booby trap

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POMZ stake-mounted fragmentation mine with a simple boobytrap attached. The intended victim (a deminer) first disarms the trip-wire initiated pull-fuze mounted on the top. Then, mistakenly believing that the device is now safe to remove, he pulls the stake out of the ground. However, this action frees the arming lever on the pinless F1 grenade concealed underneath, which flies off, activates the zero-delay UZRGM fuze and triggers detonation

A booby trap is a trap designed to kill or severely injure a human. As the word trap implies, they often have some form of bait designed to lure the victim towards it. However, in other cases the device is placed on busy roads or is triggered when the victim performs some type of everyday action e.g. opening a door, picking something up or switching something on. Booby traps should not be confused with mantraps which are designed to catch a person. Lethal booby traps are often used in warfare, particularly guerilla warfare, and traps designed to cause injury or pain are also sometimes used by criminals wanting to protect drugs or other illicit property, and by some owners of legal property who wish to protect it from theft. Booby traps which merely cause discomfort or embarrassment are a popular form of practical joke.^{[citation needed]}

Etymology

Ray Mears suggested that the booby trap name came from the skill of catching boobies - a sea bird, when out at sea. Bait would be placed in the middle of a noose, when the Booby landed on deck to eat the food, the noose would be tightened to catch the bird by the legs.^{[citation needed]}

Military booby traps

A booby trap is distinguished from a land mine by the fact that it is an improvised weapon, often made from some item of ordnance such as an artillery shell, grenade, or quantity of high explosives, whereas a land mine is manufactured for its specific purpose. A booby trap is always concealed or disguised in some way so that it either cannot be seen or looks harmless. Typically, a booby trap will be hidden inside, behind or underneath another object. Part of the skill in placing booby-traps lies in having knowledge of human psychology e.g. exploiting people's natural curiosity or acquisitiveness. A common trick is to provide victims with a simple solution to a problem e.g. leaving only one door open in an otherwise secure building, thereby luring them straight toward the firing mechanism. Attractive or interesting objects are frequently used as bait in order to lure victims into triggering the booby trap. For example, troops could leave behind empty beer bottles and a sealed wooden packing case with "Scotch Whisky" marked on it before leaving an area. The rubble-filled packing case might be resting on top of an M5^[1] or M142 firing device,^[2][3] connected to some blocks of TNT or to some C4 explosive stuffed into the empty fuze pocket of a mortar shell. Alternatively, the weight of the packing case might simply be holding down the arming lever of an M67 grenade with the safety pin removed. Either way, when the case is moved the booby trap detonates, killing or severely injuring anyone in the immediate area.

Purpose-built booby-trap firing devices (e.g. the M142 universal firing device^[4]) exist which allow a variety of different ways of triggering explosives e.g. via trip wire (either pulling it or releasing the tension on it), direct pressure on an object (e.g. standing on it), or pressure release (lift/shift something) etc.

Almost any item can be booby-trapped in some way. For example, boobytrapping a flashlight is a classic tactic: a flashlight already contains most of the required components. First of all, the flashlight acts as bait, tempting the victim to pick it up. More importantly, it is easy to conceal a detonator, some explosives, and batteries inside the flashlight casing. A simple electrical circuit is connected to the on/off switch. When the victim attempts to turn the flashlight on to see if it works, the resulting explosion blows their hand or arm off and possibly blinds them.^[5][6]

The only real limitations on the intricacy of booby-traps are the skill and inventiveness of the people placing them. For example, the "bait object" (e.g. a cash box in a corner of the room) which lures victims into the trap may not in fact be booby-trapped at all. However, the furniture which must be pushed away in order to get to the bait has a wire attached, with an M142 firing device connected to a 155mm artillery shell on the other end of it.^[7]

Technically, there are no practical limits on the maximum size of a booby trap. Theoretically, a large cache of Mark 84 bombs (or simply crates of cast TNT) fitted with an M142 universal firing device (connected to the door) could be locked inside the basement of a large office building. The amount of explosives involved might weigh many tons, and would therefore be capable of completely destroying a skyscraper. At the other end of the scale, a retractable ball-point pen could have a simple stab-detonator concealed inside it, sufficient to blow the tips of a victim's fingers off. However, as a general rule the size of most explosive boobytraps falls somewhere in the middle. Generally, smaller amounts of explosive (e.g. between 250g and 1 kg) are much easier to conceal and, since most boobytraps are rigged to detonate within a metre of the victim's body, this is adequate to kill or severely wound.^[7]

As a rule, booby-traps are planted in any situation where there is a strong likelihood of them being encountered and triggered by the targeted victims. Typically, they are planted in places that people are naturally attracted to or are forced to use. The list of likely placement areas includes:^[8]

• the only abandoned houses left standing in a village, which will be a magnet for enemy soldiers seeking shelter.
• a door, drawer or cupboard inside a building that someone will open without thinking of what might be connected to it. If a door is locked, this makes people believe there could something valuable behind it so they are more likely to kick it open, with fatal results.
• vehicles abandoned by the roadside, perhaps with some kind of victim "bait" left on the back seat.
• natural choke-points, such as the only footbridge across a river, which people must use whether they want to or not.
• important strategic installations such as airfields, railway stations and harbor facilities, all of which the invading forces will want to occupy and use.
• anything of use or value that people would naturally want to possess or which makes them curious to see what is inside it e.g. a crate of beer, a pistol, a flashlight or a discarded army rucksack etc.

A booby trap does not necessarily incorporate explosives in its construction. Examples include deadfall traps which employ heavy objects set up to fall on and crush whoever disturbs the trigger mechanism. Another non-explosive design is a concealed pit with sharpened stakes embedded in the bottom; sometimes referred to as Punji sticks. However, setting non-explosive booby traps is labour-intensive and time-consuming. Additionally, they are harder to conceal. Although non-explosive booby traps will maim the victim in some way, they rarely kill. In contrast, booby traps containing explosives are much more destructive: they will either kill their victims or severely wound them e.g. blow arms or legs off.^[9][10][8]

Effects

In addition to the obvious ability of booby traps to kill or injure, their presence has other effects. These include the ability to:

• demoralize soldiers as booby traps kill or maim comrades
• keep soldiers continually stressed, suspicious and unable to relax because it is difficult for them to know which areas, buildings or objects are safe
• make soldiers cautious instead of aggressive and confident
• create no-go areas (real or imagined) after a booby trap has killed or wounded someone
• cause a section or platoon to have to stop in order to deal with casualties, thus slowing and delaying those troops
• create confusion and disorientation as a prelude to an ambush

Booby traps are indiscriminate weapons; like anti-personnel mines they can harm civilians and other non-combatants (during and after the conflict) who are unaware of their presence. Therefore, it is vitally important for any force which places booby traps to keep an accurate record of their location so they can be cleared when the conflict is over.

Usage throughout history

World War II

Retreating British soldiers during the Battle of France in 1940 made booby traps from artillery and mortar shells. These were buried in roads behind them as they retreated, or hung from trees concealed by the leaves and rigged with tripwires concealed in the grass around the tree.^{[citation needed]}

During the Warsaw Ghetto Uprising, Jewish resistance fighters caused severe German casualties through a vast array of improvised and often elaborate booby traps, set up inside the ghetto buildings and basements. They were so effective that the German forces eventually decided to demolish every building systematically rather than risk entering.^{[citation needed]}

During Germany's retreat from the Soviets in the later years of the war, booby traps were used to slow down the advancing Russian infantry. German infantry would leave poisoned vodka bottles behind, and rig doors with basic trip mines. The same was done on the Western Front in 1944-1945 by retreating German troops. Allied troops often collected desirable weapons such as the Walther P-38 and Luger P-08 pistols for souvenirs, and these items would be left behind, rigged with explosives. If picked up, a hand would be blown off or worse. Another crafty trick involved booby-trapping a hanging picture in a house and tilting it slightly. This was designed to catch Allied officers who would be more likely to note such an imperfection, and more inclined to right it.^{[citation needed]}

The Germans were in the habit of hiding explosive charges with clockwork time delays (lasting up to a week or more) under the floorboards of buildings in villages and towns that were about to be evacuated. The Germans deliberately chose the most prominent and undamaged buildings, knowing that Allied officers would likely occupy them. Though not strictly speaking a booby trap, such time-bombs created stress and suspicion among the occupiers.^{[citation needed]}

Cold War

During the Soviet era in Eastern Europe, the Warsaw Pact countries attempted to better secure their borders with Western Europe by rigging border fences sporadically with explosive devices. These were usually fairly simple devices, often no more complicated than land mines hung on barbed wire. The mines were modified to be sensitive enough to go off if the barbed wire was tampered with or cut.^{[citation needed]}

During the Vietnam War, motorcycles were rigged with explosives by the NLF and abandoned. U.S. soldiers would be tempted to ride the motorcycle and thus trigger the explosives. In addition, NLF soldiers would rig rubber band grenades and place them in huts that US soldiers would likely burn. Another popular booby trap was the "Grenade in a Can", a grenade with the safety pin removed in a container and a string attached, sometimes with the grenade's fuse mechanism modified to give a much shorter delay than the four to seven seconds typical with grenade fuses. The NLF soldiers primarily used these on doors and attached them to tripwires on jungle paths.^[11]

The NLF also used simple but effective low-technology punji sticks hidden in pits, often smeared with human feces to increase the risk of infection.^[12]

The CIA and Green Berets countered by booby-trapping the enemy's ammunition supplies. The gunpowder in a rifle or machine-gun cartridge was replaced with high explosive. Upon being fired, the sabotaged round would destroy the gun and kill or injure the shooter. Mortar shells were similarly rigged to explode when dropped down the tube, instead of launching properly. This ammunition was then carefully re-packed to eliminate any evidence of tampering, and planted in enemy munitions dumps by covert insertion teams. False rumors and forged documents were circulated to make it appear that the Communist Chinese were supplying the NLF with defective weapons and ammunition.^{[citation needed]}

Northern Irish Troubles

During the Northern Irish Troubles, booby trap bombs were often used by the Provisional Irish Republican Army (IRA) to kill off-duty police officers, prison guards and other agents of the British state. A variety of methods were used, the most common being attaching the bomb to a vehicle so that starting or driving it would detonate the explosive. According to the Sutton Index of Deaths, 180 deaths in the Troubles were the result of booby trap bombs, the vast majority of them laid by the IRA.^[13]

Middle East

During the Al-Aqsa Intifada, some Arab-Palestinian groups made wide use of booby traps. The largest use of booby traps was in Jenin during Operation Defensive Shield where a large number of explosive devices were planted by insurgents. Booby traps had been laid in the streets of both the camp and the town, ready to be triggered if a foot snagged a tripwire or a vehicle rolled over a mine. Some of the bombs were huge, containing as much as 250 lb (110 kg) of explosives.^{[citation needed]}

Gallery

As a rule, most purpose-made military booby-trap firing devices contain some form of spring loaded firing pin designed to strike a percussion cap connected to a detonator at one end. The detonator is inserted into an explosive charge e.g. C4 or a block of TNT. Triggering the booby-trap releases the cocked firing pin which flips forward to strike the percussion cap, firing both it and the attached detonator. The resulting shock-wave from the detonator sets off the main explosive charge attached to it.

Simple booby trap: concealed pitfall with sharp spike at the bottom

USSR boobytrap firing device - pull fuze: normally connected to a tripwire

Alternative design of USSR boobytrap firing device - pull fuze: normally connected to tripwire

USSR boobytrap firing device - pressure fuze: victim steps on loose floorboard with fuze concealed underneath

Criminal and security use

Booby traps can also be applied as defensive weapons against unwelcome guests or against non-military trespassers, and some people set up traps in their homes to keep people from entering. Laws vary: the creator of the trap may be immune from prosecution since the victim is technically trespassing, or the home owner may be held liable for injuries caused to the trespasser.(See also: Mantrap)

Computer viruses

Many computer viruses take the form of booby traps in that they are triggered when an unsuspecting user performs an apparently ordinary action such as opening an email attachment.^[14]

Practical jokes

Instead of being used to kill, maim and injure, booby traps can also be used for entertainment. Practical joke booby traps are typically disguised as everyday items such as cigars or packets of chewing gum, nuts or other snack items. When the victims attempts to use the item, the trap is triggered. Two of the best known examples of this are the exploding cigar and dribble glass; others include the Snake Nut Can and shocking gum. Booby traps can also be constructed out of household or workplace items and be triggered when the victim performs a common action. Examples of this include loosening the bolts in a chair so that it collapses when sat on, or placing a bucket of water on top of a partly-open door so that when the door is fully opened, the bucket tips onto the victim.^[15] A variant is the water bucket which when "thrown" at the target, is full of confetti.

References

See also

• Anti-handling device
• Combat engineer
• DEMIRA Deutsche Minenräumer
• Improvised explosive device
• Mercury switch
• Microswitch
• Mantrap
• Spring-gun
• Booby prize

External links

• US Army Training Film from 1944 (humorous cartoon with a serious message)
• Mines & Boobytrap devices - British guide dated 1943
• How not to get caught by mines and boobytraps - US warning guide dated 1944, and still relevant
• How not to get caught by Vietnamese boobytraps - US guide dated 1969
• Army Field Manual FM531 Boobytraps - US guide dated 1965
• Photos of various booby trap trigger mechanisms
• Photos of booby trap devices used in Angola
• Booby trap concepts and detection techniques
• The Straight Dope: What's the origin of "booby trap"?
• Photos of injuries inflicted by explosive boobytraps (Warning: graphic images)
• The M142 Multi-function Boobytrap Firing Device (technical specifications)