The rain in the south is very strange. In low-lying sections along the railway, the ponding can reach the ankles. Some netizens shot a video and asked: Will the sleeper be soaked in muddy water, and the black wood will not be broken? The railway transportation is afraid that the line will be softened, the sleepers will be poor and the rails will be distorted.
On plain wood, that's true. Wood is bad when exposed to water, and mildew and hair will appear after soaking for several days. Can lie on rail, not bare wood.
Anti-corrosion sleepers for railway shall be soaked with oil before work. Pine logs are sawn into sizes and sent into closed tanks where the preservative oil is forced into the wood. Pine wood density is not low, light oil cannot enter, need pressure. The surface is black and bright after cooling, and the oil seeps out and hangs. The key lies in the inside. The oil is not only coated with a layer of skin, but drilled into the wood fiber. The immersion depth is usually 13mm upward. The surface layer of sleepers is filled with oil for a circle. If the rainwater outside the sleepers is to be infiltrated, the oil wall shall be passed first. Why not high pressure? Pine pipes are thin and cannot be penetrated by bubbles. The pressure pushes the oil into the pipe depth. This process is a watershed for the durability of sleepers.
The wood is full of holes. Once the water is drilled in, it will expand and become mildewed. After a while, it will be eaten by the fungus. Antiseptic oil fills the holes one by one, and the water road is blocked. Some people are afraid that the oil will be washed away by water and cannot be washed away. The oil pressure enters into the fiber, which is not a layer of membrane on the floating surface. It cannot be flushed by the rain and carried away by the year and month.
So anti-corrosive sleepers are designed to deal with moisture. It is not afraid of blister, but the plain sleeper without anti-corrosion. The difference between plain wood sleepers and anti-corrosion sleepers is the same as that between cotton lined sleepers and raincoats: one is wet and soft, the other is waterproof and the other is dry. The plain sleeper will be deformed after three or five days of soaking, and the anti-corrosion sleeper will be soaked for several months, and the train will be carried out in the air as it is.
It's uncomfortable to soak in water for a long time. However, wooden sleeper has advantages over cement sleeper, light and elastic. The ballast bed shall be cleaned once the water is retreated, and the damaged ballast bed shall be replaced by a single ballast bed rather than being paved in the whole section. The cement sleeper is too heavy, with poor elasticity. For the road section repeatedly soaked in water and exposed to the sun, it is easy to crack and peel. One section is a whole section, and two people cannot lift it, so the crane shall be used to seal the line. This is also the case after a storm, the first to break is not always the corrosion resistant pillows, but those that are not saturated.
It is often not the decent environment for the trunk line, but the ponding road in the mining area, the branch line of Nanfangmei in rainy season and the salt mist zone at the coastal bridge bottom. These places are wet all the year round and ordinary wood cannot support the season. The anti-corrosive sleeper leans against the layer of oil on the body. Patrol along the line in the flood season every year, pull out the gravel to see the wooden sleeper soaked with water, the inside is still dry, and the sound is clear and bright when knocked, and the wood cannot be seen one by one. The mine car rumbled over it, the steel beam on the bridge deck was vibrated straight, and the wooden sleeper at the bottom vibrated off most of the vibration by its own elasticity, so the track and bridge were less affected. In the end, the moisture resistance of wooden sleeper does not depend on the surface work, and depends on the depth of oil into the wood. Shallow water will seep in; Deep, the inside is still dry after soaking. The old maintenance personnel picked sleepers, first asked whether they were immersed in oil or not, and didn't like to see whether the color was black or not. Do not use it until it is immersed in oil.
Wood is too oily to withstand the weather. That said, the black wood beneath the tracks is the most clear.
