Fuzing Naval Weapons Systems

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

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

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

Target Detection Device

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

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

Proximity Fuzes Active Semi-Active Passive

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.

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

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.

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

Questions?