All language subtitles for S23E13 - Mountain Bikes; Rice; Lever Action Rifles (1080p AMZN WEB-DL x265 Garshasp)_track4_[eng]

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Narrator: in the late 1800s,

The american military

Tried modifying bicycles to help
Infantrymen cross rough terrain.

Cyclists
Continued experimenting,

And the first mountain bike
Was created in 1978.

The popularity of mountain
Biking has grown ever since.

Mountain bikes
Are specially designed

To perform on rough terrain.

They have a suspension
To help keep the wheels

In contact with the ground,

Deep-treaded tires
For added traction,

And powerful disc brakes
For safety.

At the core of a mountain bike
Is the small, robust frame.

It needs to be lightweight
Yet highly durable.

The factory uses a test bench
To simulate the effects

Of repeated impacts and
Vibration on the bike frame.

Three days of testing

Can simulate 10 years
Of intensive use.

The frame is made
From tubes of aluminum alloy.

Aluminum is lighter than steel
And cheaper than carbon fiber,

And it won't burst like carbon
In case of a large impact.

They cut each tube
To the required length.

They use jigs
To get consistent dimensions

And precise cutting angles.

This will be extremely important
When they assemble the frame.

Each model and size of frame
Has its own welding jig.

They start tack-welding
The tubes in place.

Then they proceed
With the final welding.

It's a delicate step
Because the tubes are very thin.

After welding,

The aluminum frame
Will undergo a heat treatment.

First, the frames
Will be heated intensely,

Then quickly quenched
In a cool bath.

This makes the metal
Easier to work with.

This next step is necessary

Because slight deformations
Are created in the frame

During welding.

Using precise measuring
Instruments and a rubber mallet

To avoid denting the metal,

A technician ensures the frame
Is perfectly parallel

To the alignment table.

It's not easy
To align the shorter tubes,

So he uses a longer rod
For this task.

After alignment, the frame

Will be heated one last time
To harden the aluminum.

Once the aluminum exhibits
The right mechanical properties,

It's ready for boring.

This crucial procedure

Makes the inside
Of the hole perfectly straight

And aligned with the frame's
Geometric design.

In the painting department,
They spray auto-grade paint,

Which then dries in an oven
For 20 minutes.

Next they use ink transfer tape

To apply the logo
On the bicycle frame.

After that logo dries
In the oven,

They will finish
With a clear coat of varnish.

Everything must be perfect.

When buying a new bicycle,
Most mountain bikers

Pay very close attention
To the quality of the paint job.

The bicycle is ready
For the final assembly.

The assembler starts
With the rear shock absorber,

Which contains oil to dampen
The suspension movement.

This way, the suspension

Doesn't bounce up and down
Uncontrollably after an impact.

The stiffness of that dampening
Is adjustable by the rider.

The assembler links the shock
Absorber to the seat stay.

He installs the handlebar

And the stem
On the steering column.

Next he installs
The rear brake caliper.

This is a hydraulic brake,
Actioned by brake fluid

That travels
Through a hydraulic hose.

It's positioned on the frame
In such a way

That anchoring clips
Don't restrict its movement.

Now it's time
To install the crankset

And the derailleurs.

These are useful
On technical terrain,

Where quick gear changes

Are key to successfully
Maneuvering trail obstacles.

He installs the rear wheel.

It's equipped with 10 cogs
And a disc brake.

Its deep-treaded tire
Will grip the ground

Of treacherous mountain paths.

Now he screws in
The front brake caliper.

It takes about an hour to fully
Assemble the mountain bike.

The fork
Provides the front suspension...

...While the rear suspension
Is connected to the rear wheel

Through a system of pivots
At the back.

As the wheel and pivots
Move back and forth,

Their movement is dampened
By the shock absorber,

Helping to keep the wheel
In contact with the ground.

Mountain bikes are engineered

To withstand the demands
Of off-road riding.

Precise manufacturing
And testing

Also ensure that the mountain
Bike will survive years of use

And abuse.

Narrator:
In many parts of the world,

Rice is the main grain.

In fact, it is a food staple

For nearly half
Of the planet's population.

Native to asia,

It has been grown and consumed
For thousands of years.

But today, machines do much
Of the harvesting and processing

In order to feed
The enormous demand.

These perfectly formed
Kernels of rice

Are essentially a crop

That has been allowed
To go to seed.

After about 150 days of growth,

The rice seed
Is ready for harvest.

Machinery strips it
From the stalks

And also suctions out
Some of the empty husks.

Trucks transport the rice
To storage facilities.

They empty it into a grated
Opening at the receiving pit.

The grates filter out some
Of the larger stalks and debris.

From the pit,

A chain conveyor moves the rice
Up to storage silos

And into warehouses.

Inside the storage facilities,

Fans blow air
Through the mountain of rice

To lower the moisture content
Substantially.

With the rice
Sufficiently dried,

It's on to the processing plant.

Here, a probe vacuums up samples

From both the front and the back
Of the massive truckload.

The probe delivers the samples
To a lab.

A technician first
Tests the moisture content

To confirm that it's on target.

He then transfers batches
To a sifting bin

To screen for bugs.

He switches on a heat lamp
To wake them up.

He shakes the rice
And scrutinizes.

He also examines the tray
Underneath for tiny bugs

That may have fallen
Through the holes.

If he finds just one moth
Or beetle,

The entire 5,500-pound truckload
Of rice will be rejected.

Next the rice falls through
Perforations

In rolling cylinders,

Screening out the straw
Which spills over the side.

The next machine sifts
Out the remaining straw bits

And any weed seed.

It also suctions out
Empty rice husks.

They're lightweight and
Pulled out with a weak vacuum.

Finally, they remove mud balls.

Free of contaminants,

The rice now spills
Between two rubber rollers,

One moving
Faster than the other.

This shears off the husks.

The rice and empty husks then
Cascade into another machine.

This is a demo version
Of the actual production one.

Weak suctioning
Pulls out the husks

To separate them
From the heavier rice.

The dehusking process
Misses a few kernels,

So next giant sifting machines
Screen out that rice.

Still in husks,

It's bigger and doesn't pass
Through the holes

In the shaking trays.

They dehusk that rice
And mix it with the rest.

Grinding machines now mill
The rice to remove the bran.

The bran spills
Out of perforations

And is recovered
For use in cattle feed.

With the bran removed, the rice
Goes from brown to white.

The final grinding polishes
The rice

To give it a pearly sheen.

This is the unmilled brown rice.

And here it is
With the bran removed.

During milling,
Some rice kernels are damaged.

This spinning, dimpled cylinder
Now separates the broken kernels

From the whole ones.

The broken rice kernels
Fall into the dimples

Of the cylinder,

And from there,
Into an internal catch pan.

They'll be used
To make cereal or beer.

The whole rice now
Moves through a color sorter.

Computerized cameras analyze it
For dark imperfections

And signal air nozzles
To blast them out of the mix.

Of course, there's also a market
For unmilled brown rice.

Now ready for packaging,

A scraper
Moves it across a table

And into plastic tubes below.

Hot jaws seal the tubes
At both ends,

And this rice is in the bag.

Brown or white,
Short or medium grain,

There are plenty of options.

Narrator:
Different types of rifles
Load the gun in different ways.

A lever-action rifle has,
As the name implies, a lever,

Which you move downwards
To load the ammunition cartridge

Into the gun's chamber.

When you pull the lever back up,

It cocks the hammer
And the gun is ready to fire.

This italian company

Makes exact reproductions
Of the renowned winchesters

Produced in the u.S.
Starting in 1866.

These lever-actions
Were a game-changer in that era,

Because you no longer
Had to reload your rifle

One cartridge at a time.

To make the barrel,

The long tube through which
The ammunition shoots,

The factory starts
With a bar of solid steel

That's one inch in diameter.

A computer-guided circular saw

Slices it
Into barrel-length pieces.

Next a computer-guided drill

Bores through the center
Of each barrel-length bar.

The drill is fluted,
Which provides a channel

For a continuous high-pressure
Flow of cutting oil.

This breaks down the metal
Shavings as the drill advances

From one end
Of the bar to the other

Over the course of five minutes.

A reamer gradually widens the
Bore to the required diameter.

This takes 15 minutes.

The diameter of the barrel

Is what determines
A firearm's caliber.

A rifle gets its name
From the next operation.

This specialized tool
Rifles the barrel,

Meaning it carves
Spiraled grooves

Into the barrel bore's
Smooth walls.

This process takes twice as long

As drilling
And reaming combined.

The grooves in the barrel put
A spin on the cartridge's bullet

As it exits the gun.

Like the perfect pass
Of a football,

This spin stabilizes the bullet,

Rendering it more aerodynamic.

That makes the shot more
Accurate over a long distance.

The next machine mills
The outside of the barrel.

This particular model
Has an octagonal barrel,

So the machine mills
Eight sides.

Another machine then
Makes threads on the back end

So the barrel can later screw
Into the adjacent part

Of the rifle.

A local foundry, meanwhile,
Forges the rifle's lever.

Workers feed solid steel bars
Into a small furnace.

The furnace temperature,

A blazing 2,200 degrees
Fahrenheit,

Softens the steel
In a matter of seconds.

While the bar is still red-hot,

They place it in a die and stamp
It with a press to bend it.

Then two more pressings
In a different die

Form the bent bar into
The basic shape of the lever.

A fourth pressing,

Against a razor-sharp die
This time,

Trims the perimeter.

The roughly shaped lever

Is now ready for machining
In the rifle factory.

There, a computer-guided mill
Works at it for eight minutes.

It meticulously shaves off
Bits of steel

Until the lever's shape
Is perfected.

The mechanical section of
The rifle is called the action.

Like the lever,
It's forged out of a steel bar.

Then, over the course
Of an hour,

It's machined to specifications

By 100 different
Computer-guided tools.

This operation
Not only finalizes

The action's external shape,

It also hollows out areas
For the internal components,

Namely the rifle's
Lever-activated loading

And firing mechanism.

But before that assembly
Happens,

The action takes a side trip
To a metal treatment plant

Where it undergoes
A two-step process.

First it's submerged for three
Minutes in a hot-water bath

With special salts
Which harden the steel.

Then a quick dip
In a second bath,

Where a coloring chemical gives
The steel an antique finish.

The action now returns
To the gun factory

To rejoin the rifle's
Other components.

Narrator: the action is
The middle section of the rifle.

The barrel screws
Onto the front of it,

While the gun's wooden handle
Attaches to the back of it.

When you pull the trigger,
The hammer hits the firing pin.

This strikes the cartridge,

Igniting
The explosive primer inside.

The blast propels the bullet
Out of the barrel of the gun.

To assemble
The rifle's firing mechanism,

Workers first attach the trigger
And the hammer spring

To a larger component
Called the trigger guard.

Then they connect the hammer
Itself with a tight-fitting pin.

The hammer spring
Provides resistance,

Allowing the hammer to hit
The firing pin hard enough

To fire the cartridge
After it's cocked.

Taking the action,

They insert the bolt
Containing the firing pin,

Then the firing pin extension.

This wedge piece links
Those two components.

They insert the trigger guard
Into the action,

Coaxing it
Into the correct position

With a few taps of a mallet.

They attach the lever
Underneath the trigger guard.

They mount a spring
On each side of the lever

To put tension on it.

Then finally, they connect the
Lever to the firing mechanism

With two sets of links.

To cock the hammer and prepare
To pull the trigger to fire,

You pull down the lever,
Then pull it back up.

After firing, you move the lever
Up and down again

To eject the spent cartridge

And reload and cock
For the next shot.

They finish assembling
The action

By attaching side plates,

One of which
Has a side-loading gate

For inserting the cartridges.

The action
Has two threaded holes --

One for attaching the magazine
To that holds the cartridges

And the other
For attaching the barrel.

Its threaded end
Requires some top filing

In order to meet the various
Strict specifications

Set out by the proofhouse.

The proofhouse is responsible
For ensuring that firearms

Conform to
All manufacturing regulations.

To attach the barrel
To the action,

They lock the barrel in a vise,

Then screw the action
On to the threaded end.

They use various tools
And gauges

To ensure the two parts
Are perfectly aligned

And that the lever closes
Completely when pulled up.

Next they insert what's called
A check cartridge

Of the appropriate caliber
Into the chamber.

This checks the internal spacing

To ensure the ammunition feeds
Correctly and fires safely.

Then they mount
A temporary stock

On the other end of the action

And send the rifle
To the proofhouse

For performance
And safety testing.

There, technicians
Place it in an enclosed chamber,

Load ammunition,
And fire twice.

The proofhouse
Hand-punches markings

Onto the bottom of the rifle.

These markings, recognized by
The european economic community,

Officially certify

That the firearm
Functions properly and safely.

The gun factory contracts
A woodworking company

To produce the rifle's stock.

It's made from a block
Of walnut.

First workers trace a template

That's in the basic shape
Of the stock.

They saw along the trace line.

This gives them a starting form,

Which computer-guided machines
Then refine.

A mill progressively
Carves the detailed profile

With a series
Of different tools.

Then they mount the stock
On a lathe,

Which rotates it
Against a sander

To smooth the surface
And perfect the shape.

The stock has two holes
In the back

To which they attach
An endpiece.

The woodshop stains
And varnishes the finished stock

And sends it to the gun factory,

Where workers attach it
To the action.

After that, they mount
The magazine tube to the action.

When you feed cartridges
Into the side-loading gate,

They drop into
The magazine tube.

Upon levering the rifle,

A carrier
Pushes up one cartridge,

Which the bolt
Then pushes into the chamber,

Preparing the rifle to fire.

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