4. The signal turns green and the arm drops. Close up of the train tooting its whistle and puffing out smoke as the signal changes and drops its arm. The train slowly builds up speed and we follow the train travelling around the track. The signal turns red again. The train stops and then gives out a huge sigh. Then looks over to the bridge and has a determined look on its, er, 'face'. Eventually the signal turns green and again the arm drops.