mantrap

Man-traps are physical security devices or constructions designed to entrap a person.

Historical usage

Historically man-traps were mechanical devices for catching poachers and trespassers. The devices have taken many forms, the most usual being like a large foothold trap, the steel springs being armed with teeth which met in the victim's leg. Since 1827, they have been illegal in England, except in houses between sunset and sunrise as a defence against burglars.^[1] Also, other traps such as special snares, trap netting, trapping pits and cage traps could be used.

The term is also generally used of individuals likely to entrap others, such as into marital agreement.

Modern usage

A man-trap in modern physical security protocols refers to a small space having two sets of interlocking doors such that the first set of doors must close before the second set opens. Identification may be required for each door, and possibly different measures for each door. For example, a key may open the first door, but a personal identification number entered on a number pad opens the second. Other methods of opening doors include proximity cards or biometric devices such as fingerprint readers or iris recognition scans. "Man-traps" may be configured so that when an alarm is activated, all doors lock and trap the suspect between the doors in the "dead-space" or lock just one door to deny access to a secure space such as a data center or research lab.

In a lower-security variation of a man-trap, banks often locate automated teller machines within the dead-space between the entrance doors and the interior lobby doors to prevent ATM robbery and night-time walk-up robberies. Entry access by ATM card to the dead-space offers additional customer protection.

Also known as an Air-lock in the security industry.

Mantraps that use deadly force are illegal in the United States, and there have been notable tort law cases where the trespasser has successfully sued the property owner for damages caused by the mantrap. As noted in the important US mantrap case of Katko v. Briney, "the law has always placed a higher value upon human safety than upon mere rights of property."^[2]

Footnotes

1. ^ B2 Non Fatal Offences Against the Person - March 2008, Oxford University Press, March 2008
2. ^ "Katko v. Briney". 183 N.W.2d 657. (Iowa Sup. Ct. 1971). 

See also

• Animal trapping
• Sally port
• Spring gun
• Katko v. Briney (important case on mantrap liability in the United States)
• Booby trap
• Access control vestibule

This article incorporates text from the Encyclopædia Britannica, Eleventh Edition, a publication now in the public domain.