Slashdot Mirror
The Top Ten Off Switches
Dan Jimbokla submitted a story that normally i would pass over, but I actually oddly enjoyed it. "CNET.co.uk has a truly funny and read-worthy article up about the top ten off switches. One of my favorite switches from the piece is #4 — The illuminated toggle switch: "This switch isn't designed for high-drain uses, typically it can only provide a maximum of 20 amps at 12 volts. That will make it suitable for a number of exciting uses though, and what it lacks in power handling, it makes up for in practicality. This switch will illuminate when the device it controls is turned on, and go off when the device is deactivated. This is logical and practical, and that has earned this switch a place in our hearts. What's more, it's far from expensive and there are even a choice of colors.""
The traditional wall mounted box with a pull lever on the side. It opens so you can see the simple mechanical switch inside. Lockable, so that you can insure that it won't get switched back on, while your hands are inside the guts of something electromechanical.
Simple, safe, and sure. That is why they have been used, and will be, for years.
#8 on the list was the Emergency Shutdown.
I used to work with a guy that had been in the Air Force in Vietnam working in some type of data center. He told me a story about an event that happened one night that forced an emergency shutdown. If I remember correctly, a water pipe burst and the data center was being flooded. As he was on duty that night, he went around shutting down all of the equipment. One machine, in particular, had an "Emergency Shutdown" lever. In training, he was told that he would never need to use it, but it was there. This seemed like an emergency, so he pulled the lever. What he didn't know was that it released a weighted blade that fell down through the backplane severing every wire in its path, essentially destroying the machine.
The aftermath was, a couple of Air Force techs spending weeks soldering the thing back together again, and he got every s#^t job that came up for the remainder of his tour.
My father worked for Imperial Oil (aka Esso) at a bulk transfer plant, and they had really, REALLY fun switches there. Gas-powered switches that you pumped up then triggered, so they would throw the blades at an insanely fast speed to minimize the chance of sparking (and therefore minimize the chance of going WOOMF). They sounded like a freaking gunshot. Great stuff.