Wiktionary
crack train
n. (context US dialect dated English) Fastest express train between two stops.
Usage examples of "crack train".
Quebec Northern Railroad spent a fortune trying to recover a trace of their crack train.
THE crack train thundered on through the bright afternoon towards the south.
That's a crack train on the New York Central railroad, and it departs for New York in about twenty minutes.
One day the crack train struck a boulder that had rolled down from the mountain fifty feet ahead of the locomotive.
The voice of the man behind the desk seemed doubled, somehow, the second section arriving just behind the first like the payoff cars of a crack train.