mantraps

Mantraps are a form of security vestibule consisting of a small enclosed space with two interlocking doors positioned such that only one door can be opened at a time. The design creates a controlled entry or exit and is used to enforce access control, prevent tailgating, and provide a security checkpoint within a facility.

Typically the outer door is opened after verification (card, PIN, biometric) and then the inner door remains locked while the system confirms the entrant. Once the outer door closes, the inner door may open, or vice versa in some configurations. Advanced implementations use interlocking steel doors, sensors, panic release provisions, and alarm and CCTV systems. Some mantraps include pressure-sensitive floors, iris or fingerprint scanners, and fail-secure or fail-safe locking depending on safety and risk considerations. Emergency egress provisions and fire code compliance are important design constraints.

Common applications include banks, data centers, government facilities, laboratories, and other high-security workplaces. They are also used in airports, border facilities, and critical infrastructure sites. While effective against tailgating and unauthorized access, mantraps are not a substitute for comprehensive security programs and can pose safety risks during evacuations or emergencies if not properly designed and maintained. The term is sometimes extended to airlock-like corridors used for controlled access or hazardous environments.