It’s basically a tired Hollywood cliche : every time the bad guy plants a bomb, it must have a visible timer indicating the amount of time remaining, and it must have an inordinate amount of wires and extra components. I’ve seen some tv bombs that appear to have entire computer systems integrated into them.
A time bomb isn’t a complex device. It’s a clock, some kind of mechanism to throw a switch, a battery able to supply enough current, and some kind of heating element to set off the first charge. (a blasting cap has both the heating element and the initiator in one convenient component)
The more complex a mechanism is, the more likely it is to fail. Furthermore, the typical “tv” bomb is so complex that cutting one wrong wire will set off the device. Well, it would in real life : the actual TV bomb generally accelerates the countdown as an “anti-tamper” mechanism.
I just cannot imagine even the dumbest mad bomber creating a device that is more complex than it has to be : if the thing is rigged with tons of anti-tamper devices, odds are at least one of them will be miswired or malfunction when the bomber tries to arm the bomb.
I read about the Vegas casino bomber, who did have a device the size of a xerox machine with reams of wiring. The FBI did not feel confident enough to cut wires on that thing, and they let it explode as I recall.
Are there any other examples? I’ve read about many cases where a local bomb squad will use a controlled explosion to destroy the wiring on a crude bomb because they do not want to disturb it by cutting wires.
With that said, if you are forced to attempt to defuse a bomb, just cut any wire, right? Preferable one leading to the battery, but any old wire will do, right?
Once all of the civilians are out of the way, all bomb disposal personnel prefer detonating the bomb over disarming it. Property damage, no matter how severe, is always preferable to risking human lives.
Bomb disposal units very rarely cut wires. But if you are forced to cut a wire, cut the wire that goes to the detonator. Then it doesn’t matter what any of the other circuitry does. If there’s no juice to the detonator, the bomb ain’t gonna go kablooey.
Some bombs have had fake detonators though with that circuit triggering the real detonator if it is cut. Since people do occasionally make fake circuits and somewhat Hollywood-ish bombs, I don’t think just blindly cutting wires would be a good idea.
Wikipedia has a picture of one of Unibomber Ted Kaczynski’s bombs. It’s a reproduction, not one of his actual bombs, but it’s probably pretty accurate. It’s not a complex Hollywood maze of wires. It’s fairly simple, as expected by the OP.
In World War II, some of the bombs dropped on London did have all kinds of fancy Hollywood style deceptive devices in them. Those bombs were big enough that blowing them up in place would have caused too much damage. When the Germans learned that they could inflict more casualties by making the triggering mechanisms more difficult to disarm, they began making them more and more complicated. Unexploded bombs also affected the morale of folks living in London, which Germany took advantage of. They sometimes even used delayed fuses specifically to increase the terror aspects of the weapons.
The OP did make me recall that unfortunate incident somewhere in South America where a woman had a ‘collar bomb’ placed around her neck, it was complicated enough that the bomb disposal squad couldn’t figure out how to safely disarm it in time and she was killed.
A google search only seems to bring up a similar but fake incident involving a woman in Australia for some reason.
edit: apparently it also killed the police officer trying to remove it, from a small segment in the below BBC report.
There was also an incident in Pennsylvania, but it is suspected that the “victim” of the collar bomb was actually a co-conspirator who was offed when things went off from the plan.
Do bomb squads typically have EE’s on site or available to analyze bomb wiring? E.g. “This looks like a six-wire Baghdad Beefcake (see Bin Laden 1995) with the wristwatch timer replaced with an IRA-style three-tier chronometer system matching McCrea (1934) and O’Daly (1985). Kim (1963)'s “Ronery Weapon from Irerand” from the University of Pyongyang’s Journal of the Glorious Red People’s Juche Revolutionary Technologies references a similar device (p. 23).”
You don’t recall correctly.
It was Lake Tahoe, not Vegas, and the FBI tried to explosively disarm it, and almost succeeded.
Of course, almost doesn’t count in disarming bombs.
Tahoe, not Vegas. And the bomb was basically a Dr. Evil technical puzzle; had the bombers gotten their money, they would have given the cops the disarm sequence. (I forget what went wrong… not that I’m sure I would have trusted their honesty and skill anyway.)
IIRC, it was triggered by one of the earliest bomb-disposal robots as they made a fairly crude attempt to disarm it.
A friend and I visited the site in the aftermath of the bombing. They had casino tables just a foot away behind ropes, with card decks hanging out of the storage chutes. I wanted to grab one and run, but the 6’5" gorilla guarding the area froze my heart with one glare.
Hi. I’m an Explosive Ordnance Disposal technician (military Bomb Squad).
To answer your questions, no, we typically don’t have an Electrical Engineer on site (although, I have my BS in E.E.). We are aiming to break the device before it functions as designed. I have many, many tricks up my sleeve that do not involve cutting wires. You’re right though–rarely are IEDs ‘over designed.’ Normally, I can cut through the bullshit and see what’s really at play.
I will look at the circuitry of the device, because there are circuits that can be designed to fire if one wire is cut. But the day I go ‘hand-jamming’ a package is a very bad day: I’m over top of the device, and that’s a bad position to be. I’d much prefer to break it with a separate charge if possible. Like I said, I have my tricks.
Robots don’t really have the dexterity to dismantle things. However, they do have the ability to lift and drag things to a less hazardous place. Say a device is in a building–I can use the robot to pick it up, and move it outside to an open field or area, where it won’t do damage to the facility.
But robots do have lots of cameras. And I will happily use that for my initial reconnaissance.
Tripler
Robot versus living, breathing bomb tech. No brainer.
I’m pretty sure the standard bomb disarming trope (“Which wire do I cut?!”) has its origins in WWII bomb disposal. There you had a situation where it often wasn’t possible to simply detonate the bombs in place, and the bombs themselves were mass-produced so the Allies could work out standard procedures for dealing with different makes.
My late father was a USN bomb disposal officer during the war. He wasn’t there for the Blitz, but he handled a lot of unexploded ordnance after D-Day, as well as clearing German booby traps. He said they gave him a jeep and a camera. He’d get a call on the radio, and drive out to where the bomb was. He was supposed to take a picture of the detonator, and then leave the camera on front seat of the jeep while he disarmed it. That way if he was blown up, the Navy would at least have a photo of what killed him … .
The one thing that always gripes me about these movies is the underlying assumption that terrorists must adhere to some well defined color code when wiring their bombs. I’d be willing to bet that they wire up their devices with whatever wire they have on hand, probably all the same color. Why go to the hassle of buying multiple spools of different colored wire and adhering to “code” when you’re just going to blow the thing up anyway?
Not that I have made many bombs, but the idea behind using different color wire is to keep it straight while building it. There is some logic there - even if you don’t plan on ever defusing it.
Yeah, and every terrorist bomb maker has their own individual style, to the extent that if the device is recovered relatively intact it can often be linked to the individual who made it.
Also the bomb may be passed to someone else to transport, arm and place so you want to make sure the other person knows basically what means what.
In addition as you imply the builder may under certain circumstances want to defuse it themselves.
All of the above also helps answer the OP I suppose in why most terrorist devices are kept relatively simple, another reason being is that the less complex it is the less that can go wrong!
