It will be bespoke for the ship it'll propel.

That means it needs to be hand crafted with Mila metric precision from a top secret bronze alloy cooked up in one of the world's biggest induction furnaces.

One being made today will be nine meters across, almost the size of those on the married mask on cast as one piece in this gigantic concrete mold.

So this is it.

This is that is the moment that is the mobile job.

That is Oh my God!

Casting itself.

It's a very exciting moment because you work for many weeks to build up this and to prepare everything.

And then you have the small time frame in one hour the birth of a propeller.

Yeah, Here you just feel more like animation, bringing some people in.

That's clothing coming up here.

Idea.

We're know that.

So time is two against.

Yeah, you need.

The metal only becomes fluid enough to pour into the cast when it reaches 1200 degrees Celsius as they pour the molten alloy from the furnace into rather delightfully named Ham, which sounds like something that belongs in the kitchen.

I'm just aware, raw energy, a lot of it.

I fell in there.

I would simply cease to exist.

Well, those splashes to get any closer to me, I'm just gonna back up.

That is the metal coming out of the actual furnace here.

Here it comes.

It's a living thing.

We're.

But I've always wanted to see something cast.

Just kidding.

It's also really, really home, like really all.

It takes 10 days for the propeller to cool, after which it's still far too rough to cut through.

Water efficient, it needs polishing.

This is where years of skill come into play.

After all the automation, Really, I'm finishing.

I was running his hand along it to do it.

The operators movements are replicated by the remote arm.

It's like an extension of his body.

These propellers are finished your tolerance of tens of minutes.

So this guy is on artist edible precision because in real life, that isn't just a beautiful thing, A piece of sculpture.

It's got a very, very big job to do for the next second.

Gerald makes it look easy, but he's got 20 years of experience.

I said, I can have a gun.

So here goes.

Not surprisingly, on a piece of scrap.

No, on a $1,000,000 propeller.

So this, Oh, uh, it's alive, right?

It's not as intuitive as our is hoping.

Biggest ticket, right?

It's really difficult.

I'm guessing that they are says perfectly, right.

Well, the pressure it supplies is related.

The pressure you apply with machine, you don't just push it on and then just leave it there.

You finesse it, though I believe that there on DNA not apply for a job as a professional propeller grind after a professional polish, not by me.

Obviously the 70 ton propeller is ready to leave the factory.

The more I see of the effort and artistry that goes into crafting this beautiful sculptural thing Saturday is to think that just like the one on ash it, it'll spend its whole life underwater unseen on that, from the moment it starts work, it will be under constant and vicious attack from a deadly force called gravitation.

When a propeller turns in water, it generates millions of tiny bubbles on the surface of the propeller blade bubbles only last for a few milliseconds before they rapidly implode, sucking in water at phenomenal speed and sending it out as supersonic micro jets their tiny.

But because there are millions off, this constant bombardment creates enough force to damage the surface of the metal, eventually eroding the blade and destroying the propeller.