Because there should construction of railways, we want to do the train track sleepers too!

因为那里要修建铁路，我们要为火车轨道做枕木呢！

youdao

The speed of train is high, to ensure regularity of the upper track and reduce maintenance workload, the requirements of settlement after construction of subgrade are extremely stringent.

列车行驶速度高，为了保证上部轨道结构的平顺性，并减少运营期间的维护工作量，对路基的工后沉降有着极其严格的要求。

youdao

Much of the work is expected to be carried out at night, with a so-called factory train laying a mile of new track and cables every night once construction is underway.

BBC: Electrification of Swansea to London trains 'by 2018'