Original subtitles

On this episode of Mythbusters, it's all aboard with Cary Grant and Tori when

they test the tall tale of a train track disaster.

That's going to be so cool.

Is it possible for a passing train to suck you off the platform?

Then Jamie and Adam take to the skies to tackle the classic classroom myth.

Learning every minute. That you can't make a concrete glider fly. This thing

done.

Who are the Mythbusters?

Adam Savage.

Ants are all over my head, man.

And Jamie Heinemann. Gets me all worked up just looking at it.

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

That was heavy.

Joining them, Grant Imahara.

Go get him, boy.

Tori Bellacci.

Somebody order some exploding pants.

And Carrie Byron. Oh, God.

They don't just tell the myths.

They put them to the test.

So, Grant, you take the train a lot, which is kind of weird because most

drive or take planes. I like the train.

That's cool. But, you know, there's this one myth, though, that if you stand too

close to a passing train, it can create suction and pull you into the train.

There is a yellow line to help protect you, so maybe that has something to do

with it.

This urban folklore conjures up every commuter's worst nightmare. Can the air

pressure caused by a fast -moving train actually suck a person right off the

platform and onto the rail?

I have an original idea.

Let's start in the small scale.

Let's go find, like, a model train and build a wind tunnel and do some testing

to see if you actually even have any suction.

The first order of business is to set up a wind tunnel and blow some smoke

across a model train.

So while Grant hops and puffs, putting the wind tunnel together, Tori and

get to go model shopping.

At San Antonio Hobby, Frank the train man has everything the guys need, and

got some positive news for the myth.

If you stand too close to a train and it's going fast enough,

It can suck you under.

Now, about those toy trains.

What's the scale on them?

This is 129th scale.

The gauge of the track is G.

Wow. I've actually been doing a lot of research on people doing aerodynamic

tests on trains, and 125th, 129th around this, this is the perfect scale for

wind tunnel tests.

So they have their working scale. And here comes the fun part, choosing their

choo -choos.

How would I wouldn't give to have one of these when I was a kid?

There's no better way of finding your inner child than stalking the aisles of

hobby store.

Let go of the trains. Let go of the trains, honey. Remember the golden rule.

What's that?

You never have too many trains.

Before the guys derail this sequence completely.

Now that.

Cool. A timely phone call from Station Master Grant gets everything back on

track.

Hello? Hey, what's up? Hey, Grant, what's going on?

Hey, I've been reading up on the research, and I have some new

you. All right, go ahead.

A freight train, it's got a much rougher aerodynamic profile than a passenger

train. A passenger train's pretty smooth, and that can generate a higher

slipstream.

So according to Grant, odd -shaped freight cars might be the best bet. But

the myth is all about an unsuspecting commuter, they take home a passenger

as well.

Man down.

Man down.

Back at Grant Central Station, our station master is busy making a wind

And using a NASA -inspired idea, it's a breeze.

What they use in regular commercial wind tunnels is a honeycomb.

many densely packed small holes.

These holes reduce turbulence from the wind source and smooth out the airflow.

And check out the big brain on Grant, because he's found a cut -price

for high -tech honeycomb, drinking straws, 47 ,000 of them.

And with the wind tunnel ready to blow, it's time to get set for the test. But

what are they looking for?

There are three areas that we're going to be looking at.

There's a high -pressure zone right in front of the train at the nose, the

slipstream, which is a thin layer of air going over the sides, and then right at

the back of the train, a low -pressure area called the wake.

Hopefully with this, we'll be able to see smoke swirling around at the back,

which would tell us that it's getting sucked into there.

So Grant thinks the wake is the key to this myth.

Could this swirling, ultra -low -pressure vortex, kind of a mini

powerful enough to pull someone off their feet and onto the rail?

Tori, for this first test, do you want to turn the wind on? And Grant, you

be the scout.

I'll turn on the smoke.

The team's wind tunnel works a treat, so testing proceeds.

First, with a passenger car.

Right there, a little cyclone.

That's where I see the little vortex.

And then the odd -shaped freight cars, which, like Grant suggested, appear to

cause more turbulence.

We're getting a lot of vortex at the end here.

It's tough to see it in real time, but the high -speed camera confirms what our

three sets of eagle eyes suspected.

The small -scale trains really do suck.

You still have a little collection of smoke right behind the train. And that's

exactly what we're looking for. Based on the experiments that we have just seen

today, I really do believe it's possible for somebody to be sucked off a

platform. Because the mini -wakes look like they could definitely pull at least

something nearby right into it.

That's a green light to proceed to the next station. And Carrie, for one, is

excited. We need full -scale, full winds, full -size people getting sucked

the train. That's going to be so cool!

Concrete glider. The classic engineering school challenge. You can't make a lead

balloon. You cannot make a glider out of concrete.

That's it. Somehow we've got to build a glider out of concrete.

Adam and Jamie are on familiar ground when it comes to taking off with crazy

contraptions. Pilot to bombardier. Pilot to bombardier. Do you read? Over. The

Mythbusters have attempted to get airborne with a jet pack.

It really is ridiculous.

Launch Jade the Simulate into the bay with bottle rockets.

And take Adam on a helium life raft ride.

Oh, it's very satisfying.

Oh, I shouldn't do that.

But this time, it's mission seemingly impossible.

Can our intrepid duo conquer the skies with a concrete glider? How are we going

to get around the fact that concrete, to my knowledge, always has like rocks and

gravel in it that's going to make it really hard to make a glider out of?

Well, the key component in concrete is Portland cement, and the gravel and the

sand and things like that can be substituted for other things, and some

are a lot lighter weight.

Oh, so, I mean, we should actually just do a bunch of testing. First of all, mix

up some concrete mixes that use lighter weight aggregates and see if we can

actually lose a lot of that heavy weight.

Yeah.

So, first up, they're going to learn how to lighten up their heavy weight

building material.

This is a standard concrete mix.

It's one part cement, two parts sand, and three parts gravel.

The gravel and sand that go in this is what is known as the aggregate.

The gravel in this particular mix is about standard, and it's about

maximum three -eighths of an inch in diameter.

In addition to the standard mix, Jamie makes up three more with various

lightweight aggregates.

beanbag foam beads, hummus, and lastly, a material made up of tiny glass

beads called microballoons.

Now they just have to let it set. And because watching concrete dry ain't

exactly Emmy award -winning material, let's come back when that's done.

Concrete. With 6 billion cubic meters made every year, it's the most common

-made substance on the planet.

Buildings, bridges, and freeways are all made of this ubiquitous material.

But the question is, can you use it to make a glider? And will it fly?

For answers, Adam and Jamie have come to Moffett Field NASA Ames Research Center

for a crash course in aerodynamics.

And glider guru Dr. Steve Smith has some good news.

I'll bet you can make a concrete glider.

The whole question is weight. So if you build a concrete glider with some

reinforcing structure inside and a lot of filler so that the concrete plus all

the other stuff is still pretty light, then, of course, the speed required to

fly to make enough lift to support its weight will come down, and you may get

down slow into the typical range that modern sailplanes fly. Have you ever

of a glider being made out of concrete?

So actually, yeah, the Germans experimented with a concrete -winged

World War II to be used as a glide bomb.

I think it had some kind of a steel core or steel structure inside for

structural strength, but they basically used concrete as a very cheap, quick way

to form a wing shape around it.

What are typical modern gliders made of? Well, the modern racing -style planes

are made out of pretty exotic materials these days. They're mostly built out

of... Carbon fiber, reinforced epoxy, Kevlar, fiberglass, all the good modern

space -age structures.

So we've been, in our research, we've turned up the glide ratio. What is that?

Well, the glide ratio is the slope that you travel along as you glide. So a

typical glide ratio for a modern sailplane might be, let's say, 40 or 60

And what that would mean is that you would glide 40 miles horizontal for

mile that you would drop, or say, 5 ,000 or 6 ,000 feet.

And so that ratio is the slope that you would make.

Now, there is definitely...

A lot of food for thought that we got from Dr. Smith here.

I thought this was totally ridiculous, and I thought maybe we'd get something

that would fall less hard.

But, I mean, the information we got here says that we ought to be able to make

something that's actually fairly respectable as aerodynamic and made out

concrete.

Back at the shop, and the concrete is ready for the weigh -in.

And no one is surprised when the standard concrete, the one with the

it, is heavier than the alternative aggregates.

Based on this first test, there's some pretty impressive variances in the

weight. Everything from foam beads at 68 pounds up to concrete at 115.

It looks like we'll be able to come up with a mixture that might be light

enough. The question is, can it stand up to the type of pressures we're going to

put it under?

We're going to have to do some strength testing.

In other words, they need to beef up their lightweight concrete recipe with

muscle. The single biggest problem with the concrete glider is the concrete.

Concrete has compressive strength but no tensile strength, which means you can

put a block of it down on the ground. You can fit hundreds of thousands of

pounds in that block, and it won't crush.

But you can make a thin sheet of it, push it through with your finger, and

crack.

So we're going to need to look at ways to strengthen the concrete.

And one of the ways is...

with an additive material that adds a structure inside the concrete that makes

it more flexible and more prone to bending without breaking.

So Adam and Jamie need to know which concrete reinforcers work best in thin

slabs. And they cast up several, including carbon fiber mesh and pre

cable.

After leaving them to cure, Jamie is ready to test their tensile strength

his trusty force gauge.

Okay, so this is cable reinforcement.

Ooh, very significant.

We tested four different types of reinforcements. Each of those increased

strength to some degree on the concrete samples.

The standout was the cable reinforcement.

So Adam and Jamie have some concrete information, and they've passed

Aerodynamics 101 with flying colors. It's time to get started on the build.

So, I don't know if you've heard, but we're going to do this as a build -off.

I hate build -offs. I know you hate the build -offs, but look at it this way.

While we might be able to make a more successful concrete glider working

together, working separately, we're going to illustrate two completely

ways of solving the problem and cover a lot more ground.

Whatever.

Ah, the pointless competition.

So loved by fans, so hated by the myth -busters.

Adam hates losing, which happens a lot. I'm going to kick your goldfish ass.

And Jamie, well, there's nothing about these head -to -head contests he enjoys,

except the cheating, which is why Adam is insisting on guidelines set in, well,

set in concrete.

There must be total secrecy.

The glider can be built to any scale, and the winner will be determined by who

achieves the longest relative flight.

So let's hear from competition Scrooge Jamie, who he thinks will win. I have no

idea who's going to win, and I don't care.

Bah, humbug.

We're back on track with the tall tale that a passing train could make your day

really suck.

The story so far has seen Cary Grant and Tori testing toy trains in a wind

tunnel, and the results mean they can move on to the next chapter.

Well, that was really interesting. Looks like we do have some suction. The small

-scale test definitely showed some smoke vortex at the end of the model train.

I guess the real question now is, is that enough suction to pull you off into

the tracks?

Well, I mean, now we need to go to full scale, and we still haven't found

anybody who's willing to let us use their train. So, any ideas how we're

to test this one?

I got an idea.

I think we should get out the chicken cannon and set that up.

and choose one of us as a test subject. Period. Random.

Not it.

And then see what effect the increased wind speed has on

our bodies.

The chicken cannon will give the team an idea of what kind of air pressure and

wind speed it takes to topple a typical guy like Tori. Wow, that's so hot on

you. Thank you. But before they turn Tori into chicken cannon fodder, they're

going to do a preliminary test with a fourth gauge and harness.

All right, ready?

I'm ready. Here comes Mr. Rain!

See how hard that was?

It was like pulling down a tree.

The force gauge clocks in at 70 pounds per square inch, which tells them two

things. Don't try this at home. We're professionals. We are professionals.

70 PSI is the kind of force a real train will need to generate to suck someone

onto the rails.

Plus, they have a number to aim for when they calibrate the chicken cannon.

So, let's dust off the MythBusters favorite.

Why do you have the chicken cannon out? Because we're going to start shooting

each other with it.

It was first used to test if a stray, high -flying bird could crash through an

airplane canopy.

This is a frozen chicken.

And this is no toy. You're watching frozen poultry propelled at 121 miles

hour.

Wow!

But on this test, the only chicken inside is nervously shuffling his feet

business end of the barrel.

I don't think it's going to push me over.

But then I've been wrong before.

Now, remember, they're not just doing this for fun. If they can work out what

kind of wind speed and air pressure knocks Tori off his feet, they'll have

data to crunch when they get to play with a full -size train.

We're just going to send Tori just straight into the fence behind us.

That'd be cool.

You're the crash test dummy after Buster.

Because he's not as easy to repair as Buster, On their first test, they're

starting at just 30 psi.

And to measure the wind speed, Grant has a handy little device called an

anemometer. What we're going to do is set Torrey up just as if he were

on a railway platform waiting for a train.

So, in other words, he's not going to be braced and ready to be hit. He's just

going to be standing on his feet just like anyone would be standing.

Wait a minute.

I'm just trying to think what is the worst that can happen here.

Anybody?

All right, let's go.

Torrey plucks up all his courage, checks the newspaper for great deals on health

insurance, and tries not to brace for the blast.

I hear funny noises.

Must be the train.

The 30 PSI gust rustles up a wind speed of 24

miles per hour, and Torrey is slightly unbalanced.

And that turns out to be good data.

Because in Europe, British Rail has set a maximum safe wind speed on the

platform of 24 miles per hour.

Apparently that threshold works. Yeah, 24 miles an hour.

Now the guys want to ramp it up and see what it takes to suck you off the

platform.

Adam and Jamie are not only taking on the myth that you can't make a glider

of concrete.

They're flying solo.

So what I'm going to do is buy a model glider kit, and I'm going to add weight

to it until it just barely achieves what I need it to achieve.

And then I will use that kit either as a mold or a guide for creating a concrete

airplane.

Remember, the rules state they can build on any scale.

So Jamie goes shopping for a toy glider to use as a mold.

This type of airplane right here has the most exceptional lift to it, much

stronger material.

Jamie selects two to test with. The first is a stealth bomber model that has

excellent lift but is extremely unstable.

And the second is a U -2 spy plane, which, with its glider -like wings, also

great lift but is less sensitive.

Well, thanks, Bob. Okay, Jamie, nice doing business with you guys. You too.

you soon. All right.

Back at M5, and while Jamie is using pragmatic shortcut, Adam is taking a

intuitive approach.

Basically, he's going to wing it.

Try to come up with a visceral understanding of exactly what it takes

something fly.

I don't just want to follow someone else's design and then have it screw up

me because, well, I just followed someone else's design.

Incredibly, Adam's make -it -up -as -you -go -along approach seems to be

working. That's cool. Right there?

That's cool.

I'm going to do some actual, like, almost kite tests with this just to try

figure out how this kind of size of glider might work.

I'm trying to learn all about everything I need to know within a day.

Okay.

Learning every minute.

It's a learning curve of precipitous proportions.

But the addition of a tail fin provides some stability.

And he seems pretty happy.

That's good. That's a good test.

Which means it's time to move on.

I want to do a little more research.

I might want to rebuild this thing in wood just to try the design out.

Still not quite as heavy as the concrete.

But if the wood flies, then...

I don't see any reason why the concrete shouldn't be able to.

Now that looks like a crash and burn.

That was about a one -to -one glide ratio.

Like it fell about, it looks about 25 feet away.

It's about how high I am.

And that was still a little bit lighter than the concrete will be.

And with take two no better, it looks like it's time for the MythBuster

plan B.

So if I had built a concrete airplane this size, I mean, it would be known as

rock.

I'm going to need to scale back, back, smaller, to try and get something

successful.

Meanwhile, Jamie has spent an hour rigorously testing his shop -bought

gliders.

Okay, that was a good test.

And he's pretty sure a hybrid of the stealth bomber wing with the fuselage of

the U -2 bomber is the best flyer.

Well, it looks like this wing design is the winner.

Next, Jamie weighs down the model to see what the maximum payload is.

Well, based on this test, I believe this is about the maximum that I could go. I

think I should be under this, but definitely no more than this.

I'm going to go ahead and weigh this now, and we'll see what kind of volume

concrete that translates to.

So according to Jamie, if he can make this glider out of concrete and keep it

less than 800 grams, he might just get this myth off the ground.

Millions of us commute by train every day. So is it possible we're just one

away from disaster?

And if a fast -moving train can really suck you off the platform, the next

generation of super trains traveling at 223 miles per hour could be lethal.

Putting his body on the line for the myth, Tari has discovered a blast of air

30 PSI, which generates a wind speed of 24 miles per hour, won't knock you off

your feet.

That was nothing. Let's do 100 PSI.

Tori, how about 50 PSI?

It blew

my cover off.

Whoa!

That was sweet!

Tori's still standing, but only just.

Didn't knock you over on your butt, though. No, but it definitely knocked me

back.

It lifted my shield, and then it just ripped the newspaper to shreds.

That 50 PSI shot of air notched up a wind speed of 46 miles per hour, and

struggled to stay standing. It looks like the team have their knockout

So really the indication, if your paper shreds when the train passes, you're

standing too close.

If you're not prepared for this kind of wind speed hitting you, I don't think

you would have the reaction time to be able to hold yourself up. You would

possibly fall into the train.

But the big question is yet to be answered. Can a full -scale train

that kind of wind speed in reverse? Will the weight at the rear of the train

suck at 46 miles per hour?

Fortunately for Torrey, he won't be the one standing on the platform to find

out.

That job goes to Buster's ballistics gel brother, Ted.

Our fall guy needs to be as lifelike as possible. That means building a rigid

frame to support the legs and gel -coated ropes to bolster the arms.

This is a ballistic material, and I've coated a piece of rope. And this is just

so that when we pull it out, the arms don't just rip off the body.

Once Ted pulls himself together, he gets filled up from the neck down.

Tory pours in enough ballistics gel to fatten up our mannequin to a healthy 200

pounds. Big enough to prove almost anyone could be sucked off a railway

to a grisly death.

Yeah, it's kind of weird looking, huh?

The weigh -in confirms he's in fighting shape.

207 pounds. He's a big boy. It's all muscle. Yeah. Okay.

Now, all Ted needs is to get ahead.

Modern gliders or sailplanes make it look so easy.

Their state -of -the -art designs and space -age materials contribute to

incredible glide ratios of over 40 to 1.

That's 40 miles of travel to one mile of vertical drop.

Adam and Jamie have got the tough job of trying to recreate that effortless

flight with a glider made of concrete.

So far, Jamie's having some success. He's made a mold from his toy glider and

carefully mixed cement, sand, fiberglass, and water into paper -thin

sections.

And the fresh concrete mix is almost ready for curing.

Jamie may be up, up, and away.

I don't know how to build airplanes.

But Adam is still grumbling. So I looked into the origins of the glider.

I come across Cayley and his proto -original coachman -carrying glider.

Cayley was an amazing aeronautical experimentalist. He died, I think, in

-1800s, 50 years before the Wright brothers' first flight with a powered

airplane. And yet, the experimentation he was doing on wing shapes and glider

shapes and the forces involved of lift and drag are absolutely...

It's astonishing, considering that his work went largely ignored for decades

after he died. His design for a glider is not what you think of as a modern

glider or airplane wing, and yet it's been proven since then that it actually

works and that it is an effective design for a glider.

I think it's as good a place as any to start with this.

So, Adam finally has a design.

Now he's got some catching up to do. Well, now I've got to draw out the

on the foam, and then I've got to start, like, sanding and sculpting it.

With the mold ready to go, Adam lays out carbon fiber mesh for strength.

And then he casts his lightweight concrete mix onto the foam mold.

And like Jamie, it's just a question of getting his concrete glider to cure.

But this being Mythbusters, time is of the essence.

I am prepping my mold to hopefully set faster than 28

days, which is the recommended setting time for this concrete.

Keeping the concrete moist in a warm environment is as much as they can do to

encourage the curing process.

Concrete sets in hours, but curing is a chemical process that takes weeks.

Jamie is first to find out if their accelerated curing technique has worked.

That's got to be about the thinnest piece of concrete you ever saw.

So far, so good. But as he assembles the wing sections, Jamie finds he has a

weightier problem than the curing process.

His maximum weight of 800 grams has been busted.

Right now it weighs about 1 ,300 grams, which is about twice what it needs to

weigh for it to be in the worst -case scenario where it just barely is flying.

And this is...

without any of the other structure on it. This is just the basic, this wing

shape. But the bereted one has an ingenious solution.

He's going to use the bottom sections of the wing as the entire wing.

This was originally just the bottom section, not a very structural part of

original wing.

But seeing as how he's so overweight, now this becomes the actual wing itself.

By putting a little bend in it, I think we'll get to the same place.

With the weight problem taken care of, assembly begins.

And in a last -minute design addition, he uses some ultralight fishing line to

add some tension to his ultra -fragile glider.

With Jamie on the runway and ready for takeoff, let's find out how his wingman

Adam is doing.

Feels good.

I've got some hopes for this.

With the Cayley glider set, it's time to release it from the mold. And using an

old model maker's trick, Adam dissolves the foam with acetone. But now he's got

an issue with excess baggage.

It's been way too long.

I don't have a target weight. Just super crazy light was what I was hoping for.

So I got a bit of work pulling out as much weight as I can.

So to get the Cayley glider down to a reasonable flying weight, Adam and his

angle grinder have got a long day ahead.

Our team of train spotters have tested toy trains for turbulence.

They've toppled Torrey with a tug of war and turned him into chicken cannon

fodder.

It's time to take this test to the full scale.

After months of searching, our researchers have found a railroad in

New Mexico, that's willing to give it up for science.

The line is still being built, but there's enough track to push this rail

engine to its legal speed limit of 79 miles per hour.

So, Robert, have you ever seen anything stuck towards the track, you know, on

the station?

Me, personally, I never have.

I've heard of it. So Robert, our driver, thinks it's plausible.

But the engine he's driving is hauling two passenger cars, which we know create

less turbulence than freight cars.

But this legend involves unsuspecting commuters waiting on a platform. So it's

really the best way to test the myth.

Yeah, I was very pessimistic about this myth until I saw the size of this train.

It's huge.

I can't believe anybody's going to give us something this big to play with.

I could see this actually being true.

If Ted could speak, he'd probably be screaming, why me?

But misery truly does love company, and he won't be alone out there.

Something else we'd like to try today, we brought a baby stroller with us.

It's not part of the myth, but train traveling parents often have their

with them.

And because it's on wheels, the guys think it will help illustrate the

effect.

The stroller may get pulled off the platform even if Ted and his 200 pounds

unmoved. Now his back wants to be to the train. It's like he's got a headphone

on. He's listening to music. He doesn't know the train's coming.

Okay. The expression says it all. Ted ain't exactly confident, but Tari thinks

his chances of survival are good.

My feeling is the train's going to go through.

There's probably going to be a lot of rumbling. It might knock the dummy over,

but I don't think the suction is actually going to be strong enough to

dummy in.

The last thing to do before the potentially lethal drive -by is to set

Grant's wind speed gauges.

With that done, it's time to set this test in motion.

Three miles away, Robert set his train rolling, slowly building up to the legal

speed limit of 79 miles per hour.

She'll be here any second.

That was

awesome!

That was intense.

Ted's been tipped sideways, and the stroller's snapped its line. In fact,

taken out of camera.

So the stroller...

The line snapped.

It got pushed so hard. Are you serious?

It sucked that way.

Oh, jeez.

My God. So any mom that has her stroller that close to the train.

Was it suction or was it more just the gust of air that pushed him over?

With so much happening so quickly, it's difficult to tell what's going on. But

the replay seems to indicate the stroller being blown along the platform.

there's no sign of Ted getting sucked onto the tracks.

The myth of the concrete glider has brought Adam and Jamie head -to -head in

aviation dogfight. And to find out who's going to be top gun and who's going to

be the goose, it's time to get a visual on the enemy bogey.

Ta -da!

Ah, well, it looks like something right out of Leonardo's day.

It's actually modeled on Cayley's glider. It is, in fact, his most

glider that carried a person.

And it weighs a bloody ton.

Yep. His thing is going to drop like a stone when he lets it go. I mean, you

see by the shape, it's not got very much lift involved.

You know, I'm guessing that it barely has any more lift than mine does.

And yet it weighs several times as much.

So I don't have a whole lot of hopes for it. Yours is a lot heavier than mine.

But it's a lot sturdier, so it kind of nicely illustrates the tradeoff. If you

go for lightweight, you get something very fragile, which is what mine is.

let's see your fragile, wilting bird of a plane.

Okay. It looks like a glider.

I did testing on something that was a foam version of this. Yeah.

And this is under the weight that I tested and still considered it to sail.

So it seems Jamie has taken Dr. Smith's advice about weight being the key and

gone for a super light design.

But will it hold together?

And Adam? Well, he's gone for stability. But will it generate enough lift to

overcome its substantial weight?

Next, and the weigh -in. In this corner.

Weighing in at... The scales confirm Adam's worst fear.

At just over 600 grams, Jamie's wilting bird is a featherweight. This is

basically concrete with a few pieces of string, and I think it's a fantastic

attempt at foiling the myth that you can't make.

A glider out of concrete.

Adam is next. And with over two kilos of Cayley glider, he's definitely in the

heavyweight division.

So with a heavy heart and glider, Adam has to feed firmly in his grasp. Let's

set up a wind tunnel test so we can figure out how many different ways

probably beaten me in this contest.

Okay.

Using Grant's drinking straw technique, Adam breezily whips up a wind tunnel.

The idea behind the drinking straws is that they make the flow of the wind

coming out of the fan completely laminar.

The blades create vortex effects and all sorts of things about the wind that are

turbulent. And by forcing them through drinking straws, make the flow much more

what we call laminar and straight.

And that should be perfect for getting a good test for us.

With the makeshift wind tunnel up and running, Adam and Jamie can measure

glider's lift -to -weight ratio.

They'll do this by weighing the glider in front of the fan.

Any lift their glider achieves will result in a weight reduction.

Yeah, I'm seeing, on average, probably about, yeah, just about a maximum 200

grams of lift there.

By my best guess, my glider was receiving about 38 % of its total weight

lift. 38 % is impressive. With a decent launch speed, that will increase, and it

may just be enough.

Next up is Adam's Cayley Glider.

Well, it's nice that I can feel some lift, but this thing is heavy.

His lift -to -weight ratio is well down on Jamie's. It's only generating half as

much lift. Yeah, it spikes up to 350.

Bye, Mike.

Glider did not seem to perform as well as Jamie's. Actually, about half as

At this stage, Adam is thinking his heavyweight contender won't stand a

against Jamie's featherweight champion.

But with both fighters ready to rumble, it's time to pack up and head back to

NASA to let these concrete creations fly.

Carrie, Grant, Tori, and Ted have survived a train track flyby.

With no sign of the mythical suction on the first run, it's take two.

But this time, the train will be going backwards with the blunt end leading and

the aerodynamic engine at the rear.

Yeah!

Dang!

Dude, look at the stroller.

Look at the stroller.

It got thrown off the platform.

Incredibly, Ted is still standing. He wasn't even blown back.

But Grant's battery of wind gauges has its own tale to tell.

On our first run with the train coming this way and the aerodynamic tip

we had parallel to the train, wind speed of 49 .9. The second run

with the flat end leading coming this way, we had on this one.

26 .8. Whoa.

So the wind speed on that run was actually less.

So according to the figures from the chicken cannon tests, both runs

enough wind to make a typical guy stumble.

But it's all blowing straight out or parallel to the track.

It looks like the turbulence moving with the train and away from the track

trumps any wake effect there may be following the train. But Grant is a

train spotter and wants just one more try.

I'm down here at ground zero monitoring these anemometers, and it is really

scary as the train passes in this huge cloud of dust and everything, and I get

stuff in my teeth.

It's very exciting, though, but scary.

Once again, Robert the driver winds his engine up to full speed.

Ted finds himself face down on the platform, and the stroller's missing in

action. But how did Grant survive the blast?

Can we calibrate it by the gravel in your face and the depth that it's gone?

Yeah.

So no one was sucked onto the train tracks for a dice with death.

And with no obvious results, it's back to the shop to study the high -speed

camera and piece together the data.

Looks like all the wind is running parallel to the train.

Yeah, I'm definitely not seeing any suction.

The first and third runs had the most violent effects, but there was no sign

any suction.

The winds blasting outwards and sideways were far stronger than any vortex that

may have been created behind.

If Ted had felt any suction, that tie rope would be as taut as fencing wire.

Knocked his headphones right off, and look at the stroller. There it goes.

It's lifting, and it's running parallel to the train in the flip stream.

All that turbulence is parallel.

So in the end, there's nothing like a full -scale test to sort the fact from

fiction. And this one looks like a foregone conclusion.

So what do we come to for conclusion for train section?

Oh, it's busted. Totally busted.

But still really, really dangerous to stand that close. You don't want to

very close.

You do not want to be there.

Let's just psycho.

Ow!

Well, Adam, what are you doing?

Time to test these things.

Are you ready?

Ready as I'll ever be. Me too.

Okay, let's go.

It's launch day, and in search of perfect test conditions, our pioneering

touch down back at the NASA Ames Research Center.

We're back at Moffett Field, hangar number two, where we shot helium

and it's ideal for the concrete glider test for the same reasons it was ideal

for helium football.

We can close the doors of this huge space and eliminate any wind.

Dr. Steve Smith, MythBuster's font of all flying facts, is there to check out

the designs.

and offer some last -minute advice.

Crucial question on this one is going to be where the center of gravity is so

that it trims. Well, where should it be? So somewhere probably between 25 and 30

percent of the length, maybe. About right here?

It turns out that it's not just about reducing all the weight possible from

this, because if it's super light but balanced incorrectly, it's still just a

stone.

Next, Jamie presents his featherweight wilting bird.

But does Dr. Smith think it'll fly more like a paperweight?

Yeah, that's impressive. That's beautiful.

Table stay bracing and everything. Look at that.

Wow. Wow.

Dr. Smith's upbeat reaction to their designs has fueled their enthusiasm. But

his advice means Adam and Jamie have some tweaking, trimming, and testing to

To get the balance right, Adam is stealing another of George Cayley's

ideas and adding a gondola.

The weight beneath the wing can be adjusted to move the center of gravity.

it should stabilize the glider in flight.

Jamie has also been busy shifting his glider's center of gravity.

further forward.

It looks stupid, but we don't care about that right now. It's a concrete

airplane. What are you going to do? It may have been called Big Nose at glider

school, but it's ready to fly.

And while Jamie has been picking his glider's nose, Adam's been getting some

launch advice.

I figured out with Dr. Smith's help.

Actually, Dr. Smith figured out with my help. And by help, I mean I supplied him

with measurements.

He was able to calculate that it should fly

At around 20 to 22 miles per hour, about 30 feet per second, if it is to hit its

ideal speed to glide ratio. And because his throwing arm won't manage two miles

an hour, never mind 22, he's got a cutting plan.

He's going to use a zip line, toe line, and quick release.

That mark is where the pin gets pulled out.

And my glider starts flying on its own. Adam then optimistically marks out a

target distance of 50 feet.

That's how far I want to travel.

Jamie, who has decided to hand launch, looks on unimpressed.

At this point, if I were to guess, there's going to be something go wrong

the kind of scheme that he's got for launching it properly.

But we'll have to wait and see.

Now, I'm about to let go of this. You got the hook?

Yep.

Oh, buddy.

Okay. Everything's in place. I'm going to go down there and grab the tow line.

Last call for the departure of Concrete Airways, flight 101.

Three, two, one, go.

Well, the launch was successful, and Adam's Cayley glider has survived

relatively intact.

But how far did it glide?

Well, let's see where I, oh, there's my 50 foot mark, 55 feet. So I didn't make

that.

Looks kind of like I hit, maybe at like 20 feet.

So I didn't get my, I didn't get my glide ratio I was hoping for.

But hold on, there's a catch.

Adam thinks his glider released from the zip line and began flying on its own at

a height of 20 feet before gliding a distance of 20 feet.

But there's been a recount.

My glider released from its catch off of its guideline at about nine feet off

the ground.

It then flew close to 34 feet before hitting the ground.

Now, four times nine is 36.

So 34 feet means I came devilishly close to a four to one glide ratio.

I'm stunned, actually. I could not be more pleased with these results.

I know I was shooting for 55 feet, but really, I was hoping for anything over a

solid drop into the ground.

It flew very stably. That is really clear, which means that, I mean, we only

one chance. I only had one chance to trim this thing so that it would fly

straight, and it did.

That is, I feel really, really good.

Incredibly, Adam has gone from underdog to top cat.

Jamie steps up to the plate, but he's stubbornly sticking to a manual launch

from the stairwell, despite Adam's successful flight.

I don't want to screw around and, you know, get some kind of, you know, line,

zip line going and all this kind of stuff. I'm just going to throw it and

what it does.

With a spring in his step, Adam measures out the target Jamie needs to exceed to

succeed. We know that Jamie's 28 feet off the ground, so if he wants to hit a

to 1 glide ratio, he's got to get his plane to hit the ground at 112 feet.

Calling all passengers for Concrete Airways Flight 102.

Okay.

In 3, 2...

One. Well, there you go.

Jamie's wilting bird took flight and then took a nosedive. In other words,

concrete glider was all concrete and no glide.

Congratulations. You won.

I'm going to enjoy this for the short while that it lasts.

Jamie's one -to -one glide ratio was not even close to matching Adam's soaring

achievement of four -to -one. And, you know, it's possible Adam will let Jamie

forget about this.

It's not really about who wins or loses. It's really just about illustrating the

concept.

But I won. But unlikely.

All gloating aside, what about the myth? Did the guys prove anything about the

concept of a concrete glider?

Aerodynamics of planes don't scale up very easily from small to human size.

But that being said, I think there is actually a tiny chance that

one could build a human -sized concrete glider. I'm not sure that I would get

into it, but I'd certainly give Buster a ride.

Well, Adam, I don't think either of us were really that happy with the gliders,

but we did prove that it can be done.

I'd call it plausible.

But not recommended.

Yeah, you know, the big thing for me is that you only got one shot at it. You

know, it's brittle. If you crash with the things, it's over.

But, you know, I think we also proved that if you really think through your

launch and you do it correctly, that you can actually get some gliding done.

We're threading a little bit, are we?

Sure.

Okay. I'll enjoy it while I can.

So we're plausible.

Plausible. But not recommended.

Exactly.