All language subtitles for S21E08 - Aluminum Canoes; Wooden Stave Bowls; Wheelchair Accessible Vans; Marimbas (1080p AMZN WEB-DL x265 Garshasp)_track3_[eng]

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Narrator:
When world war ii ended,

An american manufacturer
Of fighter jets

Needed to land new business.

The factory employed the same
Stretched-aluminum process

Used for shaping aircraft wings

And came up
With an aluminum canoe.

No fighting machine,
The aluminum canoe is designed

For a peaceful day at the lake.

Among watercraft,

The aluminum canoe is
The strong, silent type.

It resists breaking and cracking
When it comes up against a rock

Or any other underwater object.

So this is one invention that is
Unlikely to sink into oblivion.

Aluminum itself is too soft
For canoe construction.

So metals like magnesium,
Nickel, and silicone

Have been added to give it
The needed strength.

Factory employees
Unwind the aluminum alloy

Onto a work table.

Using electric shears,
They cut it to length.

They lift the metal sheet
Onto a mold

Of of part of the canoe hull.

They clamp the metal
To a hydraulic system

And activate it.

It pulls and stretches
The aluminum-alloy sheet

To the mold,
And it conforms to its shape.

The molded sheet needs trimming,

So they transfer it
To a work table,

And place a template
Over the contoured section.

They clamp it into place.

With a scribe,
One of the workers

Etches the pattern
Onto the molded aluminum.

The team then transfers
The aluminum sheet to a jig

And cuts out the pattern
Following the etched outline.

They shape and cut a second part
Exactly like the first.

The two symmetrical halves

Will form the hull
Of the aluminum canoe.

They bake the hull halves
At 390 degrees fahrenheit

For eight hours.

The heat strengthens
The aluminum

And adds rigidity to it.

Out of the oven,

A member of the team
Now aligns two halves.

It's a perfect match,
So he now lowers a large clamp.

Once in place, he turns a crank

To pull the two parts
Of the aluminum canoe together.

Now tightly, clamped,

He welds the two parts
Along the bottom.

This joins them
With a water-tight seam.

With hand clamps, he tacks
The two rounded ends together

And welds here.

He links the end welds
To the one on the bottom,

And the result is
One continuous leak-proof weld

From bow to stern.

Next, the team positions
An aluminum keel

Along the bottom seam.

They reinforce it
From the inside with the t-bar.

They drive rivets
Through the t-bar, hull,

And keel to secure the assembly.

They install
Substantial aluminum guards

On the bow and stern
Using rivets to secure them.

These guards will protect
The end welds.

They brace the base of the canoe
From the inside

With six aluminum ribs.

Welded, riveted, and with a good
Support structure,

This aluminum canoe
Has really taken shape.

They equip the rim of the canoe
With aluminum gunnels,

Pounding them with a rubber
Mallet to improve the fit.

Then a worker rolls
Non-skid paint on the inside

So it won't become slick
When wet.

They bring
Incandescent heat lamps in,

And the paint dries quickly
In the warm glow.

After just 30 minutes,
The paint is dry.

Then it's time to see
If it will float.

They transfer the aluminum canoe
To a tank of water.

They clamp a bar
Across the canoe

To apply nearly 1,000 pounds
Of pressure --

More than the weight
Of two people.

They check for leaks,
Especially around the rivets.

There are none.

Crossbars and bench seating
Complete the fabrication.

There's one last bit
Of business,

And that's the company insignia.

This aluminum canoe
Is now ready for recreation.

10 hours in the making,
The fun has only just begun.

Narrator: bowls have existed
For thousands of years.

Very early bowls,
Used to serve food or drink,

Have been found in china,
Ancient greece,

And in certain
North-american cultures.

Modern bowls can be made
From a variety of materials,

Such as ceramic, plastic,
Metal, and wood.

Wood bowls come
In many shapes and sizes.

Many different kinds of wood
Are used to make bowls,

Such as rubberwood and teak.

Acacia is also a type of wood
Used to make bowls.

Workers cut flat planks
Of acacia

Using a large circular saw.

The acacia was cut a few days
Ago in nearby plantations.

Planks are cut to thicknesses
Required for bowl production

And pre-dried on pallets,

Spaced apart
For better air circulation.

Using a table saw,
A worker cuts the wood planks,

Now kiln-dried,

Into pieces long enough
To make the bowl wall.

Another worker uses
A tilted table saw

To cut the wood
Into shapes resembling a cone.

Drying the wood eliminates water

That might cause cracking
Later on.

A worker trims the pieces,
Giving them the angle they need,

So the staves
Can be rounded later on.

Another worker smoothes
The rough side of the staves

With a spinning cutter.

This also helps
Shape the wood pieces.

Another employee lines up
The staves on a table

Before applying glue.

She spreads a wood-binding glue
Onto the sides of the staves.

Once they're
Thoroughly covered with glue,

She begins assembling the bowl
By sticking the sides together.

She assembles a few pieces
At a time,

Handing them to another worker,
Who arranges the bowl's shape

By leaning the staves
Against a center piece.

They continue the process until
All the staves are in place.

Then they'll squeeze the staves
Tightly together.

They stretch elastic bands

Around the outside
Of the eventual bowl.

The elastics,
Held in place by a steel ring,

Squeeze the staves
Firmly against each other.

With a hammer, she lightly taps
The staves into place,

Making sure they are flush
Against each other.

She turns the bowl over

To make sure none of the staves
Around the top rim

Are sticking out too far.

She then leaves the bowl to dry.

About five hours later,
They remove the elastics

And, again, leave the bowl
To harden for a full day.

A template is attached
To the eventual bowl,

In order to cut a circular
Opening for the bottom piece.

The template serves as a guide
During the cutting process.

A worker moves the bowl around,

Allowing the cutter to create
A perfectly sized hole

For the bottom section
Of the bowl.

It's made
Of the same kind of wood --

In this case, acacia.

A worker applies glue

To the edges
Of the bottom hole...

...And to the outer edge
Of the round piece

That goes in the bottom
Of the bowl.

He inserts the bottom plate

And uses a hammer to force it
Firmly into place.

After another day of hardening,

A worker places the bowl
In a lave.

With a variety of knives,
He begins shaving off the wood.

He starts on the inside wall
Of the bowl.

Then he shaves
The outside of the bowl,

Gradually giving it shape.

He then uses sandpaper to smooth
The surface of the bowl.

Another worker then uses a lave
To sand the surface of the bowl.

He makes the surface
As fine as possible.

He must have
A keen eye for detail

In order to make the bowl
Surface perfect.

A worker sprays
A foodstuff varnish

Onto the surface of the bowl.

Several layers are applied

With drying and polishing
After each one.

If required,
A stain is also applied.

They place a sticker
Identifying the manufacturer

On the bottom of the bowl.

A worker then packages
The wood bowl.

With the bowl secure,
The only thing tossed around

Will be the ingredients
You put in it.

Narrator: the minivan was
Designed with families in mind,

But it also
Revolutionized travel

For people in wheelchairs.

Retrofitted for wheelchair
Accessibility,

The minivan offers
Unprecedented mobility.

No need to wait for special
Wheelchair transportation

When there's a minivan
In the driveway.

Convert a minivan
And change a life.

A wheelchair-accessibility
Conversion

Offers the convenience
Of a ride anytime.

From the outside,
The van will look no different.

But inside, the modifications
Will be major.

The total revamp starts

With the removal of the van's
Middle and third-row seats.

They pull out the carpet
And completely strip the vehicle

From the front seats
To the back.

Underneath, a technician
Saws off the exhaust system,

And disassembles
The rear suspension.

The entire undercarriage
Behind the engine

Is about to be reconfigured

To make way
For a new lowered floor.

The team also removes
The 20-gallon fuel tank.

They'll replace it
With one of the same capacity

To fit the new configuration.

They cut out
A large section of floor

And relocate displaced wiring.

They're now ready
To roll the new floor framework

Into position below the vehicle.

This steel structure
Replaces the original one

And is strong enough

To support the additional weight
Of a wheelchair.

A motorized one can weigh
As much as four adults.

They slide the new steel floor
Into the vehicle

And lower it into the framework.

The new floor
Is significantly lower

Than the one the van came with,

And it increases the wheelchair
Passenger's headroom

By about 10 to 15 inches.

After installing
The new fuel tank, suspension,

And exhaust systems,
They return to the interior.

A technician fits and binds
Carpet underpadding to the van.

He installs the carpet
And clamps it

While the adhesive cures.

With the back of the van
Rebuilt and carpeted,

They now ready
The wheelchair ramp.

A technician applies
A gritty material

With an adhesive backing.

He simply presses it to the ramp

And smoothes out
Any air bubbles.

This gritty material will
Provide a slip-resistant surface

For the wheelchair
To move across.

He attaches a handle...

And installs
Two cable assemblies

To connect the handle
To the ramp latches.

He attaches a return spring
To the handle assembly.

He turns the handle
And tests the latches

To confirm that the mechanisms
Function properly.

The team then links
The wheelchair ramp

To the new floor
With a long hinge.

They install
Stainless-steel trim

Over the hinge to protect it

And also connect
The counterbalance cables

To the ramp.

Hidden springs
At the end of the cables

Provide tension

To significantly lighten
The load for the operator.

The ramp weighs
About 130 pounds,

But the operator ends up lifting
Just 15 of that,

Due to the spring-loaded
Tension.

They reinstall
The interior plastic panels

And repurpose the original
Second-row seatbelts.

As they finish up inside,

An employee puts
The company name

On the door of the vehicle.

The wheelchair-converted van
Is now ready for a test drive.

The operator unfolds the ramp.

He folds away the new seats
To make way for the wheelchair.

He extends the tie-down belts

And attaches them
To the wheelchair.

He wheels the passenger
Into the van...

Locks the wheelchair breaks...

And ties the chair to the floor.

There are standard seatbelts
To fasten,

And then it's time to sit back
And enjoy the ride.

Seated in the converted minivan,

The individual
Can now experience

The freedom of the road.

Narrator: the marimba
Is a musical instrument

Similar to the xylophone,

Except with a wider
And lower range of notes

And metal resonators
Underneath the keys

To amplify the sound.

While the xylophonist
Uses hard rubber mallets,

The marimbist usually strikes
The wooden keys

With a variety of mallets
Covered with wound yarn.

[ marimba music plays ]

The marimba keyboard
Is chromatic,

Meaning it includes
All the semitones

Of a musical scale --

The equivalent of the 12
White and black keys on a piano.

Each wooden key has a resonator,

An amplification tube
Underneath,

Tuned to the same note.

When the mallet strikes,
The resulting vibration

Causes the resonator
To hum that note,

Transforming the otherwise thin,
Muted sound

Into a louder, richer tone.

They keys are fashioned
From honduran rosewood,

Which is hard and dense,
Yet elastic.

After cutting
The thickness and width,

They set the dial
Of this custom-made saw

To the note they're making,

Which positions the wood to be
Cut to the correct length --

No measuring required.

Next, using a router,
They round off all the edges.

When a key has sharp edges,

It's more likely to chip
Or splinter when struck,

Even though marimba mallets
Are soft

And frequently covered
With wound yarn.

The next step
Is to drill holes at the nodes,

Which are specific
Non-vibrating points on the key.

The nodal holes are for the cord

That will suspend the key
Over it's resonator.

Now a computer-guided
Milling machine

Sculpts a very precise arch
In the underside.

This roughly tunes the key.

To fine-tune the key,

They must tune
The fundamental note

Plus the first and second
Overtones --

The subtler notes that sound
Simultaneously with it.

When the tuner strikes the key,
An electronic machine

Reads the exact frequency
Of the vibrations.

He repeatedly taps,
Takes readings,

And sands the arch...

[ sander whirs ]

[ marimba notes play ]

...Until the fundamental
And overtones are pitch-perfect.

They seal the wood with lacquer.

This protects the key
From moisture penetration,

Which would alter
The key's tuning.

For each key, they make
A resonator out of brass tubing.

The lower the note, the wider
And longer the resonator.

Some are so long, they must be
J-shaped or u-shaped

To fit under the keyboard.

To make those curves,

Workers use short,
Angled pieces of tubing

To join longer, straight pieces.

They divide the resonators
In groups

Then bolt each
Onto a painted steel rail.

There are six groups
Of resonators

On this full-range marimba.

The instrument
Is nearly 10 feet long.

The ends of the frame
Are height-adjustable.

Between the frame ends,

A center pole receives
The six resonator sections

Arranged shortest to longest.

Then,
Running over the resonators,

Wooden crossrails
Suspend the parts

To support the keyboard.

Under the lowest
And longest keys

Are those curved resonators,

Fashioned from angled,
Soldered pieces of tubing.

Posts mounted
In the wooden crossrails

Support the cotton cord running
Through the key's nodal holes.

At the end of each resonator
Is a patented tuning plug.

After using a lave to shape
A piece of hard plastic

Into a cylinder
With a required diameter,

They saw off a slice
About the size of a hockey puck.

They then quarter the slice,

Running the cuts
Just 90% of the way through.

These slots
Make the plug flexible.

Next, they drill a threaded hole
Through the center

To the same depth as the slots

And wrap the edge
In polyethylene gasket tape.

The tape smoothes the surface,

Helping the plug glide easily
Into the resonator.

Then they thread a wing screw
Into the center hole

And insert the plug

Into the corresponding
Resonator.

To tune the instrument
Before playing,

You move the plug up or down

Until the node is the exact same
Pitch as the key above.

Then you turn the screw
To push the sections outward,

Locking the plug in position.

[ marimba music plays ]

Everything from this point on
Is in the marimbist's hands.

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Topics for future shows,

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