The dad-of-two decided to take on the mammoth challenge after he retired from his job as a ticket office clerk in 2007. David, 68, had already travelled on every line in Britain so decided to try and take a picture of a train at all 2,550 railway stations in the UK. He kept meticulous handwritten notes of his adventures which show that he snapped 487 stations on 44 separate trips in 2008.