03-10-2015, 04:23 PM
They do flex quite a bit. In the first part of this video you can see a train go by carrying continuous welded rail that is pretty much the entire length of the train. It just flexes around corners.
https://www.youtube.com/watch?v=EaGgaTGAwO4
https://www.youtube.com/watch?v=EaGgaTGAwO4