Summative 6 - Fuzes Flashcards
Req, abrev, class of fuzes define
Define a fuze
A fuze is a device designed to function an item of ammunition under pre determined circumstances.
Req, abrev, class of fuzes: Abrev by position List
Expand the following abbreviations
PD
BD
PIBD
PD:
Point Detonating.
BD:
Base Detonating.
PIBD:
Point Initiating Base Detonating.
Req, abrev, class of fuzes: abvrev by function List
Expand the following abbreviations T CT MT VT CVT SQ DEL MTSQ TSQ PDSQ MO ET
T Time.
CT Combustion Time (May also be PTTF).
MT Mechanical Time.
VT Variable Time.
CVT Controlled Variable Time.
SQ Super Quick.
DEL Delay.
MTSQ Mechanical Time Super Quick.
TSQ Time Super Quick.
PDSQ Point Detonating Super Quick.
MO Multi Option.
ET Electronic Time.
Req, abrev, class of fuzes List
List the Genreal requirements (2)
and the other requirements (4)
SAFETY:
For storage and transport.
Against premature functioning.
RELIABILITY:
To High Order When Required.
OTHER: Optional delay setting. Easy time adjustment / setting. Minimum preparation for use. Multi role to minimise refusing. Standard weight. Must fit standard cavity size:
Req, abrev, class of fuzes: Classification List
What 3 categories dictate the classification of a fuze
Filing
Position
Function
Req, abrev, class of fuzes: Classification List
Fuzes classified by function have what three types?
Time
Impact
Proximity
Req, abrev, class of fuzes: Classification List
Fuzes classified by the impact function have what four types?
Super quick (SQ) graze delay Non-delay
Req, abrev, class of fuzes: Classification List
Fuzes classified by the Proximity function have what two types?
Variable time
Controlled variable time
Req, abrev, class of fuzes: Classification List
Fuzes classified by the time function have what three types?
Mechanical time
Combustion time
Electronic time
Req, abrev, class of fuzes: classification - functions List
A fuze that can use more that one function categorization is called what?
Multi-option
Mech devices and fuze components Safety principles
List
Explain what alignment is in regards to a fuze.
Which of the 3 broad fuze types should be either in or out of alignment?
having the striker offset, or ‘out of line or alignment” from the detonator by a shutter or other device that will move to be ‘in line’ when, for example, enough centrifugal force is applied to it (by firing).
Electronic - in line
mechanical - out of line
electro/mechanical - out of line
Mech devices and fuze components: Safety requirements
List
List 12 other requirements that can improve safety and reliability
Arming: Simple as possible, distinct from other process
Material compatibility
Design safety - cannot be assembled in unsafe manner, can be checked.
User inspection - be able to check state of safety features
Explosive train - barriers from main fill and detonator if using something more sensitive than Tetryl
Mechanical Lock - shutters and interrupter remain locked
Delay arming - System will remain safe until certain conditions are reached. no single circumstance should arm the fuze
In line train - no current in circuit allowed until safe separation is reached
software safety - modular, unique start and end.
Defensive programming
user drills safety- not possible to arm electro-explosives; saftey will not rely on drills
Reliability: less stringent requirement, safety reqs can reduce reliability by increasing complexity
Mech devices and fuze components: Holding devices
define
Define a holding device
A holding device locks other components in a safe position until arming is required; to unlock them when arming is required; and possibly to relock them in the armed position.
Mech devices and fuze components: Holding devices
define
Define a shear wire
A length of wire pinning a moving part to a fixed on
The wire is strong enough to hold the parts together until sufficient force is applied to the moving one.
Mech devices and fuze components: Holding devices
define
Define a striker spring and spring disc
The striker spring consists of a spiral spring surrounding the striker.
Striker separated from the detonator until overcome by a superior force.
The same function is performed by a corrugated spring disc.
Mech devices and fuze components: Holding devices
define
Define a detent / set back pin
A small metal cylinder or block working in a hole or recess.
Resting on a spiral spring under part compression.
Spring is used to keep the detent in a safe position.
Mech devices and fuze components: holding devices
define
define a Stirrup Spring and Ferrule
This consists of a thin metal cylinder with lugs turned over at each end and in opposite directions.
The lugs can be used to lock 2 concentric sleeves together and rest at opposite ends of each sleeve.
One of the sleeves is fixed and the other kept against a lug by a spring.
The lugs are designed to be straightened out by one of the forces acting on the fuze and allow the moving sleeve to be freed under action of the spring.
Mech devices and fuze components: holding devices
define
Define where and when saftey pins, cotters, and pull pins should be used.
Normally found in unspun ordnance such as mortars/rockets when centrifugal force cannot be used.
Mech devices and fuze components: holding devices
define
Define a horse head segment.
Two pivoted segments which, when closed together, prevent movement of a component
Only a rotational force (centrifugal) will cause the 2 segments to rotate out of the way
Mech devices and fuze components: Masking devices
define
Define masking device
It “masks” or obstructs the explosive train until arming is required, ensuring that accidental premature functioning of one part of the train does not affect the whole train.
