If you think that the "hoop" only exists in Journey to the West to discipline the monkey who loves to make trouble in the sky, it would be naive. In the world of railway engineering, oil injected sleepers also have their own "hoops". It's just that it's not as magical as Sun Wukong's, but it really guards the "longevity secret" of sleepers. Today, let's talk about this thing - it's not the constraint under the hoop, but the wire wrapped around the two ends of the sleeper. It seems simple, but it has the ability to make the wood "prolong life".

First, let's talk about how the sleepers came from. Most of them are made of pine wood, which is like a natural "tough man", strong and durable, and is an excellent partner of railway. But pine also has a bad problem: it is easy to crack. Imagine that a originally straight wood, under the wind and the sun and the weight of the train, gradually "grins" - cracks appear on the surface, which not only affects the appearance, but also greatly reduces the service life.

In order to solve this problem, people invented oil filling sleepers, or anti-corrosion sleepers. The manufacturing process is actually quite interesting: the workers first cut pine wood into standard size sleepers, and then send them to the factory for "deep SPA". The core of this "SPA" is the oil immersion process, which is simply to let the wood soak in an oil bath under high pressure, and the oil will penetrate into the depth of the wood, with a depth of at least 13 mm.

This is not just a matter of bubbles. Oil molecules will fill the tiny pores of the wood, forming a barrier to block the invasion of water, insects, ants and fungi. To put it bluntly, it's like putting a layer of invisible armor on wood, so that it can be "proud of the lake" for many years in the harsh outdoor environment.

But it's not enough to have this armor - the two ends of the sleeper are the most vulnerable parts, which are easy to crack due to shrinkage or expansion. At this time, "tight hoop" should be on the stage. It is the iron wire twined at both ends of the sleeper. It looks like the gold hoop on Sun Wukong's head, but its functions are quite different. Sun Wukong's "hoop" is used by Avalokiteshvara to discipline him. Once he recites the hoop curse, he rolls around with pain. In essence, it's a constraint to let the monkey obey and not make trouble. What about the "hoop" of sleepers? It is not to "discipline" wood, but to "care" it.

These wires are tightly bound at both ends, like a pair of powerful hands, clinging to the wood to prevent it from cracking in the process of use, ensuring the overall structure of the sleeper is stable. In this way, the service life of sleepers can be greatly extended, from a few years of youth to decades or even longer.

In Railway Engineering, this "hoop" is not a decoration, it reflects the cleverness of human wisdom: solve big problems through simple means. Although the wire is small, it plays a big role. It makes the sleepers still strong under the rolling of hundreds of millions of trains. It's like a veteran soldier, wearing a protector to fight.

Looking back, the manufacturing process of oil injected sleepers is actually an elaborate "health preserving journey". From pine material selection to oil treatment, and then to the reinforcement of iron wire "hoop", every step is to resist the erosion of nature.