Unstoppable (2010) on Netflix

Will Colson is starting a new job as a train conductor for the railroad. He is assigned to work with Frank Barnes a veteran train engineer. Initially there's some tension between them. Later a train that is carrying chemicals is running with no one controlling it. It is feared that if it stops or crashes into a populated area it could disastrous. Connie, an exec suggests derailing it but the man in charge refuses to do that on account of what it will cost. When attempts to stop it fail, there's fear of what they can do. But when Frank and Will have a close call with it, Frank decides to stop it themselves by coupling on to it. Will is not sure about it but sticks with Frank.