I like the contrast between natural and industrial that you've shown here - the composition works, but there are a couple of things that take away from the shot to my eyes. FIrst is the sense of movement shown by the trains... the very slight blur is in this case just distracting. My suggestion would be either to use a longer exposure and really blur these well enough to show movement (ND filter maybe? since it seems so bright out?), or just let them be caught in time - stopped but clear. Second, the sky, which is bright white and causing the upper bits of the metal to be quite blue. I realize this is hard to expose for, though, and it does kind of work to contrast between the colour below and the cold industrial tones above. Overall this is an interesting photo with a lot of potential - good effort.
The front face of the bridge is exceptionally sharp and clear, but I feel that there is not enough motion blur in the train and that there's too much at the top of the frame.