The 55-year-old actor portrays real-life engineer Jesse Knowlton in new movie 'Unstoppable' - which follows the dramatic halting of a runaway railway vehicle in northern Ohio in 2001 - and loved getting the chance to learn the skills of his character For Real.
He said: "Jesse helped teach me how to drive a train. It was exciting and liberating to have all that power at your control. I spent a couple of days with him and he is a great guy."
Although Denzel met with Jesse when preparing for the movie, he insists he didn't "imitate" the railwayman exactly in his portrayal.
He added: "I really wasn't trying to imitate him in any way. But we talked for a long time and we were able to use some of the details from his life in the film."
Though the movie is based on true events, the actor admits they "jazzed up" some scenes to make for more dramatic viewing.
He told The Daily Mirror: "There was a runaway train that was a really dangerous situation. But we jazzed it up a little."