They’re twelve feet tall, twelve feet wide and crush metal into scrap for fun. They have names like Maximum Destruction, Eradicator and Thrasher. If you’re envisioning a new breed of comic book villains, think again. They’re some of the gigantic debutantes of a new season of Monster Truck Madness. The touring circuit known as Monster Jam 2013 landed in New Hampshire last week. Sean Hurley put in some earplugs and visited the spectacle for this radio field trip.