More than 600 disadvantaged children and families will depart from South Station Saturday for a festive journey on the North Pole Express, complete with a visit from Santa Claus and a re-creation of the “Polar Express” storybook.

Twenty-five local youth charities joined with the Massachusetts Bay Commuter Railroad Co. to provide the children with a ride on decorated coaches from South Station to the Fairmont commuter rail stop in Hyde Park where Santa Claus will board the train.