Once Dr. Sattler restores power to the park, Arnold needs to reboot the computer systems. To do this, he must switch off the circuits (C1–C3 in the screenshot above), and then switch off-and-on a circuit labeled “Main”.
It’s a good thing Arnold knows what he’s doing, since these switches are only labeled C1-3, and we don’t see any documentation in the camera frame. As he turns off each circuit, different parts of the computer terminals in the Control Room shut down. This implies that different computer banks are tied to the same power circuits as the systems they control.
So, since this is a major interface for the park, let’s make this bit explicit: When designing infrequently-used but mission-critical interfaces, take great care to explain use, using clear affordances and constraints so that mistakes are very, very difficult to make.
It might look like a mistake to have all the little electrical labeling to the sides, since this cover would have to be removed to get the components where this information would be of use. But that’s perfect. A user needing to remove this panel must encounter this reference information to get to those components, and so would know where to find them. This is a brilliant example of the pattern Put the Signal in the Path. Let’s hope there are similar signs on other access panels.
Wait…where are the backups?
These are the central computer terminals that run Jurassic Park, and keep visitors safe from the “attractions.” And there is no backup power.
When Arnold turns off the main circuit breaker, the computers (and servers behind them) turn off immediately. The purpose and effect of the power switch deactivates all the systems in Jurassic Park, without any kind of warning or backup system.
For something as dangerous as deadly deadly dinosaurs—raised from the 65 million-year deep grave of extinction—the system deactivation should at least trigger some kind of warning.
Tornado sirens have backup batteries in case the city power goes out. They are a solid example of a backup system that should exist, at minimum, to warn park-goers to move quickly towards shelter. A better backup system would be a duplicate server system that automatically activates all the fences in the park.
When Arnold cycles the visitor center’s power system, it also trips the breakers for all of the other power systems in the park. Primary safety systems like that should be on their own circuit. It’s ok if the fridges turn off and melt the ice cream (though it may be an inconvenience), but that same event shouldn’t also deactivate the velociraptor pen security. Especially when the ‘raptor pen is right next to the visitor center and is a known, aforementioned, deadly deadly threat.