If you squat by the railway tracks and get closer to the black logs lying among the crushed stones, you are likely to smell a unique scent - an "industrial wind" mixed with tar and a little chemical reagent. Don't doubt it, that's the "body fragrance" of our protagonist today - anti-corrosion sleepers (commonly known as oil immersed sleepers).

Many people think that this dark layer of oil is just a "raincoat" for the wood to protect it from water. In fact, in the eyes of industry insiders, this layer of "black oil" is the "liquid armor" that puts pine wood on.

Today, let's take a look. What is the holiness of this layer of "liquid armor", and how it transformed an ordinary pine tree from a "weak chicken in the forest" to a "god of war on the rails" capable of carrying trains and rainstorm.

The 'crispy' life of ordinary pine wood

We have to admit first that this guy Songmu is born a bit "weak".

Although it is straight, easy to process, and inexpensive, it is the "chosen one" for making sleepers. But its physical properties determine that it is a 'brittle skin'. If you throw an untreated pine wood (also known as a "wooden sleeper") directly onto the railway track, it will be gnawed by fungi into a "wasp nest" and built into an "underground kingdom" by termites within two years. It will absorb enough water in the rain and crack open in the sun, making it a "model of rapid decay" in nature.

So, in order to be employed, it must be "gold-plated" - which is what we call anti-corrosion treatment.

Taking a bath is not for cleanliness, it's for filling a hole

You may think, isn't it enough to just paint the wood? Brother, you're thinking too simply. Painting is a "nail polish" that fools people. Under the rail is the battlefield, and nail polish will fall off after rubbing it twice.

The true anti-corrosion process is a cosmetic surgery that starts from the inside out.

Simply put, it's putting pine wood into a huge pressure cooker (professionally called a pressure vessel). Then, inject a special 'black technology liquid'. At this point, high temperature and high pressure will work together to forcefully inject anti-corrosion oil into the interior of the wood.

13mm: Invisible 'bulletproof layer'

Many friends think that this layer of oil is floating on the surface. Actually, it's not.

A truly qualified 'liquid armor' often has a penetration depth of over 13 millimeters. This means that from the surface of the wood to the inside of the meat, which is about a centimeter thick, everything is filled with this anti-corrosion oil.

The depth of 13 millimeters is the lifeline of the sleepers.

-Preventing biochemical attacks: Do fungi and insects want to bite? My mouth is full of preservative oil, it's a deadly poison, whoever gnaws on it will hang on.

-Waterproof and moisture-proof: The pores inside the wood are occupied by "oil", and water molecules want to enter? No place to stay, just bounced away.

-Wear resistant and durable: Even if the surface of the sleeper is worn down by a few millimeters due to long-term friction, there is still a thick "armor layer" inside, which provides strong anti-corrosion effect.

The fusion from "liquid" to "solid"

Speaking of which, you may ask, since it's called 'liquid armor', has it always been liquid?

Not really.

When it first came out of the can, it was indeed an oily liquid, and it had not yet fully solidified. But over time, or in other words, after a fixation process, these oil agents that have infiltrated the wood will gradually stabilize and even physically blend with the wood fibers.

At this point, it is no longer "oil applied to wood", but "bone growing inside wood". It merged with pine wood and became a whole.

Without this layer of 'A', the railway cannot function properly

Let's just calculate the accounts and we'll understand.

Plain sleepers without armor need to be replaced and regularly maintained after 5-10 years of use in outdoor environments. Wearing this set of "liquid armor" anti-corrosion sleepers, it is easy to dry for more than ten years or even decades without any problem.

Think about it, railway lines often have thousands of sleepers. If plain wood is used, railway workers have to carry hammers every day to replace the wood. That's not repairing railways, it's building assembly lines.

So, this dark layer of "liquid armor" uses the most ruthless means (high-pressure irrigation) to give the softest wood a steel like lifespan.