The bus pulled up in the middle of the road and, "The driver looks right at me, lets three people off the second door in the back, looks at me, closes the door, slams the throttle and splits.''

This equates to an unprecedented 17.6:1 deep-throttling capability, which means this cryogenic engine can quickly throttle up and down.

And now the engineer pulled out the throttle-valve to make up for lost time, and the clatter of the train faded into a distant roar, and its lights began to twinkle into indistinctness.