Frank Kogan

Well, what the metaphor could mean is that it's a regular full-scale wreck all right, but through our visual superpowers we can make it move slowly in our time, while in its own it retains the exact characteristics of a standard-issue kaboom! train-wreck. So the engine has the same quick speed it always had (speed being relative to the observer), but we see the wreck at one-thousandth the speed.