All language subtitles for Mythbusters S01 E22

In this wall -shaking episode of
MythBusters, That's the sound!

we're taking combustion and propulsion
to

their unnatural limits.

Can a well -aimed, high -pressure air
tank really be a lethal missile?

Could two compressed air cylinders power
the world's fastest speedboat?

Remember, Jamie, experiments like this
are 90 % mental.

And can an engine fueled by gunpowder do
anything but blow itself to pieces?

It's fast.

It's furious.

It was the lard that did it. And it's
firing on all cylinders.

Who are the Mythbusters?

Adam Savage.

And Jamie Heineman.

This is going to kill you.

Between them, more than 30 years of
special effects experience.

That's what I'm talking about!

Joining them, Tori Bellacci.

Very excited about this.

Cary Byron. Look, he cracked into his
skull.

And Grant Imahara.

Don't say anything.

They don't just tell the myth.

They put them to the test.

As Adam loves to demonstrate, there's
all sorts of interesting ways to injure

yourself on the job.

It seems danger is everywhere, but
nothing on the workshop floor has quite

the deadly potential.

of a compressed gas cylinder
accidentally snap the valve and any tank

transforms into a massive rocket with no
flight plan now that's a fact but

what's the myth well we touched upon a
little during shark

week but i don't think we finished it i
remember that tank yeah compressed air

cylinders and there are no end to the
stories that people tell about the kind

damage that they can do well this one
just made a Really big boom, but you're

talking about where they take off like a
rocket and go through a concrete wall,

right? Exactly, and that is precisely
the myth that we'll be testing.

Adam and Jamie have some experience to
draw on. Back in their JAWS special,

blew a scuba tank with a wad of C4
explosive.

Then shot another tank with a high
-powered rifle. It didn't blow up, but

sure went off.

And if a cylinder rocket can bend solid
steel, what's it going to do to a

concrete wall?

As far as I'm concerned, there really is
only one way to test this thing.

Well, yeah, we have to fire it at a
cinder block wall. So we're going to

selection of air cylinders and some
regulators on them. We're going to need

cinder block wall to fire them into and
some kind of method for...

catastrophically taken that regulator
right off. And also, we have to figure

how to make sure it actually hits the
wall. I mean, what if this thing just

of goes like that?

I think I want to be outside the
building that we're testing this inside

Yep. To test the MIF, they'll need to
aim the cylinder like a missile, devise

some way to sever the valve in a split
second, and build a wall to aim at.

They'll have to start work on the wall
first.

So Jamie's assistants, Terry and Tyler,
get commissioned as Mythbuster Masons.

So I'm going to set you up, and it's
going to be in your hands to make sure

all happens. So don't screw up.

I'll kick your butt.

Walls are useful for all sorts of
things, like holding up the roof.

So punching a high -speed hole through a
supporting wall might not be such a

good idea.

This freestanding barricade won't be
pretty, but it will be, well, great.

Meantime, Adam is checking the myth with
a man whose whole working life has been

spent under extreme pressure.

George Ratterman supplies valves and
cylinders across the USA.

And like most of us, he's heard all of
those explosive stories secondhand.

The first thing we've heard is that if
you knock off the valve to a cylinder,

they can fly right through a brick wall.

Yeah, you know, that is the myth. I've
heard that from a number of people. In

most cases, you ask them a few more
questions, you find out they actually

weren't there.

I think somebody else told them. And
most of the time what the story is, it

would take off and it would usually go
through a cinder brick wall, disappear,

go out in the field, or else possibly be
found, you know, through a couple more

fences or something.

We want to build this rig that shears
the valve right off of this. And the

test rig is a large weight in a guided
tube that comes down right on top of the

cylinder and knocks it right off. Do you
think that's going to work?

I don't know if that's going to work. I
would be concerned that you're going to

end up with an uneven break.

into only a partial break, and that's
when you're really going to get a

effect of the vessel.

And remember, we're talking an ankle
-smashing 140 -pound steel cylinder.

Even a partial shear could send this
thing ballistic.

It might also start spinning
erratically, which Jamie calls rat

To ensure that doesn't happen, the tank
needs a long, sturdy guide rail to

guarantee it takes off in a straight
line.

I've got to build a rig that does a
couple of different things. The first

is that it has to hold this tank steady
in such a place that we can drop a heavy

weight on the valve and knock it off.
The second thing is that same holder is

going to guide it as it takes off so
that once it gets going, it's aimed in a

certain direction and it'll hit the wall
at speed, we hope.

Good. It looks like it fits fine.

To sever the valve, he's fitting a
hinged 10 -foot tube to drop a 40 -pound

steel bar bang on the nozzle.

Adams borrowed some T -size tanks from
George, so all they need now is a good,

solid target.

I think we got everything.

All right. Well, get out there and try
and blow one of these cylinders through

the wall.

This military bunker is the perfect
place to test what we all hope will be

world's first and most destructive land
torpedo.

Seems Terry and Tyler did a first -rate
job.

It works for me.

I think this will do just fine.

Yeah, that seems nice and solid. It's
not quite as big as the side of a barn,

but the question remains.

can the cylinder actually hit it? So I'm
thinking that when we set up the rig

over by the door, we want to make sure
those doors are as close as we can get

them. Okay, well, they are, in theory,
rockets, so we should be careful with

them. Now, careful is a word Adam
sometimes has trouble hearing.

Now we do the Cirque du Sauvage, right?

Okay. Welcome to Cirque du Sauvage, a
one -time -only performance.

That is the power of the mind.

Now to test the power of a 2600 PSI air
cylinder and see if it can shatter a

solid brick wall.

I don't mind fingers on a chalkboard,
but that's messed up.

To help the rocket on its way, Myth Turn
Jess gets to grips with the lard.

Trust Jamie to always have a bucket or
two on hand.

It's cheap.

It's smelly, and it's a great way to
reduce friction.

It's important to be judicious about
your lard distribution, Jeff. The rig is

greased and ready, but will the steel
bar have enough momentum to break the

nozzle? This is a two -by -two -inch
solid steel bar, and it weighs,

I think, officially a heck of a lot.

That's 40 pounds dropped from a height
of 10 feet. It's a classic case of a

square peg in a round hole, and that
surely deserves a test run. Piece of a

brick right there. All right. That'll
keep the end of our piece of steel from

getting too damaged.

Three, two, one.

Oh, yeah.

That looked pretty serious.

If a 40 -pound bar can do this.

Just imagine what a 140 -pound gas tank
could do. If all goes to plan, it's

looking curtains for our wall.

Shooting the scuba tank with a 30 -06,
that was awesome.

And I have never felt like we were
totally done with that until 10 minutes

now. So Adam's after some closure.

And that opens up a world of
possibilities.

Now, here's a motor myth that's way
overdue for testing. In fact, it's a

blast from the past.

Most modern engines run on gasoline, but
it wasn't always the fuel of choice.

Some mechanical pioneers favored a more
explosive kind of combustion.

Trying to test the claim that you can
run an engine using only gunpowder.

easy enough.

Get an engine, add black powder, ignite.

Hang on a minute.

There have been a lot of people that
have tried this through the ages. Maybe

should try a few of their experiments
just to see if we can learn from their

mistakes.

Finally, we get to learn from somebody
else's mistakes.

Now, common sense tells us the words
engine and gunpowder shouldn't even be

in the same sentence.

But the respected men of science who
designed our three test engines clearly

thought otherwise.

And Torrey's not going to learn from
anyone's mistakes, because as far as we

know, not one of these engines was ever
actually built.

The gunpowder fuel they plan to use is
often called black powder. It's a

volatile mix of sulfur, saltpeter, and
charcoal.

But before the team even thinks about
putting this lethal compound in an

it's worth finding out if it really has
the kick needed to push a piston.

Well, we think there could be some
really good reasons why you'd want to

black powder in an engine. To
demonstrate that, we're going to do a

between black powder and gasoline.

For this first experiment, they custom
build a super -sized piston to test the

comparative grunt of gasoline and
gunpowder.

To check that the feel works, they need
an air pressure test.

And Carrie can't resist going along for
the ride.

Three, two, one.

Well, the piston worked.

Operations move out to the car park and
into the blast chamber.

That's an indication of how much faith
they have in the black powder.

Black powder comes with its own
oxidizer. So unlike gasoline, which you

inject a certain amount of air to get it
to combust, black powder is ready to go

all the time.

Finding which fuel produces more energy
is easy enough to measure.

A magnet sitting on top of the piston
should stick to this metal scale, just

where the piston hits the top of its
stroke.

First, the gasoline.

Then a propane flame to vaporize it.

Gas, piston, three, two, one.

The gasoline -powered piston has made
its mark. No, it couldn't have gone up

there. So it accelerated it all the way
up here.

So will the black powder measure up?

Grant's quietly confident.

Our research indicates that black powder
has a lot more energy density.

It's measured in grains, which comes
from the old Troy system of weight.

One grain is roughly equal to 1 500th of
an ounce.

So you're using 20 grains again?

You got it.

They wait for the flame to ignite the
powder.

Oh, there we go. Wow. Perfect.

They don't call it gunpowder for
nothing.

Wow, shot the magnet off the scale.

This is where the gasoline magnet got
shot to.

And there is where the black powder
magnet got shot to. Well, that's fairly

conclusive.

Black powder does have more energy
density than regular gasoline, meaning

need less of it to get the same amount
of power. So it is a sound concept.

But what happens when a sound concept
meets an unsound engine?

There's still three combustible
contraptions to put to the test.

High -pressure gas cylinders have been
around for 100 years, and legends of

their destructive potential have been
around for 99.

But could a ruptured tank really burrow
through a brick wall?

Back at the bunker, Adam and Jamie are
about to find out.

All right, I'm arming the rig.

Arming the rig means unscrewing the
protective cap.

All that remains is to pull the string
that releases the weight. That hopefully

guillotines the valve.

All right, ladies and gentlemen.

Shearing the compressed air cylinder in
3, 2, 1.

This is close to a worst -case scenario.

As feared, the valve was only partially
sheared, so the cylinder went...

Absolutely nowhere.

I'm going to wait however long it takes
for it to let go of its air because it's

got a damaged valve and that valve could
give any minute and, you know, become a

bullet. It's a very slow leak. So the
boys have 45 minutes to stand well back

and revise their plan.

Harry, Grant, and Tori are out to test
the myth that an engine can actually run

on gunpowder.

They've shown that black powder
definitely has the muscle to move a

This is where the gasoline magnet got
shot to.

And there is where the black powder
magnet got shot to. Now to build a

kind of proto -engine, specifically
designed to run on powder.

It was dreamed up by a Dutchman named
Christian Huygens more than 300 years

His blueprint was the very first to
feature a piston in a cylinder.

When the black powder ignites, expanding
gases are meant to force air out of two

valves, creating a vacuum that sucks the
piston down.

It looks pretty easy, pretty
straightforward.

Whether or not it's going to work,
that's going to be the hard part.

The design is simple and a lot easier to
build now than it would have been in

1680.

Total success means getting a near
-perfect vacuum.

That's a tricky thing to do with so many
moving parts, especially when you have

to drill a hole for the fuse.

Oh, there's a hole down here.

That's not going to give you a vacuum.

That's what the problem is.

We'd have to have that hole there to
ignite the black powder.

How are you going to get a vacuum then?

I'm just going from the designs of
Huygen.

Should we, like, raise them for the
dead?

Well, I finished my Huygens black powder
engine.

So now what we're going to do, I drilled
a little hole at the bottom cap. We're

going to fill this up with some
gunpowder, put a remote fuse in there,

and see if it does, in fact, raise up
our weight.

I am not sure if we're going to get a
good enough vacuum, and that's the whole

principle that this Huygens engine works
on.

But, you know.

There's only one way to find out.

One thing Huygens didn't specify was how
much black powder to use.

So they're starting small with five
grains.

This weight is attached to the piston.
So when the piston is sucked down, the

weight goes up.

Fire in the hole!

In three, two, one.

Okay.

So much for fire in the hole.

the weight hasn't budged in search of
more oomph tori trebles the charge to 15

grains here we go in three two one oh
god did you feel that the

vacuum it's sucking me in it was huge
yeah it sure does suck but the weight

rise a little which means the piston
moved slightly in the cylinder dude it

totally pulled it down look at this oh
if it were A vacuum it would have been

holding, like you wouldn't have been
able to pull it back.

So they up the charge from 15 to 20
grains.

In three, two, one.

It looks like Huygens' original draft is
just a little bit too drafty. We have

two things working against us.

Our seal between the piston and the
chamber isn't completely airtight. We

as tight as possible, but there's still
some leaks.

So we're not getting a true vacuum.

And then also our one -way valve,
they're not totally airtight either.

Modern machining gave the engine a
better chance of success than Huygens

have imagined.

And it still didn't work.

One black powder engine down, two to go.
But there's reason to be hopeful.

Just running through this experiment,
though, you can see why people were so

intrigued by the whole black powder
engine. It takes so little to create so

force. And soon they'll see if that
force makes or breaks an engine George

Cayley had high hopes for.

Adam and Jamie are trying to figure out
what went wrong with their first attempt

to blast an air cylinder through a brick
wall.

I can still see it.

Yeah, it hasn't moved.

In best MythBusters tradition, they
decide to tinker with just about

An extra 30 pounds of lead is shaved
down for the trigger.

Pencil rods are added to help guide the
weight.

And never underestimate the benefits of
extra lard.

And third joke here.

So this second time around, we've added
more weight. We've lubricated the whole

weight system so that it'll be...

more slippery when it goes down. And
then probably most importantly of all,

we've moved the valve placement slightly
so that the weight when it hits it will

hit right on the very tip of the valve.

And that'll provide the most leverage
and hopefully snap it more readily.

Calm, steady words from a man who's
hoping to launch a gas cylinder into the

next county. Here we go, steering the
regulator off a tank.

Attempt number two in five.

Four. Cross your fingers. Three. Two.

One.

Yeah!

That's the sound!

That is a lovely, lovely sound.

The valve has sheared clean off, and
that's a very good sign.

It looks like the cylinder flew straight
and true.

But did it have enough thrust to crack
the wall?

Oh, God.

It was the lard that did it.

At 40 miles per hour, the air tank
turned the cinder block to cinders. It

put a fair dent in the wall six feet
behind it.

No way!

I mean, it didn't go all the way
through, but it went through this one,

working its way through that one.

I was ready to see that this is not
possible. I was totally expecting it not

actually work, because it's one of those
apocryphal tales, and everyone we

talked to had heard the story, but no
one knew anybody that it happened to.

You know, this was an optimum situation
for this tank.

What this tank did is as good as it
gets.

My favorite thing is the perfect
roundness of the top of this hole. It

this entire wall back.

Although the cylinder was deliberately
aimed, you couldn't

ask for a more convincing result.

So let's call this myth totally and
spectacularly confirmed.

But the Mythbusters can't just leave it
there. They plan to double the stakes

and push this explosive experiment to
its limit.

Cary Grant and Tory are hell -bent on
proving an engine can run on gunpowder.

Fire in the hole!

But could this really be a viable
alternative to gasoline they've already

tested and been disappointed by a black
powder engine designed way back in the

17th century.

So it's back to the drawing board.

You know what our problem is going to be
is getting an engine to start and

sustain itself using black powder.

I do remember coming across a black
powder engine.

I think it was Sir George Cayley, the
guy who did the first glider, and he was

the father of modern aerodynamics.

He had wanted to make a flying machine
that was completely powered by a black

powder engine that reloaded itself.

So, I mean, I bet we could find some
plans floating around the file

Thanks to the graphics department, we
can see it would have looked something

like this.

When the powder ignites, the air expands
into the reservoir cylinder, pushing

the piston up.

Then at the top of the stroke, a
bowstring pushes the piston back down.

On each rise, the piston turns a
stopcock, which funnels more gunpowder

system. And so the cycle is repeated.
And repetition is the key to a working

engine. Maybe the gunpowder engine could
be making a big comeback here.

We could get rid of all of our fossil
fuel dependence.

Knocking up a 19th century engine poses
no problems.

And luckily, they even have a bow handy,
a leftover from the split arrow myth.

They string it over the piston, and
pretty soon, Cayley's drawing comes to

The clever part is that it reloads the
gunpowder every single time.

Hopefully. So that this fits and will
keep going and we've created an engine.

With the engines ready to go, Carrie
decides on a quick test.

We need to know how fast we need to get
out of the container. We need to know

the time between ignition and the engine
running.

In other words, how fast will Tari have
to run once he's lit the flame? He kicks

off with just five grains of gunpowder.

This amount of gunpowder is going to
force the cylinder up.

Plus the 50 pounds of pressure that the
bow is putting on it.

I don't think it's going to happen.

And for 40 seconds, it looks like it
won't. Why?

They wait.

And they wait.

Well, I think we have sufficient time to
get out of there.

Okay.

Nice. Look at the smoke range.

Yeah, let's do it again.

They reset for another test, but Tori's
bent on mischief.

Unknown to the others.

He's added way more powder than he was
meant to.

Three, two, one.

Is this the combustible black powder?

How much was in there? I put in too
much. Talk about a plan backfiring.

Carrie's going off as well.

I'm putting my foot down. You are no
longer in charge of handling any of the

black powder. Why?

Because you didn't tell us that you put
in 15 grains and I wasn't wearing my ear

protection. I'm going to kick your ass
if you ever do it again. Now that the

smoke's cleared on that little incident,
the guys know that come the test,

they'll have plenty of time to get out
of the firing line.

Well, all we're looking for to prove the
concept is to have one ignition and

then have that reset.

and do a second ignition.

If we can do that, we've proved Cayley's
idea.

I think our worst -case scenario and our
best -case scenario are generally the

same thing. A big explosion, a lot of
screaming, some fun, hopefully safe fun.

I'm feeling supremely confident,
actually, in this device.

I think it's at least going to give us
two cycles. I think it's probably going

to give us more, depending on how much
gunpowder we put in the reservoir.

They fuel up. Or should that be load up?
Remember, you don't want to put more

than you need.

Thank you, Tori. This one's going in.

That's five grains of black powder. Will
it be enough to get this engine turning

over? All right, we're lit.

Whoa!

Okay, sort of worked. The expanding
gases did push the piston up, and the

bowstring did reset the piston. But the
reload mechanism didn't. Well, reload.

Still, it's not like the whole thing's
gone up in smoke.

It actually worked, and it didn't fall
apart. We had one good stroke, but

unfortunately, our hopper seemed to have
shot or knocked out all of our

gunpowder, which blacked when it hit the
propane.

The answer? Some aluminum foil over the
hopper, which should keep the powder in

place.

Take two. Remember, for proof of
concept, the engine has to complete at

two cycles.

Once again, the engine only manages a
single stroke.

The problem this time is Carrie's reload
mechanism can't keep up.

It's happening too fast to dump the
black powder in there. It's not going to

just fall into the little groove really,
really quickly if it's just there.

Basically, the action is so fast and
violent, it doesn't have time to reload.

That means a black mark for another
black powder engine.

Adam and Jamie have already proved the
power of a well -aimed T -type air tank.

Cylinder one, wall nothing.

It was almost too easy.

I'm now wondering what we do to harm
this kind of power.

Why don't we put a saddle on it and take
a ride? What do you think?

No, no, no, a speedboat. Let's put a
couple of them in a boat and see how

we can go on the water.

That might be a little technical. In
place of a normal engine, they plan to

two monster air tanks with 5 ,200 pounds
of pent -up pressure between them.

Adam has to build a throttle that
releases both valves at precisely the

time. And Jamie needs to buy a boat that
won't blow the budget.

This one's a lean 16 -footer designed
for high speed.

It's also missing a motor, a dashboard,
and a steering wheel. So I assume it

floats, right? I've never had it in the
water, so you're going to have to go on

faith. So there you have it, a boat that
never left the driveway.

At least there should be no sentimental
attachment.

You've seen the show before, right? Oh,
yes, big fan.

So you're aware that there's a strong
likelihood that we're going to do

something horrible to your boat?

Yeah, yeah.

Do you have any kind of, like, remorse
or anything about seeing your boat, you

know, potentially turned into shrapnel?

We're sort of expecting that that could
happen to it. Selling your boat to the

Mythbusters must feel something like
selling your horse to the glue factory.

Still, the deal is struck, and it smiles
all around.

Of course, you know that the two
happiest days of a boat owner's life are

day that you buy a boat and the day that
you sell it. I think this is one of

those days.

And it's one of those days for Jamie,
too.

There's no feeling quite so rewarding as
carefully customizing your very own

speedboat. Oh, it brightens my mood when
we break out the sledgehammer. The team

has just one day to get through a
titanic amount of work.

What I'm going to do is take this pipe
and...

kind of bolted on a swivel thing on the
transom of the boat.

And I'd also have to build a kind of a
wooden paddle thingy to actually go in

the water and guide it. Ah, yes, that
would be called a rudder. And they'll

to attach it to a kind of round wheelie
watch that's up near the pointy end of

the boat.

So Adam cuts, belts in, then spot welds
the paddle thingy.

They've decided to mount the seat
between the two tanks.

And for some obscure nautical reason,
they're using Adam's posterior as a

yardstick.

The minimum is going to be like about 15
inches.

Wait, you're going too far. I'm going
inside of my hands.

Yeah, you're squeezing it.

That's 14 inches. Why Jamie needs an
accurate measure of Adam's buttocks is

anyone's guess.

But it is time they both got the lead
out.

So, with a little elbow grease...

Then some screws and a strong epoxy glue
for the baseboard. Our dual inboard

rockets are finally hauled on board.

And strapped down tight.

Dude, I love it.

I'm starting to get excited.

And although Adam's backside set the
standard, it's Jamie who'll be steering

ship.

Go ahead and have a seat.

To ensure these two cylinders fire at
precisely the same time, the factory

-fitted nozzles are being replaced with
ball valves.

They'll both be hooked up to a single
linkage, devised and built by our very

Adam Savage.

We'll have a lever here or here, and we
will activate that lever. It'll open up

the valve, releasing the pressure, and
hopefully what we'll see out of this

is what we saw out of our tank in the
concrete wall experiment.

Two hours later, and that scratch -built
throttle is up and running. It's

simple, it's purely mechanical, and it
works.

But there's still one design feature
worth considering.

I also want to make some fins.

I know it's dumb, but it'll look great
if we have, you know, no one will

it for anything but a Mythbusters boat.

I'm thinking of a couple fins shaped
like flame. I have a better idea. How

just square ones that look fighter plane
-like? They'll be like one in each

corner and a V shape.

We can just cut them on the table saw.
It'll be really fast.

What do you think?

So far as Adam's concerned, nothing says
devastating speed like a pair of flame

-shaped plywood tail fins.

Painting.

From the cut to the color, these are all
vintage hot rod class.

But this time, Jamie's calling the shot.

He might not know art, but he knows what
he hates.

Tell me you're sorry that I wasted my
time.

I'm sorry you wasted your time, and I
appreciate your allowing me to make

something a little more subtle.

Okay. Thank you.

It's a trifling tiff that shows Jamie's
really taken the project to heart.

He's proud of the boat. He's excited
about it, as am I. I mean, it looks

cool. And he wants whatever
modifications we make to reflect that

make a joke about it.

But style isn't the big issue here.

It's all about the hardware. This is a
business end.

A half -inch bore, 2 ,600 PSI coming
through each one. It was enough to drive

single 150 -pound tank through a wall
and halfway through a second wall. The

question is, is two of them enough to
drive a rocket boat?

There's only one way to get an answer.

Dress Jamie up like a walrus. I want you
to be the boat. I want you to exist as

one with the water.

And hope he floats.

Our black -powdered dynamos have already
brought two antique engines to life.

Then watch them die a sad death.

So that leaves us where?

Back at square one.

Not actually. Since we've been dealing
with an internal combustion engine, I

thinking, hey, let's try an external
combustion engine. Let's get rid of the

piston, and we'll make like a water
wheel.

Tari's thinking of Thomas Paine's 19th
century radial engine.

which does work much like a water wheel.

But what if we replaced water power with
the grunt of gunpowder?

Okay, well, well, Tori works in the
opposite direction of engineering

How about you and I go find ourselves an
internal combustion engine, something

that's already a successful engine, and
try to adapt it to black powder?

Well, it should work in theory.

Sounds good.

While Torrey starts work on his black
powder wheel, Grant and Carrie will take

regular four -stroke engine, replace gas
with gunpowder, and try to rev it up.

Before they do that, one or two
questions need answering.

The first test that we have to perform
is to see whether this spark plug can

ignite the black powder.

Using a drill, Grant will run the engine
manually to see if the spark plug's

spark is enough to ignite five grains of
gunpowder.

Fire in the hole!

Hopefully. Here we go.

Woo! Yeah!

Woo! It worked!

Okay, good.

Nice! Good. Great.

Okay, so they know a spark plug can set
off the powder. The big question is, how

will they get the gunpowder into the
engine?

An engine normally works by sucking
vaporized gasoline into the cylinder.

But the grains of black powder are too
big to be sucked, so Carrie plans to

break them down.

This is a black powder tumbler. This is
how you can make black powder. You can

put the three constituents into here,
roll them, and make a fine powder.

And the longer you roll it, the finer it
gets.

We thought maybe if we could make it a
nice fine powder, something more dusty

that could kind of just float in the
air, maybe then we could have it stuck

the intake.

They put 100 grains in the tumbler.

And voila.

And set it at tumbling. It takes a
little while, so let's see how the

progressing.

For his Thomas Paine -designed radial
engine, Tari's lined the perimeter of a

wagon wheel with metal cup.

The expanding gases from the powder,
ignited in a separate chamber, will

into the cups, causing the wheel to
spin.

Dude, it's like an 1860s circular saw.
To keep his engine running, Tario's also

rigged a hopper to reload the powder
after each blast.

Right now I have the black powder
dispenser rigged up to the rig here, and

have this little piece of steel. As it
rotates, it will push the...

The button in and releasing an amount of
black powder.

To test the wheel, Grant blasts
compressed air through the system.

That looks pretty good, man. Yeah. How
much PSI was that? That's just 125 PSI.

Black powder is going to be tens of
thousands.

With those kinds of forces in play, they
set up Torrey's wheel of misfortune in

the blast chamber. In the first test...
they'll start slow with just 15 grains

of black powder per cycle.

Initiating glow plug.

Okay, and not enough pressure to get the
wheel going.

And even with 70 grains, Wow.

Payne's wheel of steel just ain't
spinning.

Before Torrey slides into depression, he
wants to improve the compression.

And try again.

So the only modification that I did is I
cut off this big chamber, which is way

too big. We weren't getting the
compression that we need. I welded on a

tube. Hopefully it'll give us more
compression. It's more like a shotgun.

hopefully we'll get this wheel spinning.

All right, here we go in three, two,
one.

This is taking too long.

Nope, 70 grains wasn't too much. The
whole thing backfired. Gases from the

explosion were forced back up into the
hopper, which set off all the black

powder. And still, the wheel didn't
turn.

Oh, no way!

Don't even go in yet.

They've blown the hopper off, so this
experiment is pretty much over.

Not only did it not work, now we don't
have a way to...

continue to introduce black powder into
our engine.

Adjusting the charge and the timing
might have helped, but the gravity -fed

reload system looks doomed to failure
every time.

Payne's instructions were followed
precisely, so it's safe to say that like

other two engines that came before, it
just doesn't work.

But Grant, Harry, and Tori have one last
hope. They'll put gunpowder in a

lawnmower engine to see if that cuts the
mustard.

Grant's mental machinery has already
been crunching the gear, pondering a way

getting the black powder into the
engine.

And he's devised an ingenious fuel
injection system.

What this is is an air eraser, basically
a miniature sandblaster. Black powder

goes inside of this reservoir, and
compressed air goes in here.

You set this to wherever you want it to
be, and a constant stream of black

powder should be shooting out of here.

Out in the blast chamber, they set up
for the test.

The air eraser is rigged up to squirt
the black powder directly into the

combustion chamber.

Anybody else as excited about this as I
am?

Once again, Grant uses the drill to turn
the engine over. Sort of a crude

version of the starter motor you'd find
in your car.

Fire in the hole!

A second or two later, the fuel should
kick in. In this case, the powder.

We're anticipating a throaty throb and a
nice dark puff of exhaust gas.

Well, that didn't quite work.

And when Grant takes a peek inside the
casing, he sees why.

Is it all gooped up from the oil?

Yeah, there's quite a bit that's
actually kind of clumped in a wet

They're left with an engine enigma. Our
fuel needs to be dry to ignite, and as

it comes up into the cylinder, the oil
mixes with the black powder and makes a

gooey slurry that we cannot ignite.

They've got one last shot. They'll strip
down the engine, drain all the oil, and

see if the injected powder will ignite
before the engine seizes up.

There's a lot of oil in there.

And Torrey thinks their chances might be
better if they replace the spark plug,

which fires intermittently, with this
little device.

So what I did is I made this little glow
plug, and all it is is a little coil of

wire. We're going to attach it to a
battery. It'll glow red hot, and that'll

a constant source of heat to ignite the
black powder every time it enters the

chamber. He's a bright spark, isn't he?

Right. It's the moment of truth.

Will this four -stroke engine go on
gunpowder, or is it the end of the road

this myth?

Gentlemen, start your engines.

Blow plug.

Black powder.

Nothing. Zilt, zip, and buff kit. In
desperation, they put five grains of

gunpowder directly into the cylinder and
try again. Three, two.

One. We've got a fire. Come on.

Baby.

We did get one push. We got one charge.
We got one fire. Yeah, we got one

ignition.

Even a working engine won't work with
gunpowder. And for that, we should

probably all be grateful.

Do we really have to talk about this
one? No.

But we will anyway.

But you can see why, over the ages, it
was so tempting to use black powder.

got such high energy density.

It would make a good fuel.

But the stumbling block is getting the
black powder into the piston and

igniting it. Not to mention that these
are dangerous.

So you ready to wrap this one up?

Yep. Claim it.

Busted. Easy.

Busted. Busted.

So just how much fun can one man have in
a souped -up speedboat? By the looks of

it, plenty.

Adam and Jamie are ready to live out the
ultimate boyhood dream, fitting two

potentially explosive air cylinders to
an unsuspecting ski boat, then cutting

loose.

That's what it's going to be like. It's
not a fully fledged myth, but after the

success of an air cylinder blasting
through a wall, It's impossible to

It's supposedly about taking us all the
way to the end of the myth, but come on,

I think we all know that it's an excuse
to have some fun with some big, high

-powered rockets.

Step one is getting our stunt skipper
installed in his wetsuit without having

blur some parts of your screen.

Step two is filling the cylinders in the
boat with compressed air from the

truck.

These tanks are actually filled with
geese, and they're complaining.

Was that a joke?

I think that was a joke.

Fascinating.

And step three is seeing if Adam and
Jamie can finally float their own boat.

The worst case scenario, I have to say,
is that one of the tanks...

blows up, and the shrapnel ends up
ripping through Jamie's flesh and

him. So much for the pep talk.

It's a good rule of thumb that support
staff should be seen and not heard.

Jamie, so when we release you, we're
going to pull off to the right -hand

and you're going to steer to our left.

Okay?

You mean I'm going to steer off to port?

Yes, you're going to steer off to port,
you old salt.

And we'll be to the starboard.

What, left and right isn't good enough
when there's water around?

There's also plenty of spectators
around, so they'll have to be careful.

We've got a tour over here of kids in
small boats. We're going to tell you

that tour before we release you.

When all seems safe, the rocket boat is
finally cut loose from the mothership.

And remember, they're dealing here
with... twice the pressure used earlier

smash a brick wall.

Jamie's ready, and the mechanical
throttle is gently nudged forward in the

-ass direction.

Oh,

dear.

Lots of noise and lots of spray, but
that brief burst of speed...

clocked in at just over five knots on
the speed gun.

And the boat was propelled a mere 120
feet.

Well, that was a whole lot of nothing.

But Adam is more upbeat.

That was excellent.

I mean, it didn't do anything really
important, but it was cool looking.

Okay, there's no doubt we've just seen
one of the best rooster tails this side

of a barnyard. But let's face facts.

Jamie can probably swim faster than five
knots.

The boys have given themselves one more
chance to prove the concept, and they're

ready to float some ideas.

We may be able to optimize this a little
bit if we choke the outlet down, and

also we're going to try to drop it into
the water a little lower, because I'm

not sure the physics on it, but my hunch
says that the air pushing more against

the water instead of against just air.

Give us a little more.

It's a bold decision that involves a
lightning pit stop and a radical refit

the outlet valves.

The full force of all that compressed
air will now be released underwater.

Jamie is also not going to go gingerly
with the throttle this time. He is just

going to push it all the way forward on
the first go and just expend all the

power trying to get up to speed and stay
at a speed.

actually travel more than, you know, 120
feet.

Tanks are refilled and the boat's back
in position.

It's now sink or swim.

And Adam has some, well, vaguely helpful
words of encouragement.

Remember, Jamie, experiments like this
are 90 % mental. I want you to be the

boat. I want you to exist as one with
the water.

Think about the boat planning, the
physics involved.

Feel them in your body. Are you ready?

What?

I said just go for it.

The rocket boat is unleashed, and it's
anchors away.

Let's assume that hysterical laughter is
not a good sign. In fact, the boat

traveled only half the distance of its
first run.

It was about the same as the other one,
wasn't it?

No, it wasn't even close.

As for the speed gun, it was hardly
worth installing the battery.

Well, I think that would proverbially be
that.

This lavish maritime experiment turned
out to be a spectacular failure.

Maybe it's time Jamie invested in a
good, reliable outboard.

I don't think he even made it like 60 or
70 feet that time.

I don't know if you can calculate it in
miles per hour. It would be more like

miles per day.

So we have to ask ourselves, what's the
washout?

So, Jamie, how are we going to wrap this
one up? What do you call it?

Well, we did get a tank to blow through
a cinder block wall when we knocked the

valve off, so that's confirmed. I mean,
there were documented cases as well. And

you can strap some air tanks to a boat
and give it a little bit of power,

It's not that practical. It's not real
power.

Yeah, we need to go for the hydrogen and
light it.

It's another episode.

We've got to let this one go.