Safes, Vaults, and High-Security Containers
Core concepts
Safe work requires understanding ratings, construction, and locking mechanisms. Know the difference between burglary ratings (e.g., TL-15, TL-30 under UL 687) and fire ratings, and why a fire safe is not a burglary safe. Understand relockers-devices that fire to keep the door locked if the lock is attacked-and glass relock plates. Know combination locks (mechanical dial and electronic), manipulation and drilling as attack methods, and safe-opening techniques.
Servicing practice
Changing a combination requires the current combination and adherence to the dialing sequence (typically multiple turns to clear, then land on numbers). Electronic safe locks use keypad entry with time-delay and audit features. Vault doors, depositories, and high-security containers add complexity: boltwork, relocking triggers, and anchoring. Drilling requires knowing the lock's location and the relocker positions to avoid firing them.
Traps
Questions often confuse fire rating with burglary rating, or imply a relocker can be bypassed easily-relockers exist specifically to defeat that. Another trap: assuming a safe can be opened by manipulation when it has an electronic lock, or that time-delay can be overridden casually. Don't forget that anchoring and bolt-down matter for small safes.
Worked example
A TL-15 safe with a mechanical combination lock won't open. Before drilling, exhaust non-destructive options: verify the combination and dialing procedure, check for a stuck bolt or relocker, and confirm the door isn't jammed. If drilling is required, locate the lock and identify relocker positions first-drilling blindly can fire a relocker and make the job harder.