I assumed you had been a passenger in a car. Didn't think about a train. Whatever the mode, its hard getting the timing right. Pot luck in fact I think.Thanks, Brian. In fact the turbines are the only sharp bit on the image. The train moves at quite a speed and there are lots of pillars as the railway is on the lower level of the bridge so I simply look dozens with the camera pressed against the window knowing that one or two would be both in focus and hopefully reasonably composed. I got two, one of which is not as sharp, but has an interesting composition. I've used this 'technique' to good effect in the past.
My point exactly sir!@Brian Moore it's tricky to time a shot when you're travelling at 150 km/h!