Worldshaker by Richard Harland 388 pages

Col Porpentine has spent his whole life on a juggernaut, the Worldshaker commanded by his grandfather. When his grandfather announces that he has chosen Col to be groomed as his replacement, his rather calm life is turned upside down. He meets Riff, an escaped "Filthy" and begins to question the social organization onboard. He becomes persecuted at his new school and discovers that his jealous, older sister is behind the torture. The absurd solution to his social problems seem to be to betroth him to a vapid young girl. He reluctantly agrees although his heart belongs to the natural born leader, Riff. This reminded me a bit of vintage Joan Aiken (The Wolves of Willoughby Chase) and is a rousing adventure that should entertain both boys and girls.