How does the noise comes from the train while it is moving?

Question

when the train is moving, there is a pattern of noises like 'pat pit..pit pat' or something like that. what is the reason behind the noise. is it the train's own noise or the tracks' ?

Answer 1

In addition to rail joints and the things previously mentioned, it may possibly be a flat spot on a wheel. Those are somewhat notorious on freights, and you're bound to hear at *least* 1 on a longer train as it passes. (Yes they are steel, and yes they still get flat spots)

Answer 2

There are so many noises a train makes, it's hard to fully answer your question without anymore specifics.  But I think I know what particular noise you're referring to.

The noise in question would sound more like a 'click-clack' type noise.  Some rail is what is called "jointed rail", meaning the track is made up of numerous sections of rail (usually 78' in North America) joined together.  There is usually a small gap between each joint to allow for the expansion and contraction of the steel in hot and cold temperatures.

When the wheels of a locomotive and/or railcars go over the gaps, they make a noise.  Because most railcars have 2 axles to a truck (truck being a wheelset assembly), that's why you hear "click-clack" - click for the first wheel, clack for the second.

You may also notice similar noises when a train passes over a public crossing at grade, track switch, or diamond (railroad crossing at grade).

Answer 3

It is probably the flat spots you are hearing. flat spots larger than 2-inches in diameter effectivly "bad order" the car; which means that the car is set off the main on a siding at the frist oppurtuninty, until a crew can come out and fix it.

Jointed rail? only in few occasions do you come across that anymore. With today's equipment, your better off having contiuois welded rail.

Jointed Rail+Heavy Equipment=High Maintenace Cost!!!

Answer 4

it's the train passing across the part where the tracks are jointed together

the joints warp under the train's weight