CH59 - Polyurethane

"Oh, old man, this is serious."

Sambok hurriedly grabbed a jumper and draped it over the old man Hwang. Luckily, there was one lying around in the office.

The jumper from Daese Shilup was of good quality and very warm.

"Hehe, it's our director. What's going on?"

As Sambok supported him, old man Hwang collapsed into a sitting position.

It seemed like the tension suddenly released.

"What do you mean, what's going on? You'll catch a cold like this."

"That's not the important part. Listen to me."

"Nothing is more important than your health. Let's go inside."

Sambok practically carried old man Hwang into the factory.

For some reason, the factory was filled with a warm atmosphere. Steam was rising everywhere.

It felt like being inside a giant fumigation chamber.

"Old man, what exactly were you doing?"

"Can't you see? It's wet processing. Not dry, but wet!"

"What? Wet processing? What's that?"

"Listen. I've done something even Woo Sajang, the genius, couldn't think of. The answer was wet processing. If you expose the polymer to steam, it won't stick to the pipes. Then you release it into water, and it turns into thread. That's how you make polyurethane."

Although he didn't understand everything, he got the gist.

Chemical fibres like polyester release pellet-like particles into the air, but polyurethane releases them into water.

"So, you make threads in the water."

"Hehehe, it kept bursting, so I cursed and threw it into water. And what do you know? It turned into a thread! For anything that generates heat, the answer is to douse it with water."

"Wow, old man, you're a genius. How did you come up with such a brilliant discovery?"

"What's important is that it's polyurethane."

So, it's possible to make threads in water.

Well, if it's a material that reacts explosively, maybe it reacts more stably in water...

"Argh! Stop thinking! Stop thinking about it! Why do I need to know that?"

Sambok shook his head vigorously to clear his complicated thoughts.

Even with just his current task, his head felt like it was going to explode.

"Do you remember? Woo Sajang said if we have this, we can beat the Japanese."

"That's right. He said if we coat it with polyurethane or something, we can make breathable waterproof fabric."

Chansu said there were two types of breathable waterproof fabrics.

One is to coat existing nylon or polyester yarn with polyurethane and weave it into fabric, or insert a new material called Gore-Tex between existing fabrics.

Although Gore-Tex was more advanced technology, Chansu said polyurethane would be more profitable in terms of product variety.

"Since we mentioned it, I'll show you. Come here."

"No, no, no, I don't want to see it. I don't have time for this right now."

Even if Sambok saw it, he couldn't make breathable waterproof fabric right away.

He needed to report it to Chansu first, then either Chansu had to come or they had to send a sample.

"Come on, I said come here."

Old man Hwang dragged Sambok deeper into the factory, a place where others were prohibited from entering.

"Wow... Wow..."

Sambok couldn't help but exclaim.

The polyurethane, which he heard was silver, was flowing out in a golden hue.

The sight was just stunning.

"Isn't it amazing? I wanted to show you this."

"Is polyurethane originally golden?"

"What are you talking about? It's usually silver and transparent. This is just the catalyst. You can peel it off like this."

"Catalyst?"

"Yes, Woo Sajang mentioned using aramid or something like that as a catalyst. This substance is necessary to make polyurethane."

Old man Hwang rubbed the golden thread with his hand, revealing the silver thread underneath.

It was like peeling the skin off a thin electric wire.

"Wow, the golden skin is tougher than I thought."

"This is why Woo Sajang said making polyurethane was difficult. I think I've done enough. Woo Sajang will figure out how to peel it off. Then making breathable waterproof fabric will be easy, and beating the Japanese won't be a problem."

Old man Hwang caressed the golden thread with an emotional look.

Yes, once Chansu comes, he'll make it in no time.

If Polytech is selling like crazy, imagine how well the breathable waterproof fabric will sell?

Where should we expand the facilities, second factory, third factory? How much will the sales increase? Thoughts chased each other in his mind.

'... Argh! What am I thinking? Stop thinking, you fool!'

Sambok started hitting his head.

The work was snowballing.

"Yes, you must be overwhelmed thinking about beating the Japanese. I understand. I completely understand."

"No, that's not it."

"Go to Vietnam and bring Woo Sajang back. Tell him to make money with this."

"Old man, Chansu is very busy right now. It's not possible immediately."

"He has to come, even if it's hard. Otherwise, we'll be swallowed by the Japanese again."

"What? Swallowed?"

Sambok tilted his head at old man Hwang's sudden statement. It was still at least five months before Chansu could return.

"Look at the state of the country. They said they've resumed relations with the Japanese."

"Old man, there's no other choice. Diplomacy..."

Even though Sambok was also upset, it wasn't feasible to not establish relations with Japan forever.

Honestly, even now, when exporting to Southeast Asia, they ship from Busan to Japan and then transfer to larger ships there.

Most of the various sub-materials are also Japanese, and even the Karl Mayer equipment is shipped by Japanese ships.

"They'll sweet-talk us with fertilizer factories and steel plants, but it's all their ploy. They pretend to help while sucking our blood from behind. They only think of exploiting us. We can never get along with them. Never! Never!"

Old man Hwang trembled just at the thought.

"The negotiations for resuming relations with Japan are already over."

"No, it's not over yet. It's too early to give up!"

Old man Hwang glared at Sambok with wide eyes.

To him, Japan was an object of hatred, fear, and revenge.

"Old man..."

"Woo Sajang will understand my words. It's a hundred, a thousand times more important to protect our land than to guard Vietnam. He'll win, with this."

Old man Hwang wrapped the golden polyurethane around Sambok's arm.

It felt like hot noodles freshly boiled.

It was definitely hot, but strangely not.

"Chansu didn't go to protect Vietnam; he went because the Blue House forced him... Damn it."

Sambok couldn't bring himself to say that Chansu went to make money, not to protect Vietnam.

His heart ached in sympathy.

"Bring Woo Sajang. You're the only one who can."

Unconsciously, Sambok nodded.

Who else could report the creation of such an important, top-secret material?

It couldn't be reported by telex.

He had to see it with his own eyes.

He couldn't ask Chansu to return to see it!

Moreover, wouldn't he be able to sleep continuously for a week on the way to Vietnam?

He can't work on a ship!

"I wanted to experience foreign culture too."

"Are you going? Are you really going?"

"I must since you ordered it."

"Hooray! Hurrah! Here comes the man~ hurrah~"

Old man Hwang danced on the spot.

Sambok dressed the dancing old man Hwang in his work clothes and left.

****

Office

"Miss Kim."

"Yes, director."

"I'm going to Jinhae to board the LST and head to Vietnam. So, get my passport and visa ready. Distribute my work appropriately to each manager. Ah, and report the main tasks' progress via telex daily."

"Director! How can I do all that..."

"If you do, you're promoted to manager starting today."

"No problem! Have a safe trip."

Miss Kim, who had stood up to argue, bowed at a 90-degree angle.

Her fatigue flew away instantly.

"Ugh! I'm coming! Wait right there!"

With the new material sample in hand, there was enough reason to go urgently report to Chansu... and take a good week's rest.

****

Dredging Area in Phan Thiet

"Pour more! It's sliding! It's sliding!"

"Can't you see we're pouring it?"

Despite dumping dredged gravel and sand into the caisson, it sounded like the caisson was slipping.

"Get the tarp! Get the tarp! It's raining! What if the welders get electrocuted!"

"I'm sorry."

Even though it was drizzling, they couldn't stop welding.

Welding in the rain is something you should never do, but this was an emergency.

"Forget sorry, just get the tarp. Safety! Safety! Safety!"

"Safety! Safety! Safety!"

They hung the tarp over the steel plate bridging the caissons, and skilled workers continued welding while hanging from long ropes.

Though it was a temporary dam, they had to add steel plates and weld them to hold the water.

"Sajangnim, we can't hold on any longer. The caisson might get pushed, not just the Jamaica."

My father came as a representative of the workers.

He was right. We had built a dam downstream, trapping a tremendous amount of water upstream.

Even a massive dredger wreck would be slightly pushed by the water pressure. If the 4000-ton caisson was being pushed bit by bit, what could we do?

"You're right. We have to do it today."

Damn it, why did it have to rain now? I was relieved it was the dry season...

Seeing the dark clouds in the sky, it might be raining even more upstream. The water volume could increase uncontrollably in an instant.

If so, we wouldn't even be able to attempt going against the rapids and would have to evacuate.

"Stop the work and tell everyone to get out."

"Yes, sajangnim."

Whistle sound

"Everyone out! Sajangnim's going to break the dam."

"Wowaaa!"

Whistle sound

"Everyone out! Hurry up!"

Whistles blew from all directions, and the workers evacuated to the riverbank. They climbed over the warship supporting the steel plates as if it were a makeshift bridge.

"Are you really doing this?"

Major Kim approached me.

"Let's do it. Maybe the rain is an opportunity."

"Take command. I'll assist you."

"You're the fleet commander, and you want me to command?"

"Do you want to see that stupid Yankee take credit for this operation?"

Major Kim pointed to Major Smith watching from afar.

Right, if Major Kim commands the LST fleet, it's a military operation, but if I command, I can argue it's part of the dredging project.

"I have to do it."

"Just give the order to start and the explosion command. Leave the rest to me."

"Alright. Let's go."

Once this is over, I'll tell Godell to put Smith in a backwater post.

He dared to point a gun at my forehead.

"Cheongryong unit, to your positions!"

"To your positions!"

At Major Kim's command, the Cheongryong unit moved swiftly and precisely.

Whether they were blocking the floodgate with the LST or going against the current, the tension was the same.

We boarded the LST bridge.

It had been a long time since I had entered a proper bridge.

"All LSTs, engines on!"

I shouted with all my might.

This was the start.

"Entire fleet, engines on!"

"Engines on!"

The engines roared through the deck.

This was the proud 2700 horsepower, 4-cylinder engine from American GM. A reliable beast, do your best.

"Engine warm-up for 60 seconds, target RPM 120."

"Engine warm-up for 60 seconds, target RPM 120."

Warship diesel engines need warming up.

Major Kim's command was calm and precise.

Most diesel engines go up to 180 RPM, so warming up to 120 RPM was sufficient.

All the LSTs roared.

As if waiting for this moment, the sky poured rain. I couldn't tell if the heavens were helping or hindering.

"RPM 100, 105, 110, 120!"

"RPM 100, 105, 110, 120!"

As expected from the elite of the elite, they matched the RPM precisely.

"810 and 811, prepare to turn. 810 turn right at the left floodgate, 811 turn left at the right floodgate!"

"Prepare to turn!"

"Prepare to turn!"

Warships can turn in place thanks to their two screws. The floodgates were opening.

Compared to the river's power, the steel plates supported by the warship were nothing but paper.

"Ready to turn."

"Ready to turn."

They signalled readiness through radios, hand signals, and sirens.

"810 turn right, 811 turn left, turn!"

"Turn!"

With an ear-piercing siren, the two LSTs at the front began to turn.

As the supporting ships gradually moved away from the steel plates, the river water roared as if to swallow them whole.

Come on, try me!

"808 and 809, prepare to charge! Countdown 20 seconds!"

"Prepare to charge! Countdown 20 seconds!"

"Countdown 20 seconds!"

"20 seconds!"

"Start the countdown!"

"20! 19! 18! 17!..."

As the countdown approached zero, the engine noise of the charging LSTs grew louder.

In the 21st century, they would have used gas turbines, but now, it was just a diesel engine.

This 50-meter long, nearly 10-degree gradient rapid felt like a colossal wall.

In the 21st century, engines over 5000 horsepower could handle these rapids easily.

Hang in there, Cheongryong LST.

Just 10 seconds, just give it all you've got for 10 seconds, and we'll cross those rapids.

"... 5, 4, 3, 2, 1, zero!"

The moment Zero was shouted, Major Kim looked at me.

Now! Without hesitation, I shouted.

"Blow it up!"

"Blow it up!"

Boom! Boom!

When the explosives on the steel plates went off, the plates crumpled like paper.

The Jamaica, barely holding on, was the first to disappear into the rapids.

"Charge!!!!"

"Charge!!!!"

"Uwaaaaah!"

The LST's maximum speed was just 10 knots, barely 5 meters per second, but it felt like the bow lifted.

A huge muddy wave engulfed the ship.

"Go! Forward!!! @@$$%^^!!!"

"Break through! Break through!! ㅆ%^^&&!"

Curses flew from all directions.

No matter how elite they were, in extreme tension, swearing was rampant.

Kwoaaaah

It felt like a typhoon was hitting.

Rocks the size of adult heads banged against the deck as they passed.

"Increase speed!"

"This is maximum speed!"

"Charge forward!"

"Don't give up! Charge! Goooo!"

A noise like nails on a chalkboard resonated through my entire body.

The LST screamed as if it had never experienced such waves before.

We have to go! We must go.

"Just once! No more, just this once!"

A massive wave lifted the LST's bow high.

It felt like a giant rock was pounding the bottom of the ship, like thunder.

Boom! Boom! Boom!

I couldn't keep my mind straight.

White spray exploded all around.

The muddy water pouring down was several times thicker than the pouring rain.

"Kraaaaaah!"

"Kraaaaaaah!"

Screams echoed through the communication channel.

No, everyone around me was screaming.

"It's a success! It's a success!"

"We've crossed! We crossed the waterfall!"

"We crossed!"

"Cheongryong unit, hurray!"

Even with muddy water splashing everywhere, everyone ran out to the deck and cheered.

"Daese Shilup, hurray!"

The Daese employees watching from the riverbank shouted at the top of their lungs.

"Good job, everyone."

"Good job, Woo Sajangnim."

"Cheongryong unit, cheer!"

"Wowaaa!"

I had the honour of being with the legendary Cheongryong unit.

As rumoured, they were an incredible unit.

'It's an honour to be together.'

I also stepped out onto the deck and spread my arms wide.

The pouring rain washed away all the hardships.

We were the first in the 20th century to cross the Mekong River's rapids with a 1500-ton warship.

TL/n :-

Polyurethane often abbreviated PUR and PU refers to a class of polymers composed of organic units joined by carbamate (urethane) links.

In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from a wide range of starting materials. This chemical variety produces polyurethanes with different chemical structures leading to many different applications.

These include rigid and flexible foams, coatings, adhesives, electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL).

Foams are the largest application accounting for 67% of all polyurethane produced in 2016.

Gore-Tex is W. L. Gore & Associates's trade name for waterproof, breathable fabric membrane. It was invented in 1969. Gore-Tex blocks liquid water while allowing water vapor to pass through and is designed to be a lightweight, waterproof fabric for all-weather use.