October 24, 2018 • 13 mins
If you live in a big city in a cold climate, you should keep an eye out for 100-pound cast-iron manhole covers suddenly launching 50 feet into the air. It’s unnervingly common and we’ll tell you why.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
Hey, everybody walks into the podcast. Josh, and there's Chuck,
and there's Jerry. So let's get going. You found this stuff,
and I think I had heard of this before, because
I believe I just kind of happened upon it on
our website. But uh, this now scares me for when
I go to New York. I wasn't scared until you
(00:22):
just said that you were scared. Now I'm scared because
you would usually be scared before I was scared. Yeah,
but I guess I hadn't thought it through. And and actually,
you know the spoiler at the end, will will leave.
It's not a ton of people actually get hurt. But
I read about exploding manhole covers, and I think that
that this is gonna like land on my head one
day and I will die. And you would if it
(00:44):
landed on your head, Yes, you would die, because we're
talking about exploding manhole covers and they've been known to go.
I saw a hundred feet in the air at least fifty,
says the How Stuff Works article. And these things are
enormously heavy, like eighty five to three hundred pounds. And
for those of our friends who live outside the US
and Liberia. That's thirty five to thirty five. So the
(01:06):
mere fact that a manhole cover has not landed and
killed somebody landed on someone and killed them by now,
is sheer luck? It sounds that way, yeah, because it
happens a lot, especially depending like if you're in New York.
I mean, it happens in cities all over the country
for sure, but um, if you're in New York, you're
(01:27):
in the home of exploding manhole covers for a couple
of reasons where we'll talk about, um and it happens
pretty frequently. So, um it is. It does seem to
be what you just said, sheer luck that no one's
died from it yet, and maybe someone has and we
just hadn't found out about it because apparently the FDN
Y is not required to um report the number of
(01:49):
incidents and the only source of any numbers on this
stuff is con Edison and they're the ones who is
responsible for this thing, so they may be fudging the numbers. Well, yeah,
there's a council councilman named Donovan Richards where there was
at the time of this article, that has introduced or
reintroduced a bill that said, hey, we need more transparency
(02:10):
into this, and like you guys need to start issuing
like annual reports on how many of these things are
catching on, fire, smoking, exploding. Right, and the the fire
chief that had fire chief of f d N why
leaned into the mic and said, with all due respects,
up yours. The fire chief is John Travolta. By the way,
(02:30):
his and his dalmatian went right now, he did that
like flicking underneath the chin thing with his paw. Man,
I wish I could teach my dog to do that.
Oh man, Yeah, they'd have to be able to turn
their paw around. That would be odd YouTube sensation. Yeah,
I think I think the world would forgive the dog
(02:50):
if if for not turning the pall around, Like just
just doing it in any way would be pretty pretty great.
Does mama know any tricks? Yeah, she can deal with cards.
But it's it. I finally got Nico shaking now, so
consider that a big victory. Oh yeah, that is a
big victory. I um, I taught Mo to give high five.
(03:11):
She's pretty good at that, okay, high five, but then
every once in a while she'd be like such a
brow thing to do, you know, right, all right, So
I think we should talk about why this actually what
what events lead to this to happen? Yeah, there's actually
like a there's science behind it. Yeah. So let's say
we're just gonna keep picking on New York because their
(03:33):
underground system and their infrastructure everyone knows can be quite
old and dangerous at times. It's it's the again though,
it's the home of exploding man holes, right for a reason.
So um, New York has the large, the world's largest
and oldest electrical system underground electrical system underground. Good catch man.
(03:55):
So they have the largest and oldest they have just
my emboggling amount of cables, thousand miles of cable and
two hundred sixty four thousand man holes, right yeah, initially
when because they they talk about vented manholes to help
solve this, and I was like, just replace them all.
And then I saw two hundred sixty four thousand, I
was like, right, And I imagine that each one costs
(04:17):
a pretty decent amount because they make them heavy so
that you know, teenagers don't make off with them or something.
I would guess why else would you make them heavy? Uh,
I don't know. It's a good question, because it means
make them sturdier cars drive over these things. Okay, Okay,
that's one. They tried balsa wood and it didn't work
out right well because everybody kept stealing the balsa wood
(04:40):
man hole covers. So. Um, So you have like this,
like ninety thousand miles of cable or wire underground and
hundreds of thousands of manhole covers. So you have a
recipe for disaster. Considering that that thousand miles of wiring,
five percent of it is almost a hundred years old
(05:01):
or older. Yeah, and and they're supposed to have a
lifespan of about forty years. So if you've got a
hundred year old wire down there, you're you're asking for
trouble when it rains or snows, or when saltwater gets
in there from salting streets. And that's basically what happens. Yeah,
So this is this is this is the science behind it.
(05:21):
They actually know what causes exploding manhole covers, at least
in New York. Right. What you have is these very
old wiring and you have, um, you know, even like
a manhole cover that isn't grated or slotted to allow gases,
event like, it's not water tight, so when it snows
New York ice is over there assaults their streets, and
(05:43):
so the slush when the snow melts becomes saltwater. And
over time, the saltwater goes and trickles down and it
corrodes the wires, the insulation around the wires. And these
are wires that these giant New York rats have already
been mealing on for years for some trees. That's another
big problem with it, too, right, I mean, like fifty
(06:04):
pound rats just taken out these wires as much as
they like because they love to eat rubber insulation apparently,
because they're stupid the worst. So you've got these wires,
they're starting to get freight. You they're getting freed in
part by the salt water. But the other thing that
the saltwater is doing is that when these wires are
freight and the actual wiring itself is exposed, salt water
(06:25):
is particularly conductive. So because of this, the chlorine and
the sodium ions in there, they have an electrical charge themselves,
and water is conductive by itself to like, you know,
there's like the whole thing from um Fear and Loathing
in Las Vegas, where um Laslow wants hunter Thompson to
drop the toaster in the or the hair dryer in
(06:46):
the bathtub with I mean there's a grape fruit at
his head instead. That's because water is conductive, and Laslow
was hipped to that kind of thing, right, Yeah. And
I remember in in high school, even like when we
did conductivity experiments, it was always saline. It was always saltwater, right,
And so so water is conductive. Saline or saltwater is
super conductive. So when you um, it's not actually super conductive,
(07:10):
but you know what I mean, not in the scientific term, right.
So when you have this frayed wire that saltwater comes
in contact with the wire arcs that in and of
itself is not good because it's going to short out
your electrical system. But the problem is is when those
wires are afraid and the insulation is worn away, it
starts the insulation itself starts to kind of smolder and
(07:32):
bubble and and and flame up itself, which produces gases. Yeah,
so that's the big problem. So what you've got down
there is um gas is being released, gases building up,
building up pressure. Then you have that electrical arc that's
like a bolt of lightning. Basically those two things meet
up and say how you doing, and it ignites and
(07:54):
it could lead to and like we said, sometimes it's
smoldering and smoking. I've seen them literally just on fire,
which is almost as disconcerting. It's like, hell, it totally is.
But sometimes it will actually if they meet in the
right way, into the right conditions, it will cause that
explosion and send a possibly three pound manhole cover a
(08:15):
hundred m well fifty ft into the air. Right, well,
let's take a break real quick and we'll come back
because we've got more stuff on exploding manholes that you're
gonna love, Okay, dude. So the gas goes boom and
(08:51):
the manhole cover goes flying into the air, and the
House of Works articles did a really good job of
of comparing that to UM, an internal combustion engine, like
the pistons in it, and it's it's it's basically the
same thing. Like the piston presses air down and a
little bit it takes just a little bit of fuel
mixed in with the air to make it combustible because
(09:12):
it's compressed. And then when you introduce UM fire through
the spark plug, then that that compressed gas air expands
very quickly it explodes, is what you call it, and
then the piston goes up. That's the exact same thing
that's happening in exploding manhole when there's gas build up, right, Yeah,
it's just that pressure of the compressed gases suddenly released
(09:34):
violently and it explodes outward. And again it's the same
thing that's happening in your car engine, but on a
New York City street. Yes, I'm reading this stuff. I'm
thinking this is cool and a little scary. But I thought,
all right, but this happens probably like once every few years,
or a few times a year, maybe in two thousand sixteen,
(09:56):
and this is manhole incidents just in New York. So
as this exploding manhole incidents or just like catching fire
or smoking or whatever. I think any time a manhole
cover goes or a manhole goes awry, they would call
it an incident. In two thousand sixteen, there were nineteen
hundred and eight of them, and in two thousand fifteen
there were almost three thousand, eight hundred manhole incidents. Yeah,
(10:21):
which is a great fan name, actually manhole incident. Yeah, yeah, yeah,
it does all sorts of stuff to the imagination or
the manhole incident, maybe um or balsa wood manhole I
saw that in the same year, two thousand fifteen, in February,
February alone, and I'm sorry, in one week in February,
(10:42):
there was six hundred manhole incidents in New York. How many,
I mean do the math. That's a lot in a day.
And again, this is just what's con Edison is is
telling the media like, who knows if there's more. There's
nobody running around counting all this. The only people who
have their finger on the pulse of a eploding manhole
covers is Kan Edison, and you know they're the ones
(11:03):
who are responsible for it. Yeah. So despite this um,
it turns out remarkably that people are usually not injured.
It's sort of a rare thing for an actual human
injury to happen. And as far as I know, there's
never been someone killed by a manhole cover exploding. That
is not true. Oh really, I looked it up, man,
(11:24):
But it's not in New York. There there there has
to be somebody who died in New York New York.
Boston has another problem with it itself, like I guess
Chicago does, like any major city with an old electrical infrastructure,
manhole covers and salty snowmelt is going to have exploding
manhole covers. DC has a problem with it, but there's
comes from natural gas supposedly, and they only have like
(11:46):
an average of like thirty eight a year, I think.
But Boston has a problem with it too. And in
uh two thousand sixteen, there was a freak accident where
high school art teacher was driving in Boss and a
manhole cover exploded and rose up just enough to come
through her windshield from a movie and killed her. Um instantly. Yeah, man,
(12:13):
if that happens to you, your number is up. Yeah.
That's like when the tree fell on the guy's truck
across from my house at times sitting in a stoplight. Yeah.
Or the actress who was in Chicago riding her bike
through the park and a tree fell over on her.
I think we talked about that, like a tree falls
on you while you're moving, like that's yeah, you're you're
(12:34):
not escaping that, No, you're not. Man, that is really sad.
What it is? What a terrible way to end? Yeah,
I know, Well here's it gets even worse. She was
a beloved art teacher, as they all are Yeah, well
I don't know. There's the jerk art teachers too, are
mad they're teaching you know. Uh, well, let's see. Thanks
a lot for joining us. If you want to hang
(12:54):
out with us, we're all over social media. Just look
us up and uh you can hang out with us
at all. I'm on the web stuff you should know. Uh,
and we'll see you next time. Watch out for those manholes.
Everybody m
Hey, everybody walks into the podcast. Josh, and there's Chuck,
and there's Jerry. So let's get going. You found this stuff,
and I think I had heard of this before, because
I believe I just kind of happened upon it on
our website. But uh, this now scares me for when
I go to New York. I wasn't scared until you
(00:22):
just said that you were scared. Now I'm scared because
you would usually be scared before I was scared. Yeah,
but I guess I hadn't thought it through. And and actually,
you know the spoiler at the end, will will leave.
It's not a ton of people actually get hurt. But
I read about exploding manhole covers, and I think that
that this is gonna like land on my head one
day and I will die. And you would if it
(00:44):
landed on your head, Yes, you would die, because we're
talking about exploding manhole covers and they've been known to go.
I saw a hundred feet in the air at least fifty,
says the How Stuff Works article. And these things are
enormously heavy, like eighty five to three hundred pounds. And
for those of our friends who live outside the US
and Liberia. That's thirty five to thirty five. So the
(01:06):
mere fact that a manhole cover has not landed and
killed somebody landed on someone and killed them by now,
is sheer luck? It sounds that way, yeah, because it
happens a lot, especially depending like if you're in New York.
I mean, it happens in cities all over the country
for sure, but um, if you're in New York, you're
(01:27):
in the home of exploding manhole covers for a couple
of reasons where we'll talk about, um and it happens
pretty frequently. So, um it is. It does seem to
be what you just said, sheer luck that no one's
died from it yet, and maybe someone has and we
just hadn't found out about it because apparently the FDN
Y is not required to um report the number of
(01:49):
incidents and the only source of any numbers on this
stuff is con Edison and they're the ones who is
responsible for this thing, so they may be fudging the numbers. Well, yeah,
there's a council councilman named Donovan Richards where there was
at the time of this article, that has introduced or
reintroduced a bill that said, hey, we need more transparency
(02:10):
into this, and like you guys need to start issuing
like annual reports on how many of these things are
catching on, fire, smoking, exploding. Right, and the the fire
chief that had fire chief of f d N why
leaned into the mic and said, with all due respects,
up yours. The fire chief is John Travolta. By the way,
(02:30):
his and his dalmatian went right now, he did that
like flicking underneath the chin thing with his paw. Man,
I wish I could teach my dog to do that.
Oh man, Yeah, they'd have to be able to turn
their paw around. That would be odd YouTube sensation. Yeah,
I think I think the world would forgive the dog
(02:50):
if if for not turning the pall around, Like just
just doing it in any way would be pretty pretty great.
Does mama know any tricks? Yeah, she can deal with cards.
But it's it. I finally got Nico shaking now, so
consider that a big victory. Oh yeah, that is a
big victory. I um, I taught Mo to give high five.
(03:11):
She's pretty good at that, okay, high five, but then
every once in a while she'd be like such a
brow thing to do, you know, right, all right, So
I think we should talk about why this actually what
what events lead to this to happen? Yeah, there's actually
like a there's science behind it. Yeah. So let's say
we're just gonna keep picking on New York because their
(03:33):
underground system and their infrastructure everyone knows can be quite
old and dangerous at times. It's it's the again though,
it's the home of exploding man holes, right for a reason.
So um, New York has the large, the world's largest
and oldest electrical system underground electrical system underground. Good catch man.
(03:55):
So they have the largest and oldest they have just
my emboggling amount of cables, thousand miles of cable and
two hundred sixty four thousand man holes, right yeah, initially
when because they they talk about vented manholes to help
solve this, and I was like, just replace them all.
And then I saw two hundred sixty four thousand, I
was like, right, And I imagine that each one costs
(04:17):
a pretty decent amount because they make them heavy so
that you know, teenagers don't make off with them or something.
I would guess why else would you make them heavy? Uh,
I don't know. It's a good question, because it means
make them sturdier cars drive over these things. Okay, Okay,
that's one. They tried balsa wood and it didn't work
out right well because everybody kept stealing the balsa wood
(04:40):
man hole covers. So. Um, So you have like this,
like ninety thousand miles of cable or wire underground and
hundreds of thousands of manhole covers. So you have a
recipe for disaster. Considering that that thousand miles of wiring,
five percent of it is almost a hundred years old
(05:01):
or older. Yeah, and and they're supposed to have a
lifespan of about forty years. So if you've got a
hundred year old wire down there, you're you're asking for
trouble when it rains or snows, or when saltwater gets
in there from salting streets. And that's basically what happens. Yeah,
So this is this is this is the science behind it.
(05:21):
They actually know what causes exploding manhole covers, at least
in New York. Right. What you have is these very
old wiring and you have, um, you know, even like
a manhole cover that isn't grated or slotted to allow gases,
event like, it's not water tight, so when it snows
New York ice is over there assaults their streets, and
(05:43):
so the slush when the snow melts becomes saltwater. And
over time, the saltwater goes and trickles down and it
corrodes the wires, the insulation around the wires. And these
are wires that these giant New York rats have already
been mealing on for years for some trees. That's another
big problem with it, too, right, I mean, like fifty
(06:04):
pound rats just taken out these wires as much as
they like because they love to eat rubber insulation apparently,
because they're stupid the worst. So you've got these wires,
they're starting to get freight. You they're getting freed in
part by the salt water. But the other thing that
the saltwater is doing is that when these wires are
freight and the actual wiring itself is exposed, salt water
(06:25):
is particularly conductive. So because of this, the chlorine and
the sodium ions in there, they have an electrical charge themselves,
and water is conductive by itself to like, you know,
there's like the whole thing from um Fear and Loathing
in Las Vegas, where um Laslow wants hunter Thompson to
drop the toaster in the or the hair dryer in
(06:46):
the bathtub with I mean there's a grape fruit at
his head instead. That's because water is conductive, and Laslow
was hipped to that kind of thing, right, Yeah. And
I remember in in high school, even like when we
did conductivity experiments, it was always saline. It was always saltwater, right,
And so so water is conductive. Saline or saltwater is
super conductive. So when you um, it's not actually super conductive,
(07:10):
but you know what I mean, not in the scientific term, right.
So when you have this frayed wire that saltwater comes
in contact with the wire arcs that in and of
itself is not good because it's going to short out
your electrical system. But the problem is is when those
wires are afraid and the insulation is worn away, it
starts the insulation itself starts to kind of smolder and
(07:32):
bubble and and and flame up itself, which produces gases. Yeah,
so that's the big problem. So what you've got down
there is um gas is being released, gases building up,
building up pressure. Then you have that electrical arc that's
like a bolt of lightning. Basically those two things meet
up and say how you doing, and it ignites and
(07:54):
it could lead to and like we said, sometimes it's
smoldering and smoking. I've seen them literally just on fire,
which is almost as disconcerting. It's like, hell, it totally is.
But sometimes it will actually if they meet in the
right way, into the right conditions, it will cause that
explosion and send a possibly three pound manhole cover a
(08:15):
hundred m well fifty ft into the air. Right, well,
let's take a break real quick and we'll come back
because we've got more stuff on exploding manholes that you're
gonna love, Okay, dude. So the gas goes boom and
(08:51):
the manhole cover goes flying into the air, and the
House of Works articles did a really good job of
of comparing that to UM, an internal combustion engine, like
the pistons in it, and it's it's it's basically the
same thing. Like the piston presses air down and a
little bit it takes just a little bit of fuel
mixed in with the air to make it combustible because
(09:12):
it's compressed. And then when you introduce UM fire through
the spark plug, then that that compressed gas air expands
very quickly it explodes, is what you call it, and
then the piston goes up. That's the exact same thing
that's happening in exploding manhole when there's gas build up, right, Yeah,
it's just that pressure of the compressed gases suddenly released
(09:34):
violently and it explodes outward. And again it's the same
thing that's happening in your car engine, but on a
New York City street. Yes, I'm reading this stuff. I'm
thinking this is cool and a little scary. But I thought,
all right, but this happens probably like once every few years,
or a few times a year, maybe in two thousand sixteen,
(09:56):
and this is manhole incidents just in New York. So
as this exploding manhole incidents or just like catching fire
or smoking or whatever. I think any time a manhole
cover goes or a manhole goes awry, they would call
it an incident. In two thousand sixteen, there were nineteen
hundred and eight of them, and in two thousand fifteen
there were almost three thousand, eight hundred manhole incidents. Yeah,
(10:21):
which is a great fan name, actually manhole incident. Yeah, yeah, yeah,
it does all sorts of stuff to the imagination or
the manhole incident, maybe um or balsa wood manhole I
saw that in the same year, two thousand fifteen, in February,
February alone, and I'm sorry, in one week in February,
(10:42):
there was six hundred manhole incidents in New York. How many,
I mean do the math. That's a lot in a day.
And again, this is just what's con Edison is is
telling the media like, who knows if there's more. There's
nobody running around counting all this. The only people who
have their finger on the pulse of a eploding manhole
covers is Kan Edison, and you know they're the ones
(11:03):
who are responsible for it. Yeah. So despite this um,
it turns out remarkably that people are usually not injured.
It's sort of a rare thing for an actual human
injury to happen. And as far as I know, there's
never been someone killed by a manhole cover exploding. That
is not true. Oh really, I looked it up, man,
(11:24):
But it's not in New York. There there there has
to be somebody who died in New York New York.
Boston has another problem with it itself, like I guess
Chicago does, like any major city with an old electrical infrastructure,
manhole covers and salty snowmelt is going to have exploding
manhole covers. DC has a problem with it, but there's
comes from natural gas supposedly, and they only have like
(11:46):
an average of like thirty eight a year, I think.
But Boston has a problem with it too. And in
uh two thousand sixteen, there was a freak accident where
high school art teacher was driving in Boss and a
manhole cover exploded and rose up just enough to come
through her windshield from a movie and killed her. Um instantly. Yeah, man,
(12:13):
if that happens to you, your number is up. Yeah.
That's like when the tree fell on the guy's truck
across from my house at times sitting in a stoplight. Yeah.
Or the actress who was in Chicago riding her bike
through the park and a tree fell over on her.
I think we talked about that, like a tree falls
on you while you're moving, like that's yeah, you're you're
(12:34):
not escaping that, No, you're not. Man, that is really sad.
What it is? What a terrible way to end? Yeah,
I know, Well here's it gets even worse. She was
a beloved art teacher, as they all are Yeah, well
I don't know. There's the jerk art teachers too, are
mad they're teaching you know. Uh, well, let's see. Thanks
a lot for joining us. If you want to hang
(12:54):
out with us, we're all over social media. Just look
us up and uh you can hang out with us
at all. I'm on the web stuff you should know. Uh,
and we'll see you next time. Watch out for those manholes.
Everybody m
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