In the railway system, some choices may seem like technical issues, but they are actually economic considerations. Sleepers - The seemingly ordinary pieces of wood under the railway tracks are typical representatives. Faced with plain sleepers and oil immersed sleepers, many people's first reaction is to choose the one with the lower price. But those who truly settle this account know that spending an extra 30% on costs in exchange for several times longer service life may be the most cost-effective investment in the railway industry.

Let's talk about the origin of the sleepers first. Most railway sleepers in China are made of pine wood, especially Pinus massoniana and Pinus sylvestris var. mongolica. Pine wood has straight patterns, moderate strength, and is easy to process, but it has a fatal weakness - it is naturally afraid of water and insects. Plain wooden sleepers (untreated pine wood sleepers) in outdoor environments are like bread exposed to the air, quickly moldy, rotten, and infested with insects. In humid and rainy areas, the lifespan of plain sleepers may only be 3-5 years.

So, how can we turn weak pine wood into the 'hard bones' of railways? The answer is: oil immersion anti-corrosion process.

The production process of oil immersed sleepers is not complicated, but extremely crucial. Simply put, pine logs are cut and shaped before being sent into a huge high-pressure tank. First evacuate, then inject high-temperature anti-corrosion oil, and use high pressure to allow the oil to penetrate deep into the wood. After oil immersion treatment, the oil immersion depth of the sleepers can often reach over 13mm. This depth ensures that even if the surface wears or cracks, there is still sufficient anti-corrosion layer protection inside.

This process is like giving wood a 'deep therapy', not only filling the cell cavities, but also forming a protective layer on the outer layer of the wood. Water cannot enter, insects and bacteria cannot bite, and the lifespan of wood has undergone a qualitative change since then.

Now let's settle the accounts.

Assuming the price of plain sleepers is 1000 yuan per cubic meter, and assuming that the price of oil immersed sleepers is 30% higher, which is 1300 yuan. Judging solely from the price, it seems that plain sleepers are more "cost-effective". But if we extend the time, the result will be completely different.

The lifespan of plain sleepers is conservatively estimated to be only 4 years, while the lifespan of oil immersed sleepers easily exceeds 15 years, and some can even reach over 25 years. That is to say, the lifespan of oil immersed sleepers is 3-6 times that of plain sleepers.

Assuming a railway requires 10000 cubic meters of sleepers:

-Choose plain sleepers with an initial investment of 10 million yuan, but they need to be replaced every 4 years and 5 times every 20 years, with a total cost of up to 50 million yuan

-Choosing oil immersed sleepers, the initial investment is 13 million yuan, but it may only need to be replaced once within 20 years (or even not), with a total cost of only 13 million yuan

This account does not include the construction cost of replacing sleepers, indirect losses caused by railway shutdown, and safety hazards caused by corrosion of sleepers. In fact, the most expensive part of railway maintenance is not the materials themselves, but the operational interruption caused by replacement operations. A pillow changing operation may require blocking the line for several hours, disrupting the entire operation schedule, and these hidden costs are far higher than the price difference of the sleepers.

More importantly, the security account. The plain sleepers will have internal corrosion that is hard to find by the naked eye in the later period of use, which is likely to fail suddenly on a rainstorm night or when a heavy load train passes by. Even if the surface of the oil immersed sleeper cracks, the 13mm anti-corrosion layer inside can still maintain structural integrity. This reliability is difficult to measure with money.

Sleepers are the foundation of railways. If the foundation is not solid, the earth will move and the mountains will shake. The oil immersion process brings not only an extension of lifespan, but also a long-term wisdom. Spending 30% more per cubic meter results in several times longer lifespan, significantly reduced maintenance costs, and irreplaceable security.

This is probably the most worthwhile 'premium'.