AWDC Chapter 25

## Chapter 25: Tunnel Construction

This marks the end of Toma’s childhood.

The surveying revealed the tunnel’s length to be 1200 meters.

Even in modern Japan, this wouldn’t be a simple task, although not an insurmountable one.

What gave those working on the project here the confidence to complete it was the poles planted on the Lean Ridge.

Before starting the tunnel’s trial excavation, I hammered many poles into the ground.

I showed them that if the poles were placed so that they appeared as one, they would invariably form a single straight line.

“Like this, if you stick the poles on the ridge so they look like one, it will be straight on both sides of the ridge.”

I accepted Jim’s advice and explained with confidence.

“That’s right. If you stand the poles so they look like one, it will certainly be a straight line. I don’t understand the difficult theory, but Toma-san is definitely not wrong.”

The craftsmen, who were usually unenthusiastic about learning letters and numbers, were convinced when they actually saw the poles and lines in front of them. It’s okay to lie, but it’s important to explain confidently in front of the people. I keenly felt how much more convinced they were when I spoke with confidence rather than telling the truth about my own anxieties.

I truly thought that politicians become liars as an occupational hazard.

In any case, we accurately planted the poles on the Lean Ridge to form a single straight line. Furthermore, we wrote graduations on the poles and measured the elevation difference. This allowed us to determine, almost by actual measurement, that the north and south entrances of the ridge had a 10-meter difference in elevation, and we would proceed with digging accordingly.

Then, after trial excavations of 100 meters each on both the north and south sides, we found that the geology was not weak and had sufficient strength to proceed with tunneling.

What I feared most was that the ground of the Lean Ridge would be too soft, and the tunnel would collapse.

Even in Japan, there are several examples of tunnels that were abandoned after being successfully completed because the ground was too soft.

There are mountains in Tohoku where a tunnel was dug, rails were laid, and a railroad was opened, but the ground was so soft that it collapsed due to an earthquake, and a new tunnel had to be dug.

It was because of these concerns that I prioritized the tunnel trial excavation.

So many tunnels were dug. Railroad facilities spanning tens of kilometers were abandoned.

If this damage were to befall the poor Robertson family, it would be irreparable. The plan to bring water to the desert would never be possible again.

In any case, it looked like the tunnel could be built thanks to the trial excavation.

The geology of the tunnel was such that it was easy to dig through the clay soil once the topsoil was removed, and there was little risk of collapse.

As the tunnel was dug, it became longer, and the task of removing the excavated soil to the outside became troublesome.

To solve this problem, I devised the trolley that Ladapole built.

The trolley ran lightly on the rails laid on the ground of the tunnel.

The excavated soil was loaded onto the trolley, and it could be carried to the tunnel exit by the power of just one person.

The excavated soil from the north side of the Lean Ridge was thrown onto the cliffs of the Mulan River and piled up to form a flat area.

The soil transported by trolley from the south side is being piled up to become the embankment of the reservoir that will eventually be built.

Once the worry about the geology being too soft was almost gone, a worry about it being too hard arose.

With the current softness of the ground, we were able to dig more than 5 meters, sometimes even exceeding 10 meters, in a single day.

However, I was guessing that the middle of the ridge would probably be a rocky area.

If that were the case, we wouldn’t be able to dig even a few centimeters a day.

I was researching explosives in preparation for that situation.

I had grasped the manufacturing method of dynamite with my knowledge from my previous life.

There are various types of explosives. There are many types of gunpowder used for fireworks and gunpowder used in wars depending on their purpose.

Among them, there is nothing easier to carry or more controllable in terms of explosion volume than dynamite.

After the tunnel trial excavation was completed and the tunnel excavation work began to move, I left the subsequent work to Jim Keene and Ladapole.

Now, I focused on the development of dynamite with Krim.

Krim, like a doctor, was skilled at compounding medicines, which was very helpful in making gunpowder.

I myself knew to some extent the raw materials and manufacturing methods of dynamite.

However, it was not easy to actually make it.

Krim never tired of changing the ratio of the raw materials many times to find the optimum one.

And together with me, he went out into the desert to test the power of the gunpowder.

Thanks to that, we were able to create something with performance that could be called dynamite in about half a year.

Road construction and waterway construction were handled by John.

Ladapole was in charge of building the waterway to dam a part of the Mulan River and lead it to the tunnel entrance.

Toma and Jim Keene were in charge of tunnel construction.

Roy Keene was in charge of constructing the settling pond.

Each of them shared responsibility and supervised.

I decided to go and solve any construction problems that arose.

A tremendous explosion was heard in the desert, “Dadaaan!”

“This is amazing,” someone muttered.

Dynamite exploded while Roy Keene, John, and Jim Keene watched.

A crater 5 meters deep and nearly 10 meters in diameter was formed in the ground where soil and stones had sprung up.

“If we use this, we can easily crush hard rocks,” Krim explained proudly.

“That’s right. It won’t be difficult to dig waterways with this,” John and Jim Keene agreed.

“Ah, if this is only used for land excavation, there will be no problems.”

However, Roy Keene seemed to sense the danger of the explosive.

Nobel invented dynamite. He was said to have felt deep sorrow that it was not only used for peaceful purposes such as mine development, but also for war.

I also hesitated greatly about whether to teach the world about explosives.

A kitchen knife is used for cooking, but it is also used for murder. The point is that depending on the person who uses it, tools can be used for peaceful purposes or for war.

It may be sophistry, but I decided to use explosives in this world with that in mind.

Naturally, I thought that this dynamite would demonstrate its power if we encountered hard bedrock during tunnel excavation.

During the construction, I took a break once every two weeks and went home.

Each time, Ilse warmly welcomed me.

As a sign of gratitude, I lit a bath for Ilse.

“Ah, how wonderful this feels. When I take a bath, I feel like I’m in paradise.”

Such a voice came from the bathtub.

Ilse thought that the luxury of this world was taking a bath.

It was a great effort to draw enough water to fill a bath in this water-scarce village.

That is why Ilse could only take a bath a few times a month.

“Ilse, if we can get water to the desert, you can take a bath every day.”

“How happy I would be if that were the case.”

Ilse and I had such conversations many times through the wall of the bathroom.