Hello, everyone.

This is Enta.

We currently have a job site where we're installing ground anchors.

The drilling will be up to 70 meters long.

I'm really struggling with this drill hole, which is an unusually long one lol

That said, we actually installed a 60-meter anchor last year as well.

I’m happy that being entrusted with a long anchor makes me feel like my technical skills are being recognized.

 

It's really tough when it's long.

You have to pay attention to the drill’s torque, as well as both the air and water.

I've become sensitive to the sounds of machines, so I'm careful about them.

 

But the casing still gets eaten away!

This expression, “being eaten,” is commonly used; it’s what’s colloquially known as “jamming.”

This often happens in places where there are no (or very few) slimes returning.

However, no matter how neatly the hole is drilled, the casing will still be eroded.

"Jamming" sounds like a nice term, but,

Artistically speaking, the image of the casing being "eaten" by the mountain fits perfectly, lol.

 

It seems they got stuck again this time—apparently, the drill bit got jammed at around 60 meters after finishing the drilling, and they’re completely stuck!

Apparently, they ended up leaving about 10 of them behind...

 

This is the scariest risk of drilling.

The casing that got eaten this time already cost an absurd amount of money lol (100 million!! lol)

I can't help but laugh lol

This is why ground anchor work is so expensive.

These days, a large drilling machine costs around 20 million.

And yet, consumables such as casing cost more than 30,000 yen per 1.5 meters.

For example, if 10 φ115 casings were to break at the tip, the cost would be 10 casings × 35,000 yen = 350,000 yen.

That's how the inner and outer lines get kinked or chewed through and end up getting lost.

Consumables that cost an outrageous amount of money.

On top of that, it’s struck with a hammer tens of thousands of times. And it rotates tens of thousands of times.

So there's a very good chance it could break.

The cost of the broken parts is at least 100,000 yen.

Even if just one hydraulic hose bursts, it’s not unusual for it to cost tens of thousands of yen.

 

There's always the risk that it could break at any moment.

That’s why I can’t take on low-paying jobs just in case that happens.

Let's say I took on a low-paying job and did the work.

Let's say the casing breaks or something like that, resulting in a loss of 500,000 to 1,000,000 yen.

That means we’d suddenly be in the red. (Business isn’t a charity, after all, lol.)

 

That's why anchor installation is expensive—the cost is calculated with that in mind.

There have been a lot of long-span ground anchor projects lately, so the risks are pretty high, lol.

If we can keep drilling with anchors about 10 meters long, the risk will be lower, but since the casing gets thinner and thinner, it’s a consumable item.

The bits wear down quickly, and with long anchors, a single bit just isn't enough to handle one of them.

And the amount in bits is crazy, lol.

Since that cost is factored into the price, it stands to reason that it would end up being more expensive when you consider risk diversification, right?

On top of that, there are expenses and all sorts of other things to factor in, lol.

 

See you later.