Thanks for calling <a href=" http://www.sullivans.com.au/attractions/#whoever ">zithromax z pak 250 mg tablet</a> Alton Bob- you are correct. Air is used to RELEASE the brakes on a train, not to engage them. Thus, a locomotive shutting down would have ensure that the train could not move. Compressed air would have had to have been pumped into the train-line to release the brakes and the only way that I know for that to happen is for someone to open the brake valve.