A much more lengthy write-up was on HN front page a couple months ago. Here's a quote from it [1]:
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Decades after “the machine” radically remodeled a portion of Harvey’s Wagon Wheel Casino, Big John’s masterpiece bomb maintains legendary status at the FBI. Bureau agents acknowledge that it is unlikely that even modern bomb squads and technology could make much headway disarming Big John’s improvised explosive without setting it off...the Harvey’s bomb was the largest domestic bomb ever to explode in the United States until the bombing of the World Trade Center in 1993...why so few people these days seem to remember...Jonkey’s speculation is succinct: “Nobody died.”
Also, another great narrative of the event was posted a little while ago from the Damn Interesting podcast. Links to the discussions below; follow through for the podcast and transcript.
The casino operation wanted to open part of their gambling area that was not damaged. And they did build this big wall and put a big picture window in it so that the gamblers could watch the FBI process the crime scene for the next few weeks.
I can't help but think that the bomb maker was inspired by the movie Juggernaut[1], which came out just a few years before this event. In that movie, the bomb maker designed and built-in several layers of booby-traps, including vibration switches, layers of detonation circuits, etc. as was used here. Not a bad movie, FWIW.
I'm curious how such a device would be approached with today's knowledge, seeing that one of the links mentioned in the comments noted that it's still being used in FBI training.
I always wondered if the problem with the shaped charge was that the battery served to keep it from somehow being mechanically detonated rather than the battery being used to provide power for detonation. Seemed like the kind of red herring this bomb maker would use but I can't imagine how that would be hidden from x-rays.
Either the switches activate the battery or they activate the trigger circuits (probably both).
I should also note that, unless you had extremely detailed pictures of the switches themselves (or part numbers), you could easily use a combination of switches which appears to do one thing but instead does another, so X-Rays and a wiring diagram wouldn't necessarily be helpful in discovering the actual path of electricity. You could maybe do something clever with a very sensitive electrometer, but that would take way too long.
Arming it doesn't seem like the hard part to me. I think the hard part, with all the foil based triggers and spring loaded screws, would be construction and QA and making sure you don't kill yourself activating the thing because there's some filings completing a circuit you didn't know about.
I realize addressing such a downvoted comment is frowned upon here, but since there might be others who believe your paranoid attitude is credible, I would just point out that the chances of the USG not already knowing about Hacker News are zero.
If you really believe that merely sending your IP and a referer from Hacker News to a public .gov site will get you put on a terror watchlist (somehow), why are you not hiding your IP from Hacker News itself?
and an explanation of the triggers https://dh1rvgpokacch.cloudfront.net/atavist/1/video/iphone/...