Posted on 03/19/2015 2:46:35 PM PDT by EveningStar
Underground explosions caused by electrical arcing shot manhole covers into the air at a busy downtown Indianapolis intersection on Thursday, disrupting commuters, closing businesses and raising concerns about safety as the city prepares to host the Final Four next month.
Indianapolis Power & Light officials said Thursday that the arcing — electrical current jumping a gap in a circuit — occurred in 120-volt underground cables and caused the system to short-circuit.
(Excerpt) Read more at abcnews.go.com ...
Sorry... that was me. I ate Taco Bell.
Doubt it.
Maybe 120 kilovolt. That'd do it, and more.
Isn’t it sexist to call them manholes???
They got to fix this NOW! Can’t have the Final Four affected!
Has several German restaurants and bars, a stage, gymnasium, meeting rooms, it is spectacular.
I thought then that it might be a sauerkraut-related catastrophe.
Only if the electric sparks ignited some methane buildup or there was a natural gas leak somewhere.
This story is no good without VIDEO!
If they run the power cables through the sewer tunnels, that could easily be the case.
Well, woman holes was considered an even more of a bad idea. So... you know.
There's a story about a manhole cover that sealed the bomb shaft for a nuclear test. After the test, they never found it, speculating that it went into space.
Reminds me of the story where a manhole cover was blown into space from an underground atomic explosion in New Mexico back in September of 1957. It beat Sputnik in space by two months and is said to have gone over 150,000 MPH making it the fastest manmade object ever. It might be the first object to make it to interstellar space, I think it could be headed for Antares, IIRC.
No way. Even a 480V 3 PH dead short, while quite impressive, couldn't do that.
Maybe a 120V control circuit took out the big juice (13,800V or such)?
A little quick Google work puts that speed estimate into question.
According to Wikipedia, the test in question (called "Pascal B") had a yield of only 300T (0.3 kT). Using the Unit Juggler, I discover that this yield is about 1255 GJ (gigajoules).
A object going at 150,000 mph (67 kilometers per second) and weighing 2000 lb (as the manhole cover in question is said to have weighed) would amass a kinetic energy of no less than 2248 GJ, almost twice as much as the total energy of the atomic bomb said to have propelled it.
Also, I would think that an object a meter or so in size, exiting the atmosphere at that speed, would have (a) caused a shockwave that would probably have broken windows a couple of hundred miles away (b) created an extremely bright flash as atmospheric heating raised its temperature to white-hot, leading to (c) its probable complete conversion to metal vapor.
Not the first time this has happened in Downtown Indy.
There was another incident yesterday, and four more over the last four years.
What caused the others?
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