Safety Fuse
Definition
A black powder-cored initiating cord burning at approximately 8-10 mm/s. Used for controlled delay ignition; forensic signature is black powder residue at the termination point. Distinguished from detonating cord (PETN core) by its slower burn rate and deflagrating rather than detonating behaviour.
- Core material
- Black powder
- Burn rate
- Approximately 8-10 mm per second
- Action type
- Deflagrating (burning), not detonating
- Forensic marker
- Black powder residue at the termination point
- Contrast item
- Detonating cord (PETN core, detonates)
Common questions
Why does the burn rate matter to an investigator reconstructing an event?+
Because the rate is fairly consistent, the length of unburned or recovered fuse remnant lets an examiner back-calculate an approximate delay between ignition and detonation, which helps place a suspect at the scene relative to the blast.
Can safety fuse and detonating cord be confused visually at a scene?+
Both can look like a thin cord, but their cores differ chemically and their combustion behaviour differs sharply. Laboratory examination of the residue and any surviving core material distinguishes a deflagrating black powder fuse from a detonating PETN cord.
What does recovered residue at the termination point tell an examiner?+
Black powder residue at the end of a burned length confirms the fuse actually functioned to completion at that point, which helps corroborate or challenge witness accounts of how an ignition train was assembled.
Related terms
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