News reports state that an SUV drove over the manhole cover and then it flew up in the air. How in the world could just driving over it cause it to fly up in the air? It had to fly up at least 5 feet to hit the woman’s windshield. I’d guess that it weighed about 50 pounds…
An explosion of flammable or inflammable gasses is the most likely cause. In the news it was listed as a 200 lb cover.
I agree with the explosion, it has happened the past. But the news said nothing about any explosion, just that the passing SUV caused it to flip up in the air.
But it won’t be the first time that eyewitnesses were wrong…
200 pounds, that makes it even more impossible to have been flipped up by a passing car.
It isn’t at all impossible. And it isn’t the first time this has happened. These covers are supposed to be tack welded at the edges to prevent this, but this one might have gotten broken loose by the snow plows. I’ve seen that happen too.
I’ve also seen the supporting structure under a manhole cover collapsed by plowing operations, leaving the steel ring and the cover sunken and free to move.
No tack welding of mh covers on our city streets. Before they repaved our street we had a rocking manhole cover in front of our house that would gibe loud ckunks every time a car drove over it. It never became dislodged from it’s location though.
What? Are You Kidding Me? Doesn’t That Reporter Know That The PC Police Have Cracked Down On The Term “Manhole” ?
That wasn’t a manhole cover that flew through the air, it was a “Personhole Cover” !
Some of these vent some pretty stinky fumes and it wouldn’t surprise me that some methane could build up or a natural gas line could leak and Bam!
CSA
This Is Not All That Uncommon. Google It. My Computer’s Too Slow To Download Some Of The Many Stories (And Even One Caught On Video) And Post Them.
CSA
just to lighten things up a bit… (Bratislava)
A few years ago after a Jennerhole cover jumped up and caused a serious accident the Mass Dept. of Highways had an initiative to tack weld all the covers on highways in the Boston area. Apparently they missed one. Or perhaps they only pretended to have an initiative.
Will video surveillance reveal a Chaparral 2J driving over the cover and sucking it into the air? Seriously, Mythbusters with the usual amount of creativity were able to launch manhole covers with sewer pipe ends sealed and an optimum methane fuel/air ratio. It was reported this was a storm drain not a sewer making methane gas unlikely. Common sense answer’s natural gas leak theory could be “plausible”.
I guess it depends on the weld, but I would think the constant flexing caused by countless large trucks and cars driving over it, would weaken the weld.
Still trying to figure out how the manhole cover got to be flying 5 feet into the air. One possibility comes to mind is that it was dislodged by an inch or two, and that allowed it to pivot. The SUV hit it, pushed down on the open end with a lot of impulse, and flipped it into the air.
I remain skeptical for a round cover with a flange all around to somehow be flipped up. That would require half the flange to be missing. Reporters don’t always get the stories right.
I saw a cover on a sidewalk near me dislodged recently, so there was an inch of open space on one end. I suspect that if you hit that end with a (very large) sledgehammer, it would pivot and perhaps flip up, but I’m not clear on the dynamics.
Bing, it’s not unheard of in areas with constant winter thermal cycling combined with very old and often crumbling structures under the manhole cover rings, and wear and tear from huge snowplows with heavy plow equipment on the front and sanding equipment on the back. I’ve seen broken support rings, collapsed substructures (old ones are usually made of bricks), and winter weather… which even causes roads to buckle. We have one road in the north end of Hooksett (Rt 3 just before Allenstown) that’s so rippled that everyone who knows the road drives on the shoulder past the rippled section.
Yeah, one occasionally flips up, and it’s usually an old one with a crumbling substructure… often on the highway. Trouble is, there are thousands and thousands of old manhole covers on highways around Boston.
It’s Usually Some Type Of Underground Explosion That Launches These Iron Pucks.
This Is Supposed To Be Another Flying Personhole Cover Incident That I Can’t Download On This P.C.
link:
"Manhole cover sent flying by blast is caught on video - Fox 5 …"
…or this link:
"Buffalo manhole cover sent flying over 200ft … - Daily Mail"
www.dailymail.co.uk/.../Manhole-cover-sent-flying-blast-caught…
CSA
Mythbusters has little credibility, as far as I’m concerned
It was entertaining, but if you buy into some of the stuff they labeled as “credible” . . . then you probably buy into the whole “chemtrails” conspiracy, also 
I doubt that the vehicle she was driving flipped the…as TSM called them…“Jennerhole cover” (I like that one), and it hit her car. It may have been flipped into the air by another car…or an explosion. The car she was driving would have flipped it and it hit the underside of her car.
These things weigh well in excess of 150#. My wife drove truck for the gas company and they contracted me to make a hand crane that the workers could use to remove the covers. It still took two men’s weight to move the cover except for a few really big guys.
Yosemite
I didn’t realize they were that heavy. I complained to myself last year when the street crew put a cover back on with the stripe going at right angles to the stripe on the road. I thought can’t they at least get the stripe going the right way. Now I understand why once they got it on again, the least of their worries was which way the stripe was going.
Bing: “Reporters don’t always get the stories right.” Tell me it isn’t so. (heavy sarcasm).