The Jet Engine

The Jet Engine is a special machine that appears in the sixth season episode "Thomas and the Jet Engine". Thomas goes to Brendam Docks to collect it from Cranky. Cranky gets huffy after Thomas tells him to hurry up, and accidently switches it on, sending Thomas rocketing off down the line, only stopping when the jet engine runs out of fuel. Note that this would not happen in real life, for the following reasons: a jet engine would never be transported carrying fuel, Thomas would have surely derailed at the speed he was going at, and, even if he didn't, the friction would have ground his wheels down to nothing.