18 – The ride operates with 6 trains.
There are actually six total trains that make up the Big Thunder Mountain Railroad family. Their names are: I.M. Brave, I.B. Hearty, I.M. Fearless., U.B. Bold, U.R. Courageous and U.R. Daring. What fun names to set the expectation of what is about to occur once your train leaves the station.