SA06 Fuzes Flashcards
Define Fuze
A fuze is a device designed to initiate an explosive munition at the correct time or place.
Requirements of a Fuze
Safety - Storage/handling
- Pre-mature functioning
Reliability
Additional requirements of a Fuze
Optional delay setting
Must fit standard cavity sizes
Easy time adjustment & set
Min preparation time for use
Multi rolled to minimise refusing
Standard weight
Two types of masking devices
Non delay arming or masking shutters and slides
Delayed arming shutter
Advantages of electronics in fuzes
Lowers cost due to multi role function
Versatility in arming
Mechanical preparation or initiation
3 Mechanisms found in Mechanical Time fuzes
THIEL - British MT Fuzes
JUNGHANS - American MT Fuzes
DIXI - Swiss Fuze
Types of Timed Fuze
Mechanical
Combustion
Electronic
Main design function of a Timed Fuze
Designed to function after a predetermined time whilst in flight
Impact Fuze actions
Superquick
Non Delay
Graze
Delay
Explain Graze
Interior mechanism of graze action fuzes is arranged so when the projectile is checked in flight or receives an appreciable deceleration a movable part carry’s the detonator forward to the needle.
Requirements and Classification of fuzes - REMEMBER THIS QUESTION
Forces acting on a fuze
- Setback
- Centrifugal
- Spin decay
- Creep forward
- Set forward
- Air or gas pressure
- Stored energy
Intro to Prox fuzes - REMEMBER THIS QUESTION
How does prox fuze function?
- On firing, setback breaks the ampoule or electrolyte which floods the energiser.
- Clock starts (CVT only) and the shutter starts to Clock starts (CVT only) and the shutter starts to rotate.
- An electric igniter is short circuited until 3 - 5 seconds after firing.
- Transmitter radiates radio waves.
- Nearing the target… Doppler effect activates
- FUZE DETONATES.
What is the required number of independent forces during the arming sequence?
Two
What are the 3 safety and arming mechanisms
Holding Device
Locking Device
Safety Device
What are 3 categories of Fuzes
Filling
Position
Function
What is a bore riding pin?
A pin held under tension which is released upon exit of the barrel - arms the projectile
What is the role of booster and what is it made of?
CE Pellet
Carries the explosive wave from the detonator and transfers it to the main fill
One mechanical deice is a shutter, name three more.
Horse head segments
Bore riding pin
Centrifugal balls
4 Settings for Multi Option Fuze
Proximity
Super Quick
Delay
Near surface burst
Intro to Prox fuzes - REMEMBER THIS QUESTION
What is Doppler effect?
- Radio waves are emitted by the fuze, some of the waves are reflected and picked up by the receiver.
- The time taken to return affects the Reflected waves, which interfere with the radiated waves to give a beat known as the Doppler effect.
- As the fuze gets closer to the set target distance the impulses increase to a defined peak value and the fuze functions.
Principle Requirements
Functions at the desired moment
Remains safe in handling, before and during loading
Remains bore and muzzle safety immediately after firing
Arms after leaving the muzzle
