2.1.3 Flashcards
- Define an Explosion
A violent release of energy in the form of heat, light and a large volume of gas / pressure rupturing a confining structure.
- Types of Explosion?
Physical (or mechanical)
Chemical
Nuclear
- Define a Physical Explosion
A rupture of contained gas or vapour release rapidly, with NOISE and VIOLENT movement
- Define a Chemical Explosion
Extremely rapid reaction of a chemical system to produce a rapid expansion of gas and heat
- Define a Nuclear Explosion
A sudden release of enormous quantities of heat by fission or fusion processes
- Define a Blast
A violent disruptive effect caused by an explosion. From the explosion there will be a evolution of heat and gases and a SHOCK FRONT starting from the centre
- What are the phases of a Blast?
SHOCK front
POSITIVE pressure phase (compression)
NEGATIVE pressure phase (rarefaction)
- What are the effects of a blast wave:
Reflection?
Diffraction?
R - It bounces backs or reflects out at an angle from a boundary
- Incident wave: incoming wae - Reflected wave: wave that is bounced back
D - Breaking up or SCATTERING of a wave by an obstacle
- The blast wave is thrown back at an angle to the original path, and/or
- The bouncing back of a wave after it strikes a boundary
Breaking up or scattering of a wave by an obstacle
1 . Basic Principle of a Fuel Air Explosion?
Creating an aerosol cloud of fuel air mixture
then detonated for an explosive effect
- List the 7 main targets of FAE
SCPMSBC Structures Concentrations of AFV and SP guns Parked aircraft Minefield clearance Ships Bunkers / trenches Concentrations of troops in the open
- Using the Probability Product Rule, what is the
probability of a kill, given P(L) (Lethality) = 60%, P(R)
(Reliability) 80% & P(H) (Chance of hit) = 60%?
P(K) = P(H) x P(R) x P(L) PK = .6 X .8 X .6 PK = .288 or 29%
- What are the 6 main types of targets most frequently
engaged by fire?
PEVSACx
People Vehicles Structures Equipment Aircraft Complex
- List the 3 levels of damage which an ammunition
designer may wish to achieve in regards to Target Analysis?
Disablement
Destruction
Neutralisation
- On the battlefield there are 3 types of key target groups that present themselves to land forces, list them?
People
Attack on Armour
Aircraft in flight
- Kinetic & Chemical are 2 main sources of energy employed in ammo design. Briefly describe each?
KINETIC Energy
- In the form of a solid missile (a "shot") - dissipates energy on impact - requires no triggering device to control the energy release
CHEMICAL Energy
- In the form of a substance
- has considerable potential energy relative to its mass,
- can be released when suitably initiated
- What are the types of aircraft targets? (3)
FSH
Fast moving
Slow moving
Helicopters
- Aircraft Damage Criteria What is the standard criteria for damage and their effect on the target? (6)
KK-Kill target suffers IMMEDIATE and catastrophic disintegration
K-Kill destroyed in < 10 secs
A-Kill < 5 mins
B-Kill < 5 hours
C-Kill mission abort (mission unable to be achieved)
E-Kill target may complete the mission but will require repair before flying again.
- Aircraft Vulnerabilities (8)
Air frame Aircrew Fuel tanks Engines Power transmission systems Flight controls Avionics Bomb load
- Types of Warheads against aircraft (7+)
BFF…SkScSpC
Blast Frag Frag + blast Special Kinetic energy Discrete and Continuous rod Shaped Charges Sub-projectiles Cluster
- Effects of Altitude (4)
Density
Miss Distance
Attenuation
Altitude increases / warhead increases
- Reduction of Aircraft Vulnerable Areas (5)
ABCSS Armouring Burying sensitive components Concentrating sensitive components Separating components Self-sealing fuel tanks
- What is the effect of Miss Distance?
Increase miss distance = increase NEQ
A greater NEQ is required as the miss distance increases
- Personnel - Types of damage? (2)
Physical
Mental
- The most efficient mode of attack against personnel requires…? (3)
High PROBABILITY of a hit
Rapid TRANSFER of energy
NO unnecessary OVERKILL
- What type of shells are Fragment attack PRODUCERS (3)
GPP
Generic HE projectiles
Pre notched containers
Pre formed fragments
- Control of Fragment SIZE is ACHIEVED by what? (4)
CTQV
- Case material and its mechanical properties
- Thickness of the wall
- Quantity of explosive and its position in relation to the fragmenting case
- VOD
- Control of Fragment VELOCITY is CONTROLLED by? (3)
DwAxCd
- Density of the wall material
- Amount of explosive behind the fragment wall
- Charge density and velocity of detonation
- What are the factors affecting performance of fragmentation?
DOHA
- DISTRIBUTION of frag:
- Spin rate will influence but not pattern
- Usually symmetrical on longitudinal axis
- Angle of arrival - Orientation of projectile
- Effective distribution when angle is vertical
- Increasing amount of frag is projected into the air or ground as the angle changes - Height of burst
- 2-4 metres is best
- achieved by fuzes - Average area of exposed target
- Target posture
- Terrain
- PPE
- The severity of casualty or type of wound depends on what? (3)
Actual energy transferred
Rate of transfer of energy from projectile to target
Tumbling/yawing reduces energy transfer
- FACTORS AFFECTING energy transfer of Frag weapon onto personnel (3)
Mass and velocity
Cross sectional area
fragment stability
- List the 3 basic modes / methods of attack to defeat armoured vehicles and fortifications
KCC
Kinetic energy
Chemical energy
A combination of both
- Types of Armour Construction
RSPFECS
Rolled homogenous armour Spaced homogenous Ply Face hardened Explosive reactive armour (ERA) Composite (Chobham) Slat (bar)
- APC & MICV (IFV) assessment criteria?
F - firepower kill
P - payload kill (Inf in the back)
- What are the types of shot failure when striking armour? Explain each
Barrelling - Shot bellies at the midpoint due to direct compression failure. Shot fails to penetrate.
Shattering - Severe hoop stresses are set up at the nose, due to hardness of the metal. Shot cracks
Lateral bending - The shot is subject to lateral stresses at high angle of attack
- What are ways to Increase Penetration? (5)
Lengthening of the BARREL Lengthening the PROJECTILE RA - Rocket Assistance Improve STEADINESS of shot Use of segments long rod penetrators
- HEAT - Factors affecting Shape Charges (5)
Cone diameter Shape of liner Liner material Stand-off distance Rate of spin
- Types of chemical energy ammunition
HEAT
HESH (HE Squash Head)
Plate charges
- Behind Armour Effects
BAE contribute to lethality of attack
Effects may be physical, psychological or physiological
- BAE TYPES (4)
Luminescence
Spalling
Heat/fires
Overpressure
- Methods of weapons/Delivery of Plate Charges (5)
GGMAM
Guns
Grenades
Mines
Aircraft bombs
Missiles
Factors taken into consideration in the defeat of armour (4)
Residual energy
Accuracy
Reliability
Lethality
- Description of Kinetic Energy
In the form of a solid missile/projectile, which dissipates it’s energy on impact and requires no triggering device to control the energy release.
- Description of Chemical Energy
In the form of a substance, with a considerable potential energy, relative to it’s mass, which can liberate that energy when suitably initiated. Such materials are familiar as HE and the initiation mechanism as the fuze.
- General Principles of HESH?
Rebounding tension wave meets further primary shock wave
Large scab is detached from the rear surface
- HESH Scab size in reference to its diameter
generally 1.25 to 1.5 times its own diameter
Velocity of scab 30 - 130 metres pers sec
- What are the factors affecting the performance of HESH? (3)
Calibre
Angle of attack
Striking velocity
- HESH performs well against? (3)
Emplacements
Pill-boxes
Concrete structures
- Types of armour that defeat HESH (4)
Spaced armour
Skirting plates
Grooved
Reactive armour
- Secondary effects from HESH (2)
Anti-personnel effects
Damage to sensitive equipment
- What does “APDS-T” stand for?
Armour Piercing Discarding Sabot - Trace
- What are the 2 parts of Discarding Sabot?
Petal
Pot
- 2 types of stabilisation used for Kinetic Energy Weapons?
Fin
Spin
- What does “APCNR” stand for
Armour-piercing Composite Non Rigid
- What the 3 types of Ballistic Requirements
Internal
(Intermediate)
External
Terminal
- What are the FACTORS affecting the performance of shaped charges? (5)
- Cone diameter
- Shape of liner
- Liner material
- Stand-off distance
- Rate of spin
- With a shaped charge the residual energy after penetration lies within what materials? (2)
- Unconsumed part of the jet
- Fragments of metal
- What is the principle of Shaped Charges?
If the energy from a HE charge could be FOCUSED or channeled to a point, it would be reasonable to expect that extremely high local energy levels could be achieved
- How do shaped charges achieve their effect?
Intense concentration of kinetic energy
- What is the Secondary effect of Shaped Charges
Anti-personnel effects from the fragmentation of the external casing
- Means of spin compensation for shaped charges/projectiles
Slipping driving bands
Fluted liners
Spin compensated liners
- What are the primary effects of an explosion
Blast
Heat
Fragmentation
- List the different types of fuel for FAE
L A B E K A P
Liquidated gases Acetylene Butane Ethylene oxide Kerosene Aluminium Propylene oxide
- Advantages of FAE
Greater overpressures than HE
Requires little or no oxygen in the molecular structure
3-5 times hotter than HE
- Basic techniques used in the attack of aircraft in flight (4)
Blast
Frag
Blast and Frag
Special KE
- Frag Warheads. Explain wastage and how a frag warhead can be made more EFFICIENT
- 80% inefficient.
Efficiency improved by:
- HE+Frag in narrow beam/ in one chosen direction
- KE Warheads - External & Terminal Ballistic Requirements? (3 + 1,1)
Small cross section
High mass
High velocity
Ext B: Aerodynamic design
Term B: Hard material
- SC Stand-off distance for Shaped charges?
5 CD - best performance
- Plate Charges. What are they also known as?
Miznay-Schardin Effect
Plate charge
EFP
Self forging fragment
- Decribe burning to detonation
Sudden accelerating of a flame front until a shock wave is formed.
- When explosives are confined in a tube and ignited at one end, the gas generated cannot escape.
- Pressure builds up the burn rate which may accelerate to sonic velocity
- A shock wave of formed and transforms into a detonation.
Define Deflagration
Subsonic combustion that usually propagates through thermal conductivity of Iayers
Define Detonation
Supersonic exothermic front Accelerating through a medium that drives a shock front directly in front of it
What are the requirements for Propellants (5)
Give regular ballistics not produce excessive flash or smoke not cause undue erosion be relatively easy ignited be stable for storage under Worldwide conditions
List the Ways for the Initiation of Explosives (8)
Direct heat Percussion and Stabbing Friction Electrical Initiation Shock Waves Electromagnetic fields Laser Chemical Reaction
What are the requirements for Explosives? (6)
Performance Sensitivity Stability and behaviour in storage Water resistance Consistency Thermal behaviour
What is Brisance
The shattering effect of explosives
Regarding Blast Pressure, what is:
Dynamic Pressure?
Incident pressure?
Quasi-Static Pressure
Reflected Pressure
DP
Results from high wind velocity & increased density of the air behind the shock front
IP
Pressure exerted at right angles to the travel of the shock front
Q-S P
When an explosion occurs with a structure - overpressure eventually settles
RP
Instantaneous build-up of pressure occuring when a shockfront strikes a rigid surface
- Chemical Explosions must exhibit what? (4)
Rapid expansion
Evolution of heat
Rapidity of reaction
Initiation of reaction
- Disadvantages of FAE
FAE is dependent on weather conditions
What is Mach stem?
Occurs when the reflected blast wave coiside wit hte original wave
- TA
Slides re: Atks on Pers, amr and a/c
- What are the general principles Regarding an A/C target? (2)
Types of A/C targets
- Fast, slow, Helo
Vulnerability
Parts of the A/C (8)
- A/C Damage Criteria: “Second Criteria” used by Industry ? (3)
F t -Flight Kill : a/c will be unable to fly within (t)
C t -Continuance Kill: a/c will be unable to continue with (t)
E t -Effectiveness Kill: a/c will be grounded for repair by (t)
Classification of High Explosives. What are the 2 types; list 2 examples each
Primary Explosive: Very sensitive
Mercury Fulminate, Lead Azide, Lead Styphnate
Secondary Explosive: relatively insensitive
TNT, RDX
- Armour “Kill” types and descriptions (3)
K Kill - destroyed
Firepower Kill - Main armament and/or crew unable to operate the system
Mobility Kill - Vehicle unable to move due to running gear and/or engine disabled
- What are the design characteristics of HESH?
6 “must”
- Head must be collapsible
- Head must not be pointed
- HE must have a high VoD
- Explosive be plastic in nature
- Fuze must be in the base
- Inert bitumous pad in nose
