Railway Line Fixing

This is the way that they heat the rails, then join them together for some reason, I think maybe because we have had earthquake damage and the gaps between pieces of rail have got further apart especially over the cold winter months, than is desired. Not sure but it made an interesting spectacle when they lit a "wick" of diesel along the tracks and made a lot of smoke.
I wish I could say it was a screaming hot runaway train instead!