1. Fuzing
Naval Weapons Systems

2. Introduction Why do we have a fuze? Must be reliable and dependable
Trigger explosive reaction
Keep weapon safe when not needed
Must be reliable and dependable
Safing and Arming Mechanism

3. Functions of the Fuze Keep weapon safe Arm weapon
Recognize or detect target
Initiate detonation
Determine direction of detonation
Special Fuzes only

4. 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

5. Target Detection Device

6. Target Detection Device (Four Basic Categories)
Impact or Contact
Ambient - Environmental factor
Timer
Proximity
Impact/Contact
HE-PD
Harpoon missile – delayed fuze
Ambient
Mines – depth sensing
Timer
HE-VT or HE-MT
Bombs – can explode hours after impacting the ground
Cluster bombs – break apart a certain distance above ground
FAE – same as cluster bombs, to get the fuel to spread across a large area.
Proximity
HE-RF, HE-IR
SM-2
Acoustic
Continuous Rod

7. Fuze Classification by fuze operation
Proximity Fuzes:
Active
Semi-Active
Passive
Timed Fuzes
Point Detonating Fuzes
Delay Fuzes
Command Detonated Fuzes

8. Proximity Fuzes
Active
Semi-Active
Passive

9. Safing & Arming Mechanism
Safety & Arming Sensor:
Barrier between the TDD and the warhead
Can be physical or mechanical
Missiles arm after being accelerated for a certain amount of time.

10. 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

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

12. 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

13. Questions?