CH47 - Caisson

*Thud, thud, thud.*

Today again, U.S. soldiers flocked to the Dae-se Group workers' canteen. It seemed new recruits had arrived.

"How much is this?"

"The uniform is $20, and the boots are $30. If you buy the set, we'll throw in a pair of socks."

Polytech uniforms and boots had a reputation among the soldiers as luxury items, so the new recruits came to our canteen as soon as they arrived.

"Is it okay to wear this in the unit?"

"These products comply with the U.S. Army Uniform Regulation AR670-1. If you go to the building next door, they'll attach your unit insignia and name tag."

"Okay, great."

Our uniforms and boots were specially approved for military supply, so soldiers could purchase and wear them directly.

"Damn, I got issued these Japanese uniforms..."

The soldier paid for the goods and threw away the Japanese uniform and boots.

Since the already supplied Japanese uniforms couldn't be discarded, some soldiers received them instead of our products. Officially, there was competitive supply, but in reality, our products accounted for 100% of the additional supply.

In other words, Sam-bok was really hustling.

Even running the acquired factory at full capacity wasn't enough.

Historically, the U.S. military had around 300,000 troops annually, so by next year, we could achieve a $10 million sales revenue from uniforms and boots alone.

We had already sold $500,000 worth of items in the canteen, so $10 million in sales was no dream.

Even the commanders preferred our products for reconnaissance missions, so there was no real competitor.

"How much is this combat backpack?"

"$30."

"And this mosquito net?"

"$2."

"I'll take two pairs of socks."

"Here you go. That's $2."

Business was really good, whether it was new recruits or existing soldiers.

We operated the canteen with three staff members, but it was so busy that we barely had time to breathe.

When new recruits arrived, the money box overflowed with dollars stuffed into sacks and pressed down with our feet.

"Hey, recruit. Buy another mosquito net. You should get at least six pairs of socks. You need to change them daily."

"Yes, sir!"

Sergeant Mark appeared out of nowhere.

Since he was promoting our goods, I threw him a cold bottle of cola in return.

"What brings you here, Mark?"

"Came to drop off laundry. It's soaked with sweat."

"It's $2 for washing and drying."

"The boots are a free service, right?"

"For you, Mark, sure."

Our canteen had now also become a laundry service.

No soldier would sit by the water faucet and hand wash, so all the drudge work fell to us.

Of course, we didn't hand wash either. We used makeshift washing and drying machines.

With plenty of motors around, it wasn't difficult.

No one cared if we used as much groundwater as we wanted.

"Did you hear?"

"Hear what?"

"They're expanding the supply base here. I heard they're even setting up a heavy equipment repair base."

"Really?"

I pretended to be surprised, widening my eyes.

Of course, BR would never reject my proposal.

"That's not all. They say another 50,000 troops will be deployed near Quy Nhon. You'll make a fortune, CS. Just think of the laundry fees."

"Wait, 50,000 troops?"

What was he talking about?

Why would a supply base need 50,000 troops?

And they're going to deploy Tiger Division around Quy Nhon?

They're sending 50,000 U.S. troops where the Tiger Division is stationed?

"Maybe it's to block the Ho Chi Minh route. They plan to use Quy Nhon as a supply base."

"Is that so?"

"Is the port construction going well? I hope they don't have to transfer 50,000 men from transport ships to LSTs."

"Don't worry, it's going well."

Mark, being from the engineering corps, casually leaked information. It seemed he had reported back to headquarters that the port construction schedule had been accelerated using the caisson method.

People always try to take credit for good results.

"Did the operation to block the Ho Chi Minh route start this early?"

The Ho Chi Minh route was a supply line starting from North Vietnam, passing through the Laos and Cambodia borders, and attacking the left flank of South Vietnam.

It was believed to be a path where Viet Cong soldiers pushed ox carts, but that was far from the truth.

It was a proper road even using bulldozers, and since the U.S. feared a third world war, they didn't invade the border, allowing the Viet Cong to pour most of their forces into the Ho Chi Minh route. No matter how much the U.S. bombed, the damage was immediately repaired, and unexploded bombs were defused promptly.

Laos and Cambodia, claiming neutrality, blocked U.S. entry, while South Vietnamese warlords, focusing on profit, betrayed by selling U.S. weapons instead of cutting off the Ho Chi Minh route.

North Vietnam exploited neutral countries for bold attacks, South Vietnam stabbed the allies in the back, and the U.S. continued to supply both sides. It was a war that couldn't be won.

"This is happening a year earlier than expected. The Tiger Division needs to arrive soon..."

When the operation to block the Ho Chi Minh route begins, Quy Nhon will become a hornet's nest. It will serve as a supply base.

But it wasn't all bad for me.

Historically, Han-shin Logistics became a conglomerate by handling logistics in Quy Nhon.

What I need to be careful about is getting shot while trying to support the logistics. This could end my life.

Our military protection is needed along the supply routes.

For that, we need a division-sized force, not just an advanced team from the Tiger Division.

What is the president doing?

He should send the main force of the Tiger Division quickly.

Doesn't he know what's happening here?

Even if I oversee port construction, I can't meddle with deployment issues.

I can't even nag via telex... Damn it.

Should I hint that in the 21st century, Quy Nhon has become a famous resort and international port?

Wouldn't it be fine to plant the seeds now?

Bang.

"Boss! Everything is ready."

"Ready?"

While I was lost in thought, my father burst into the canteen.

"The preparations for the caisson launch are complete. The concrete curing test result is 12Mpa, which is a pass."

"Oh, really? It's finally dry."

The most difficult thing in the tropics is that concrete doesn't dry well. We had to cover it with large waterproof sheets and steam it with charcoal to expedite the process.

Alright, let's focus on what I need to do.

"Lead the way. Let's go."

"Yes, sir."

**

I climbed onto the command post roof.

"Welcome, Master. Here's the radio."

Silver now called me Master.

He handed me the radio wrapped in orange tape, symbolizing the site supervisor.

"How's the weather?"

"I checked with the military. The weather in Quy Nhon is good today."

Weather is the most critical variable when moving large structures.

If the wind or waves are slightly strong, large structures like caissons can end up in the wrong place.

"Everyone, standby."

<Everyone, standby.>

<Everyone, standby.>

The radio for site supervisors connected to each team leader when I pressed the button.

"Dredging team leader, have you checked the bottom?"

<Yes, 2 no issues. We've confirmed the rubble base level, and ground test is passed. Even after driving piles ten times, they didn't move cm.>

The team leaders began to report as if they were civil engineers.

They were originally hired as skilled workers, but many were teachers or government employees with great qualities and enthusiasm, so they learned quickly.

Once we return to Korea, we'll be able to establish a solid Dae-se Construction organization. The thought alone made my heart race.

"Okay. Good."

Typically, the ground is reinforced with sand piles before laying rubble on the seabed, but Quy Nhon port doesn't need that.

The seabed in this area is hard rock solid enough to support large-scale resorts in the 21st century.

In short, this coastline has natural conditions perfect for building a large port. In that sense, Vietnam turning Quy Nhon base into a resort in the 21st century can be seen as a victory performance.

"Caisson team leader, are you ready?"

<Ready. >

"Start flooding! Pump on!"

<Pump on!>

To float the caisson on the barge, we need to fill it with water up to one-third.

That way, it gains a stable center of gravity and doesn't tip over.

"Flooding 1, 9, 15!"

<1, 15 9, flooding!>

"Flooding 2, 8, 14!"

<2, 14 8, flooding!>

Time passed slowly.

As seawater was added to the 4700-ton caisson, the barge began to sink gradually.

Gulp.

Silver was nervously swallowing next to me.

Filling it with water was easier said than done. If the barge tilted and the caisson shifted to one side, it would immediately cause a major accident.

We had to consider the balance even while filling it with water. I was a veteran.

To be honest, it was amazing.

Even though the caisson was smaller than the ones in the 21st century, we had completed this structure in just ten days.

Our staff worked tirelessly, their eyes turning red with effort.

Especially on Sundays, when holiday pay was included, everyone scrambled to work.

Team leaders had to force them to sleep, threatening to send them back to Korea if they didn't rest.

Sho

ooo...

The barge sank enough for waves to touch the caisson. Okay. One-third was filled.

"Stop flooding!"

<Stop flooding.>

"Everyone, disembark from the barge."

<Everyone, disembark! Disembark!>

I carefully checked that all the staff had left the barge. Now, it was time to float the caisson.

It had to go well... no, it had to succeed.

"Mr. Jin Dalrae, are the tugboats ready?"

<Yes. 3 Main 1, Sub 2, and are all ready.>

The most important and challenging step remained.

Floating the caisson and placing it in the intended location. The first caisson to be placed was the most difficult and crucial.

I entrusted the main 1 to my father.

It wasn't a regular tugboat but one equipped with a small crane to remove the caisson's bulkhead (water blocking steel plate).

It was a difficult and dangerous task, but it had to be done.

Only by taking responsibility for such tasks could one become a leader.

"We're floating the caisson. Main 1, pull it!"

<Main 1, moving out!>

My father pulled the chain connected to the caisson with the tugboat.

The caisson, perched on the barge, splashed into the sea. Dragging a ten-story apartment building into the water created a magnificent spray.

"Wow, it's floating."

"Wow, it really floats. A cement block floats on water!"

People on the shore jumped up and down in excitement.

"Focus. We're just getting started. Slowly, slowly, move forward!"

<Slowly! Move forward!>

The caisson was pulled by a thick chain.

The sea is truly amazing. It can float anything.

"Okay, Mr. Jin Dalrae. We're almost there. Slow down."

<Slow down!>

"Sub 2, hit the left."

<Hit the left!>

"Sub 3, what are you doing? Support it."

<Sub 3, support.>

The tugboats, though small, were powerful and equipped with tires all around, allowing them to push and support.

In the 21st century, tugboat operators made quite good money even in ports.

You need a strong heart and quick thinking to handle situations, and without experience, you couldn't get work.

Honestly, I didn't expect my father to handle the tugboat so well when I helped him practice.

It was a relief.

"Okay. The direction is good. Get it in position."

<Stop! Stop! 2, turn more! Turn more.>

<3, move forward a bit. Come to my side.>

My father not only drove but also led the operation exceptionally well.

With this sense, he could even become a pilot.

"Check the buoy! The position is good."

<Buoy checked. Caisson is in position. Should we remove the bulkhead?>

"Remove the bulkhead if it's in position. Safety! Safety! Safety!"

<Safety! Safety!>

The crane removed the bulkhead attached to the caisson. As the thick steel plate was removed, seawater rushed into the caisson in an instant.

"Careful! Careful!"

<Not that bulkhead. Open the rear one first!>

My father shouted at the crane operator.

If you open the front door first, the second should be the rear one to maintain balance.

But the crane operator touched the side door attached to the front.

"Damn it."

<Don't move!>

My father, for some reason, climbed onto the caisson from the crane. No, no! He'll die.

"What are you doing! Safety! Safety!"

<Safety! Safety!>

I yelled in panic, but my father shouted safety along with us.

He precariously climbed onto the caisson bulkhead lid and ran toward the rear bulkhead.

A hammer was already in his hand.

Bang! Bang!

He hit the lock pin precisely, and the large bulkhead fell into the sea with a splash.

The caisson, which had been swaying unstably, finally stopped moving.

"Are you crazy! Jin Dalrae!"

<This is how work gets done!>

"Come down, now!"

<Get the crane over here! Then I can come down!>

My father climbed onto the crane and connected the crane cable to the remaining bulkhead. In no time, he removed the bulkhead, and the caisson settled horizontally on the seabed.

<Caisson 1. Set horizontally.>

"Phew, good work. Successful landing."

I took a deep breath and exhaled.

A small land was created on the sea.

Filling the caisson grids with seawater and laying the top plate was left, but that wasn't difficult.

We just needed to repeat this 99 more times to complete the port.

<Hooray! Hooray! Long live Korea!>

My father planted a Taegukgi (Korean national flag) on the caisson as if it were Korean territory.

When did he prepare that? My father, really...

"Wow! Hooray, hooray!!!"

The staff, who had been watching silently, jumped and cheered. They continuously shouted hooray along with my father.

Why do people shout 'Long live Korea' when they're happy? It's their hard-earned achievement.

'My father, such a romantic.'

I couldn't fully blend into this era's sentiment, but watching them made me feel good.

Today, I should enjoy this atmosphere.

Click.

I turned on the overall loudspeaker switch.

"Thank you for your hard work during the all-night operations. The first caisson was successfully installed, overcoming a big hurdle. Let's celebrate."

"Wow!!!"

Now we can make and install caissons faster.

In construction, if the first button is done right, the speed picks up.

"Let's enjoy this moment. Get beer and snacks from the PX in my name. Drink and sing to your heart's content. Tomorrow, everyone gets a paid day off."

"Wow!!!"

The cheers were so loud that the crane shook.

"Master, can I join too?"

"Of course, Silver. Were you planning not to come?"

I should have a drink today too.

Well done, Woo Chan-soo!

TL Note - 

A caisson is a watertight retaining structure used in geotechnical engineering. Here are the main types:

Box Caisson: A prefabricated concrete box with sides and a bottom. It's set down on prepared bases and filled with concrete to become part of permanent works, such as bridge piers' foundations. Elaborate anchoring systems may be required to prevent floating, especially in tidal zones.

Open Caisson: Similar to a box caisson, but without a bottom face. Used in soft clays or where there may be large obstructions in the ground. It's also employed for installing deep manholes, pump stations, and reception pits for micro tunnelling and pipe jacking.

Pneumatic Caisson: A watertight chamber open at the bottom and containing air under pressure. Used for construction work underwater.

Monolithic Caisson: A single, solid structure that's sunk into the earth. It can serve as the substructure for bridges, buildings, or other large constructions