Time is an untrustworthy creditor, always wanting to take everything back, turning it into dust and mud. In nature, wood is definitely the easiest "soft persimmon" to compromise on. After years of wind and rain, it either becomes moldy or infested with insects, and eventually can only silently rot in the corners. But have you ever wondered why railway sleepers laid in the wilderness, exposed to the sun and rain, and subjected to repeated crushing by hundreds of tons of steel beasts, can still stand firm for decades?

There is actually no magic behind this, only a carefully planned 'cheating'. And the protagonist of this cheating is the seemingly unremarkable pine wood and the almost cruel oil immersion baptism.

Oil immersion treatment is essentially transforming pine wood. Throw the wood into a huge processing tank, vacuum and pressurize it, and let the anti-corrosion oil pour into every cell of the wood like an infusion. Can you guess how deep this oil can penetrate? Thirteen millimeters or more. Don't underestimate this number, it means it's not just a matter of applying a layer of putty on the surface, but rather that from the inside out, the pine wood has been marinated from "little fresh meat" to "old cured meat".

I have seen a pillow that has been used for fifteen years being dug out. The surface has been worn down like an old man's hand, but when it is cut open with a saw, the inside is still dense and oily, as if time has pressed the pause button thirteen millimeters away. This is the chip of that gambling game - using a deep immersion to exchange for decades of stability.

Of course, this craft also has its own temperament. Pine wood needs to be carefully selected, not too tender as it is prone to cracking when oil enters; Too old is not good, the fibers are stiff and cannot eat oil. If there is any difference in temperature, pressure, or time when entering the jar, the product that comes out will be defective.

And the railway is probably the least compassionate place in the world. Rainstorm, scorching sun, train wheels running day and night, occasionally there is a nail to prick a needle. Ordinary wood? I have already collapsed. But anti-corrosion sleepers are different. Oil soaked pine wood is like a golden bell cover, water cannot enter, insects cannot bite, and it can even withstand the crushing of hundreds of tons on trains with its teeth. You feel smooth while scrolling through your phone on the high-speed rail, but behind you are sleepers pounding against the ground.

Oil soaked sleepers have a special toughness. It can deform slightly under heavy pressure, absorb vibrations, and then quickly rebound after the pressure disappears. This kind of "flexible and adaptable" personality is exactly the guarantee that railway safety needs the most. Moreover, because the oil has been immersed into the deep layer, it is not afraid of water and tide. Even in the rainy season in southern China, where rainstorm is pouring, or in the cold zone with perennial snow, it can be as stable as Mount Tai.

Old Zhang from the anti-corrosion sleeper factory retired last year. Before leaving, he stood at the entrance of the oil immersion workshop, watching the new batch of pine wood being lifted into the cans by the crane. Suddenly, he said a philosophical sentence: "In our industry, we're not betting on wood, we're betting on time. You can't win against time, but you can negotiate a condition with it

I think the 13 millimeter oil immersion depth is probably the price negotiated between humans and time. Not deep or shallow, just enough for an ordinary pine tree to silently stand as a small milestone under the railway tracks.

And every roaring train is time inspecting the goods.