NARRATOR: The great North American covered bridge, an icon of early engineering ingenuity.

Thousands of these uniquely distinctive structures once knit this land together.

♪ ♪ But today, the few that remain are under threat.

Abandoned, burned, or destroyed by flash floods and storms.

(wood crumbling) WOMAN (tearfully): Oh, my God.

The bridge is gone.

♪ ♪ The devastation was absolutely total.

NARRATOR: Now, a team of master craftsmen and elite engineers... MAN: Whoa, whoa, whoa, whoa!

Stop!

NARRATOR: ...battle torrential rain and blizzards... STAN GRATON: If this isn't out of the floodplain, Mother Nature is going to take it.

Go on ahead.

NARRATOR: ...to rebuild one of the world's longest single-span covered bridges.

GABE MATYIKO: I don't think we've ever jacked anything this large and this heavy up this high.

Let it down-- whoa!

NARRATOR: What are the engineering secrets that enable these huge spans?

(thunder rumbling) And what can we learn from the world's oldest covered bridges in China, where engineers face the same challenge-- to save these historic wonders before they're lost forever.

(translated): We're losing more and more of our woven arch beam bridges.

DON AIREY: Concerned?

Yeah, very concerned.

NARRATOR: "Operation Bridge Rescue," right now, on "NOVA."

♪ ♪ (birds chirping) NARRATOR: In the heart of upstate New York, 40 miles southwest of the capital, Albany, lies the small town of Blenheim.

♪ ♪ Fewer than 400 people live here, but the town once boasted a landmark that put it on the map-- a covered bridge with one of the longest single spans in the world-- the Old Blenheim Bridge.

This distinctive structure was also one of the last surviving twin-lane covered bridges.

AIREY: It is more than a symbol.

It is more than a structure.

It is an icon of our cultural identity.

♪ ♪ NARRATOR: Covered bridges were once a common sight across much of North America, with single spans up to 360 feet.

They connected communities and expanded the early road network.

♪ ♪ Where timber was abundant, craftsmen covered their bridges, making the structures last far longer.

TERRY E. MILLER: You have to admire the bridges as workmanship of a different time.

A wooden bridge left in the open would last nine or ten years, because when water gets in there, rot sets in, and the bridge fails.

But covered can last indefinitely.

NARRATOR: North America had an estimated 15,000 covered bridges.

But today, over 90% are gone.

In 2011, Hurricane Irene smashes into the east coast of America.

(waves crashing) It slams North Carolina, then blasts the rural heart of New England.

The storm reaches as far inland as Vermont, with flash floods destroying two historic covered bridges here, including the 140-year-old Bartonsville Bridge.

WOMAN: Listen to that.

I don't like that at all.

MAN: There it goes.

WOMAN (tearfully): Oh, my God!

NARRATOR: This was the event that also wiped out Blenheim's cherished covered bridge-- a National Historic Landmark.

MISSY GRAHAM: It was the heart of the town.

It was our small claim to fame.

(laughs) The longest single-span wooden covered bridge in the world.

It was always there.

It was always something you could depend on.

♪ ♪ AIREY: Hurricane Irene was almost a biblical flood event.

The devastation was absolutely total.

The area received some 15 inches of rainfall.

Roads were washed out, infrastructure was destroyed, communications were virtually eliminated.

NARRATOR: The floodwater here rose so high, that it lifted the Old Blenheim Bridge wholesale, up off its stone abutments, carrying it a short way downstream, before it was dragged underneath a roadway and smashed to smithereens.

GRAHAM: When we came down the morning after the flood, there was pieces of the bridge, just scattered all over here.

There was a big chunk of the roof that was laying up against the other side of the guard rail.

(voice trembling): Just... the destruction.

It was hard to believe it was even possible.

And there was just this empty spot where the covered bridge used to be.

(water rushing) The bridge is gone.

♪ ♪ I felt like I'd lost a loved one.

It felt like I had lost a friend that I'd known my whole life.

♪ ♪ NARRATOR: After years of effort, the residents of Blenheim have secured $6.7 million to rebuild their lost bridge, attract tourists, and help kick-start the town's recovery.

AIREY: Thanks to everybody for taking the time out to come down to the town board meeting, NARRATOR: Head of the Blenheim Recovery Committee is Don Airey.

AIREY: With that bridge, that historic landmark being rebuilt, we feel that we could almost close the door and find some permanent closure, although never forget, the catastrophic day of August 28, when Hurricane Irene struck.

♪ ♪ NARRATOR: To take on the unique engineering challenge of rebuilding the Old Blenheim Covered Bridge, the town has enlisted one of the last surviving covered bridge craftsmen-- Stan Graton II.

AIREY: Stan's a true craftsman.

A rare breed in terms of being able to have the skill set, the mindset, and the drive to recreate these original icons of early America.

Saving them, preserving them, and in this case, recreating them for future generations to appreciate.

NARRATOR: Stan is a third-generation timber bridge builder.

Today, he works with his cousin J.R., his father, Stan, Sr., and his son Garrett, passing down knowledge and tools.

STAN: I've been in the family business since 1976, and we build and restore covered bridges.

STAN: Yep.

NARRATOR: But recreating the Old Blenheim Bridge will test even a builder of Stan's pedigree.

STAN: Down!

Beautiful.

It's a massive structure.

It's going to be 36 feet high at the peak, 226 feet long.

It's going to be right up there with the top projects that we've done.

NARRATOR: There are no original blueprints of the bridge.

Luckily for Stan, government engineers surveyed the structure back in 1936, producing detailed plans.

J.R.: We're duplicating the exact design of the old bridge.

We've changed the species of wood from spruce to Douglas fir, because you can't get a spruce that big and that quality anymore.

And we're using galvanized steel instead of wrought iron, and it's the only the compromises we made.

NARRATOR: The Old Blenheim Bridge was built by Nicholas Montgomery Powers in 1855.

♪ ♪ To construct it, he assembled the structure on land in Blenheim village, while masons built the stone abutments next to the creek.

Between the abutments, they installed temporary scaffolding.

The team then dismantled the bridge and rebuilt it, piece by piece, on top of the scaffolding.

Once in place, they removed the supports, allowing the bridge to settle onto its abutments.

But erecting bridges like this over fast-flowing rivers was risky.

One worker was killed building the Old Blenheim Bridge.

STAN: It's more dangerous working over the water.

Men were a lot hardier back then than they are today, I don't work as hard as my grandfather did, I know that.

NARRATOR: So now they need to find a safer technique to build the New Blenheim Bridge.

The solution?

Build the bridge's two outer walls, and one central wall, flat on land, next to the creek, then raise them vertically.

Brand-new concrete abutments will elevate the bridge higher above the creek, protecting it from future floods.

Once they've added the siding and rafters, they must move the 100-ton structure, intact, up onto its new abutments.

A daunting challenge.

STAN: Jerry!

Hey, Stan!

How're you doing, buddy?

NARRATOR: But one that this man, Jerry Matyiko, relishes.

Nice seeing you again.

Nice to see you.

He is a character, he is a character, yep.

Known him for quite a while.

He's a great guy, a wealth of knowledge 24 feet up, and how tall is it?

30 feet?

30 feet.

♪ ♪ NARRATOR: Jerry's been moving supersize structures for over 50 years.

Go on ahead!

NARRATOR: He's moved over 1,000.

We move everything from outhouses to lighthouses.

We've moved airport terminals, smokestacks, theaters, gymnasiums, monuments.

You name it, we've moved it.

NARRATOR: On the island of Martha's Vineyard, Jerry recently relocated the 160-year-old Gay Head Lighthouse, in danger of toppling off the crumbling cliff.

♪ ♪ (motor rumbling) (cheering, cork pops) MAN: To Gay Head Light!

The people were all glad to have us there to save the lighthouse.

It's just something sacred to the people on Martha's Vineyard.

♪ ♪ NARRATOR: But launching a 226-foot-long, 100-ton bridge into thin air over this creek is an entirely new challenge for Jerry.

JERRY: This bridge is just so much bigger than the other covered bridges.

This is the biggest and the tallest and the longest ever built.

It's going to be really something.

NARRATOR: For this job, one option would be to use a giant crawler crane to pick up the bridge and move it over the creek.

But this could be risky.

JERRY: It's got limits on what it can lift, at what angles.

And you know, there are cranes that tip over.

NARRATOR: A safer option would be to set the bridge on tracks and roll it up onto the abutments.

But a tight turn could derail this scheme.

Rolling on railroad rails is good for going straight, but we have to make a sharp turn.

It's just no way you could have rolled it on rollers.

NARRATOR: So this is Jerry's plan.

First, they will build a temporary roadway across the creek.

Then he'll install eight sets of powered hydraulic wheels under the bridge.

These should help steer the bridge around the sharp turn and drive it onto the roadway.

Once in position, Jerry will use hydraulic jacks to raise the bridge 25 feet.

(hydraulics pumping) He will then set rollers underneath the bridge and use hydraulic push rams to inch the massive structure onto the concrete abutments.

At least, that's the plan.

JERRY: There's a lot of problems that can happen.

One of the hardest parts is going to be making the turn.

It's going to be a hard time.

NARRATOR: But there's another dangerous threat to this ambitious plan.

This is definitely in the floodway.

Any snowpack during the winter is going to end up melting and coming down.

And if we do not get this out of this floodway before spring, it will end up in pieces like the original bridge.

(forklift's signal beeping) NARRATOR: That means Stan and Jerry have just nine months to build the New Blenheim Bridge and move it into place before spring meltwater floods the worksite.

(forklift's signal beeping) The first step of the build is to assemble the bridge's skeleton from over 6,000 timber beams.

It is a massive jigsaw puzzle.

All the members are numbered, I for interior, N for north, S for south.

And we really need to be careful not to use up the wrong one in the wrong spot.

NARRATOR: Just like the old bridge, the secret to the New Blenheim Bridge's huge span is her three vertical walls, called trusses.

These will be built with a slight arch, or camber, for increased strength.

Each truss will be made up of dozens of interconnecting triangles.

These distribute the weight of traffic throughout the structure.

The taller interior truss makes the bridge a rare two-lane crossing.

Within this truss, a vast, triple-laminated arch will add even more strength.

78 separate timbers will make up the base of the three trusses.

It's critical the joints between these timbers hold strong, so they will use an ingenious sawtooth joint to lock the beams together.

J.R.: Those sawtooth joints work like a ratchet.

It's probably the strongest actual wood joint that you can come up with.

NARRATOR: The team uses power tools to cut the teeth of the sawtooth joint, but then, they use traditional tools to finish the joint, just as Nicholas Powers did for the original bridge.

♪ ♪ They must cut each tooth with extreme precision.

An ill-fitting joint could fail and cause the bridge to collapse.

MIKE EENIGENBURG: We need a nice tight-fitting joint.

This is where all the tension is in the bridge, so most of the structure of the bridge boils down to these joints here.

♪ ♪ NARRATOR: They use ten galvanized steel bolts to lock each saw-tooth joint together.

200 years ago, when iron was more expensive, bridge builders would often use wooden dowels, known as tree nails or trunnels, driven through the timbers to secure them.

♪ ♪ After five months cutting and hauling more than 63 tons of timber, Stan completes the first two trusses of the New Blenheim Bridge... STAN: Yup!

NARRATOR: ...one exterior truss, and the taller central truss that will form the peaked roof.

♪ ♪ But the clock is ticking.

It's now November, and the team has just four months until their worksite is likely to flood.

We're a month and a half behind where we wanted to be.

We've got a critical path, because of the spring floods, the snowmelt.

It's starting to worry me a little bit.

We've got to have this out of this riverbed and up onto the abutments.

NARRATOR: To keep the build moving, their next challenge: use two cranes to raise each truss up vertically.

But there's a problem.

The trusses are so long, that if each crane pulls at just a single point, the timber will flex and could snap.

To guard against this, Stan will rig each crane to pick up the truss at two separate points, and underneath, he'll add extra towers of wooden blocks, called cribs.

This spreads the load, supports the truss, and reduces flexing as it rises.

At least, that's the theory.

STAN: Every bit of that needs to be supported.

If it isn't supported correctly, you would snap it in half.

WOODY: Okay, we're going to bring it up until we get movement.

We're gonna go slow, guys.

NARRATOR: A pair of slings connects the cranes to the central truss.

Both cranes are gonna boom up and hold their load.

NARRATOR: Crane supervisor Woody gears up for the first big lift.

Okay, guys, here we go.

Yep, coming up!

♪ ♪ Watch for movement.

(radio beeps) J.R.: We have to watch it, that it doesn't slide towards us or away from us.

So we have to keep the cranes so that they're picking straight up.

(crane winch straining) (clanking) WOODY: Cable up.

Looking good.

(pounding) (wood straining) NARRATOR: But just as the truss approaches vertical... Stop, stop!

NARRATOR: ...it starts to slide off its supports.

MAN: Whoa, whoa!

MAN 2: Stop!

NARRATOR: The wooden support towers shift, leaving the truss barely supported.

WILLIAM ADAMS: Just the weight of the bridge.

It's trying to slide out as you're lifting up.

Could slide out entirely if we don't fix it.

NARRATOR: Stan's team rushes to rebuild the towers.

Yep, down!

NARRATOR: With the supports shored up, they restart the lift.

Woody!

Okay, both cranes, cable up.

Cable up easy.

♪ ♪ NARRATOR: Disaster narrowly averted, the central truss is vertical.

(crane whining) STAN: Beautiful!

What are we doing next, Stan?

Got to use this cheap labor while you got it.

(laughs) Jerry bought me a couple of cigars, actually.

Doing a major pick like this, kind of relaxes you.

(radio beeps) WOODY: Okay, both cranes, cable up.

NARRATOR: The team races to reset the cranes and lift the first outer truss.

(radio beeps): Okay, both cranes, go.

(creaking) ♪ ♪ 38, 39, 40.

Nothing's shifting at all.

♪ ♪ (radio beeps): That looks good!

♪ ♪ STAN: Good!

Let's get her plumbed up, buddy!

Getting these two stood up is a big milestone.

AIREY: It's been six years since I've seen these trusses.

It's just coming back to life again.

And it's a rebirth of, of what we lost.

NARRATOR: With two out of three trusses vertical, this distinctive bridge starts to reclaim its rightful place in the landscape.

♪ ♪ Beginning in the 1800s, each region developed its own distinctive style of covered bridge.

MILLER: They evolved kind of independently in different areas.

Oregon bridges are distinctive.

They look like bridges in Oregon, nowhere else.

Iowa has the only flat-roofed bridges in the country.

Pennsylvania bridges look different from Ohio bridges.

The builders worked from intuition, from experience, because there was no science of engineering.

NARRATOR: But the North American covered bridge was not the first of its kind.

Wooden covered bridges were also built in the medieval cities of Central Europe.

The Chapel Bridge in Lucerne, Switzerland, has stood since 1333 and is the oldest surviving wooden covered bridge in Europe.

♪ ♪ But some of the oldest and most spectacular timber- covered bridges in the world were built in the remote forests of subtropical China.

In the southeast of the country, visionary engineers developed a completely unique building technique to link remote villages.

♪ ♪ Professor Jack Liu has been researching these elaborate structures for 22 years.

(translated): We call this structural form the woven arch beam bridge.

A single log can't cross a 20- or 30-meter-wide river.

So we combined them to form an architectural structure.

NARRATOR: But unlike American covered bridges, the Chinese did not use trusses.

Instead, they developed a very different system of interwoven beams to create an arch.

Engineers wove one span of three beams with a second span of five beams.

They used simple mortise and tenon joints to connect the beams together.

They added extra cross supports and a bridge deck.

Finally, they built a timber structure on top to protect the arch beams and provide shelter from the wind and rain.

LIU (translated): The roof protects the timbers, but it also provides a place where villagers can meet and relax.

♪ ♪ Also in some places, the bridges house markets and form the center of village life.

Or they provide space for people to worship.

We see that there is a small shrine inside each covered bridge.

♪ ♪ NARRATOR: But these bridges do have an engineering Achilles' heel.

(translated): If the woven timber beams do not have a heavy building on top, the entire structure is at risk.

NARRATOR: Gravity alone holds the woven timbers in place.

Forces pushing upwards from beneath the structure, such as wind and floodwater, can loosen the mortise and tenon joints, eventually tearing the beams apart.

To combat these forces, early bridge builders added ever more weight on top, to lock the beams down tighter.

(translated): It's critical that the weight compresses the arch structure.

The building above is vital to the arch below.

They work together in perfect harmony.

♪ ♪ NARRATOR: The more heavily tiled, the more massive the stone flooring, the stronger the woven arch beam bridge became.

(thunder rumbling) But today, these exquisite wonders are under threat, just like their American counterparts.

In 2016, three historic Chinese covered bridges were washed away by Typhoon Meranti.

LIU (translated): We're losing more and more of our woven arch beam bridges.

So this is a major problem in this region.

NARRATOR: The battle is underway to repair and rebuild these iconic crossings before their engineering secrets are lost for good, in both the East and the West.

STAN: So, you guys good?

NARRATOR: But time is the enemy.

In upstate New York, Stan races the clock to reconstruct the Blenheim covered bridge before spring meltwater floods the worksite.

MAN: One more?

NARRATOR: It's taken six months of arduous work to assemble and raise the bridge's three trusses.

Perfect!

NARRATOR: These will form the skeleton of its unusual two-lane crossing.

AIREY: It's exciting, watching it happen again.

Words don't describe it.

STAN: Really excited to have this done.

All three trusses are stood now.

♪ ♪ NARRATOR: Their next task, before they attempt to raise the bridge to its final location, is to install its outer walls and rafters.

(drill buzzing) (saw whirring) The town hopes to incorporate part of the old bridge into the new, creating a link through time.

GRAHAM: It'll be like taking a little bit of the bridge's soul and, and putting it into the new bridge.

♪ ♪ NARRATOR: But this will not be easy.

AIREY: This is where we've got the stored material of the old covered bridge.

STAN: We'll do some digging and see what we can find.

It's hard to look at, a little bit.

A little hard to look at.

♪ ♪ There's an old sawtooth joint.

AIREY: Oh, yeah.

This probably speaks to the power of that water, being able to break it up like a toothpick.

STAN: That's a rafter!

AIREY: All right, so that's a candidate.

AIREY: Okay, that's... STAN: Four and a half.

Three and seven eighths.

STAN: We found one rafter that was amazingly intact.

So this'd be the piece that we can actually put into the bridge just where it was in 1855.

It'd be part of their closure, I think.

♪ ♪ It's like a phoenix, you know.

It's destroyed, and then it's rebirthed now.

(drill whirring) AIREY: Feels like a small part of the old bridge is back.

It means a lot.

NARRATOR: Just a month remains to complete and move the bridge out of the floodway.

But as they battle to fit the final rafters, winter bites.

(birds crowing) Three consecutive snowstorms pummel Blenheim.

AIREY: We've received over 50 inches of new snowfall in the past two weeks.

Concerned?

Yeah, very concerned.

NARRATOR: The snow not only slows the build, but also increases the risk of a catastrophic spring flood.

AIREY: Trees trap the snow in terms of shading, uh, the terrain traps the snow.

And we've got three, four feet of snowpack that has to get somewhere.

And where it's going to go?

To the Schoharie Creek.

NARRATOR: As temperatures rise and the snow melts, floodwater could soon consume the worksite and destroy all the team's hard work.

That would be the worst-case scenario.

The gun is loaded.

We have no other choice but accelerate the lifting of the bridge onto the abutments as soon as possible.

♪ ♪ NARRATOR: It's only when a covered bridge is high enough above the floodplain, and carefully maintained, that it will last.

There's one in America that has survived everything nature has thrown at it.

Just an hour northwest of Blenheim stands the Hyde Hall Bridge.

This is the oldest surviving covered bridge in America and has endured almost two centuries of wind, rain, and snow.

MILLER: The first generations of bridges would have been replaced as traffic became heavier.

Very few of that early layer are still in existence.

NARRATOR: Built in 1825, the Hyde Hall Bridge is still standing, her original trusses protected by her carefully maintained roof and siding.

In China, the oldest surviving woven-beam covered bridge is hidden in the remote 1,000-year-old village of Yueshan-- "the Village of the Moon and Mountain."

The Rulong Dragon Bridge is almost 400 years old.

It's an engineering mystery how this exquisite structure has survived not only four centuries of typhoons, but also devastating earthquakes.

Professor Liu investigates the bridge's secrets.

LIU (translated): The bridge is asymmetrical, but also very beautiful.

So, this is a very, very special bridge.

NARRATOR: How has the Rulong Bridge survived for so long?

A clue lies hidden high up in the roof of the structure-- hundreds of complex brackets, called "dougong."

(translated): They're not just decoration.

They're also a kind of shock absorber.

♪ ♪ NARRATOR: This test simulates an earthquake and shows how the dougong absorb the forces and help stabilize the heavy tiled roof.

(creaking) The intricate brackets help legendary buildings, like the Rulong Bridge, roll with the punches.

(translated): A dougong looks quite simple, but it's not easy to make.

(hammer tapping) Only a few masters know how to make dougong.

NARRATOR: Today, Master Wu is putting the finishing touches to a brand-new bridge.

Once complete, the 143-foot-long Tunfu Bridge will be China's longest single-span covered bridge.

♪ ♪ And just like its historic counterparts, it has an extraordinarily complex system of dougong to make it earthquake-proof.

Master Wu assembles individual dougong to form sets of brackets.

He uses bamboo nails to join them together.

(translated): In ancient times, there were no iron nails, only bamboo nails.

The bamboo nail fits in here and will not rot for hundreds of years.

They are very strong.

♪ ♪ NARRATOR: The dougong are slightly loose, allowing the roof to absorb movement.

This skilled craftsmanship should help Master Wu's new woven-beam bridge survive nature's wrath for generations to come.

But back in upstate New York, the future of the new Blenheim covered bridge hangs precariously in the balance.

It's now March.

As temperatures rise, torrential rain hits the worksite, and the dense snowpack melts in the hills to form streams.

(water rushing) This deluge runs into the Schoharie Creek, causing water levels to rise.

AIREY: The rise is much higher than we want and could imperil the bridge.

Thus, the big push to get the bridge on the abutments.

MAN: Whoa!

NARRATOR: As the creek expands, water creeps ever closer to the bridge, just as the team faces the most complex stage of this operation.

They must now move the New Blenheim Bridge off the flooding creek bank up onto its abutments.

This move is a two-stage operation.

Stage one involves steering the bridge on wheels around the sharp turn and onto a temporary roadway that the team has erected over the creek.

It's taken nine weeks to build the temporary roadway from steel girders and heavy timber beams.

Everything is now set for heavy-move maestro Jerry Matyiko to prepare the bridge for its journey.

That's if he can get his equipment onto site.

JERRY: Whoa, hat down, hat down.

Positioning these wheels can get a little bit tricky.

And the river's up, so that'll delay us even more.

MAN: Come on.

GABE: Whoa!

Free!

NARRATOR: Jerry works with his son Gabe.

GABE (laughs): Sweet!

GABE: This has been pretty much my dad's baby, but I'm here for the move.

It's pretty awesome.

NARRATOR: Finally, it's go time.

We're ready.

GABE (on radio): All right, Dad, come on ahead.

♪ ♪ NARRATOR: The front and rear hydraulic wheels are powered by diesel engines.

But it's elbow grease that powers the steering.

Chains run between the wheel sets.

Cranking the chains pulls the wheels left or right.

GABE: P.J.!

P.J.!

Tighten up.

NARRATOR: 24-year-old P.J.

is in charge of steering the massive structure.

GABE: All right, go to the next one, go to the back.

NARRATOR: One wrong move could end in disaster.

That's good.

P.J.

HAILE: You got to make sure everything's tight, everything is in perfect lined order.

Nothing can be off, because one fraction of an inch could potentially kill somebody.

(engines idling) NARRATOR: Just as they get going, they hit a problem.

The bridge is so heavy that it sinks into the waterlogged creek bank.

That gravel is screwing me up, it's loose.

Now, I've gotta get off of this soft gravel.

NARRATOR: Fortunately, Jerry's got a plan.

Hold up!

All stop.

Dig out a little bit, Gabriel.

Clean out a little bit.

NARRATOR: They lay down wooden boards to help the wheels grip and drive the bridge out of the hole.

JERRY: Don't need no more.

GABE: All right, move ahead, let's go.

NARRATOR: But they immediately hit the next obstacle.

♪ ♪ Somehow, they have to turn the bridge to line up with the roadway.

GABE: We gotta get into a really hard turn, a 90-degree turn.

Just about as hard as you can, as you can go.

And the harder we get into the turn, the more you gotta keep those dollies heading in the right direction and in sync with each other.

So you got the dollies in the front aiming straight towards the bridge and the dollies in the back going at a 90-degree angle.

♪ ♪ Stop!

Stop!

Stop.

Everybody stop.

You should be heading right there.

Dad, I can't turn anymore.

It'll fall off the embankment.

NARRATOR: Gabe has run out of road to turn-- and the clock is ticking.

With creek levels rising rapidly, they scramble to widen the roadway near the front wheels.

GABE: All right.

Everybody ahead-- go.

Nice and slow, moving ahead.

All right, let down!

NARRATOR: But the loose rubble underneath the roadway is close to collapsing.

GABE: Let down-- whoa!

Stop!

Stop!

NARRATOR: Keep going and the bridge could slide into the river.

GABE: I opened up the dollies, and there's inches to spare here.

NARRATOR: At this angle, there's simply not enough space to get the front wheels onto the temporary roadway.

They're stuck.

What we're doing is, we're actually going to just hold this end stationary while the back comes around.

It's gonna just basically pivot like that.

Once we get to where we want to be, then we stop again, straighten everything up, continue across the bridge.

NARRATOR: But making space to swing the rear of the bridge around won't be easy.

They need to shift tons of earth-- and fast.

♪ ♪ STAN: We're limited with the real estate that we have to work with, so it's gonna be real tight.

Go on ahead!

♪ ♪ NARRATOR: They slowly swing the rear of the bridge around to line it up with the roadway across the creek.

Finally, with inches to spare, everything lines up.

GABE: All right, we're gonna move it ahead on three.

One, two, three, let's go!

♪ ♪ We're on a roll now.

♪ ♪ JERRY: Gabriel!

We got about, oh, maybe eight feet to go.

We want to hit it on the button.

It's kind of a one-shot-deal scenario.

♪ ♪ Is that it?

Little bit, give me a touch!

I think we're there.

Whoa!

Oh.

Chock it up!

NARRATOR: After an epic battle against the elements, stage one of the move is complete.

The New Blenheim Bridge sits across the creek.

But the creek is still rising, and stage two of the move will expose the bridge to even more danger, as they raise it up 25 feet and slide it onto the abutments.

Hi, kids!

You got the pictures of the wheels.

NARRATOR: There's just time for Jerry to catch his breath and hopefully inspire the next generation to look after this landmark.

It's the longest single-span covered bridge ever built.

GRAHAM: These kids went through something pretty traumatic.

And I think them seeing this bridge rebuilt?

It feels like home again.

The new bridge is gonna be higher than the old bridge.

The flood won't take it away.

So hopefully, if you take care of it, it'll last longer than you kids will, or your grandkids.

(laughing) NARRATOR: Without the next generation of craftsmen, the engineering knowledge needed to build these enigmatic structures could be lost to history, in America and in China.

(hammer tapping) ♪ ♪ So the Chinese are taking a highly proactive approach-- building huge museums to the art and science of covered bridge construction, like this one in Qingyuan.

(speaking Chinese) NARRATOR: They're also teaching the woven arch technique in schools.

(Mr. Hu speaking Chinese) (students counting) (translated): The kids really have fun in this class.

They explore the structure of the bridge.

This is the most important learning, but also the most exciting.

(speaking Chinese) (translated): The number of masters who can build these bridges is decreasing.

There are only a few left.

If we don't pass on these skills, we will lose them, and this would be a great loss for our country.

So we must give our children bridge-building knowledge as early as possible.

(translated): I look at the pictures and see the masters who built the covered bridge.

I admire them.

I think when I grow up, I want to be a bridge builder.

♪ ♪ NARRATOR: The future of Chinese woven beam bridges seems to be in good hands.

But in Blenheim, New York, the future of this covered bridge remains balanced on a knife-edge.

The 100-ton structure is finally over the creek, but not yet safely on its abutments.

The team must race to complete the second stage of the move.

Lifting the bridge up onto its supports will require 12 hydraulic jacks to raise the structure 25 feet into the air.

Only when the bridge reaches its final height can they then slide it onto the new abutments, out of danger from the rising creek.

♪ ♪ The jacks can only raise the bridge 16 inches at a time, so the blocks support the bridge until the jacks are retracted and reset for the next big push.

♪ ♪ JERRY: We got 2,000 four-foot, 6 x 6 oak blocks.

It's just a nice big block party.

♪ ♪ GABE: I don't think we've ever jacked anything this large and this heavy up this high.

HAILE: 18 to 20 feet doesn't seem that high when you're just looking at it, but once you get up there, and there's water over here-- we're already about ten foot up, so we're gonna be about 35 foot up, and it's kind of creepy when you're up there.

JERRY: Watch yourself!

Higher you go, the slower it goes.

♪ ♪ ♪ ♪ (hammer pounding) I think we're there!

NARRATOR: The team raises the bridge the full 25 feet, but it won't be safe until they slide it across onto the abutments, using steel beams, rollers, and hydraulic push rams.

GABE: All right, guys.

I'm gonna start pushing-- let me know if it does not move.

MAN (on radio): I'm ready when you are.

GABE: All right, pushing in three.

One, two, three, go.

(creaking) NARRATOR: Gabe extends the push rams.

Moving?

MAN: Moving!

GABE: That sounds great!

NARRATOR: These inch the bridge towards the abutments.

♪ ♪ GABE: Well, we only got about another six, seven feet to go, and we'll be over the abutment.

Final push.

♪ ♪ NARRATOR: It takes three hours to push the bridge across to its footings.

Looking good, looking good.

We're gonna get that plumb bob right over that X.

We don't need all them fancy stinking lasers and all that.

We just got a plumb bob.

NARRATOR: The big question-- will the bridge and the abutments line up?

This is one of the more nerve-racking portions, because of how crucial the alignment is, whether the bridge and the abutment are all on the same page.

'Cause I know my bridge is right on.

It's just a matter of, "If it doesn't fit, it's their fault."

Four.

Three.

Two.

You want more?

Yes, yes.

♪ ♪ GABE: I'm one up-- whoa, whoa, whoa.

I'm good!

Spot on!

NARRATOR: Now, just to lower the bridge onto the abutments.

♪ ♪ Touchdown.

GABE: She made it!

♪ ♪ NARRATOR: After almost seven years, the Old Blenheim Bridge is reborn, and the community can finally welcome back an old friend.

(laughs) ♪ ♪ GRAHAM: It's beautiful.

I can't believe it.

It looks just like the old bridge.

You were, like, this big the last time we went across the bridge.

GIRL: It's crazy.

Huge beams, and all my family and friends here, it's just amazing.

NARRATOR: A walkway will link the crossing to the west bank.

It's taken $6.7 million, 176 tons of timber, and some ingenious engineering, but one of the world's longest single-span covered bridges is back where it belongs.

BILL CHERRY: Good afternoon, everybody.

Thank you for joining us at the ribbon-cutting ceremony.

There you go, and... (cheering) GRAHAM: It's kind of like a phoenix, a phoenix rising from the ashes, except for us it was water.

(cork pops, people cheer) GRAHAM: I think it represents a new beginning.

And I hope that someday I will be able to bring my grandkids here.

ALL: To the bridge!

♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪