Door Bomb and Safety Catches





Ghost trap

Once ghosts are bound by the streams from the Proton Packs, they can be trapped by a special trap. It has two parts: The trap itself, that is roughly the size of a toaster, and the foot pedal activation switch, which connects to the trap box by a long black cord.


To open the trap, a ghostbuster simply steps on the foot pedal. For a second the trap sparks with some unknown energy and opens to reveal a supernatural light within. Once open, the bound ghost can be manipulated down towards the trap.


When the ghost is close to the trap, the Ghostbuster steps on the foot pedal again. Lots of special effects later, the ghost gets sucked down into the trap and it closes.

With a ghost contained inside, a red indicator light illuminates near the handle to let users know that a dangerous thing is contained within. (Also, it emits smoke, but I suspect that’s a side effect rather than a feature that’s been added in.) The trap can be held by the long handle or (and this is the way the Ghostbusters themselves tend to carry it around) by the cord.


The design of the trap has so many great aspects. The separate control keeps the ghostbuster a safe distance from both the proton streams, the trap, and the ghost. And the use of a foot pedal as a switch keeps his hands free to keep a defensive grip the proton gun. I should also make note of the industrial design of the thing: The safety stripes, the handle, and the shape tell of a device handmade by scientists that is dangerous and powerful.

Still, some improvements

If the activation was wireless rather than a foot pedal, the Ghostbuster would be free to move to wherever was most tactically sound, rather than constrained to standing near it. Wireless controls have their own tradeoffs, of course, and those may not be acceptable in the mission-critical scenarios of ghostbusting. If that control was also hands-free (gestural, vocal, ocular, brain) then you’d keep the goodness of the hands-free pedal.

The red light is a little ambiguous. It could just mean “power on,” which doesn’t help. Blinking should be used very judiciously, but here it’s warranted, so I’d make that blink to say “Dangerous thing contained. Release only with caution.” Let’s presume the thing automatically locks when a ghost is trapped and can only be unlocked by the containment unit (the next post). Even better might be several lights blinking, perhaps both around the trap doors and around any controls that might release the ghost, e.g. the foot pedal. You could even make it blink similarly to the “working” light animation of the Proton Packs to tie the equipment together.

One problem that’s familiar to software designers is that’s that the control is a stateless toggle, i.e. it looks and behaves the same whether you’re opening the trap or closing the trap. If the trap doesn’t automatically lock with a ghost in it, that’s a major problem. Imagine if the activator had hid behind a curtain to trap a poltergeist and wasn’t sure if he’d accidentally stepped on it. A UX 101 rule of thumb is that controls should indicate the state of the thing they’re controlling. So the pedal should have a signal to indicate whether the trap is open or closed, even though the trap itself conveys that pretty well. Even better if that signal is something that can be felt with the foot. Maybe it’s a rocker switch? (Like this Linemaster, but more exaggerated.)

Lastly, we can also presume that the trap has a power source, and that there’s a time pressure to get the trap to the containment unit before that power source dies. But where’s that information? So some indication somewhere of how much power and time is left for that would be very useful to avoid all that work (and, you know, property damage) going to waste.

Small improvements, but each would improve it and not take away from the narrative.