1. Fuzing
Lesson 13

2. 3 Components of a Warhead?
Fuze
Explosive Fill
Warhead Case

3. Introduction What is a fuze?
Devise designed to detonate, or set forces into action to ignite or detonate the charge under specific conditions
What is the difference between fuse and fuze?
Fuse – simple pyrotechnic
Fuze – more complicated device

4. Functions of the Fuze Keep weapon safe Arm weapon
Recognize or detect target
Initiate detonation

5. Basic Fuzing System Safing Warhead Warhead TDD And (sensor) Arming
Target
Detecting
Device
TDD
(sensor)
Warhead
Safing
And
Arming
Device
Warhead
Explosive
Output
Lead
Detonator
Detonator
Target Detecting Device
Saving and Arming Device

6. Fuzing Catagorization
Fuzes catagorized by the manner of fuze operation
i.e. by target sensor
Fuze Catagories
Impact or contact
Ambient
Timer
Proximity

7. Impact Fuze Contact Typical Sensor mechanisms
Detects weapon’s first impact with an object
Output initiate the detonator
Typical Sensor mechanisms
Displacing an inertial mass
Stressing a piezoelectric crystal
Short-circuiting a coaxial transmission line
Interrupting an electrical circuit

8. Impact Fuze
Sidewinder
Mk-46 Torpedo*
Tomahawk
Harpoon

9. Ambient Fuze Senses particular environment Depth charges Air pressure
Mark XI

10. Timer/Delay Fuze
Preset time elapse a timing devise will send a fire signal to the detonator
Mechanical, electronic, igniferous, or chemical
Can be combined with impact fuze….

11. Proximity Fuze Most complex class of fuze
Developed by US and England early in WWII…why?
Called Variable Time (VT) to mask their true nature
Can be Active, Semi-active, or passive
Electromagnetic – range gates
Magnetostatic – presence of magnetic flux
Acoustic – acoustic distrubances
Seismic – similar to acoustic, however lower bandwidth and extremely sensitive

12. Proximity Fuzes
Active
Semi-Active
Passive

13. Safing & Arming Mechanism
Safety & Arming Sensor:
Barrier between the TDD and the warhead
Isolate detonator from the booster
Warhead
Target
Detecting
Device
TDD
(sensor)
Missiles arm after being accelerated for a certain amount of time.
Safing
And
Arming
Device
Explosive
Output
Lead
Detonator

14. Activation Forces Used to arm the warhead Time Acceleration (Setback)
Deceleration (Creep)
Centrifugal
Impact
Time – timer, can be variable or mechanical
Example – 5” round: HE-VT or HE-MT
Acceleration – fuse contacts get set back into the warhead by the acceleration of the weapon
SM-2
Decleration – used for burrowing into the target
Harpoon
Centrifugal – arming, the rotational force of the warhead arms it.
BLU-97 submunitions – rotational motion as it travels to the ground
Impact – Gotta hit the thing.
GBU’s

15. Redundancy in Fuze System
Safety - Devices placed in series in firing path for safety.
Reliability - Components placed in parallel in firing path for arming & firing reliability.

16. Redundancy in Fuze System
Safety and Arming devices
arranged in series for safety
Detonators and Target
Sensors arranged in parallel for reliability A B
System S F

17. Questions?