When defusing a bomb, why can’t you just cut all wires at once?


When defusing a bomb, why can’t you just cut all wires at once?

In: 3949

In theory, it’s possible that an attacker could have foreseen such an attempt, as design a weapon that responded to the loss of conductivity/power on a circuit as a trigger for detonation.

That’s essentially what bomb disposal robots do. They put a small explosive up against the bomb and detonate it to physically move all the bomb parts away from each other, breaking all the wires at once.

But, if you’re a clever evildoer, bombs can be made with mechanical protection for their detonators – like putting them inside the pipe with the explosive. The wires charge up a capacitor and when the electrical input goes away the bomb detonates. If you cut wires in such a bomb, you set it off while you’re right next to it, not good.

Because “cut the blue wire” is a movie/TV trope and not based on reality. There are many, many way to build a bomb’s detonation device. “Cut the wire” was just something that would build tension on screen


Most bombs are simple and cutting the power or detonator wires would disarm it. But it’s trivial to design bombs with failsafes so that if it were tampered with, it would explode. Of course, there is no standardization of such design, and certainly no standard colors (i.e. “cut the green wire” is ridiculous)

There have been bombs specifically designed to fool the disposal people with the actual trigger mechanism obscured. Cutting the “obvious” wire being what causes the detonation.

Sometimes X-ray machines are used to examine the bomb, but in reality, if it’s not clear how to defuse it, they will just evacuate and blow the bomb up “in place”.