[Targan]

I watched a really interesting documentary just the other day, it was from series 2 of Strip the City, episode 3: Chicago Swamp City. The main topic of the program was the amazing shared cooling system for buildings in downtown Chicago, but part of it was also about how Chicago's elevated rail system is maintained and the systems in place to mitigate against the buckling of rails during extreme heat.

As the Aussie members of this forum have testified many times before, Australia is well accustomed to extreme temperature swings, mostly in the hot direction. We don't have anywhere near as many rail lines as the US and Europe do, but some of the ones we have are very long and some were built to support absolutely massive loads for the remote mines across the country. Heat buckling can be a real problem here too.

The question I have is can welded rail be adversely affected by extreme cold? Do rails contract in the cold as much as they expand in the heat, and if so, do the welds crack?