Formative 11 Revision Flashcards
What are the major components of the Fuze MR3005?
- Fuze Body
- Fuze Base
- Firing Pin assembly
- Rotor assembly
- Priming Relay
When the ___ of the firing pin spring is greater than the _____, the firing pin will begin to move _____ . This movement is ____ by balls acting on the ____ _____ ramp. At this stage the fuze is ____ ____ and is at least 15m from the barrel
Self destruct will occur when _____
-When the FORCE of the firing pin spring is greater than that of the SETBACK FORCE, the firing pin will begin to
move FORWARD. This movement is IMPEDEDE by balls acting on the SELF DESTRUCT ramp. At this stage the fuze is FULLY ARMED and is at least 15m from the barrel.
-The projectile has not hit a target after 6-16 secs time of flight
Why is there a slipping ring on the 84mm HEAT?
-As not to impart too much spin and provide forward obturation
What does the distance tube do?
- Provide optimum stand-ff
- Acts as a shock transmitter for the piezo-electric crystals
What 84mm Prac variants are there and what is their difference to the 84mm HEAT?
- Cart 84mm Prac ATK TPT 141
- Cart 84mm Prac TP 552
- It is ballistically matched to the Cart 84mm HEAT 551 but has no fuze system, booster or explosive warhead and is fin stabilised
Describe the functioning of a 84mm HEAT after firing
- Primer ignites propellant in cart case.
- Propellant gases acting on the rear of the projectile ignites rocket motor delay
- Rocket motor delay burns for approx 45 miliseconds and prijectile leaves barrel
- Delay composition ignited intermediate and ignition charge
- Ignition charge initiates rocket motor charge, burns for approx 1.5 seconds
- Delay unit ejected from rocket at approx 15m from the muzzle
- Setback force moves both safety sleeves rearwards, unlocks rotor
- Arming spring moves rotor 270 degrees to the armed position
- Detonator is now connected to firing circuit by the contact piece
- On impact, 5 piezo-electric crystals convert impact shock into electrical current
- Current passes through four layer diode via contact piece and funcstions electric detonator in rotor.
- Detonator functions booster pellets, in turns functions HE fill and forms jets
What are some precautions of the 84mm HEAT and why?
-A UXO is extremely sensitive to electro static discharge and must not be subject to vibration
Why is the 84mm HEDP fin stabilised?
-So not to degrade the formation of the jet from the shape charge
Label the 84mm HEDP
label diagram
A _______ in the fuze allows the projectile to pass through ______ ______ equivalent to _____ planks from _____ without functioning.
A MASK SAFETY in the fuze allows the projectile to pass through MULTIPLE TARGETS equivalent to 40MM PINE planks from 0 TO 20M without functioning.
How many pre selection ranges are on the 84mm Illum 545C?
- Seven
- 300m-2100m
What is the safety wait time for the 554C and why?
-60 minutes to allow capacitor bleed down
How many safety arrangements are there on the F555 (SAD) fuze and what are they?
- Three
- Inertial safety
- Centrifugal safety
- Combined safety
Why are there raised ridges on the 84mm Illum 545C?
-For fuze setting in low light
What is the Fuze V447 MTSQ fitted to?
-Cart 84mm HE 411B