When I was a child, I saw pine trees in the northeast forest area just peeled off, with a light yellow wood that smelled of pine resin. But if anyone tells me that this piece of wood will go to the railway in the future to carry steel rails and cushion the bottom of pillows, I definitely think he's talking nonsense. Later on, I learned that in order for wood to make a name for itself on the railway, it had to learn a craft: to make itself greasy enough.
This craft is called oil immersion anti-corrosion in the industry. Calling it white means impregnating the wood with anti-corrosion oil from the outside to the inside, making it emit a strong and unpleasant odor from the inside out. Most of the materials selected are pine wood, not inherently steel and iron. On the contrary, pine wood has moderate softness and hardness, straight texture, high yield, and high cost-effectiveness, making it very suitable for the demand of railway sleepers with large quantities.
The first step in oil immersion is to feed the pine wood into the processing tank and vacuum it first. Then the hot anti-corrosion oil pressed in. Oil can be drilled into every crevice and hole, but relying solely on the cracks in the wood itself can only soak the surface, and the anti-corrosion effect will be unsatisfactory. So we still need to apply pressure - a few megapascals, and the oil will squeeze in along the pre made marks, squeezing into the gaps between the wood fibers, squeezing into the cavities of the resin channels, and squeezing into every corner that is invisible to the naked eye.
After this process, the oil seeped into the wood to a depth of at least thirteen millimeters or more. What is the concept of thirteen millimeters? Take a ruler and see, it's about the width of an adult's thumb nail cover. This means that from the surface to the inside, the entire layer of "keratin" on the wood has turned into oil soaked armor. Scratching with a knife still produces wood, but this wood is no longer the pine wood it used to be in the woods - it is covered in anti-corrosion material all over its body, unable to be splashed with water, unable to be bitten by bacteria, and unable to be opened by insects.
If such a greasy sleeper is laid on the railway, it truly becomes the one who eats this bowl of rice. The biggest fear on the railway is the few sleepers under the steel rails that don't work. Rain blisters, moisture evaporation, sun exposure, frost swelling, ordinary wood in that environment will loosen its nails and rot its heart in three or two years. The train runs unsteadily, and even the road studs cannot be firmly grasped. The pine wood that can be soaked in oil is different. Its belly is filled with anti-corrosion oil, and water cannot penetrate at all. Bacteria and fungi look at the oily wood and turn their heads to run away - whoever likes to gnaw on it, I can't get out of my mouth anyway. The insects were also too tired to handle it, and after taking a few bites, they covered their mouths and forgot about each other in the world of rivers and lakes.
Even better is the toughness of this oil immersed wood. Pine wood already has elasticity, but after being oiled, it not only does not become brittle, but also increases its toughness. When the train presses over, it can tremble and bounce slightly along with it, relieving a few of the overwhelming impact force and then transmitting it obediently to the ballast below. If cement sleepers are placed under the railway tracks, they can easily loosen the screws due to hard impact; When replaced with oil immersed sleepers, the stuffiness was just right, like putting a ripe cowhide cushion on the railway tracks.
The job of sleepers can be summed up in one sentence - white pine wood cannot go far, and greasy sleepers cannot be crushed.
