Mantrap
Mantraps are physical security devices or constructions designed to trap, disable, or kill a human.
Historical usage
Historically, mantraps 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]
Other traps such as special snares, trap netting, trapping pits, fluidizing solid matter traps[2] and cage traps could be used.
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 court case of Katko v. Briney, "the law has always placed a higher value upon human safety than upon mere rights of property."[3]
Modern usage
In modern physical security protocols, a man trap 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.[4] They are also known as air locks in the security industry.
In a manual man trap, a guard locks and unlocks each door in sequence. An intercom and/or video camera are often used to allow the guard to control the trap from a remote location.
In aquatic situations and in space, man traps are known as air locks. This is counterintuitive, because the exact same design is used for the opposite purpose. A man trap is used to keep an individual in, whereas an airlock is used to facilitate ingress or egress.
In an automatic man trap, identification may be required for each door, sometimes even 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.[5] Other methods of opening doors include proximity cards or biometric devices such as fingerprint readers or iris recognition scans.
Metal detectors are often built in, in order to prevent entrance of people carrying weapons. Such use is particularly frequent in banks and jewelry shops.
Fire codes require that automatic man traps allow exit from the intermediate space while denying access to a secure space such as a data center or research lab.[6] A manually operated man trap may allow a guard to lock both doors, trapping a suspect between the doors for questioning or detainment.[7]
In a lower-security variation of a mantrap, 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 walk-up robberies. Entry access by ATM card to the dead space offers additional customer protection.
Footnotes
- ↑ B2 Non Fatal Offences Against the Person - March 2008, Oxford University Press, March 2008
- ↑ Fluidized sand mantrap
- ↑ "Katko v. Briney". 183 N.W.2d 657. (Iowa Sup. Ct. 1971).
- ↑ Kouba Systems frequently asked questions, retrieved Jul 11, 2012
- ↑ Kouba Systems frequently asked questions, retrieved Jul 11, 2012
- ↑ Kouba Systems frequently asked questions, retrieved Jul 11, 2012
- ↑ Kouba Systems frequently asked questions, retrieved Jul 11, 2012
See also
- Animal trapping
- Sally port
- Spring gun
- Katko v. Briney (important case on mantrap liability in the United States)
- Booby trap
- access control
- security
Sources
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press
External links
The dictionary definition of mantrap at Wiktionary
Media related to Mantraps at Wikimedia Commons- Novacomm, Inc. - The manufacturer of the Access Control Vestibule
- Conversations about Access Control Vestibules
- ACV Patent
- Bank Robber trapped in ACV
- The Access Control Vestibule™ or Mantrap Security System
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