properties of propellents?
- An acceptable high energy
- A predictable burn rate
- An acceptable low-flame temperature
- Capability of being easily ignited
- Capability to produce smoke or flash
- Capability to produce toxic fumes
- Cheap, easy, and rapid manufacture
- A long shelf life under all environmental conditions
What are the 2 categories of propellents?
Solid
Liquid
Types of Liquid propellants?
- Mono propellant
- Bi-propellant
Properties of NC?
- Creamy white fibres
- Porous and hygroscopic
- Burns quickly and efficiently
- Extremely erosive to weapon systems
- Dry NC is sensitive to spark, impact and friction
Properties of NG?
- Colourless oily liquid, smells of almond
- Burns with a green flame
- Very sensitive to impact and friction
- Dissolves NC
- Soluble in acetone and alcohol
- Poisonous - handling can cause severe headaches
Where are the single-base propellants used?
- Small arms
- Secondary charges for mortars
- Igniters
What are the disadvantages of single-base propellants?
- Less powerful than cordite
- Not easy to ignite
- Too brittle to use in cord form
- Generally more hygroscopic and therefore subject to ballistic change from atmospheric conditions
What are composite propellants?
They are a physical mixture of fuel and oxidant, with binders. They do not contain NC.
What are the different types of additives?
Remember the acronym CDF LAMPS
C - Coolant
D - Decoppering agents
F - Flash inhibitors
L - Lubricants
A - Anti-wear
M - Moderants
P - Plasticisers
S - Stabilisers
What are the ways of controlling the propellant burn rate?
- Propellant composition
- Shape of propellant
- Size of propellant
What are the 3 types of burning rates?
- Progressive
- Neutral
- Degressive
What are the different propellant shapes with burning type?
- Progressive burning
* Rosette
* Multi-tubular - Neutral
* Tubular
* Slotted tubular
* Cogged
* Star Centre - Degressive burning
* Cord
* Flake
* Strip/ ribbon
What are the different shapes of propellants?
- Rosette
- Multi-tubular
- Tubular
- Cogged
- Star center
- Flake
- Ribbon
- Cord
- Ball Powder
- Slotted groove tube
- Slotted tubular
- Drilled tube
- Axial drilled
- Cruciform
- Scroll
Advantages of double base propellants?
- Easily ignited
- Higher energy rating than single based
- Higher flame temperature
- Higher burning rate
Disadvantages of double base propellants?
- Can cause excessive weapon erosion
- More costly to manufacture
- More dangerous to manufacture
Where are double-base propellants used?
- In cordites
- In form of ballistite for primary cartridges in mortars
- SAA where high bulk energy is required
Where are triple-base propellants used?
In charges for artillery pieces and tank guns
Properties of triple-base propellants?
- They are normally cooler than double base
- Lower bulk energies than double base
- More difficult to ignite
What are the different types of high explosives?
- Composition Explosive (CE) - Tetryl
- TR1 - Tetryl replacement 1
RDX 98.75%, Polyethylene wax 1.25% - RDX - Cyclotetramethylenetrinitromine
- TNT - Trinitrotoulene
- PETN - Pentaerythritoltrinitrate
- Picric Acid - Trinitrophenol
- Comp B - RDX 59.5%, TNT 39.5%, Wax 1%
- PE no. 4 - RDX 88%, stabilisers 12%
- HMX - Cyclotetramethylenetetranitramine
- C4 - RDX 91%, stabiliser 9%
- Explosive D (Dunnite) - Ammonium 2,4,6-trinitrophenolate
What is the VoD of primary explosives?
- CE - 7500 mps
- RDX - 8450 mps
- TNT - 6950 mps
- PETN - 8300 mps
- Picric acid - 6800 mps
- Comp B - 7800 mps
- PE4 - 8200 mps
- HMX - 9120 mps
- C4 - 7500 mps
- Explosive D - 7150 mps
- ANFO - 1100 - 2700 mps
