How do they avoid “clack-clack” sounds on high-speed trains? Are the rails made without gaps? And how do they manage thermal expansion then?

Question

How do they avoid “clack-clack” sounds on high-speed trains? Are the rails made without gaps? And how do they manage thermal expansion then?

In: 1047

Answer 1

Why is everyone focused on the rails, when it is clearly not the rails who make the sound?

OP, the clak clak sound comes from “flat spots” (direct translation from german) on the wheel that happen when high speed trains have to initiate a high power break. On regular track and in most situations, the wheels have anti blocking features, like a car does.

Sometimes these fail, or the track conditions make the wheel simply glide over it, thus scraping flats into it. Sometimes the material is pushed onto other parts of the wheel, and it makes the sound even louder. If the train keeps going now what you hear is the typical clak clak sound.