Fuze terminology and types

Question 1

1. What does a creep spring do?

Answer 1

Prevent creep action of a firing pin during slowing of a fuze body

Question 2

2. What is centrifugal force/spin?

Answer 2

Centrifugal force is like a merry-go-round

Question 3

3. What is an impeller?

Answer 3

Mechanical devices turned by air flow or water as it moves through it

Question 4

4. What are the five non-explosive components of a fuze?

Answer 4

Firing pin
Rotor
Escapement device
Detent
Slider 

(FREDS)

Question 5

5. What is the detent?

Answer 5

Held in place by a spring to ensure that they don’t unlock until the proper velocity of spin or acceleration is achieved

Question 6

6. What is the slider?

Answer 6

Held back by a detent which is released by setback

Question 7

7. What is a rotor?

Answer 7

Object which revolves around a stationary component like gears

Question 8

8. What does an escapement device do?

Answer 8

Regulates transmission of energy

ex) system that drives the rotor (ie. coil spring)

Question 9

9. What are the fuze type classification?

Answer 9

Point detonating
Base detonating
Point initiating-base detonated (PIBD)

Question 10

10. What are the options on a point detonating fuze?

Answer 10

Superquick and Delay

Question 11

11. What is impact inertia?

Answer 11

Continuing motion of fuze parts upon sudden deceleration of the fuze body

Question 12

12. What are the two types of PIBD?

Answer 12

Mechanical (spit back)

Electrical (PE/Lucky)

Question 13

13. What are the three types of time fuze?

Answer 13

PTTF powder train time fuse
MT Mechanical time
ET electrical time

Question 14

14. How can you identify a PTTF?

Answer 14

Three rings, made of brass, and all have vent holes

Question 15

15. How mechanical time works?

Answer 15

Use centrifugal force and wound springs to motivate escapement devices

Uses setback to release detents

Question 16

16. What are the three types of pressure?

Answer 16

Direct
Fluid (hydrostatic)
Air (barometric)

Question 17

17. What is pyrotechnic delay?

Answer 17

A device added to a firing system which transmits the ignition flame after a predetermined delay time

Question 18

Arming forces

Answer 18

Acceleration/setback
Deceleration
Sustained acceleration
Creep spring
Centrifugal force
Impellers

Question 19

What is the firing pin?

Answer 19

Strikes detonator when a direct action force is applied (impact)

Question 20

What is a fuse?

Answer 20

Used to initiate explosive train in ordnance items

Question 21

What is impact?

Answer 21

A direct action force that drives a firing pin into the detonator when the fuze impacts with a target

Question 22

How long do powder train time fuzes burn?

Answer 22

Fixed time: usually 15 seconds

Variable time: 5-20 seconds

Question 23

Similarities/differences between electronic and mechanical timer

Answer 23

Used for the same purpose
ET is more modern
ET relies on electricity rather than springs and centrifugal force
ET may include a mechanical backup

Question 24

Two types of proximity (VT) fuzes

Answer 24

Passive - fuze emits no signal

Active - signal is transmitted and reflected

Question 25

How to identify a VT fuze

Answer 25

Plastic, glass, or light metal radome in order to let signals pass through, encloses an antenna and permits maximum passage of RF energy to detect target

Question 26

What do VT fuzes have when used in anti-aircraft mode?

Answer 26

Self-destruct backup. Otherwise, impact backup

Question 27

Types of fuzes

Answer 27

Point detonating
Base detonating
Point initiated-base detonated
Powder train time fuze
Mechanical time
Electronic time
Variable time
Clockwork delay (Mechanical long delay)
Magnetic
Seismic
Acoustic
Fatigue Action
Chemical long delay
Pyrotechnic delay
Pressure