This was inspired by the Pit thread about the bank robber blown up by a bomb strapped to his chest.
It is an action movie convention that bombs, both professionally and amateurly made, are chock full of failsafes that will cause the bomb to explode if the wrong wire is cut or they are fiddled with some other way. I assume that this is not particularly true and is based on both the desire of the writer to make the scene as exciting as possible without wasting mental energy to come up with something original. I also assume that some of this comes from the dangerous activity of disarming dud bombs, where they lie in a state suspended between exploded, which is what by all rights they should be, and unexploded, which they happen to be. Yes, they are dainty things and a wrong move, a right move, or no move at all can set them off.
However, besides the vagaries introduced when somebody who doesn’t really know what he’s doing builds a bomb, and enough of these fellows blow themselves up to prove they don’t, are there failsafes built into the typical amateur’s bombs? And I won’t get into the sheer nonsense of cutting the green wire versus the red wire as these guys probably build stuff like I do and the wires are probably all the same color: whatever was laying around the house (my Orange Period has ended and I am now in my Red Period unless I find what’s left of the orange wire first). And did the Warsaw Pact countries go beyond building the explosives and actually make timing mechanisms and even off-the-rack time bombs for busy terrorists so there is some accuracy to the TV bomb expert saying, “I recognize this bomb! Cut the red wire first and the green wire second and whatever you do DON’T CUT THE BLUE WIRE!” or is this Hollywood bullshit?
And why don’t more bomb squads, in Hollywood and real life, use the LAPD’s trick of sending in a radio-contolled robot that blasts the timer with a shotgun? Few electronic or mechanical timers will still work after you pump a load of #4 birdshot through them.
Most basic timers have the timer mech complete a circuit and thus can be cut without incident.
Slightly more advance would be an interuption of the circuit leads to triggering, which makes cutting any wire very troublesome to say the least.
Many bombs don’t even use timers, but some type of actuation based on movement.
Alot of bomb clearing time is spent trying to figure out what type of device it is. Also, the nature of the bomber mind is also such that they love booby traps and tend to build them in. The pysche part of bomb squad verus bomber is usually prethough by a bomb maker.
Couldn’t you just make it so cutting any wire will blow the thing up? Of course, if the bombmaker wants to be able to disarm it, I suppose there should be some mechanism for that.
Or the bomber could just make sure he uses wires with only one color of insulation.
Bomb squad boss: Okay, you’ve taken the cover plate off. Now reach in with your pliers and cut the green wire.
Poor sod holding the pliers: There aren’t any green wires.
Boss: Well, what colors are there?
Poor sod: Colors? There’s only one! All the wires are red!
Boss: Been nice knowing you.
On a Discovery-channel-like-program about the British Army vs the IRA, the IRA really did start using sophisticated triggering mechanisms. Open it the wrong way, cut the wrong wire and boom. The British then started using remote systems as well as the good old “blow it up in place” strategy. Note that the latter wouldn’t usually set of the explosives in the bomb. Small boom, no big boom. A neat trick.
robertliguori: I don’t think I’d cut every wire at once; unless you have non-conductive pliars and none of the wires are touching, you’d stand a good chance of shorting two or more wires on each other.
It seems the consensus is clear: bombs in Hollywood work way different than in real life. Just like computers, and relationships, and anything else remotely complicated.
P.S. - for the “most ridiculous idea for a bomb” award, could I nominate Executive Decision? Their “bomb tech” worked his way past laser trip wires and vibration sensors (this bomb was on a plane BTW), opened the top and found a bunch of stuff including… a 5 1/4" hard drive with the top off.
Just watch the timer with the big numbers on it, wait until it gets to 1 second, then cut anything you like. It’ll work every time. Unless you’re James Bond, then do it when the timer says 007 seconds.
Who the hell needs a timer with a display on it, anyway?
Well, if you want to argue movie physics, all the bombs need a big red LED readout telling you how long you have 'til it blows.
I always figured the best thing for that would be to have the thing blow at 1:27- the guy looks at it, oh yeah, we have plenty of ti—
Seriously though, I understand most anti-personell and anti-armor land mines have some sort of anti-tamper option.
Realize that land mines are by necessity chunks of explosives you leave laying about. One does not want ones’ opponent to manage to find them, dig them up, and salvage the explosives, or the intact mine, for later use against those who laid it originally.
Thus, most have some way of being rigged, usually optionally, to have an anti-tamper, typically some sort of pressure switch on the bottom so that if it’s lifted, the charge is triggered.
So a “bomb” being booby-trapped is not purely a work of fiction. Yes, things like that found on Executive Decision were bordering on hyperbolic, but as I understand it, most of Kazynski’s “Unabomber” devices had one or more anti-tamper switches. Or at least, had multiple means of detonating, so it’d go off whether it was lifted, opened, shook or tilted, etc. (Much of which could be done with a single “pendulum” switch.)
Although my knowledge is now somewhat dated due to leaving the military for college and then going on with life, I do have some experience in the field of bomb disposal. Most of the movie bombs are just Hollywood fabrications. Most Hollywood explosions are greatly enhanced with gas to make nice fireballs.
When I was in the field, it was acknowledged that the British EOD (explosive ordnance disposal aka. bomb squads) teams had a lot worse things to deal with (from the IRA) than we did in the US. Most of what we were dealing with in the US were old fashioned (but potentially lethal) pipe bombs filled with smokeless powder and set off with hobby fuse. With most of these, you are pretty safe as long as you don’t light a match. :smack:
Believe me, the bomb disposal teams are mostly sharp. They will search the area before setting up a command post. They will try to do everything remotely and do have robots. What they don’t feel safe moving will be blown in place if possible. If not, chances are x-rays will be taken before anything is done. They do have “dearmers” such as the shotgun mentioned above.
Let’s just leave it with stating that the color of the wire really doesn’t matter. The circuitry the wire is hooked to is more important. Regardless, a bomb disposal tech will very rarely (read never) actually cut a wire with a diagonal cutting pliers like in the movies.
Well, for what it’s worth, I once built a movie prop timer with big red LED numbers. Then we wanted to cut a wire and have the countdown freeze. There was no such wire. I had to almost double the complexity of the circuit to create a wire with that behaviour. So somehow I doubt any bomb-maker would.
That said, if I were to build a bomb, I’d build the circuitry so cutting the wrong wire would blow it up
If I ever built a bomb, I’d set up a false timer that would deactivate if any wire is cut. The real timer circuit, which would be underneath the explosives and out of sight, would keep going and detonate the bomb as planned.
On second thought, maybe we shouldn’t put all these ideas out on the intarweb for potential psychos to find. Not that they have any shortage of devious ideas of their own.
On the other hand, I hate movie cliches, and I’d love to see a movie that featured a bomb like Diceman describes.
If I ever built a bomb, all of the wiring would be done on a printed circuit board and with micro chips. I’d like to see the hero cut through my microprocessor with his diagonals.
Well to counter all the “perfect bomb” ideas I have an idea to get around Nanoda’s comments:
I could imagine a little device with multiple little non-conductive guillotine’s extending out and one button press would activate them all at the same time. Having an x-ray done to make sure you get all the wires would be the trick. Anything wrong with this idea?
