A vault door is a reinforced barrier designed to secure high-value locations such as bank vaults, safe rooms, and secure storage facilities. Constructed from robust materials such as steel and concrete, these doors are engineered to resist mechanical, thermal, and chemical attacks. They often feature sophisticated locking mechanisms including time locks, combination locks, and biometric systems, which ensure controlled access. The design and construction of vault doors adhere to stringent standards, such as those specified by Underwriters Laboratories in the United States, which classify doors based on their resistance to professional-grade tools.
The physical integrity of vault doors is complemented by advanced security features. These may include seismic detectors, motion sensors, and surveillance systems that monitor and record access attempts. The doors' substantial weight and thickness also serve to deter breaches by brute force. In more sensitive installations, vault doors may be equipped with systems to maintain an internal atmosphere distinct from the outside, protecting contents from fire, water damage, or contamination. This integration of multiple defensive layers ensures that vault doors provide a formidable barrier against unauthorised access, thereby safeguarding valuable or sensitive assets within.