Theory of Design Flashcards
Definition of a grenade
a grenade is a small explosive store designed for projection by hand or from a personal weapon or a launcher may be used
Categorisations of grenades
Categorised by the intended means of delivery , and the payload
- hand thrown
- projected (rifle / gun fired)
- discharger (weapon / vehicle launched)
Grenade payload types
HE anti pers (offensive - defensive) HEAT and Dual Purpose (Heat and Frag) Smoke (signalling and screening) Chemical / Irritant Flash or noise Incendiary Prac Ilum
Typical grenade components
Body Filling Frag Fuze cavity Fuze
Fuze components
Safety Pin Fly off lever Spring Striker Detonator Delay Pellet
Offensive grenades
To stun or disorientate
Rely on blast effect
Defensive grenades
Project frag at high velocity
Used fm a defensive position
40mm low pressure cavity
used to lower pressure in the cart case so the round is fired at a lower velocity, and there is less recoil to the firer
Definition of SAA
Ammo for weapons such as pistols, rifles and machine guns below 20mm calibres
Parts of an SSA round
Cart Case
Ignition system
Propellant charge
Bullet/projectile
SAA Cart case purpose:
- holds propellant charge, incorporates ignition system, retains bullet, provides obturation
- is influenced by the roll of the ammo, the type of weapon, bullet design, and ignition system
SAA Cart case must be:
- elastic to expand and contract,
- resist corrosion
- withstand transportation and handling
- have a hard base and soft mouth
SAA Cart Case types:
Rimmed, semi rimmed, rimless
SAA Ignition System
Berdan - cap and anvil
Boxer - cap and separate anvil
Rimfire
SAA propellant types
Single and double based
SAA Bullets:
- design is governed by role
- short range = low velocity, snub nose
- long range = shaped for aerodynamics, streamlined
length is limited by external ballistics - spin stabilised becomes unstable over time
Solid or filled
What is ‘set up’
the expansion of the rear of the bullet combined with setback.
in this position, the cart case has expanded from the expansion of gas as the propellant combusts, and the bullet has engaged the rifling
FFR Principles
When a gas is compressed within a container, pressure is transmitted in all directions. If an opening is present and pressure is maintained by burning propellant, the pressure at the closed end is greater than that at the open end. Energy expended gives velocity to escaping gasses, causing the rocket to move in the direction of the closed end.
FFR consists of two sections:
Motor and Warhead
FFR Motor consists of:
Casing Combustion chamber propellant ignitor nozzle/s find (if not spin stabilised)
FFR Nozzle - Describe
‘De Laval Nozzle’ = Convergent-divergent type
Purpose is to convert heat and pressure to KE
Compresses gas to provide thrust / forward propulsion
High pressure sub sonic gas transferred to low pressure supersonic gas
Describe Thrust Alignment (FFR)
where the thrust doesn’t pass through the centre of gravity of a rocket, causing it to pitch or yaw.
Cg changes as fuel is consumed/depleted
How to overcome Thrust Alignment (FFR)
spinning the rocket during motor burn reduces the affect of thrust alignment, but too fast and the effects will be increased
mitigate by:
- manufacturing to closer tolerances
- impart slower rate of spin
- reduced rocket motor burn time
- addition of fins
Definition of mines
An explosive or other material normally encased, designed to destroy or damage vehicles, boats or aircraft, and designed to kill, wound or incapacitate personnel.
May be detonated by the action of the victim, passage of time, or by controlled means.
Types of mines
Anti Tank
Anti Personnel
Anti Helicopter
Types of Anti Tank Mines
Pattern mine Bar mine Scatterable Shielder Side attack / Off route Area defence weapon ACEATM
Types of Anti Personnel Mines
Pressure activated
Omni Directional Frag
Directional Frag
Characteristics of Mine Systems
All weather capability, 24hr capability psychological effects contributes to EN destruction CBRN resistant Cost effective
Operational Characteristics of Mines;
Sensitive Easy to lay Easy to arm Resistant to countermeasures Delay arming Neutralisation / Sterilisation Remote control Recording (paperwork)
Mine Components
WARHEAD
- HE Blast - anti pers / tank
- Shrapnel - anti pers / helicopter
- Shaped charges/EFPs - tank belly / top
SENSOR and FUZE
- mechanical (pressure/contact or double impulse)
- electronic (discriminatory)
SAFETY and ARMING UNIT
POWER SOURCE
CASE
Methods of Mine Laying
hand mechanical scatterable vehicle shielder artillery aircraft
Mine countermeasures
Hand Breaching
Mechanical Breaching (flails, rollers, ploughs)
Explosive Breaching (Python, PELCC Personnel
Explosive Lance Clearance Charge)
Fuel Air Explosive
Electromagnetic Breaching
RCL Recoilless Principal
- if two equal weights can be fired in opposite directions at equal velocity the weapon will be recoilless
- can use countershot of half weight, IF fired at twice the velocity
- countershot replaced by rapid stream of light gas
- obturated breech replaced by venturi
Advantages of RCL
no recoil
low weight
man portable
Disadvantages of RCL
low velocity
signature (caused by gas, heat, dust, seismic, acoustic)
large propelling charge
What causes the signature of a RCL
Signature is caused by portion of propellant gasses escaping rearward, plus frag from cart case = BBDA
Types of RCL
HE HEAT HEDP SMK ILUM ASM PRAC
How does a perforated cart case work: RCL
Gas from the burning propellant expands through holes into the outer chamber and is forced rearwards through venturi
How does blow out disc work: RCL
propellant charge ignited on firing,
pressure builds from expanding gasses
disc ruptures, propelling projectile forward
propellant gasses escape through breech hole and out through venturi
Mortars are used for;
neutralising, suppresive and destructive indirect fire
Types of Mortar fire:
Preparation covering defensive counter bty fire harrassing smoke ilum
Characteristics of mortars
smooth bore
no recoil
restricted to over 800 mils firing
muzzle loaded
Components of a mortar
Base plate
Barrel
Bipod
Sight
Current Mortar natures in service
SMK, ILUM, HE, TRG
Current Artillery Gun
M777A2
has Optical Fire Control System and
Digital Fire Control System
M777 Rate of Fire
max: 4 rpm for 2 min
sustained: 2 rpm to 30 min
after 30 min, 1 rpm
Artillery natures
HE SMK ILUM PRAC
Guided (excalibur)
SMART
Artillery Propellant
MACS High Triple Base
MACS Low Single Base
Precautions when handling tank ammo
Handle with gloves, and PPE
Principles of Employment of Armour
Mission Comd
Combined Arms
Sustainment
Manoeuvre Space
120mm Components (Armour)
CCC Combustible cart case Case base and seal assemble Electric primer Combustible disc and propellant containment bag Main charge propellant Spring disc and retaining ring
Bases of SAA Carts
Rimless
Rimmed
Semi rimmed
Belted
Design of SAA - bullet is secured into the mouth of the cart case to:
Seal against moisture
Prevent accidental removal
Retention by cart case to allow gas build up (bullet pull)
Methods of securing SAA bullet into mouth of cart case
Press fit Caneluring Indenting Stabbing Coming Crimping
