Railway Tracks Expansion.

[modeller]

Years ago railway lines were made up of 60ft lengths with a small gap to allow for expansion, however all that changed when they started welding lines together. How was the expansion problem solved, bearing in mind when we do have a hot summer some lines do still buckle.

[Zacs-Master]

A few years ago but still relevant
http://www.theanswerbank.co.uk/How-it-Works/Question262930.html

[Teddio]

Compare this to a guitar string. The string is under tension. If the temperature of the string is increased, its length will remain constant. The tension in the string will decrease and the pitch of the note will decrease.

[Cathyhuns]

The tension in the railway lines has to be adjusted for the expected temperature. If lines buckle it's either because the maintenance teams didn't make the correct adjustments, it turned out hotter than expected or it's hotter than the lines can be adjusted for.